A 64-year-old man was transferred to the Internal Medicine Department from the Cardiology Department due to a fever of over 38.3 °C, of more than 3 weeks' evolution with no source of origin after 5 weeks of studies.
On admission, the patient was being treated with gliclazide (1-1-1) and acarbose (1-1-1) to control type 2 diabetes mellitus, Atorvastatin (0-0-20 mg) to control hypercholesterolemia, quinapril (5 mg-0-5 mg) to control arterial hypertension and, finally, acetylsalicylic acid (0-150 mg-0) as vascular accident prophylaxis. In addition to these pathologies, the patient had severe aortic valve stenosis together with moderate aortic insufficiency, which required valve replacement with Mitroflow bioprosthesis no. 23 in March of the year of admission.
When the patient was admitted to the Cardiology Department, a five-week febrile condition was detected in a patient with a prosthetic valve; a transesophageal echocardiogram ruled out the presence of endocarditis or functional valvular alterations, and empirical intravenous treatment with Vancomycin was started (given the existence of a prosthetic valve despite not clearly demonstrating vegetation), improving until he was asymptomatic and afebrile when discharged from Cardiology a week later. During discharge, the patient underwent periodic body temperature controls, and 4 weeks later a new elevation was detected, which led him to our hospital and he was admitted for the second time to the Cardiology Department, where endocarditis was again ruled out by transesophageal echocardiography, so he was transferred to the Internal Medicine Department, with a diagnosis of Classical fever of unknown origin to be studied.
After admission, fever of over 38.3°C, with peaks of up to 39°C, blood pressure of 150/70 mm of mercury, and a heart rate of 104 beats per minute were confirmed. On physical examination the patient was normal colour and normal depth, cardiac auscultation showed no murmurs, pulmonary auscultation showed preserved vesicular murmur with no evidence of rhonchi, crackles or wheezing; the abdomen was not painful and there was no evidence of splenomegaly; ENT examination showed no evidence of infectious foci; neurological examination showed no evidence of meningismus, strength or sensitivity deficit, or alteration of cranial nerves or osteotendinous reflexes; the examination also showed no evidence of lymphadenopathy.
Complementary tests were performed for the study of fever of unknown origin according to protocol7 with a haemogram showing 14,000 leukocytes (70% neutrophils and 5% cayates) and 1371 g/dl haemoglobin. Biochemistry showed normal renal and hepatic function with normal glycaemia. A peripheral blood smear was performed which confirmed the haemogram data with no other pathological findings. Chest X-ray showed no pathological findings or changes with respect to previous admissions. A paranasal sinus X-ray showed hypoplasia of the left frontal sinus. The transesophageal echocardiogram showed no evidence of endocarditis, abscesses or fistulas, together with a normofunctioning aortic prosthesis. Subsequently, a Ga67 scintigraphy was performed, with no tracer deposits in the thoracoabdominal region. To complete the study of fever of unknown origin, tumour markers (alpha-fetoprotein, CEA-II, Ca 19.9n Ca 125II, BR 27.29, total PSA, Ca 15.3, specific neutrophil enolase, Ca 72. 4) which were normal and the study of immunological markers (ENA antinuclear antibodies, rheumatoid factor, C-reactive protein, ASLO, anti-DNA antibodies, ANCA, anticardiolipin antibodies, anti-smooth muscle antibodies, antimitochondrial antibodies, ANA and LKM) which were negative.
On admission, blood cultures were taken after taking body temperature above 37.5 °C, and all four were positive for Leuconostoc spp. and the antibiogram showed sensitivity to amoxicillin-clavulanic acid and tobramycin, antibiotherapy that was started from that moment onwards.
Due to the existence of the bioprosthesis, the patient was treated for 8 weeks as if it were endocarditis, despite there being no evident lesions on transesophageal echocardiography.
Periodic check-ups were carried out for 1 year after discharge without any febrile or clinical findings that would lead to any new suspicion of complications or valve complications.