Case presentation
A 30-year-old man was admitted to the hospital with intermittent fever
for three months. He had received antibiotics for 6 weeks due to the
negative culture endocarditis 3 years ago. At admission, his temperature
was 38 degrees centigrade with normal vital signs. Abnormalities in the
physical examination were mild cyanotic lips, hyperpigmentation
(lipodermatosclerosis) in both legs, splenomegaly, and a mid-systolic
murmur in the second left intercostal space. In his past medical
history, he had blood culture-negative endocarditis twice in 25 and 27
years of age and also TOF early in his life. His past surgical history
consists of Blalock-Taussig shunt in 1994, tetralogy of Fallot total
correction (TFTC) in 2001, pulmonary valve replacement (PVR) with a
bioprosthetic valve in 2010, and Bentall procedure for native aortic
valve endocarditis (NVE) along with mechanical PVR in 2015. In all three
surgeries, pathological results were positive for infection and
endocarditis [15]. There was not a history of animal contact, recent
travel, or any suspicious contact, he just mentioned eating local cheese
occasionally and he was the only person with fever in his family.
According to the history of BCNE in our patient and a documented fever,
we performed several examinations to rule out infective endocarditis. In
early laboratory data, white blood cell count was 5700 ×
109/L (4000-10000 × 109/L) with 58%
polymorphonuclear leukocytes, hemoglobin level was 12.1 gr/dL (13-16
gr/dL), platelet cell count was 124000 (150,000 to 450,000 platelets per
microliter), serum creatinine was 2 mg/dL (0.6-1.5 mg/dL), erythrocyte
sedimentation rate was 120 mm/h (0-15 mm/h), and C-reactive protein was
31 mg/L (<6 mg/L).
Urine analysis, viral markers, Coomb’s wright, and 2ME tests were all
negative. Other examinations such as Covid-19 PCR and blood culture (six
times) were also negative.
We found right axis deviation, first degree atrioventricular (AV) block,
right bundle branch block (RBBB), and left posterior hemiblock on his
electrocardiography (ECG). The chest spiral computed tomography (CT)
scan was normal and without any pathologic findings. In TEE we didn’t
find any particular evidence regarding IE and his ejection fraction (EF)
was 40%.
According to the former history of BCNE in this patient, the history of
PET/CT scan involvement, and also the European heart association
guidelines in endocarditis, PET/CT scan was performed. Hyper metabolic
lesions were seen over the aortic and pulmonary prosthetic valves along
with ascending aorta graft, aortic arch, and proximal root of pulmonary
artery involvement, all in favor of infective endocarditis, diffuse
increased metabolic activity of sternum which may represent
osteomyelitis and also right sub-pectoral adenopathy (Figure 1). Based
on modified Duke’s Criteria in this patient, our suspicion was more
towards endocarditis.
After the PET/CT scan report, we have performed other examinations to
find the organism responsible for BCNE especially brucellosis and Q
fever due to the region we practice. Blood and sera samples of this
patient were referred to the National Laboratory for Plague, Tularemia,
and Q fever of Pasteur Institute of Iran. The Real-time PCR and IFA (IgG
phase I; 1:16384, IgG phase II; 1:16384) were positive for C.
burnetii and Q fever endocarditis was confirmed. We also examined the
previous samples from the last valve replacement for C. burnetii, which
was also positive. After the diagnosis, the proper treatment with
doxycycline 100mg every 12 hours and hydroxychloroquine 200mg every 8
hours was initiated and the patient’s fever was resolved.
We discharged our patient with the stable condition, suggested to follow
up his status with intermittent serological testing every three months
and PET/CT scan, a consultant with cardiologist and infectious disease
specialist and prescribed doxycycline 100mg every 12 hours and
hydroxychloroquine 200mg every 8 hours for 2 years due to the prosthetic
valve with a regular eye examination.
In three months, follow-up patient’s inflammatory indices such as ESR
and CRP were within normal ranges, C. burnetii serologic test, and
sternum uptake in PET/CT scan were decreased.