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.