Prevalence and risk factors associated with ectoparasite infestation of buffaloes in an Amazonian ecosystem

Prevalence and risk factors associated with ectoparasite infestation of buffaloes in an Amazonian... Background: The water buffalo (Bubalus bubalis) is well adapted in some regions of the Amazon. Of all Brazilian states, Pará contains the largest number of this species, with 510,000 animals, approximately 38% of the Brazilian buffaloes. Despite the socioeconomic importance of bubaline farming in the northern region, little is known about the prevalence of ectoparasites that affect buffalo herds. This study aimed to identify the species of buffalo ectoparasites in the municipality of Santarém, Pará, and to determine possible risk factors related to ectoparasitic infestation. A cross-sectional study was conducted by sampling 60 rural properties and 621 buffaloes for ectoparasites. When present, ectoparasites were collected for subsequent identification. Results: Of all the animals sampled, 18.5% (115/621) had ectoparasites, 7.8% (49/621) had ticks from the species Rhipicephalus (Boophilus) microplus and Amblyomma cajennense (sensu stricto), and 11.5% (72/621) had lice from the Haematopinus tuberculatus species. Six animals presented mixed infestations of ticks and lice. Among the sampled farms, 51.6% (31/60) had at least one animal infested with ectoparasites. The prevalence of ticks and lice on buffaloes was associated with the farm site, with higher prevalence (11.5% ticks, 15.4% lice) in animals at dry land (OR: 16.7 and 5.7 for ticks and lice, respectively) when compared with floodplains (0.5% ticks, 3.4% lice). Buffaloes aged 1 to 12 months had more ticks whereas buffaloes aged 13 to 24 months had more lice (P < 0.05). Conclusions: Buffaloes bred in the municipality of Santarém present different levels of tick and lice infestation according to the direct influence of Amazon ecosystem characteristics. The floodplain environment, widely used for buffalo farming, contributes toward minor ectoparasite infestations in these animals. Keywords: Amazon ecosystem, Bubalus bubalis, Buffalo, Ectoparasite, Lice, Tick Background are drying out and pastures become available. This There are 1.78 million buffaloes in Brazil, of which floodplain production system is extensive and character- 507,000 (38%) are found in Pará state, northern region ized by minimal animal management [2]. of Brazil [1]. In Santarém, and throughout the western Buffaloes are known for being resistant to tick infesta- region of the state, buffaloes are raised either on dry tions. However, some tick species parasitize buffaloes, al- land (regular farms) or/and inhabit floodplain ecosys- though usually at a lower intensity than in cattle [3]. tems through 6–8 months of the year, when the rivers The tick species Rhipicephalus (Boophilus) microplus and Amblyomma cajennense complex typically parasitize buffaloes [4–6]. There have been few reports about tick parasitism in buffaloes in Brazil. In the states of São Paulo and Minas * Correspondence: ah.minervino@gmail.com 1 Gerais, southeastern region, a natural infestation of R. Laboratório de Sanidade Animal, Universidade Federal do Oeste do Pará, LARSANA/UFOPA, Rua Vera Paz, s/n, CEP 68100-000 Santarém, Pará, Brasil (B) microplus and Dermacentor nitens was reported in Full list of author information is available at the end of the article © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Batista et al. Parasites & Vectors (2018) 11:335 Page 2 of 9 buffaloes, the ticks mainly parasitizing the groin and Methods axilla, perineum, udder and other regions where the skin Study area is thinner and the hair shorter [4]. In Rio de Janeiro, also This study was carried out in the municipality of in the southeastern region of Brazil, 82.3% of buffalo Santarém, in the western region of the state of Pará, herds show tick infestations; nonetheless, other ectopar- northern Brazil, and included properties located in dry asites have not been considered in previous studies in areas (conventional properties) and in floodplain areas; this region [7]. Amblyomma sculptum, the vector of the latter are extensively found along the banks of the Brazilian spotted fever, which has low host parasitic Amazon River and are inundated annually. In addition, specificity, has previously been found in buffaloes [8]. during the drought period, these areas provide natural Among the species of ectoparasites that affect buffa- pastures that are used for livestock activities; animals are loes, Haematopinus tuberculatus lice are specific to transported to the floodplains where they remain for up buffaloes, and thus the main ectoparasite of the species to 8 months of the year, only returning to the dry areas [8, 9]. In Brazil, Silva et al. [10]suggestthat H. tuberculatus during the peak flood of the Amazon River [11]. The may be involved in transmission of diseases, such as buffalo herd in this municipality consists of approxi- anaplasmosis. mately 8,364 buffaloes, distributed across 232 proper- Very little is known about the risk factors related to ties [1]. Figure 1 presents the studied area. the presence of ticks or lice in buffaloes, especially in the Amazon region, which presents a unique farming Experimental design system that strongly utilizes floodplains. This study A cross-sectional study was carried out with a two-stage aimed to identify the species of ectoparasites in buffa- sampling procedure. The first stage included sampling of loes in the municipality of Santarém, Pará, and to de- rural properties. Sample size calculation was performed termine the possible risk factors related to parasitic with the software Epi Info (CDC), using the following infestation. data: population size: 232 farms; frequency of expected Fig. 1 Municipality of Santarém with the dry land and the floodplain areas used for buffalo breeding Batista et al. Parasites & Vectors (2018) 11:335 Page 3 of 9 tick infestation (farm-level): 82% [7]; confidence level: were retained if the P-value from the logistic regres- 95%;confidencelimits: 8.4%.Accordingly,we calcu- sion was < 0.05, otherwise they were removed from the lated that 60 farms (clusters) needed to be sampled, final model. Model validity and reliability was assessed representing 25.9% of the total number of properties on using the Hosmer-Lemeshow goodness-of-fit test [16]. which buffaloes were raised in the municipality. To se- Analyses were performed at two levels: (i) individual lect the farms, a systematic sampling approach was animal-level, which considered the prevalence among adopted from the list of producers registered at the theentirepopulationsampled, and (ii) herd-level, Agency of Agricultural Defense of the State of Pará in which evaluated the prevalence across all farms sam- the year of 2015. pled. Each farm was considered a sampling unit, which The second sampling stage matched the number of could be positive (when at least one animal on the animals collected from each rural property, calculated property was infested with ticks or lice) or negative on site considering the total number of buffaloes in the (when no animal on the property was infested with farm according to a statistical formula for disease detec- ticks or lice). tion [12], assuming the following values: 95% confidence Statistical analyses were performed using Minitab 17 level; expected prevalence of ticks on buffaloes of 15% software (Minitab Inc., State College, USA). Differences [4]; test sensitivity of 95%. were considered significant when P-values were ≤ 0.05. When the farms were visited to collect samples, an Prevalence and abundance rates, along with mean in- epidemiological questionnaire was used to obtain infor- festation intensity and mean crowding were calculated, mation related to farm location (dry land or floodplains), with respective 95% CIs, in accordance with the report herd size, type of herd (beef or dairy), type of pasture, by Bush et al. [17], using the Quantitative Parasitology type of grazing, presence of mixed overgrowth pasture 3.0 software [18]. In this study, prevalence refers to the (presence of undesired plants such as bushes and shrubs number of infested buffaloes/number of examined buffa- in the pasture), pasture resting, control of ectoparasites loes × 100. Mean abundance refers to the total number (if any), and presence of wild animals. Individual details of ticks collected/total number of buffaloes analyzed. of each animal such as sex, age, breed, type (beef or Mean intensity refers to the total number of ticks col- dairy) and origin (born at farm or bought) were ob- lected/number of infested buffaloes. Mean crowding refers tained. We also checked if the buffaloes were maintained to the degree of species-specific ectoparasite interactions with other animal species, and if they were transported observed on the same host. to floodplains. Results Ectoparasite collection General characteristics After appropriate containment, the buffaloes were Sixty farms and 621 buffaloes were sampled. Of these, examined in predefined body areas (neck, ears, back 34 (56.6%) farms were located on dry land areas, and 26 and tip of the tail), and the ectoparasites found were (43.3%) on floodplain areas. Two farms (3.3%) were con- collected from each animal, particularly ticks and lice. sidered medium-sized herds (101–500 animals), 24 The collected ectoparasites were placed into plastic (40%) were considered small herds (16–100 animals), tubes containing absolute alcohol, and were subse- and 34 (56.6%) were considered micro herds (1–15 ani- quently morphologically identified through specific mals). Of the 621 animals, 385 (62.0%) were female and characteristics [13–15]. 236 (38.0%) were male, 153 (24.6%) were calves (1 to 12 months), 222 (35.7%) were heifers (12 to 24 months) Statistical analysis and 246 (39.6%) were adults (over 24 months). The ani- Two distinct buffalo conditions were considered for mals were raised for beef (229, 36.9%) and for dairy statistical data analyses: presence/absence of ticks and (392, 63.1%). They belonged to the following breeds: presence/absence of lice. Thus, univariate analysis was Jafarabadi, 1 (0.16%); Mediterranean, 96 (15.4%); Murrah, performed by Chi-square or Fisher’s exact test (less than 88 (14.1%); and crossbreeds, 436 (70%). From the total five observations in at least one cell in the contingency sampled 70 (11.2%) were purchased from other farms, and table) to investigate the association of ticks or lice and 551 (88.7%) were born at the properties. possible risk factors obtained through an epidemiological Nineteen farms (31%) had cultivated pastures, 36 questionnaire. Subsequently, a multivariate model was (60%) farms had native pasture and five (8.33%) farms built by including every hypothesized risk factor which had mixed pasture (native and cultivated). In terms of had a P-value < 0.200 from the univariate analysis. A grazing management, 42 farms (70%) used the continuous logit binary logistic regression with a hierarchic back- system, 14 (23%) used the alternating system and four ward stepwise elimination method was used with the (7%) used the rotational system. Mixed overgrowth pas- lowest risk category was taken as the baseline. Variables tures were present in most of the farms (55/60). Of the Batista et al. Parasites & Vectors (2018) 11:335 Page 4 of 9 farms visited 60% (36/60) controlled ectoparasites total number of ectoparasites present on the animal. (spraying and injectable antiparasitic drugs). Most of However, all collected lice were of the H. tuberculatus the farms (55/60) moved part of their buffalo herd to species, and were at the adult stage of their life-cycle. floodplain areas during a period of the year. Analysis of risk factors for the presence of ticks and lice Prevalence of ectoparasites The prevalence of ticks and lice on farms (herd-level) Of the 60 sampled properties, 31 (51.6%) contained was 31.6% (19/60) and 33.3% (20/60), respectively. animals with ectoparasites (lice and ticks); of the 621 Table 3 shows the results of the univariate analysis of buffaloes sampled, 115 (18.5%) had ectoparasites, with risk factors related to the presence of ticks and lice on 49 animals (7.9%) parasitized by ticks, 72 (11.6%) para- the farms. Regarding tick infestation at the herd-level, sitized by lice (H. tuberculatus) and six parasitized by the logistic regression model resulted in the farm site both ticks and lice. detected as the only significative risk factor, with A total of 95 ticks were found, including 1 larva, 1 farms located on dry land being more infested by ticks nymph and 93 adults. The nymph and adults were all (OR = 25, 95% CI: 3.0–205.9, P =0.001) thanfarms on identified at the species level. The nymph and 48 adults the floodplain. The logistic regression for lice infest- (9 males, 38 females) belonged to R. (B.) microplus, ation at the herd-level (data not shown) had a signifi- while the other 45 adults (22 males, 23 females) cant result (P = 0.038) for the Hosmer-Lemeshow belonged to Amblyomma cajennense (sensu stricto). The goodness-of-fit test, thus the model does not fit with larva was identified as belonging to the genus Amblyomma. the data and the predicted probabilities deviate from Five of the tick-parasitized animals presented mixed infest- the observed probabilities in a way that the binomial ation by the two species of ticks identified. Table 1 shows distribution does not predict. the number, sex and life-cycle stage of the ectoparasites Of the 621 buffaloes evaluated, 49 (7.8%) were infested found on the buffaloes. by ticks and 72 (11.5%) were infested by lice. Table 4 Among the two tick species, the most frequently shows the risk factors linked to the presence of ectopar- found was R. (B.) microplus, which infested 26 buffa- asites in the buffaloes (individual animal-level). Murrah loes, while A. cajennense (sensu stricto)infested 23ani- (ticks: 6/88, 6.8%; lice: 12/88, 13.6%), Mediterranean mals. Considering the occurrence of ticks per animals, (ticks: 4/96, 4.2%; lice: 1/96, 1.0%) and crossbreed animals 23 buffaloes were infested by 1 adult tick, 23 were (ticks: 39/436, 8.9%; lice: 59/436, 13.5%) were infested by infested by 2–4 adult ticks, and 3 animals were infested ticks and lice. The single Jafarabadi buffalo examined had by 5 or more ticks. Regarding the R. (B.) microplus no ticks or lice. There was no association between buffalo species, 13 buffaloes were infected by 1 tick, and 12 breed and the prevalence of ticks or lice. buffaloes were infected by 2–4 ticks. Regarding the A. The binary logistic regression model of tick and lice cajennense (sensu stricto), 10 buffaloes were infected by infestation at the individual animal-level is presented in 1 tick, 11 animals were infected by 2 to 4 ticks, and 2 Table 5. The factors age, farm site and origin of animal animals were infected by 5 ticks. Table 2 presents the were associated with a higher infestation of ticks in the prevalence, mean intensity, mean abundance, mean multivariate analysis. Animals raised on dry land are crowding, and their respective 95% CI values of tick 16.7 times more likely to be infested by ticks than buf- infestation on the parasitized buffaloes. falo raised at floodplains (95% CI: 2.3–123.3; P = 0.006). We do not present information on the number of lice Animalsaged1-12 monthsweresix timesmorelikely per animal as, depending on the collection conditions, to be infested with ticks than those aged > 24 months the number of individuals collected may differ from the (95% CI: 2.5–14.5; P= 0.0001) and buffaloes bought from other farms were more likely to be infested by ticks than animals born on farm (OR: 3.6; 95% CI: 1.4–9.2; Table 1 Total number, life-cycle stage and species of P = 0.007). For lice, age and farm site were retained in the ectoparasites identified on buffaloes on 60 farms a a a final model and related with a higher infestation. Buffalo Ectoparasite Larva Nymph Adult Total aged 13–24 months had more lice than young animals Male Female (1–12 m) (OR: 3.8; 95% CI: 1.8–8.0; P = 0.001). Similarly Ticks as tick infestation, buffalo raised on dry land are more Rhipicephalus (Boophilus) – 1/1 9/6 39/19 49/26 likely to have lice than animals at floodplains (OR: 5.7; microplus 95% CI: 2.6–12.8; P =0.001). Amblyomma sp. 1/1 – 22/9 23/13 46/23 Lice Discussion Haematopinus tuberculatus –– 320/72 320/72 In the present study, 7.9% of all examined animals had Total number of ectoparasites found/number of infested buffaloes ticks, which is lower than the prevalence rates found in Batista et al. Parasites & Vectors (2018) 11:335 Page 5 of 9 Table 2 Prevalence, intensity, abundance and crowding of tick infested buffaloes in Santarém, Pará, Brazil a b c d Tick Prevalence (%) Mean intensity Mean abundance Mean crowding (95% CI) (95% CI) (95% CI) (95% CI) Rhipicephalus (Boophilus) microplus 4.03 2.00 0.08 2.60 (2.62–5.89) (1.56–2.40) (0.05−0.11) (2.14–3.07) Amblyomma cajennense (sensu stricto) 3.70 2.00 0.07 2.74 (2.36–5.51) (1.52–2.57) (0.05–0.11) (2.06–3.59) The number of infested buffaloes/number of examined buffaloes × 100 Total number of collected ticks/number of infested buffaloes Total number of collected ticks/total number of analyzed buffaloes The degree of interaction of a parasite with individuals of the same species in the same host Abbreviation: CI, confidence interval Table 3 Univariate analysis of risk factors related to the presence of ticks and lice at the farm-level in the municipality of Santarém, Brazil Risk factor Ticks Lice a a Positive/total (%) P OR (95% CI) Positive/total (%) P OR (95% CI) Farm location < 0.001 24.00 (2.91−198.10) 0.002 7.66 (1.93−30.43) Dry land 17/34 (50.0) 17/34 (50.0) Floodplain 1/26 (3.85) 3/26 (11.5) Herd size na na na na Medium 0/2 (0.0) 1/2 (50.0) Micro 6/34 (17.6) 6/34 (17.6) Small 12/24 (54.1) 13/24 (54.1) Animals go to floodplain area 0.003 0.25 (0.03−1.64) 0.741 0.72 (0.11−4.76) Yes 15/55 (27.2) 18/55 (32.7) No 3/5 (60.0) 2/5 (40.0) Type of pasture 0.019 0.066 na Cultivated 9/19 (47.3) 6/19 (31.5) Mixed 3/5 (60.0) 4/5 (80.0) Native 6/36 (16.6) 10/36 (27.7) Type of grazing 0.001 0.097 na Alternating 9/14 (64.2) 8/14 (57.1) Continuous 5/42 (11.9) 11/42 (26.1) Rotational 4/4 (100.0) 1/4 (25.0) Mixed overgrowth pastures 0.126 0.27 (0.04−1.79) 0.509 2.11 (0.22−20.26) Yes 15/55 (27.7) 19/55 (34.5) No 3/5 (60.0) 1/5 (20.0) Control ectoparasites 0.066 2.41 (0.73−7.96) < 0.001 11.00 (2.24−53.86) Yes 14/36 (38.8) 18/36 (50.0) No 4/24 (16.6) 2/24 (8.3) Presence of wild animals 0.907 0.91 (0.20−4.12) 0.443 0.57 (0.13−2.41) Yes 15/51 (31.3) 16/51 (31.3) No 3/9 (33.3) 4/9 (44.4) Calculated using Chi-square or Fisher's tests Type of pasture: cultivated vs mixed (OR: 0.60, P = 1.00); cultivated vs native (OR: 4.50, P = 0.015); mixed vs native (OR: 7.50, P= 0.06) Type of grazing: alternating vs continuous (OR: 13.32, P < 0.0001); alternating vs rotational (OR: 0.19, P = 0.278); continuous vs rotational (OR: 0.02, P = 0.0008) Notes: A farm was considered positive when at least 1 of the examined animals was infested with lice or ticks. Herd size: micro (1−15 animals); small (16−100 animals); medium (101−500 animals). Mixed overgrowth is the presence of undesired plants such as bushes and shrubs in the pasture Abbreviations: OR, odds ratio; CI, confidence interval; na, not available. Batista et al. Parasites & Vectors (2018) 11:335 Page 6 of 9 Table 4 Univariate analysis of risk factors related to infestations of buffaloes by ticks and lice (individual animal-level) in the municipality of Santarém, Amazon region, Brazil Risk factor Ticks Lice a a Positive/total (%) P OR (95% CI) Positive/total (%) P OR (95% CI) Sex 0.908 1.03 (0.56−1.88) 0.260 0.74 (0.43−1.20) Male 19/236 (8.0) 49/385 (12.7) Female 30/385 (7.7) 23/236 (9.7) b d Age (months) < 0.001 0.002 1–12 29/153 (18.9) 10/153 (6.5) 13–24 10/222 (4.5) 39/222 (17.5) > 24 10/246 (4.0) 23/246 (9.3) Type 0.209 1.50 (0.79−2.86) 0.149 1.48 (0.86−2.53) Dairy 35/392 (8.9) 21/229 (9.1) Beef 14/229 (6.1) 51/392 (13.0) c e Herd size 0.006 0.025 Micro 12/218 (5.5) 17/218 (7.8) Small 37/347 (10.6) 51/347 (14.7) Medium 0/56 (0.0) 4/56 (7.1) Farm site < 0.001 25.81 (3.53−188.50) < 0.001 5.07 (2.28−11.29) Dry land 48/420 (11.5) 65/420 (15.4) Floodplain 1/201 (0.5) 7/201 (3.4) Origin 0.102 1.88 (0.87−4.07) 0.020 Bought 9/70 (12.8) 14/70 (20.0) Born on farm 40/551 (7.2) 58/551 (10.5) Maintained with other animals 0.010 0.46 (0.25−0.84) 0.249 1.38 (0.79–2.40) Yes 25/420 (5.9) 53/420 (12.6) No 24/201 (11.9) 19/201 (9.4) Calculated using Chi-square or Fisher's tests Age (months): 1–12 vs 13–24 months (OR: 4.96, P = 0.001); 1–12 vs > 24 months (OR: 5.52, P = 0.001); 13−24 vs > 24 months (OR: 1.11, P = 0.814) Herd size: micro vs small (OR: 0.49, P = 0.033); micro vs medium (OR: 6.84, P = 0.134); small vs medium (OR: 13.65, P = 0.005) Age (months): 1–12 vs 13–24 months (OR: 0.33, P = 0.002); 1–12 vs > 24 months (OR: 0.68, P = 0.321); 13−24 vs > 24 months (OR: 2.07, P = 0.009) Herd size: micro vs small (OR: 0.49, P = 0.014); micro vs medium (OR: 1.10, P = 1.000); small vs medium (OR: 2.24, P = 0.146) Abbreviations: OR, odds ratio; CI, confidence interval Note: Herd size: micro (1−15 animals); small (16−100 animals); medium (101−500 animals) Pakistan (52.5% [19]), Cuba (27.7%) [20] and India prevalence, intensity, abundance and mean crowding. In (56.7%) [21]. The prevalence of ticks at the herd-level Minas Gerais State, Brazil, the prevalence of R. (B.) was 31.6%, which was less than the 82.3% prevalence microplus ticks in buffaloes ranges between 15.4–38.5% rate found in Rio de Janeiro farms [7]. Buffaloes raised throughout the year [4]. Considering the lack of data in the Santarém region were infested by two tick species, from buffaloes, our results from tick abundancy, inten- R. (B.) microplus and A. cajennense (sensu stricto), both sity and crowding are hard to discuss, and more studies of which have already been identified as parasites typic- need to be done with evaluation of infestation in different ally found in buffaloes [8, 22]. seasons. It is important for report that the samples were Of the 60 sampled farms, 33.3% harbored animals obtained during the dry season, the period when it is pos- infested by H. tuberculatus lice, indicative of the prom- sible to raise buffalos in floodplain areas since during the inence of this parasite in bubaline species and their pres- wet season the fields are flooded [2]. ence in the farms in this region. Regarding the The univariate analysis at the herd-level demonstrated prevalence of infested animals with lice our prevalence an association of tick infestation with different risk fac- rate of 11.6 % was close to the infestations rates found tors (type of pasture, type of grazing, etc.), but only the in Italy [23] and Pakistan [24]. farm site was retained in the final logistic regression Of the two tick species identified, the R. (B.) microplus model, indicating that other risk factors were associated and A. cajennense (sensu stricto) presented similar with the main effect of farm site. Farms on dry land had Batista et al. Parasites & Vectors (2018) 11:335 Page 7 of 9 Table 5 Logit binary logistic regression of tick and lice infestation in buffaloes in the municipality of Santarém, Amazon region, Brazil Variable Ticks Lice b b OR 95% CI P OR 95% CI P Age (months) 1 to 12 5.99 2.48–14.51 0.001 Baseline 13 to 24 1.05 0.42–2.64 0.922 3.83 1.83–8.01 0.001 > 24 Baseline 2.07 0.95–4.53 0.069 Farm site Dry land 16.68 2.26–123.27 0.006 5.72 2.55–12.83 0.001 Floodplain Baseline Baseline Origin Bought 3.61 1.42–9.15 0.007 –– Born on farm Baseline –– Only factors that remained significantly associated in the final model (P < 0.05) are included Logit binary regression analysis with Backward stepwise elimination in a hierarchic model. Hosmer-Lemeshow goodness-of-fit test: P = 0.233 (ticks), P = 0.480 (lice) Abbreviations: OR, odds ratio; CI, confidence interval animals with more ticks and this difference could be lice infestation at the herd-level presented a model that explained by the biological cycle of ticks, which may does not fit to the data, probably due to a limited be interrupted when flooding occurs between February amount of data (n = 60 farms) and similarity of results; and June. The periodic flooding of grazing area and these data are, therefore, not shown. the constant movement of animals to reach newly Themultivariateanalysisofliceinfestationsatthe unflooded areas during the ebb period (e.g. the period individual animal-level included only age and farm site when the river is drying), are both factors that may in the final model. Dry land animals were 5.7 times reduce the tick population in the environment and more likely to be infested with lice than floodplain ani- animal infestation [25]. mals, which might be explained by the biological cycle At the individual animal-level, the multivariate analysis of H. tuberculatus, which is completed within the host of tick infestations included in the final model the follow body. Moreover, maintenance of the parasite on the body risk factors: farm site, age and origin of animals. Young of floodplain animals may be impaired by the daily periods buffaloes were more susceptible to tick infestation, spent in the water, searching for food. The parasites are consistent with previous literature data [19]. In our found in greater concentrations around the ears, base of study, animals aged between 1 and 12 months were six horns, side of the neck, around the scrotum or udder, and times more likely to be infested with ticks than those especially at the tip of the tail [15, 27]. Some of these areas aged > 24 months. Sex, breed and aptitude were not would be submerged during water grazing or movement associated with tick infestation in buffaloes. Similarly of the buffaloes in floodplain areas. to the herd-level analysis, the animals raised in flood- In this study, animals aged over 12 months had a plains had lower tick infestation. Previous research in greater prevalence of lice than young animals (aged 1-12 India demonstrated that animals brought for grazing months). Studies indicate that young buffaloes are more on pasture lowlands had lower mature tick populations susceptible to infestation by H. tuberculatus [28]. Our when compared with stall-fed buffaloes on dairy farms results may be related to the grazing habits of buffaloes and this occurred supposedly because of predation of in floodplain areas, where part of the body remains sub- ticks by birds in the field [26]. merged during grazing and movement across pastures. Considering the origin of animals (born on property or Given that younger animals are smaller, a more substan- bought from other farms) the buffaloes that were bought tial proportion of the body would be submerged while from other farms were more likely to be infested by ticks. accompanying adult animals, possibly explaining the This was probably due to the source of animals, usually lower prevalence of lice in younger animals observed in bought from dry land for the purpose of reproduction [2]. our study. The univariate analysis of lice infestation at the Despite presenting significant results of the univariate herd-level indicated association with several risk factors analysis the risk factors herd size and origin of animal (age, herd size, origin), but the multivariate analysis for were not significant in the multivariate analysis and Batista et al. Parasites & Vectors (2018) 11:335 Page 8 of 9 removed by backward stepwise elimination from the Author details Laboratório de Sanidade Animal, Universidade Federal do Oeste do Pará, final regression model. For lice, only age and farm site LARSANA/UFOPA, Rua Vera Paz, s/n, CEP 68100-000 Santarém, Pará, Brasil. were associated with the parasite infestation. 2 Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, The ticks and the lice founded in buffaloes have been FMVZ/USP, Av. Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo, SP 05508-270, Brazil. Mestrado em Medicina e Bem estar animal, previously related as vectors of important pathogens Universidade Santo Amaro, Av. Prof. Eneas de Siqueira Neto, 340, São Paulo such Babesia sp. and Anaplasma marginale [10, 29, 30], 4 04529-300, Brazil. Programa de Pós-Graduação em Recursos Naturais da but limited information is available regarding piroplas- Amazônia, Universidade Federal do Oeste do Pará, PGRNA/UFOPA, Av. Mendonça Furtado 2240, CEP 68100-000 Santarém, Pará, Brasil. mosis in cattle from Santarém and nearby municipalities. Thus, further studies are required to investigate whether Received: 5 February 2018 Accepted: 25 May 2018 buffaloes act as a significant reservoir of tick species and also the role of buffaloes in the epidemiology of piro- plasmosis in ruminants in the region. References 1. IBGE. Produção da pecuária municipal. 47th ed. 2015. http://biblioteca.ibge.gov. Buffaloes bred in the municipality of Santarém pre- br/visualizacao/periodicos/84/ppm_2015_v43_br.pdf. Accessed 18 Oct 2016. sented different levels of infestation by ticks and lice, 2. Vale WG, Minervino AHH, Neves KAL, Morini AC, Coelho JAS. Buffalo under which was mainly influenced by the unique characteris- threat in Amazon Valley, Brazil. Buffalo Bull. 2013;32:121–31. 3. Nithikathkul C, Polseela P, Changsap B, Leemingsawat S. Ixodid ticks on tics of the Amazon ecosystem. The floodplain environ- domestic animals in Samut Prakan Province, Thailand. Southeast Asian J ment, widely used for buffalo farming, contributes to the Trop Med Public Health. 2002;33:41–4. minor infestation rates by ectoparasites in these animals. 4. Rocha U, Serra O, Grock R, Serra R. Natural buffalo infestation from the states of São Paulo and Minas Gerais, Brazil, by Boophilus microplus (Canestrini, 1997) and by Anocentor nitens (Neumann, 1897), Acari, Ixodidae. Conclusions Arq Inst Biol (Sao Paulo). 1969;36:197–9. 5. Nava S, Beati L, Labruna MB, Cáceres AG, Mangold AJ, Guglielmone AA. Buffaloes bred in the municipality of Santarém present Reassessment of the taxonomic status of Amblyomma cajennense (Fabricius, different levels of tick and lice infestation according to 1787) with the description of three new species, Amblyomma tonelliae n. sp., the direct influence of Amazon ecosystem characteris- Amblyomma interandinum n. sp. and Amblyomma patinoi n. sp., and reinstatement of Amblyomma mixtum Koch, 1844, and Amblyomma sculptum tics. The floodplain environment, widely used for buffalo Berlese, 1888 (Ixodida: Ixodidae). Ticks Tick Borne Dis. 2014;5:252–76. farming, contributes toward minor ectoparasite infesta- 6. Benitez D, Cetrá B, Florin-Christensen M. Rhipicephalus (Boophilus) microplus tions in these animals. ticks can complete their life cycle on the water buffalo (Bubalus bubalis). J Buffalo Sci. 2012;1:193–7. Abbreviation 7. Corrêa FN, Cunha NC, Rangel CP, Fonseca AH. Ticks on buffaloes CI: confidence interval (Bubalus bubalis) in the state of Rio de Janeiro, Brazil. Brazilian J Vet Parasitol. 2012;21:313–4. Acknowledgements 8. Bastianetto E, Leite RC. Aspectos epidemiológicos e controle das doenças We thank the CNPq for the research productivity fellowship granted to Antonio parasitárias em bubalinos. Ciência Anim Bras. 2009;10:1–17. Humberto Hamad Minervino, Solange Maria Gennari and Arlei Marcili. The authors 9. Veneziano V, Santaniello M, Carbone S, Pennacchio S, Morgoglione ME, are grateful to Dr Marcelo Bahia Labruna for his support during this study. Schioppi M, et al. Lice (Haematopinus tuberculatus) in water buffalo farms from central Italy. Ital J Anim Sci. 2007;6:926–7. Funding 10. Da Silva AS, Lopes LS, Diaz JDS, Tonin AA, Stefani LM, Araújo DN. Lice This research was funded by National Council for Scientific and outbreak in buffaloes: evidence of Anaplasma marginale transmission by Technological Development - CNPq, Brazil (Grant # 486318/2013-3). sucking lice Haematopinus tuberculatus. J Parasitol. 2013;99:546–7. 11. Minervino AHH, Cardoso C, Ortolani EL. Características do sistema produtivo Availability of data and materials da pecuária no município de Santarém, Pará. Acta Amaz. 2008;38:11–6. The data supporting the conclusions of this article are included within the 12. Cannon RM, Roe RT. Livestock disease surveys. A field manual for article. veterinarians. Canberra: Australian Bureau of Animal Health, Department of Primary Industry, Australian Government Publishing Service; 1982. 13. Barros-Battesti D, Arzua M, Bechara H. Carrapatos de importância medico- Authors’ contributions veterinaria da região neotropical: Um guia ilustrado para identificação de AHHM, SMG and AM designed the study and obtained funding. HRB, DRO, especiés. São Paulo: Vox/ICTTD-3/Butantan; 2006. CS and ACM participated in the execution of the experiment. HRB and CS 14. Martins TF, Onofrio VC, Barros-Battesti DM, Labruna MB. Nymphs of the performed tick identification. AHHM, SMG, LESB and FNB wrote the manuscript. genus Amblyomma (Acari: Ixodidae) of Brazil: descriptions, redescriptions, All authors read and approved the final manuscript. and identification key. Ticks Tick Borne Dis. 2010;1:75–99. 15. Chaudhuri RP, Kumar P. The life history and habits of the buffalo louse, Ethics approval Haematopinus tuberculatus (Burmeister) Lucas. Indian J Vet Sci. 1961;31:275–325. This study was approved by the Animal Use Committee from the Federal 16. Hosmer DW, Lemeshow S. Applied logistic regression. Chicago: Wiley; 2000. University of Western Pará (Authorization #04008/2015). 17. Bush AO, Lafferty KD, Lotz JM, Shostak AW. Parasitology meets ecology on its own terms: Margolis et al. revisited. J Parasitol. 1997;83:575. Consent for publication 18. Rózsa L, Reiczigel J, Majoros G. Quantifying parasites in samples of hosts. Not applicable. J Parasitol. 2000;86:228–32. 19. Tasawar Z, Nasim S, Lashari MH. The prevalence of ixodid ticks on buffaloes Competing interests at private animal farm Bibipur, Multan. Glob Vet. 2014;12:154–7. The authors declare that they have no competing interests. 20. Obregon D, Rodriguez Diego JG, Roque E, Aleman Y. Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) en búfalo (Bubalus bubalis), en Cuba. Publisher’sNote Rev Salud Anim. 2010;32:132–4. Springer Nature remains neutral with regard to jurisdictional claims in 21. Singh NK, Rath SS. Epidemiology of ixodid ticks in buffaloes (Bubalus bubalis)of published maps and institutional affiliations. Punjab, India. Buffalo Bull. 2018;35:347–53. Batista et al. Parasites & Vectors (2018) 11:335 Page 9 of 9 22. Hussain Soomro M, Parveen Soomro S, Bachal Bhutto M, Akbar Z, Yaqoob M, Arijo AG. Prevalence of ticks in buffaloes in the upper Sindh Pakistan. Buffalo Bull. 2014;33:323–7. 23. Cringoli G, Musella V, Maurelli MP, Morgoglione ME, Santaniello A, Condoleo R, et al. Helminths and arthropoda in buffalo farms from the Lazio region (Italy). Vet Res Commun. 2009;33:129–31. 24. Kakar MN, Kakarsulemankhel JK. Prevalence of lice species on cows and buffaloes of Quetta, Pakistan. Pak Vet J. 2009;29:49–50. 25. Diamant G, Strickland RK. Manual on livestock ticks for Animal Disease Eradication Division personnel. USDA ARS. Washington: US Department of Agriculture, Agricultural Research Service; 1965. 26. Miranpuri GS. Ticks parasitising the Indian buffalo (Bubalus bubalis) and their possible role in disease transmission. Vet Parasitol. 1988;27:357–62. 27. Lau H. Piolho dos búfalos: biologia e controle. A Hora Veterinária. 1993;13:53–6. 28. Lau H, Costa N, Batista H. Infestação natural de piolhos em búfalos. Belém: Embrapa-Cpatu; 1980. 29. Obregón D, Oliveira MCS, Tizioto PC, Funnes ME, Martínez S, Roque E, et al. Diagnóstico de Babesia bovis en búfalos de la región occidental de Cuba a través de un ensayo de nPCR. Rev. Salud Anim. 2012;34:101–8. 30. Da Silva JB, André MR, da Fonseca AH, de Albuquerque Lopes CT, da Silva Lima DH, de Andrade SJT, et al. Molecular and serological prevalence of Babesia bovis and Babesia bigemina in water buffaloes in the north region of Brazil. Vet Parasitol. 2013;197:678–81. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Parasites & Vectors Springer Journals

Prevalence and risk factors associated with ectoparasite infestation of buffaloes in an Amazonian ecosystem

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Biomedicine; Parasitology; Entomology; Tropical Medicine; Infectious Diseases; Veterinary Medicine/Veterinary Science; Virology
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Abstract

Background: The water buffalo (Bubalus bubalis) is well adapted in some regions of the Amazon. Of all Brazilian states, Pará contains the largest number of this species, with 510,000 animals, approximately 38% of the Brazilian buffaloes. Despite the socioeconomic importance of bubaline farming in the northern region, little is known about the prevalence of ectoparasites that affect buffalo herds. This study aimed to identify the species of buffalo ectoparasites in the municipality of Santarém, Pará, and to determine possible risk factors related to ectoparasitic infestation. A cross-sectional study was conducted by sampling 60 rural properties and 621 buffaloes for ectoparasites. When present, ectoparasites were collected for subsequent identification. Results: Of all the animals sampled, 18.5% (115/621) had ectoparasites, 7.8% (49/621) had ticks from the species Rhipicephalus (Boophilus) microplus and Amblyomma cajennense (sensu stricto), and 11.5% (72/621) had lice from the Haematopinus tuberculatus species. Six animals presented mixed infestations of ticks and lice. Among the sampled farms, 51.6% (31/60) had at least one animal infested with ectoparasites. The prevalence of ticks and lice on buffaloes was associated with the farm site, with higher prevalence (11.5% ticks, 15.4% lice) in animals at dry land (OR: 16.7 and 5.7 for ticks and lice, respectively) when compared with floodplains (0.5% ticks, 3.4% lice). Buffaloes aged 1 to 12 months had more ticks whereas buffaloes aged 13 to 24 months had more lice (P < 0.05). Conclusions: Buffaloes bred in the municipality of Santarém present different levels of tick and lice infestation according to the direct influence of Amazon ecosystem characteristics. The floodplain environment, widely used for buffalo farming, contributes toward minor ectoparasite infestations in these animals. Keywords: Amazon ecosystem, Bubalus bubalis, Buffalo, Ectoparasite, Lice, Tick Background are drying out and pastures become available. This There are 1.78 million buffaloes in Brazil, of which floodplain production system is extensive and character- 507,000 (38%) are found in Pará state, northern region ized by minimal animal management [2]. of Brazil [1]. In Santarém, and throughout the western Buffaloes are known for being resistant to tick infesta- region of the state, buffaloes are raised either on dry tions. However, some tick species parasitize buffaloes, al- land (regular farms) or/and inhabit floodplain ecosys- though usually at a lower intensity than in cattle [3]. tems through 6–8 months of the year, when the rivers The tick species Rhipicephalus (Boophilus) microplus and Amblyomma cajennense complex typically parasitize buffaloes [4–6]. There have been few reports about tick parasitism in buffaloes in Brazil. In the states of São Paulo and Minas * Correspondence: ah.minervino@gmail.com 1 Gerais, southeastern region, a natural infestation of R. Laboratório de Sanidade Animal, Universidade Federal do Oeste do Pará, LARSANA/UFOPA, Rua Vera Paz, s/n, CEP 68100-000 Santarém, Pará, Brasil (B) microplus and Dermacentor nitens was reported in Full list of author information is available at the end of the article © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Batista et al. Parasites & Vectors (2018) 11:335 Page 2 of 9 buffaloes, the ticks mainly parasitizing the groin and Methods axilla, perineum, udder and other regions where the skin Study area is thinner and the hair shorter [4]. In Rio de Janeiro, also This study was carried out in the municipality of in the southeastern region of Brazil, 82.3% of buffalo Santarém, in the western region of the state of Pará, herds show tick infestations; nonetheless, other ectopar- northern Brazil, and included properties located in dry asites have not been considered in previous studies in areas (conventional properties) and in floodplain areas; this region [7]. Amblyomma sculptum, the vector of the latter are extensively found along the banks of the Brazilian spotted fever, which has low host parasitic Amazon River and are inundated annually. In addition, specificity, has previously been found in buffaloes [8]. during the drought period, these areas provide natural Among the species of ectoparasites that affect buffa- pastures that are used for livestock activities; animals are loes, Haematopinus tuberculatus lice are specific to transported to the floodplains where they remain for up buffaloes, and thus the main ectoparasite of the species to 8 months of the year, only returning to the dry areas [8, 9]. In Brazil, Silva et al. [10]suggestthat H. tuberculatus during the peak flood of the Amazon River [11]. The may be involved in transmission of diseases, such as buffalo herd in this municipality consists of approxi- anaplasmosis. mately 8,364 buffaloes, distributed across 232 proper- Very little is known about the risk factors related to ties [1]. Figure 1 presents the studied area. the presence of ticks or lice in buffaloes, especially in the Amazon region, which presents a unique farming Experimental design system that strongly utilizes floodplains. This study A cross-sectional study was carried out with a two-stage aimed to identify the species of ectoparasites in buffa- sampling procedure. The first stage included sampling of loes in the municipality of Santarém, Pará, and to de- rural properties. Sample size calculation was performed termine the possible risk factors related to parasitic with the software Epi Info (CDC), using the following infestation. data: population size: 232 farms; frequency of expected Fig. 1 Municipality of Santarém with the dry land and the floodplain areas used for buffalo breeding Batista et al. Parasites & Vectors (2018) 11:335 Page 3 of 9 tick infestation (farm-level): 82% [7]; confidence level: were retained if the P-value from the logistic regres- 95%;confidencelimits: 8.4%.Accordingly,we calcu- sion was < 0.05, otherwise they were removed from the lated that 60 farms (clusters) needed to be sampled, final model. Model validity and reliability was assessed representing 25.9% of the total number of properties on using the Hosmer-Lemeshow goodness-of-fit test [16]. which buffaloes were raised in the municipality. To se- Analyses were performed at two levels: (i) individual lect the farms, a systematic sampling approach was animal-level, which considered the prevalence among adopted from the list of producers registered at the theentirepopulationsampled, and (ii) herd-level, Agency of Agricultural Defense of the State of Pará in which evaluated the prevalence across all farms sam- the year of 2015. pled. Each farm was considered a sampling unit, which The second sampling stage matched the number of could be positive (when at least one animal on the animals collected from each rural property, calculated property was infested with ticks or lice) or negative on site considering the total number of buffaloes in the (when no animal on the property was infested with farm according to a statistical formula for disease detec- ticks or lice). tion [12], assuming the following values: 95% confidence Statistical analyses were performed using Minitab 17 level; expected prevalence of ticks on buffaloes of 15% software (Minitab Inc., State College, USA). Differences [4]; test sensitivity of 95%. were considered significant when P-values were ≤ 0.05. When the farms were visited to collect samples, an Prevalence and abundance rates, along with mean in- epidemiological questionnaire was used to obtain infor- festation intensity and mean crowding were calculated, mation related to farm location (dry land or floodplains), with respective 95% CIs, in accordance with the report herd size, type of herd (beef or dairy), type of pasture, by Bush et al. [17], using the Quantitative Parasitology type of grazing, presence of mixed overgrowth pasture 3.0 software [18]. In this study, prevalence refers to the (presence of undesired plants such as bushes and shrubs number of infested buffaloes/number of examined buffa- in the pasture), pasture resting, control of ectoparasites loes × 100. Mean abundance refers to the total number (if any), and presence of wild animals. Individual details of ticks collected/total number of buffaloes analyzed. of each animal such as sex, age, breed, type (beef or Mean intensity refers to the total number of ticks col- dairy) and origin (born at farm or bought) were ob- lected/number of infested buffaloes. Mean crowding refers tained. We also checked if the buffaloes were maintained to the degree of species-specific ectoparasite interactions with other animal species, and if they were transported observed on the same host. to floodplains. Results Ectoparasite collection General characteristics After appropriate containment, the buffaloes were Sixty farms and 621 buffaloes were sampled. Of these, examined in predefined body areas (neck, ears, back 34 (56.6%) farms were located on dry land areas, and 26 and tip of the tail), and the ectoparasites found were (43.3%) on floodplain areas. Two farms (3.3%) were con- collected from each animal, particularly ticks and lice. sidered medium-sized herds (101–500 animals), 24 The collected ectoparasites were placed into plastic (40%) were considered small herds (16–100 animals), tubes containing absolute alcohol, and were subse- and 34 (56.6%) were considered micro herds (1–15 ani- quently morphologically identified through specific mals). Of the 621 animals, 385 (62.0%) were female and characteristics [13–15]. 236 (38.0%) were male, 153 (24.6%) were calves (1 to 12 months), 222 (35.7%) were heifers (12 to 24 months) Statistical analysis and 246 (39.6%) were adults (over 24 months). The ani- Two distinct buffalo conditions were considered for mals were raised for beef (229, 36.9%) and for dairy statistical data analyses: presence/absence of ticks and (392, 63.1%). They belonged to the following breeds: presence/absence of lice. Thus, univariate analysis was Jafarabadi, 1 (0.16%); Mediterranean, 96 (15.4%); Murrah, performed by Chi-square or Fisher’s exact test (less than 88 (14.1%); and crossbreeds, 436 (70%). From the total five observations in at least one cell in the contingency sampled 70 (11.2%) were purchased from other farms, and table) to investigate the association of ticks or lice and 551 (88.7%) were born at the properties. possible risk factors obtained through an epidemiological Nineteen farms (31%) had cultivated pastures, 36 questionnaire. Subsequently, a multivariate model was (60%) farms had native pasture and five (8.33%) farms built by including every hypothesized risk factor which had mixed pasture (native and cultivated). In terms of had a P-value < 0.200 from the univariate analysis. A grazing management, 42 farms (70%) used the continuous logit binary logistic regression with a hierarchic back- system, 14 (23%) used the alternating system and four ward stepwise elimination method was used with the (7%) used the rotational system. Mixed overgrowth pas- lowest risk category was taken as the baseline. Variables tures were present in most of the farms (55/60). Of the Batista et al. Parasites & Vectors (2018) 11:335 Page 4 of 9 farms visited 60% (36/60) controlled ectoparasites total number of ectoparasites present on the animal. (spraying and injectable antiparasitic drugs). Most of However, all collected lice were of the H. tuberculatus the farms (55/60) moved part of their buffalo herd to species, and were at the adult stage of their life-cycle. floodplain areas during a period of the year. Analysis of risk factors for the presence of ticks and lice Prevalence of ectoparasites The prevalence of ticks and lice on farms (herd-level) Of the 60 sampled properties, 31 (51.6%) contained was 31.6% (19/60) and 33.3% (20/60), respectively. animals with ectoparasites (lice and ticks); of the 621 Table 3 shows the results of the univariate analysis of buffaloes sampled, 115 (18.5%) had ectoparasites, with risk factors related to the presence of ticks and lice on 49 animals (7.9%) parasitized by ticks, 72 (11.6%) para- the farms. Regarding tick infestation at the herd-level, sitized by lice (H. tuberculatus) and six parasitized by the logistic regression model resulted in the farm site both ticks and lice. detected as the only significative risk factor, with A total of 95 ticks were found, including 1 larva, 1 farms located on dry land being more infested by ticks nymph and 93 adults. The nymph and adults were all (OR = 25, 95% CI: 3.0–205.9, P =0.001) thanfarms on identified at the species level. The nymph and 48 adults the floodplain. The logistic regression for lice infest- (9 males, 38 females) belonged to R. (B.) microplus, ation at the herd-level (data not shown) had a signifi- while the other 45 adults (22 males, 23 females) cant result (P = 0.038) for the Hosmer-Lemeshow belonged to Amblyomma cajennense (sensu stricto). The goodness-of-fit test, thus the model does not fit with larva was identified as belonging to the genus Amblyomma. the data and the predicted probabilities deviate from Five of the tick-parasitized animals presented mixed infest- the observed probabilities in a way that the binomial ation by the two species of ticks identified. Table 1 shows distribution does not predict. the number, sex and life-cycle stage of the ectoparasites Of the 621 buffaloes evaluated, 49 (7.8%) were infested found on the buffaloes. by ticks and 72 (11.5%) were infested by lice. Table 4 Among the two tick species, the most frequently shows the risk factors linked to the presence of ectopar- found was R. (B.) microplus, which infested 26 buffa- asites in the buffaloes (individual animal-level). Murrah loes, while A. cajennense (sensu stricto)infested 23ani- (ticks: 6/88, 6.8%; lice: 12/88, 13.6%), Mediterranean mals. Considering the occurrence of ticks per animals, (ticks: 4/96, 4.2%; lice: 1/96, 1.0%) and crossbreed animals 23 buffaloes were infested by 1 adult tick, 23 were (ticks: 39/436, 8.9%; lice: 59/436, 13.5%) were infested by infested by 2–4 adult ticks, and 3 animals were infested ticks and lice. The single Jafarabadi buffalo examined had by 5 or more ticks. Regarding the R. (B.) microplus no ticks or lice. There was no association between buffalo species, 13 buffaloes were infected by 1 tick, and 12 breed and the prevalence of ticks or lice. buffaloes were infected by 2–4 ticks. Regarding the A. The binary logistic regression model of tick and lice cajennense (sensu stricto), 10 buffaloes were infected by infestation at the individual animal-level is presented in 1 tick, 11 animals were infected by 2 to 4 ticks, and 2 Table 5. The factors age, farm site and origin of animal animals were infected by 5 ticks. Table 2 presents the were associated with a higher infestation of ticks in the prevalence, mean intensity, mean abundance, mean multivariate analysis. Animals raised on dry land are crowding, and their respective 95% CI values of tick 16.7 times more likely to be infested by ticks than buf- infestation on the parasitized buffaloes. falo raised at floodplains (95% CI: 2.3–123.3; P = 0.006). We do not present information on the number of lice Animalsaged1-12 monthsweresix timesmorelikely per animal as, depending on the collection conditions, to be infested with ticks than those aged > 24 months the number of individuals collected may differ from the (95% CI: 2.5–14.5; P= 0.0001) and buffaloes bought from other farms were more likely to be infested by ticks than animals born on farm (OR: 3.6; 95% CI: 1.4–9.2; Table 1 Total number, life-cycle stage and species of P = 0.007). For lice, age and farm site were retained in the ectoparasites identified on buffaloes on 60 farms a a a final model and related with a higher infestation. Buffalo Ectoparasite Larva Nymph Adult Total aged 13–24 months had more lice than young animals Male Female (1–12 m) (OR: 3.8; 95% CI: 1.8–8.0; P = 0.001). Similarly Ticks as tick infestation, buffalo raised on dry land are more Rhipicephalus (Boophilus) – 1/1 9/6 39/19 49/26 likely to have lice than animals at floodplains (OR: 5.7; microplus 95% CI: 2.6–12.8; P =0.001). Amblyomma sp. 1/1 – 22/9 23/13 46/23 Lice Discussion Haematopinus tuberculatus –– 320/72 320/72 In the present study, 7.9% of all examined animals had Total number of ectoparasites found/number of infested buffaloes ticks, which is lower than the prevalence rates found in Batista et al. Parasites & Vectors (2018) 11:335 Page 5 of 9 Table 2 Prevalence, intensity, abundance and crowding of tick infested buffaloes in Santarém, Pará, Brazil a b c d Tick Prevalence (%) Mean intensity Mean abundance Mean crowding (95% CI) (95% CI) (95% CI) (95% CI) Rhipicephalus (Boophilus) microplus 4.03 2.00 0.08 2.60 (2.62–5.89) (1.56–2.40) (0.05−0.11) (2.14–3.07) Amblyomma cajennense (sensu stricto) 3.70 2.00 0.07 2.74 (2.36–5.51) (1.52–2.57) (0.05–0.11) (2.06–3.59) The number of infested buffaloes/number of examined buffaloes × 100 Total number of collected ticks/number of infested buffaloes Total number of collected ticks/total number of analyzed buffaloes The degree of interaction of a parasite with individuals of the same species in the same host Abbreviation: CI, confidence interval Table 3 Univariate analysis of risk factors related to the presence of ticks and lice at the farm-level in the municipality of Santarém, Brazil Risk factor Ticks Lice a a Positive/total (%) P OR (95% CI) Positive/total (%) P OR (95% CI) Farm location < 0.001 24.00 (2.91−198.10) 0.002 7.66 (1.93−30.43) Dry land 17/34 (50.0) 17/34 (50.0) Floodplain 1/26 (3.85) 3/26 (11.5) Herd size na na na na Medium 0/2 (0.0) 1/2 (50.0) Micro 6/34 (17.6) 6/34 (17.6) Small 12/24 (54.1) 13/24 (54.1) Animals go to floodplain area 0.003 0.25 (0.03−1.64) 0.741 0.72 (0.11−4.76) Yes 15/55 (27.2) 18/55 (32.7) No 3/5 (60.0) 2/5 (40.0) Type of pasture 0.019 0.066 na Cultivated 9/19 (47.3) 6/19 (31.5) Mixed 3/5 (60.0) 4/5 (80.0) Native 6/36 (16.6) 10/36 (27.7) Type of grazing 0.001 0.097 na Alternating 9/14 (64.2) 8/14 (57.1) Continuous 5/42 (11.9) 11/42 (26.1) Rotational 4/4 (100.0) 1/4 (25.0) Mixed overgrowth pastures 0.126 0.27 (0.04−1.79) 0.509 2.11 (0.22−20.26) Yes 15/55 (27.7) 19/55 (34.5) No 3/5 (60.0) 1/5 (20.0) Control ectoparasites 0.066 2.41 (0.73−7.96) < 0.001 11.00 (2.24−53.86) Yes 14/36 (38.8) 18/36 (50.0) No 4/24 (16.6) 2/24 (8.3) Presence of wild animals 0.907 0.91 (0.20−4.12) 0.443 0.57 (0.13−2.41) Yes 15/51 (31.3) 16/51 (31.3) No 3/9 (33.3) 4/9 (44.4) Calculated using Chi-square or Fisher's tests Type of pasture: cultivated vs mixed (OR: 0.60, P = 1.00); cultivated vs native (OR: 4.50, P = 0.015); mixed vs native (OR: 7.50, P= 0.06) Type of grazing: alternating vs continuous (OR: 13.32, P < 0.0001); alternating vs rotational (OR: 0.19, P = 0.278); continuous vs rotational (OR: 0.02, P = 0.0008) Notes: A farm was considered positive when at least 1 of the examined animals was infested with lice or ticks. Herd size: micro (1−15 animals); small (16−100 animals); medium (101−500 animals). Mixed overgrowth is the presence of undesired plants such as bushes and shrubs in the pasture Abbreviations: OR, odds ratio; CI, confidence interval; na, not available. Batista et al. Parasites & Vectors (2018) 11:335 Page 6 of 9 Table 4 Univariate analysis of risk factors related to infestations of buffaloes by ticks and lice (individual animal-level) in the municipality of Santarém, Amazon region, Brazil Risk factor Ticks Lice a a Positive/total (%) P OR (95% CI) Positive/total (%) P OR (95% CI) Sex 0.908 1.03 (0.56−1.88) 0.260 0.74 (0.43−1.20) Male 19/236 (8.0) 49/385 (12.7) Female 30/385 (7.7) 23/236 (9.7) b d Age (months) < 0.001 0.002 1–12 29/153 (18.9) 10/153 (6.5) 13–24 10/222 (4.5) 39/222 (17.5) > 24 10/246 (4.0) 23/246 (9.3) Type 0.209 1.50 (0.79−2.86) 0.149 1.48 (0.86−2.53) Dairy 35/392 (8.9) 21/229 (9.1) Beef 14/229 (6.1) 51/392 (13.0) c e Herd size 0.006 0.025 Micro 12/218 (5.5) 17/218 (7.8) Small 37/347 (10.6) 51/347 (14.7) Medium 0/56 (0.0) 4/56 (7.1) Farm site < 0.001 25.81 (3.53−188.50) < 0.001 5.07 (2.28−11.29) Dry land 48/420 (11.5) 65/420 (15.4) Floodplain 1/201 (0.5) 7/201 (3.4) Origin 0.102 1.88 (0.87−4.07) 0.020 Bought 9/70 (12.8) 14/70 (20.0) Born on farm 40/551 (7.2) 58/551 (10.5) Maintained with other animals 0.010 0.46 (0.25−0.84) 0.249 1.38 (0.79–2.40) Yes 25/420 (5.9) 53/420 (12.6) No 24/201 (11.9) 19/201 (9.4) Calculated using Chi-square or Fisher's tests Age (months): 1–12 vs 13–24 months (OR: 4.96, P = 0.001); 1–12 vs > 24 months (OR: 5.52, P = 0.001); 13−24 vs > 24 months (OR: 1.11, P = 0.814) Herd size: micro vs small (OR: 0.49, P = 0.033); micro vs medium (OR: 6.84, P = 0.134); small vs medium (OR: 13.65, P = 0.005) Age (months): 1–12 vs 13–24 months (OR: 0.33, P = 0.002); 1–12 vs > 24 months (OR: 0.68, P = 0.321); 13−24 vs > 24 months (OR: 2.07, P = 0.009) Herd size: micro vs small (OR: 0.49, P = 0.014); micro vs medium (OR: 1.10, P = 1.000); small vs medium (OR: 2.24, P = 0.146) Abbreviations: OR, odds ratio; CI, confidence interval Note: Herd size: micro (1−15 animals); small (16−100 animals); medium (101−500 animals) Pakistan (52.5% [19]), Cuba (27.7%) [20] and India prevalence, intensity, abundance and mean crowding. In (56.7%) [21]. The prevalence of ticks at the herd-level Minas Gerais State, Brazil, the prevalence of R. (B.) was 31.6%, which was less than the 82.3% prevalence microplus ticks in buffaloes ranges between 15.4–38.5% rate found in Rio de Janeiro farms [7]. Buffaloes raised throughout the year [4]. Considering the lack of data in the Santarém region were infested by two tick species, from buffaloes, our results from tick abundancy, inten- R. (B.) microplus and A. cajennense (sensu stricto), both sity and crowding are hard to discuss, and more studies of which have already been identified as parasites typic- need to be done with evaluation of infestation in different ally found in buffaloes [8, 22]. seasons. It is important for report that the samples were Of the 60 sampled farms, 33.3% harbored animals obtained during the dry season, the period when it is pos- infested by H. tuberculatus lice, indicative of the prom- sible to raise buffalos in floodplain areas since during the inence of this parasite in bubaline species and their pres- wet season the fields are flooded [2]. ence in the farms in this region. Regarding the The univariate analysis at the herd-level demonstrated prevalence of infested animals with lice our prevalence an association of tick infestation with different risk fac- rate of 11.6 % was close to the infestations rates found tors (type of pasture, type of grazing, etc.), but only the in Italy [23] and Pakistan [24]. farm site was retained in the final logistic regression Of the two tick species identified, the R. (B.) microplus model, indicating that other risk factors were associated and A. cajennense (sensu stricto) presented similar with the main effect of farm site. Farms on dry land had Batista et al. Parasites & Vectors (2018) 11:335 Page 7 of 9 Table 5 Logit binary logistic regression of tick and lice infestation in buffaloes in the municipality of Santarém, Amazon region, Brazil Variable Ticks Lice b b OR 95% CI P OR 95% CI P Age (months) 1 to 12 5.99 2.48–14.51 0.001 Baseline 13 to 24 1.05 0.42–2.64 0.922 3.83 1.83–8.01 0.001 > 24 Baseline 2.07 0.95–4.53 0.069 Farm site Dry land 16.68 2.26–123.27 0.006 5.72 2.55–12.83 0.001 Floodplain Baseline Baseline Origin Bought 3.61 1.42–9.15 0.007 –– Born on farm Baseline –– Only factors that remained significantly associated in the final model (P < 0.05) are included Logit binary regression analysis with Backward stepwise elimination in a hierarchic model. Hosmer-Lemeshow goodness-of-fit test: P = 0.233 (ticks), P = 0.480 (lice) Abbreviations: OR, odds ratio; CI, confidence interval animals with more ticks and this difference could be lice infestation at the herd-level presented a model that explained by the biological cycle of ticks, which may does not fit to the data, probably due to a limited be interrupted when flooding occurs between February amount of data (n = 60 farms) and similarity of results; and June. The periodic flooding of grazing area and these data are, therefore, not shown. the constant movement of animals to reach newly Themultivariateanalysisofliceinfestationsatthe unflooded areas during the ebb period (e.g. the period individual animal-level included only age and farm site when the river is drying), are both factors that may in the final model. Dry land animals were 5.7 times reduce the tick population in the environment and more likely to be infested with lice than floodplain ani- animal infestation [25]. mals, which might be explained by the biological cycle At the individual animal-level, the multivariate analysis of H. tuberculatus, which is completed within the host of tick infestations included in the final model the follow body. Moreover, maintenance of the parasite on the body risk factors: farm site, age and origin of animals. Young of floodplain animals may be impaired by the daily periods buffaloes were more susceptible to tick infestation, spent in the water, searching for food. The parasites are consistent with previous literature data [19]. In our found in greater concentrations around the ears, base of study, animals aged between 1 and 12 months were six horns, side of the neck, around the scrotum or udder, and times more likely to be infested with ticks than those especially at the tip of the tail [15, 27]. Some of these areas aged > 24 months. Sex, breed and aptitude were not would be submerged during water grazing or movement associated with tick infestation in buffaloes. Similarly of the buffaloes in floodplain areas. to the herd-level analysis, the animals raised in flood- In this study, animals aged over 12 months had a plains had lower tick infestation. Previous research in greater prevalence of lice than young animals (aged 1-12 India demonstrated that animals brought for grazing months). Studies indicate that young buffaloes are more on pasture lowlands had lower mature tick populations susceptible to infestation by H. tuberculatus [28]. Our when compared with stall-fed buffaloes on dairy farms results may be related to the grazing habits of buffaloes and this occurred supposedly because of predation of in floodplain areas, where part of the body remains sub- ticks by birds in the field [26]. merged during grazing and movement across pastures. Considering the origin of animals (born on property or Given that younger animals are smaller, a more substan- bought from other farms) the buffaloes that were bought tial proportion of the body would be submerged while from other farms were more likely to be infested by ticks. accompanying adult animals, possibly explaining the This was probably due to the source of animals, usually lower prevalence of lice in younger animals observed in bought from dry land for the purpose of reproduction [2]. our study. The univariate analysis of lice infestation at the Despite presenting significant results of the univariate herd-level indicated association with several risk factors analysis the risk factors herd size and origin of animal (age, herd size, origin), but the multivariate analysis for were not significant in the multivariate analysis and Batista et al. Parasites & Vectors (2018) 11:335 Page 8 of 9 removed by backward stepwise elimination from the Author details Laboratório de Sanidade Animal, Universidade Federal do Oeste do Pará, final regression model. For lice, only age and farm site LARSANA/UFOPA, Rua Vera Paz, s/n, CEP 68100-000 Santarém, Pará, Brasil. were associated with the parasite infestation. 2 Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, The ticks and the lice founded in buffaloes have been FMVZ/USP, Av. Prof. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo, SP 05508-270, Brazil. Mestrado em Medicina e Bem estar animal, previously related as vectors of important pathogens Universidade Santo Amaro, Av. Prof. Eneas de Siqueira Neto, 340, São Paulo such Babesia sp. and Anaplasma marginale [10, 29, 30], 4 04529-300, Brazil. Programa de Pós-Graduação em Recursos Naturais da but limited information is available regarding piroplas- Amazônia, Universidade Federal do Oeste do Pará, PGRNA/UFOPA, Av. Mendonça Furtado 2240, CEP 68100-000 Santarém, Pará, Brasil. mosis in cattle from Santarém and nearby municipalities. Thus, further studies are required to investigate whether Received: 5 February 2018 Accepted: 25 May 2018 buffaloes act as a significant reservoir of tick species and also the role of buffaloes in the epidemiology of piro- plasmosis in ruminants in the region. References 1. IBGE. Produção da pecuária municipal. 47th ed. 2015. http://biblioteca.ibge.gov. Buffaloes bred in the municipality of Santarém pre- br/visualizacao/periodicos/84/ppm_2015_v43_br.pdf. Accessed 18 Oct 2016. sented different levels of infestation by ticks and lice, 2. Vale WG, Minervino AHH, Neves KAL, Morini AC, Coelho JAS. Buffalo under which was mainly influenced by the unique characteris- threat in Amazon Valley, Brazil. Buffalo Bull. 2013;32:121–31. 3. Nithikathkul C, Polseela P, Changsap B, Leemingsawat S. Ixodid ticks on tics of the Amazon ecosystem. The floodplain environ- domestic animals in Samut Prakan Province, Thailand. Southeast Asian J ment, widely used for buffalo farming, contributes to the Trop Med Public Health. 2002;33:41–4. minor infestation rates by ectoparasites in these animals. 4. Rocha U, Serra O, Grock R, Serra R. Natural buffalo infestation from the states of São Paulo and Minas Gerais, Brazil, by Boophilus microplus (Canestrini, 1997) and by Anocentor nitens (Neumann, 1897), Acari, Ixodidae. Conclusions Arq Inst Biol (Sao Paulo). 1969;36:197–9. 5. Nava S, Beati L, Labruna MB, Cáceres AG, Mangold AJ, Guglielmone AA. Buffaloes bred in the municipality of Santarém present Reassessment of the taxonomic status of Amblyomma cajennense (Fabricius, different levels of tick and lice infestation according to 1787) with the description of three new species, Amblyomma tonelliae n. sp., the direct influence of Amazon ecosystem characteris- Amblyomma interandinum n. sp. and Amblyomma patinoi n. sp., and reinstatement of Amblyomma mixtum Koch, 1844, and Amblyomma sculptum tics. The floodplain environment, widely used for buffalo Berlese, 1888 (Ixodida: Ixodidae). Ticks Tick Borne Dis. 2014;5:252–76. farming, contributes toward minor ectoparasite infesta- 6. Benitez D, Cetrá B, Florin-Christensen M. Rhipicephalus (Boophilus) microplus tions in these animals. ticks can complete their life cycle on the water buffalo (Bubalus bubalis). J Buffalo Sci. 2012;1:193–7. Abbreviation 7. Corrêa FN, Cunha NC, Rangel CP, Fonseca AH. Ticks on buffaloes CI: confidence interval (Bubalus bubalis) in the state of Rio de Janeiro, Brazil. Brazilian J Vet Parasitol. 2012;21:313–4. Acknowledgements 8. Bastianetto E, Leite RC. Aspectos epidemiológicos e controle das doenças We thank the CNPq for the research productivity fellowship granted to Antonio parasitárias em bubalinos. Ciência Anim Bras. 2009;10:1–17. Humberto Hamad Minervino, Solange Maria Gennari and Arlei Marcili. The authors 9. Veneziano V, Santaniello M, Carbone S, Pennacchio S, Morgoglione ME, are grateful to Dr Marcelo Bahia Labruna for his support during this study. Schioppi M, et al. Lice (Haematopinus tuberculatus) in water buffalo farms from central Italy. Ital J Anim Sci. 2007;6:926–7. Funding 10. Da Silva AS, Lopes LS, Diaz JDS, Tonin AA, Stefani LM, Araújo DN. Lice This research was funded by National Council for Scientific and outbreak in buffaloes: evidence of Anaplasma marginale transmission by Technological Development - CNPq, Brazil (Grant # 486318/2013-3). sucking lice Haematopinus tuberculatus. J Parasitol. 2013;99:546–7. 11. Minervino AHH, Cardoso C, Ortolani EL. Características do sistema produtivo Availability of data and materials da pecuária no município de Santarém, Pará. Acta Amaz. 2008;38:11–6. The data supporting the conclusions of this article are included within the 12. Cannon RM, Roe RT. Livestock disease surveys. A field manual for article. veterinarians. Canberra: Australian Bureau of Animal Health, Department of Primary Industry, Australian Government Publishing Service; 1982. 13. Barros-Battesti D, Arzua M, Bechara H. Carrapatos de importância medico- Authors’ contributions veterinaria da região neotropical: Um guia ilustrado para identificação de AHHM, SMG and AM designed the study and obtained funding. HRB, DRO, especiés. São Paulo: Vox/ICTTD-3/Butantan; 2006. CS and ACM participated in the execution of the experiment. HRB and CS 14. Martins TF, Onofrio VC, Barros-Battesti DM, Labruna MB. Nymphs of the performed tick identification. AHHM, SMG, LESB and FNB wrote the manuscript. genus Amblyomma (Acari: Ixodidae) of Brazil: descriptions, redescriptions, All authors read and approved the final manuscript. and identification key. Ticks Tick Borne Dis. 2010;1:75–99. 15. Chaudhuri RP, Kumar P. The life history and habits of the buffalo louse, Ethics approval Haematopinus tuberculatus (Burmeister) Lucas. Indian J Vet Sci. 1961;31:275–325. This study was approved by the Animal Use Committee from the Federal 16. Hosmer DW, Lemeshow S. Applied logistic regression. Chicago: Wiley; 2000. University of Western Pará (Authorization #04008/2015). 17. Bush AO, Lafferty KD, Lotz JM, Shostak AW. Parasitology meets ecology on its own terms: Margolis et al. revisited. J Parasitol. 1997;83:575. 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