American Journal of Epidemiology

MEYER, ERNEST; JARROLL, EDWARD L.

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112860pmid: 6986081

GLEZEN, W. PAUL; COUCH, ROBERT B.; TABER, LARRY H.; PAREDES, ABEL; ALLISON, JAMES E.; FRANK, A. L.; ALDRIDGE, CLIVE

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112865pmid: 7352453

Influenza B virus infections were documented In Houston, Texas, in 726 patients with febrile respiratory illnesses who presented to representative primary care facilities during the 1976–1977 respiratory disease season. This epidemic followed a “herald wave” of illness associated with influenza B during the preceding spring. Over one-half the virus isolates were from children aged 5–19 years, and school absenteeism rates indicated that about 40 per cent of the students in the Houston area were III enough to miss school during the epidemic. The rapid rise in the number of cases among students after the school holiday recess demonstrated the importance of school attendance for the rapid dissemination of influenza viruses. During the later phase of the epidemic, most of the cases were preschool children and adults. In addition to disease of the respiratory tract, the epidemic was accompanied by cases of Reye's syndrome at a rate expected for an urban area.

PONS, VINCENT G.; CANTER, JANE; DOLIN, RAPHAEL

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112871pmid: 7352457

An extensive outbreak of influenza caused by A/USSR/77 (H1N1) virus occurred in February, 1978, at the University of Maryland, College Park, Maryland, and the outbreak was studied by virus isolation, serology, clinical questionnaire and outpatient chart review. Among students who returned questionnaires, clinical attack rates were extraordinarily high (73.2% of those ≤23 years of age and 45.7% for those >23 years (p < 0.001)), and rates were higher in students who lived on campus (p < 0.05). Employing the criterion of hemagglutination inhibition titer ≥16, 89.8% of those ≤23 years of age had evidence of infection by March, 1978. Illness was generally mild, and no complications were reported. The extent and rapid spread of this outbreak suggested that only immunoprophyiaxis or rapidly acting control measures such as chemoprophylaxis would be effective in this institutional setting with a highly susceptibie population.

LINNEMANN, CALVIN C.; SCHAEFFER, ANN E.; BURGDORFER, WILLY; HUTCHINSON, LESLIE; PHILIP, R. N.

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112872pmid: 7352458

The epidemiology of Rocky Mountain spotted fever (RMSF) in relation to the distribution of the human population and infected ticks has not been defined. A study was undertaken in Clermont County, Ohio, to describe the distribution of population in a highly endemic focus of RMSF and to determine the prevalence of ticks infected with rickettsiae of the spotted fever group. This area was compared to another area of similar size in the same county where the incidence of RMSF was much lower. The population in the highly endemic area was distributed diffusely throughout the area, allowing maximum interfacing of the human population and the tick vector. The population distribution in the other area differed from the endemic area in that most of the population was concentrated in one town. Of 1168 Dermacentor variabills collected in the endemic area, 18 (1.5%) were infected, compared to four (1.2%) of 339 ticks in the other area. Past studies of infected ticks have not identified the specific strains or species of spotted fever group rickettsiae. In this study, 11 rickettsiae were serotyped by microimmunofluorescence. Four were Rickettsia rickettsil, five were R. montana, and two were unclassified rickettsiae of the spotted fever group.

HAYNES, SUZANNE; FEINLEIB, MANNING; KANNEL, WILLIAM B.

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112873pmid: 7352459

An extensive psychosocial questionnaire was administered to 1674 coronary free individuals participating in the Framingham Heart Study between 1965 and 1967. The respondents were followed for the development of coronary heart disease (CHD) over an eight-year period. Women (aged 45–64 years) who developed CHD scored significantly higher on the Framingham Type A behavior, suppressed hostility (not showing or discussing anger), tension, and anxiety symptoms scales than women remaining free of CHD. Type A women developed twice as much CHD and three times as much angina as Type B women. In a multivariate analysis, Framingham Type A behavior and not discussing anger were independent predictors of CHD incidence when controlled for the standard coronary risk factors and other psychosocial scales. Men exhibiting Framingham Type A behavior, work overload, suppressed hostility (not showing anger), and frequent job promotions were at increased risk of developing CHD (especially in the age group 55–64 years). Among men aged 45–64 years, Type A behavior was associated with a twofold risk of angina, myocardial infarction, and CHD in general, as compared to Type B behavior. The association was found only among white-collar workers and was also independent of the standard coronary risk factors and other psychosocial scales. This prospective study suggests that Type A behavior and suppressed hostility may be involved in the pathogenesis of CHD in both men and women.

ROSENBERG, LYNN; HENNEKENS, CHARLES H.; ROSNER, BERNARD; BELANGER, CHARLENE; ROTHMAN, KENNETH J.; SPEIZER, FRANK E.

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112874pmid: 7352460

The relation of oral contraceptive (OC) use to the risk of hospitalization for myocardiai infarction (MI) was evaluated among 121,964 US nurses who responded to a mail questionnaire. There were 156 women who reported having been hospitalized for MI before the menopause, and 23 (15%) were OC users at the time of the MI. Of 3120 controls matched to the cases for menopausal status at the time of the MI and for age, 304 (10%) were using OCs at the time of the MI. The apparent increase in the risk of MI for current OC users was not explained by cigarette smoking, hypertension, elevated cholesterol or other identified risk factors for MI. We estimated that OC use increased MI risk 1.8-fold overall and 2.8-fold among nonsmokers without other risk factors. The increase in risk attributable to the combined effect of current OC use, cigarette smoking and hypertension was considerably greater than what would be predicted from the sum of the separate effects of these factors.

COSTELLO, HELEN D.; SNIDER, DIXIE E.

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112875pmid: 6986082

Cancer morbidity and mortality were examined among 11,894 Puerto Rican participants in a US Public Health Service preventive therapy trial begun in 1957. The mean duration of follow-up was 18 years (range 16–19 years). No statistically significant difference in overall cancer rates was observed between the participants in the trial assigned isoniazid and those assigned placebo. There were also no significant differences between the groups when rates for specific types of cancer and age-speciflc cancer rates were compared. No trend toward an increasing cancer rate in the isoniazid group was observed with the passage of time. The mortality rate due to cancer was similar in the two groups. These data coupled with other information reported in the literature provide substantial evidence that isoniazid, when given in the usual therapeutic doses, is not carcinogenic in humans.

HOOK, ERNEST B.; LAMSON, SCOTT H.

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112876pmid: 6444345

A “leveling” in the first order exponential increase of the rate of Down's syndrome with maternal age over 40 years of age has been suggested by others in review of data reported by five-year maternal age interval. In contrast, data reviewed here analyzed by one-year interval reveal no evidence for such an effect when the observed rates (O) at each maternal age in the 40–49-year age range and in the 45–49-year age range are compared with those predicted (P) from first order exponential equations derived from data in the 33–44-year age range. The sign of O – P is not predominantly negative as would be expected if there were a “leveling” effect. Part of the evidence for leveling in previous studies may derive from the fact that rates have been plotted at the midpoints of the intervals rather than at the true mean maternal ages of mothers having births in these five-year intervals. It is shown that in the three data sources considered here, the difference between the quinquennial mean maternal age and the interval midpoint is greater at older ages than at younger ages. Thus, plotting rates at the midpoint of five-year intervals results in significant graphic underestimate of the rates, and may result in a slight leveling effect. It is suggested that selective underascertainment of births to those in the older maternal ages in previous studies may also have contributed to the leveling effect observed earlier.

BLANCK, RONALD R.; REAM, NORMAN; DEEGAN, MICHAEL

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112877pmid: 7352461

Concentrations of the serum immunoglobulins IgG, IgM, and IgA as well as rheumatoid factor were studied in a group of 80 intravenous and nonparenteral heroin users who were US soldiers servlng in Vietnam and who were unique in their use of unadutterated heroin. Significant elevations of IgM out of normal range and IgG above controls were found in intravenous heroin users, while significant elevations of IgA above controls were found in nonparenteral heroin users. Rheumatoid factor was not found in either group. Evidence is presented to support the hypothesis that IgM elevation may be due to bacterial or other contamination but not to liver disease. The higher IgA in non-parenteral heroin users is postulated to reflect local antibody synthesis. The failure to detect rheumatold factor in this study supports the view that the stimulation of rheumatoid factor is due to excipients or contaminants not found in the “uncut” drug.

LINOS, ATHENA; WORTHINGTON, JOHN W.; O'FALLON, MICHAEL; KURLAND, LEONARD T.

1980 American Journal of Epidemiology

doi: 10.1093/oxfordjournals.aje.a112878pmid: 7352462

A study of the incidence and prevalence of rheumatoid arthritis conducted in Rochester, MN, during the period 1950 through 1974 revealed an average annual incidence rate of 28.1 per 100,000 population for males and of 65.7 per 100,000 for females. These rates include classic, definite, and probable cases. Age-specific rates generally increased with age. The secular trend of the incidence in males and females differed. Rates for males, although fluctuating, remained relatively stable throughout the entire 25-year period, whereas rates for females declined dramatically during the last 10 years of the study. The decline was present both in cases presenting as definite at the time of earliest diagnosis and in the probable cases. NO explanation was found for the observed decline, but the authors believe that a factor introduced in the 1960s and acting selectively on females has affected the incldence rates. From recent evidence, it could be inferred that oral contraceptives and postmenopausal estrogens are likely causes. Prevalence rates for January 1, 1975, were 4.0 per 1000 for males and 10 per 1000 for females. Among adults, prevalence rates were 5.8 per 1000 for males and 13.4 for females. Mortality among the patients with rheumatoid arthritis was not different from that for the total Olmsted County populatlon.