Right-sided
infective endocarditis due to methicillin-resistant Staphylococcus aureus (MRSA) is strongly associated with
intravenous drug abuse,
congenital heart disease, or previous medical treatment and is rare in healthy patients without a history of
drug abuse. Here, we present a case of an 18-year-old male with no
drug abuse history and no medical burden who was diagnosed with MRSA tricuspid valve
endocarditis. Due to initial symptoms which indicated community-acquired
pneumonia and radiological finding of interstitial lesions, empiric
therapy with
ceftriaxone and
azithromycin was started. After the detection of Gram-positive cocci in clusters in several blood culture sets,
endocarditis was suspected, and
flucloxacillin was added to the initial
therapy. As soon as methicillin resistance was detected, the treatment was switched to
vancomycin. Transesophageal echocardiography established the diagnosis of right-sided
infective endocarditis. A toxicological analysis of hair was carried out, and no presence of
narcotic drugs was found. After six weeks of
therapy, the patient was fully recovered. Exceptionally, tricuspid valve
endocarditis can be diagnosed in previously healthy people who are not drug addicts. As the clinical presentation commonly resembles a respiratory
infection, a misdiagnosis is possible. Although MRSA rarely causes
community-acquired infections in Europe, clinicians should be aware of this possibility.