Rickettsiae exposure related to habitats of the oriental house rat (Rattus tanezumi, Temminck, 1844) in Salaya suburb, Thailand

Abstract

Rickettsial zoonotic diseases, in particular scrub typhus, murine typhus, and tick typhus, are caused by Orientia tsutsugamushi , Rickettsia typhi , and Rickettsia honei infections. Rickettsiae exposure is typically related to a rodent host in various habitats of marginal regions, including between rural areas and communities such as the Salaya suburb. This allows the oriental house rat (OHR), a highly adaptive species, to live in close proximity to the community and possibly introduce rickettsial diseases. To understand rickettsial exposure in the OHR from different habitats, knowledge of disease exposure can serve as baseline information for disease management and prevention. A total of 185 OHRs from three unrelated habitats were assessed using a standard indirect immunofluorescence assay (IFA) for specific antibody reaction to O. tsutsugamushi , R. typhi , and R. honei . The presence of antibody in the OHR to rickettsiae, either scrub or murine typhus, was associated with the habitat, whereas tick typhus had general exposure. This finding shows the OHR to be a potential reservoir host for rickettsial diseases along the borders of geographic regions in the suburban environment.

Orientia tsutsugamushi dynamics in vectors and hosts: ecology and risk factors for foci of scrub typhus transmission in northern Thailand

“…There have been 32 published scrub typhus investigations in vectors and hosts in Thailand since 1952 [6,19,59,[67][68][69]. Ten studies report testing vectors and/ or hosts for O. tsutsugamushi using molecular methods, including PCR and 16S ribosomal RNA amplicon sequencing from several sites around Thailand [19,59,64,66,[68][69][70][71][72][73].…”

Molecular Detection of Bartonella Species in Rodents Residing in Urban and Suburban Areas of Central Thailand

“…Of these, R. tanezumi and R. exulans were reported as major species of Rattus in Thailand [40]. Interestingly, R. tanezumi is a synanthropic rodent species mostly found in suburban environments, including residential and agricultural areas [41]. In urban areas, some species of Rattus were also reported such as R. norvegicus and R. rattus [35].…”

Prevalence and Molecular Characterization of Rickettsia spp. from Wild Small Mammals in Public Parks and Urban Areas of Bangkok Metropolitan, Thailand

“…Two studies recently reported on the seroprevalence of R. typhi in rodents from Thailand [ 39 , 40 ]. Chareonviriyaphap et al (2014) [ 39 ] reported a 23.7% seroprevalence of R. typhi in wild rodents collected from 10 provinces across four regions of Thailand (central, northern, northeastern, and southern parts of Thailand).…”

“…In the suburbs of Bangkok, the seroprevalence of murine typhus exposure in oriental house rats ( R. tanezumi ) ranged from 32.31 to 64.15%. It should be noted that positivity was mainly found in human-dominated habitats (i.e., residences and animal shelters) and that no murine typhus antibody positivity was reported in rats captured in agricultural fields [ 40 ].…”