CLINICAL COMMUNICATION TO THE EDITOR
Challenges in the Clinical Management of
Blood-Culture Negative Endocarditis: Case of
Bartonella henselae Infection
To the Editor:
A 53-year-old Caucasian man presented with an episode
of syncope, nausea, vomiting, and 6 weeks of recurrent
fevers (up to 40°C). He had a congenital bicuspid aortic
valve for which he underwent aortic valve replacement in
1976, a second aortic valve replacement for blood-culture
positive bacterial endocarditis in 1986, and a third aortic
valve replacement in 1999 for prosthetic valve failure. He
reported no recent travel but had multiple pets, including
rabbits, cats, kittens, and hamsters.
Physical examination showed a heart rate of 103 beats/
min, blood pressure of 73/50 mm Hg, fever of 39.5°C, and
oxygen saturation via pulse oximetry of 100% on room air.
Heart examination demonstrated tachycardia and 2/6 sys-
tolic murmur at the right upper sternal border. No stigmata
of endocarditis were observed. Chest radiograph was nor-
mal. Electrocardiogram demonstrated sinus tachycardia and
an interventricular conduction delay.
Laboratory values were signiﬁcant for the following:
white blood cell 6.7 ϫ 10
L, platelets 70 ϫ 10
dium 103 mmol/L, blood urea nitrogen 56 mg/dL, and
creatinine 2.08 mg/dL. Troponin level was 0.69 mg/dL with
normal creatine phosphokinase and creatine kinase-MB.
Bacterial and fungal blood cultures were negative. Trans-
thoracic and transesophageal echocardiograms were nega-
tive for endocarditis (Figure 1A).
Despite empiric intravenous antibiotic therapy with van-
comycin and piperacillin/tazobactam, the patient remained
febrile. Full-body computed tomography scan revealed an
enlarged spleen. Extended-spectrum blood cultures were
negative for typical culture-negative organisms (Haemophi-
lus, Aggregatibacter, Cardiobacterium hominis, Eikenella
corrodens, and Kingella). The patient became afebrile, and
platelet count improved to normal range after doxycycline
therapy was started for possible rickettsial infection. Rick-
ettsial extended serologies came back negative.
On hospital day 14, the patient acutely decompensated,
requiring endotracheal intubation, ventilatory support, and
vasopressor therapy. Repeat transesophageal echocardio-
gram revealed a large vegetation extending from the ven-
tricular aspect of the prosthetic aortic valve (Figure 1B).
Bartonella henselae immunoglobulin-M titer at 1:64 dilu-
tions was detected, and B. henselae DNA in serum was
highly positive by polymerase chain reaction molecular
assay. Gentamicin was started. Surgical aortic valve re-
placement was deemed unsound because of hemodynamic
instability. The patient’s condition continued to deteriorate,
and he died on hospital day 25.
Bartonella was ﬁrst reported as a cause of endocarditis in
and is an emerging common cause of culture-nega-
with a mortality of 7% to 12%.
contact and preexisting valvular disease or history of val-
vular surgery are the major risk factors for B. henselae
Conﬂict of Interest: None.
Authorship: All authors had access to the data and played a role in
writing this manuscript.
Requests for reprints should be addressed to Divya Gupta, MD, Fellow
in Cardiovascular Medicine, Emory University School of Medicine, 1365
Clifton Rd, NE Suite AT-503, Atlanta, GA 30322.
E-mail address: firstname.lastname@example.org
Figure 1 (A) TEE at admission. (B) TEE at day 14 of
0002-9343/$ -see front matter © 2011 Elsevier Inc. All rights reserved.