Human seroreactivity against Bartonella species in the Democratic Republic of Congo

Objective: To assess the presence and identity of Bartonella species in a pool of human blood samples from DRC Congo. Methods: Blood ( 120 c L) was collected anonymously from Congolese patients and placed on calibrated filter papers. Bartonella serology determination was performed using an indirect immunofluorescence assay (IFA) against six specific Bartonella antigens and Coxiella burnetii (C. burnetii) antigen. The end cut off value for Bartonella sp. was a titre greater than 1:200. Results: None of the patients was positive for Bartonella elizabethae, Bartonella vinsonii subsp. vinsonii or Bartonella vinsonii subsp. arupensis nor for C. burnetti, but 4.5% of the 155 samples were positive for either Bartonella henselae, Bartonella quintana, or Bartonella clarridgeiae. Conclusions: This preliminary study presents the first report of Bartonella species in the DR Congo and the first report of antibodies to Bartonella clarridgeiae in an African human population. Although few experimental trials have established the link between fleas and Bartonella transmission, the repeated detection of similar Bartonella species in fleas and humans in several countries suggests that Bartonellosis could be another flea borne disease which specific reservoirs are still unknown.