Infective endocarditis associated with Bartonella henselae: A case series

Bartonella Endocarditis in Spain: Case Reports of 21 Cases

Blood culture negative endocarditis (BCNE) is frequent in infective endocarditis (IE). One of the causes of BCNE is fastidious microorganisms, such as Bartonella spp. The aim of this study was to describe the epidemiologic, clinical characteristics, management and outcomes of patients with Bartonella IE from the “Spanish Collaboration on Endocarditis-Grupo de Apoyo al Manejo de la Endocarditis infecciosa en España (GAMES)”cohort. Here we presented 21 cases of Bartonella IE. This represents 0.3% of a total of 5590 cases and 2% of the BCNE from the GAMES cohort. 62% were due to Bartonella henselae and 38% to Bartonella quintana. Cardiac failure was the main presenting form (61.5% in B. hensalae, 87.5% in B. quintana IE) and the aortic valve was affected in 85% of the cases (76% in B. henselae, 100% in B. quintana IE). Typical signs such as fever were recorded in less than 40% of patients. Echocardiography showed vegetations in 92% and 100% of the patients with B. henselae and B. quintana, respectively. Culture was positive only in one patient and the remaining were diagnosed by serology and PCR. PCR was the most useful tool allowing for diagnosis in 16 patients (100% of the studied valves). Serology, at titers recommended by guidelines, only coincided with PCR in 52.4%. Antimicrobial therapy, in different combinations, was used in all cases. Surgery was performed in 76% of the patients. No in-hospital mortality was observed. One-year mortality was 9.4%. This article remarks the importance for investigating the presence of Bartonella infection as causative agent in all BCNE since the diagnosis needs specific microbiological tools and patients could benefit of a specific treatment.

Clinical and Echocardiographic Characteristics of Bartonella Infective Endocarditis: An 8-Year Single-Centre Experience in the United States

BACKGROUND

Infective endocarditis due to Bartonella species is rare. The clinical and echocardiographic characteristics are not well defined. We aimed to investigate the clinical and echocardiographic findings of Bartonella endocarditis in the contemporary era.

METHODS

The infective endocarditis (IE) registry and echocardiographic database at our institution were retrospectively analysed to evaluate the clinical and echocardiographic features of Bartonella endocarditis.

RESULTS

Between January 2008 and December 2015, there were 11 patients with Bartonella IE (0.84% among a total of 1,308 cases of definite IE): median age 54 (30-69) years, all male, 9 Caucasian, 10 had a history of cat exposure, 10 had a pre-existing valvulopathy including 6 patients with a prosthetic valve with prosthesis age range between 3 to 5 years and 1 patient with implantable cardioverter defibrillator (ICD). Bartonella henselae was responsible for all the cases. Echocardiographic evidence of IE was found in 6 of 11 patients on transthoracic echocardiography (TTE), and 6 of 8 on transoesophageal echocardiography (TEE). Bartonella IE was associated with significant valvular destruction and dysfunction on echocardiography. Nine (9) patients were managed surgically with excellent outcomes, including two patients who failed initial medical therapy. Two (2) patients who were managed medically had progression of valvular dysfunction. At a median follow-up of 6 months, there were no deaths attributable to IE or other cardiovascular causes.

CONCLUSION

In a contemporary single-centre cohort in the United States, Bartonella IE remains rare, but should be considered when pathogen could not be identified in patients with suspected IE, especially those with prosthetic valves or bicuspid aortic valve (BAV). The vast majority of patients with Bartonella IE were managed surgically with excellent outcomes.

Bartonella species as a cause of culture-negative endocarditis in South Africa

Previous reports have highlighted the high prevalence of blood culture negative endocarditis (BCNE) in South Africa. The Tygerberg Endocarditis Cohort (TEC) study is an ongoing prospective cohort study of patients with confirmed or suspected IE presenting to Tygerberg Academic Hospital, Cape Town, South Africa. Current analysis includes patients that presented between November 2019 and August 2020. Forty four (44) patients have been included in this ongoing study. Fourteen of the 44 patients (31.8%) had BCNE. Further analysis of the patients with BCNE identified Bartonella species as the most common causative organism (n=6; 43%). Other causes included Mycoplasma species (n=2). No cause could be identified in 4 of the 44 patients (9%). Bartonella quintana was identified with PCR of valvular tissue as the causative organism in 4 of the 5 patients that underwent urgent surgery. The patients with Bartonella IE (n=6) had an average age of 39 years with equal gender distribution. The common clinical features were clubbing (n=5; 83%), anemia (n=4; 66.6%), haematuria (n=3; 50%), acute on chronic severe regurgitant lesion (n=3; 50%) and acute severe regurgitant lesion (n=2; 33.3%).The aortic valve was involved in 5 of 6 patients. During a mean follow-up period of 251 days after diagnosis, no major adverse events occurred. Bartonella-associated IE is an important cause of BCNE in the Western Cape of South Africa. Imaging findings (in patients with BCNE) of significant valvular destruction with large vegetations on the aortic valve not affected by congenital or rheumatic valve disease should raise the suspicion of Bartonella-associated IE.