Culture-negative endocarditis due to Bartonella quintana

Abstract

Bartonella spp. was first described as a possible cause of culture-negative endocarditis in 1993, and has since emerged as a significant cause of this condition worldwide. We describe a complicated case of culture-negative endocarditis in an immune-competent male patient, which was confirmed on resected heart valves to have been caused by Bartonella quintana by broad-range 16S ribosomal RNA polymerase chain reaction. The objective of this report is to highlight the clinical, diagnostic and therapeutic challenges of Bartonella endocarditis.

Bartonella Species as a Cause of Culture-negative Endocarditis in South Africa 

“…(4-6,15) The rst case was described in 1993 and another case was reported recently. (16,17) Our ndings are in keeping with data from other developing countries where Bartonella species are the most common cause of BCNE contrasting with developed countries that report C. burnetii as the commonest cause of BCNE. (7,11,18) The reasons for the lack of reporting of Bartonella species as a cause of BCNE in South Africa are probably multifactorial.…”

“…Previous case reports from South Africa and a case series from the United States also identi ed B. quintana as the causative species in BCNE. (16,17,21) A case series from Japan identi ed B. henselae as the causative species in ve cases of BCNE. (19) B. henselae has been detected on blood PCR in up to 10% of HIV-positive patients in South Africa whereas no cases were detected in the non-HIV infected control cohort.…”

“…(4) In all but one of the patients, the aortic valve was involved, which is in keeping with previous reports. (16,21) All patients had hemodynamically severe incompetence of either the aortic (n=5) or mitral (n=1) valve with clinical features of acute (n=2), acute on chronic (n=3) or chronic (n=1) incompetence. Historically, acute IE and acute valvular incompetence is associated with S. aureus IE and these patients often do not demonstrate the classical ndings of clubbing and anemia as these features take time to develop.…”

Infective endocarditis in Africa: an urgent call for more data

“…6,7 These organisms vary according to geographical location, but the available evidence would suggest that the Bartonella species are the most common in Africa. 6,8,9 Serology to detect active infection with these difficult-to-culture organisms as well as broad range PCR of valve tissue to detect 16S rRNA for bacteria and ITS2 for fungi was only performed in a small number of the studies included. This limitation might have contributed to the observation that in more than half of the patients a causative organism was not identified.…”