Investigation of multiple infections with zoonotic pathogens of rodents in northern Vietnam.

Abstract

Rodents are important reservoir hosts for several zoonotic pathogens such as Rickettsia, Leptospira and Bartonella. Studies on the prevalence of zoonotic pathogens in Vietnam are data deficient, and there is a scarcity of data on multiple co-infections of zoonotic pathogens to date. This study examined the prevalence of Rickettsia spp., Leptospira spp., and Bartonella spp. and the co-infection of these pathogens in rodents captured in three provinces of northern Vietnam - Ha Giang, Lao Cai and Cao Bang. In total, 133 rodents of 25 species were screened for pathogen prevalence by real-time PCR. Very high infection rates were found for each pathogen, with 42 of 133 rodents (31.6%) positive for Bartonella and 33 of 133 (24.8%) positive for Rickettsia (5.3% were positive for Rickettsia typhi, and 19.5% were infected with Rickettsia spotted fever group). Additionally, 24 rodents (18%) were positive for Leptospira. Double infection among these three pathogens was found in 26 of 133 rodents (18.8%), with the highest dual infection rates for Rickettsia and Bartonella co-infection (40%) and Leptospira and Bartonella co-infection (up to 40%), followed by Rickettsia and Leptospira co-infection (20% of animals investigated). One case of triple infection was documented for a house rat (Rattus cf. rattus species group) trapped in Ha Giang province. Our survey indicates that rodents in northern Vietnam may host multiple zoonotic pathogens simultaneously; thus, rodents contribute significantly to the increased risk of transmission of multiple zoonotic infections from animals to humans.