<i>Bartonella henselae</i> and <i>Bartonella quintana</i> seroprevalence in HIV-positive, HIV-negative and clinically healthy volunteers in Gauteng, South Africa

Abstract

Bartonella is a genus of opportunistic, Gram-negative bacilli transmitted from animals to human hosts. Bartonellae are newly emerging pathogens that can cause a variety of clinical manifestations in both immunocompromised and healthy persons. The aims were to determine the IgG and IgM seroprevalences of Bartonella henselae and Bartonella quintana in immunocompromised and immunocompetent individuals using an immunofluorescence assay (IFA). A total of 382 HIV-positive outpatients of the Chris Hani Baragwanth HIV-clinic, 382 retrospective residual samples from HIV-negative antenatal patients, and 42 clinically healthy volunteers were tested using a commercially available IFA kit to determine the prevalence of IgG and IgM antibodies to B. henselae and B. quintana. The IgM and IgG seroprevalences for the HIV-positive patients were 14% (53/382) and 32% (121/382), respectively, compared to 18% for both IgM (62/342) and IgG (63/342) in the HIV- negative antenatal patients. Similarly, the prevalence for IgM was 17% (7/42) and IgG was 19% (8/42) for the clinically healthy volunteers. HIV-positivity appears to be a significant risk factor for Bartonella infection, compared with healthy subjects. Although IFAs have a high sensitivity for Bartonella antibody detection, they have various limitations including cross-reactivity with other closely-related human pathogens.