Culture-negative Infective Endocarditis in an Afebrile Old Woman: A Case Report

Infective endocarditis (IE) is an uncommon infectious disease involving both endocardium and heart valves, which is associated with a high rate of morbidity and mortality. The absence of classical signs/symptoms of IE leads to difficulties in diagnosis of this clinical entity. Being negative-culture and afebrile upon presentation have been reported in some case series.

A 69-year-old Caucasian woman presented with fatigue, tachycardia, and a mild swelling of left-sided knee. About 4 months before the index admission, she had a swelling and aching of left-sided wrist which was improved. Then, she developed a left-sided knee swelling and aching with a limited range of motion which was continued with a right-sided knee arthralgia. The limited range of motion and aching improved within 5-7 days spontaneously. All tests for the detection of brucellosis and rheumatologic diseases were negative. The transesophageal echocardiography revealed a fixed mass sizing 5 8 mm on aortic valve non-coronary cusp suspicious for vegetation in trans-gastric view. Blood cultures were negative at three times before the initiation of empirical antibiotic therapy. She was given ampicillin-sulbactam regimen and the regimen continued for 3 weeks and she discharged home on co-amoxiclave regimen. After a year, echocardiography revealed the resolution of vegetation.

The diagnosis of IE in elderly patients with unspecific signs and symptoms is of great importance in our daily practice. Timely detection and proper management of such cases can improve the outcomes of patients.