Investigation of rodent-borne diseases in public park and urban areas of Bangkok metropolitan

Abstract

In 2018-2019, extensive field studies were conducted to investigate parasites/pathogens carried by small mammals in the area of Bangkok Metropolitan. The green areas such as urban public parks could exist an animal-human interface and potential risk of zoonotic disease transmission particularly in the big city. In total, 197 small mammals (5 species), i.e. synanthropic rodents: Rattus exulans, Rattus norvegicus and Rattus rattus-complex Scadentia: Tupaia belangeri and Insectivore: Suncus murinus were captured and examined for infections of macroparasites and microbial pathogens (i.e. Angiostrongylus spp., Leptospira spp., hantavirus, and Orientia tsutsugamushi as proposed for observation in the present study). For Angiostrongylus infection, the rat lung worms were found in pulmonary artery and lung tissues of 17 small mammals, yielding 8.76% prevalence of infection. Based on morphological identification, all the nematodes were identified as Angiostrongylus malaysiensis. In terms of microbial pathogens, only pathogenic Leptospira interrogans was detected (4.3% total prevalence of infection) in seven small mammals from the 3 study sites: Tawee Wanarom Park, Thonburirom Park and Wachirabenchathat Park, whereas hantavirus and Orientia tsutsugamushi were not presented in the animal tissues. Greater prevalences of both A. malaysiensis and L. interrogans infections were found in animals from public parks compared to those from citified areas (e.g. Inside buildings or offices). Multivariate analyses (with Generalized Linear Model) identified potential host intrinsic and extrinsic factors that could explain A. malaysiensis and L. interrogans infection statuses in Bangkok Metropolitan. These results provided essential information not only to assess the existence of potential zoonotic health threats for humans in Bangkok, but also provided cautious information to the Bangkok Public Park Office, Bangkok Metropolitan Administration for further implementation of disease prevention in the parks and nearby communities.