Survey of rodent-borne pathogens in Singapore reveals the circulation of Leptospira spp., Seoul hantavirus, and Rickettsia typhi

Jane Griffiths,Diyar Mailepessov,Lee Ching Ng,Chern-Chiang Siew,Patrik Johansson,Patrick Lam,Hwee Teng Low,Grace Yap,Hui Ling Yeo

doi:10.1038/s41598-021-03954-w

Jane Griffiths, Diyar Mailepessov + Show 7 more

Open Access

https://doi.org/10.1038/s41598-021-03954-w

Copy DOI

Abstract

Rodents living alongside humans increases the probability of encounter and also the transmission of rodent-borne diseases. Singapore’s cosmopolitan urban landscape provides a perfect setting to study the prevalence of four rodent-borne pathogens: Seoul hantavirus (SEOV), Leptospira species, Rickettsia typhi and Yersinia pestis, and identify the potential risk factors which may influence rodent density and transmission of rodent-borne diseases. A total of 1143 rodents were trapped from 10 unique landscape structures throughout Singapore. Real-time quantitative Polymerase Chain Reactions were used to detect pathogenic and intermediate Leptospira spp. and Yersinia pestis, whereas the seroprevalence of SEOV and R. typhi were analysed by Enzyme-Linked Immunosorbent Assay and Immunofluorescence Assay respectively. Multivariable logistic regression analysis was used to evaluate the association between prevalence of infection in rodent reservoirs and risk factors. Most of the rodents were caught in public residential developments (62.2%). Among the tested rodents, 42.4% were infected with Leptospira spp., while 35.5% and 32.2% were seropositive for SEOV and R. typhi respectively, whereas Yersinia pestis was not detected. Furthermore, risk factors including habitat, species, gender, and weight of rodents, influenced prevalence of infection to a varying extent. This study highlights the presence of Leptospira spp., SEOV and R. typhi in Singapore’s rodent population, suggesting the need for effective rodent management and sanitation strategies to prevent further circulation and transmission to humans.

Highlights

Rodents living alongside humans increases the probability of encounter and the transmission of rodent-borne diseases
Animal work was approved by Defence Science Organisation (DSO) National Laboratories Institutional Animal Care and Use Committee (DSO/IACUC/05/13) and performed in compliance with the National Advisory Committee for Laboratory Animal Research (NACLAR) Guidelines, Singapore
Rattus norvegicus and Rattus rattus, were selected for further analysis, as other species were present in low numbers

Summary

Introduction

Rodents living alongside humans increases the probability of encounter and the transmission of rodent-borne diseases. Rattus norvegicus can be found exploiting infrastructures such as sewers systems[15], false floors and burrowing under buildings and c oncrete[16,17] while Rattus rattus, known to be agile c limbers[18], can be found indoors[19] taking refuge in false ceilings and wall c avities[20] Both species are known to be carriers of several rodent-borne zoonotic pathogens including Leptospira, hantaviruses, rickettsiae and Yersinia pestis and these pathogens are known to cause disease in humans in Southeast Asia as well as g lobally[21,22,23,24,25]. The occupational risk of leptospirosis infection was previously reported by Chan et al in abattoir workers, cleaners and sewer workers[36,37]

Methods

Results

Discussion

Conclusion