Discussion
Q fever, a zoonotic infectious disease, can present with chronic manifestations rather than intermittent fever. The most common chronic complication is endocarditis with a high rate of morbidity and mortality. In addition to endocarditis, osteomyelitis is another chronic Q fever complication [16-18]. C. burnetii grows on the abnormal cardiac valve along with the prosthetic valve and causes Q fever non-specific manifestations, therefore chronic Q fever is hardly diagnosed and because of several antimicrobial treatment resistance, it is hardly treated too. One of the risk factors for chronic Q fever is valvular surgeries which our patient underwent several times [19, 20].
Due to the high prevalence of C. burnetii in our country, we should consider it as an important agent for BCNE [21, 22].
Despite the great medical development, infective endocarditis is still a concern in both diagnosis and treatment and the best option for early diagnosis and immediate treatment is to consider IE as a possible diagnosis [23, 24]. Even nowadays the mortality rate caused by IE reaches 30% annually [25]. Echocardiography is a non-invasive diagnostic evaluation in IE which can detect the vegetation accurately without a significant difference from the surgical view. In some cases like ours, there is no evidence suggesting IE in echocardiography, therefore normal ECG cannot rule out IE diagnosis [26].
To identify extra cardiac IE manifestations, classification, and also management, PET/CT scan is helpful. In our patient all the studies except PET/CT scan couldn’t reveal the IE evidence, therefore we should declare that performing PET/CT scan is a necessary evaluation in IE cases or even in those with suspicious IE diagnosis [27, 28].