Persistent Bartonella quintana Infection in Macaques at Primate Research Institute, Japan

Bartonella quintana, the causative agent of trench fever, is a louseborne bacterial pathogen. During 2016−2017, we investigated B. quintana infection in macaques housed at 2 primate research institutes in Japan. We isolated B. quintana from 3 wild-caught Japanese macaques, which had been introduced into 1 institute in 2009. The macaques had received periodic ivermectin treatment every 1–2 years to control blood-feeding arthropods. Whole-genome comparisons revealed that the 3 isolates exhibit higher homology to a Japanese macaque–derived strain than to rhesus macaque–derived or human-derived strains. In addition, in all 3 isolates, the bepA locus was absent; we classified the trwL locus as structural variant C, consistent with known Japanese macaque–derived strains. Our findings suggest that B. quintana bacteremia in the macaques might have persisted for 7–8 years in captivity, and that the bacterium was not accidentally transmitted to them from humans by reverse zoonosis.