Prevalence of Bartonella spp., Borrelia spp., and piroplasmid in HIV-infected symptomatic individuals in Brazil: a cross-sectional study

Abstract

Abstract Background Bartonella spp., Borrelia spp., and piroplasmid are increasingly recognized as vector-borne pathogens worldwide, with documented circulation in arthropod vectors and animal reservoirs in Brazil. The purpose of this study was to assess whether Bartonella exposure and/or infection were associated with specific clinical and epidemiological characteristics in HIV-infected symptomatic patients living in Brazil. The second aim was to determine if infection with a piroplasmid or Borrelia species might be detected in these patients. Methods Epidemiological and medical history were collected for each of 75 HIV-positive participants. In a blinded manner, we assessed the presence of anti-Bartonella antibodies by indirect immunofluorescence assays (IFA) using B . henselae , B . koehlerae , B . quintana , and B . vinsonii berkhoffii (genotypes I and II) as antigens. A cut-off dilution of 1:64 was selected as a seroreactivity titer. We evaluated infection by amplifying Bartonella spp., Borrelia spp. , and piroplasmid DNA from blood using quantitative polymerase chain reaction (qPCR) and digital PCR (dPCR). qPCR was performed before and after BAPGM (Bartonella alpha-Proteobacteria Growth Medium)-enriched blood culture for up to 28 days, and statistical analyses were conducted in an exploratory framework. Results Seroreactivity to at least one Bartonella antigen was found in 47/75 (62.7%) participants. The most frequent seroreactive species were B. henselae (57.3%), and B. vinsonii subsp. berkhoffii genotype II (44.0%). Bartonella seroreactivity was associated with systemic manifestations (11/47 seroreactive vs. 1/28 non-seroreactive patients; OR = 8.25, 95% CI 1.00–68.2; p = 0.026). All participants were negative for Bartonella and Borrelia spp. qPCR and dPCR. Two participants had a low positive partition number by piroplasmid dPCR, which was not repeatable by retesting. Conclusions In this cohort of HIV-infected symptomatic patients, exposure to Bartonella species was frequent, but molecular evidence confirmed by sequence analysis of Bartonella, Borrelia, and piroplasmid infection was not found. The clinical relevance of Bartonella seroreactivity remains to be clarified.