Rickettsial seropositivity in the indigenous community and animal farm workers, and vector surveillance in Peninsular Malaysia

Abstract

Rickettsioses are emerging zoonotic diseases that are often neglected in many countries in Southeast Asia. Rickettsial agents are transmitted to humans through exposure to infected arthropods. Limited data are available on the exposure of indigenous community and animal farm workers to the aetiological agents and arthropod vectors of rickettsioses in Peninsular Malaysia. Serological analysis of Rickettsia conorii and Rickettsia felis was performed for 102 individuals from the indigenous community at six rural villages and 87 workers from eight animal farms in Peninsular Malaysia in a cross-sectional study. The indigenous community had significantly higher seropositivity rates for R. conorii (P<0.001) and R. felis (P<0.001), as compared to blood donors from urban (n=61). Similarly, higher seropositivity rates for R. conorii (P=0.046) and R. felis (P<0.001) were noted for animal farm workers, as compared to urban blood donors. On the basis of the sequence analysis of gltA, ompA and ompB, various spotted fever group rickettsiae closely related to R. raoultii, R. heilongjiangensis, R. felis-like organisms, R. tamurae, Rickettsia sp. TCM1, R. felis, Rickettsia sp. LON13 and R. hulinensis were identified from tick/flea samples in animal farms, indigenous villages and urban areas. This study describes rickettsial seropositivity of the Malaysian indigenous community and animal farm workers, and provides molecular evidence regarding the presence of rickettsial agents in ticks/fleas infesting domestic animals in Peninsular Malaysia.

Emerging Microbes & Infections (2017) 6, e18; doi:10.1038/emi.2017.4; published online 12 April 2017

• Peninsular Malaysia
• Rickettsia
• seropositivity
• vector surveillance

Acknowledgments

We thank all the participants in this study. We also thank Professor Yvonne Lim, Department of Parasitology, University of Malaya, Mr Saidon, Department of Orang Asli Development (JAKOA), Department of Veterinary Services, Ministry of Agriculture and Agro-Based Industry, Malaysia for assistance in the samples collection. We also thank Mdm Harvinder Kaur (Department of Medical Microbiology, Faculty of Medicine, University of Malaya) and Miss Meeta Devi Nurkunasegran (Department of Medical Microbiology, Faculty of Medicine, University of Malaya) for their technical assistance in this project. This study was funded by University of Malaya Research Grants (RP013-2012A/E), Ministry of Science, Technology and Innovation E-Science Fund (SF014-2015), and Postgraduate Research Fund (PG026-2012B).

Supplementary Information for this article can be found on the Emerging Microbes & Infections website (http://www.nature.com/emi)