721 Tropical Biomedicine 31(4): 721–727 (2014) Molecular detection of Entamoeba histolytica and Entamoeba dispar infection among wild rats in Kuala Lumpur, Malaysia Lau, Y.L. 1* , Jamaiah, I. 1 , Rohela, M. 1 , Fong, M.Y. 1 , Siti, C.O.S. 1 and Siti, F.A. 1 1 Department of Parasitology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia * Corresponding author email: lauyeeling@um.edu.my Received 28 February 2014; received in revised form 2 April 2014; accepted 8 April 2014 Abstract. Entamoeba histolytica infection is the third-greatest parasitic disease responsible for death in the world. Wild rats harbouring E. histolytica can be the possible reservoir hosts for human amoebiasis. There were numerous studies on prevalence of intestinal parasites among wild rats in Malaysia but none has reported E. histolytica. Rats were captured from Sentul and Chow Kit areas, Kuala Lumpur, Malaysia. The preserved stool samples were used for microscopy examination and molecular analysis. Out of 137 samples collected, 12 were positive for E. histolytica / E. dispar / E. moshkovskii microscopically. Two E. histolytica (1.4%), 1 E. dispar (0.7%) and 6 mixed infections of E. histolytica and E. dispar (4.3%) were detected using PCR. This is the first report of molecular detection of E. histolytica/dispar infection among wild rats in Malaysia. This study provides useful information about the potential risks of zoonotic agents and the importance of developing control measures to prevent zoonotic transmission. INTRODUCTION Rats have adapted to live in close association with human, using our agriculture and waste as their own food resources and our buildings are excellent rat homes. Rats are hosts of more than 60 known diseases. They are able to and play both direct and indirect roles in the transmission of human diseases (Ratzooman, 2010). Entamoeba histolytica infection is the third-greatest parasitic disease responsible for death in the world after malaria and schistosomiasis (Voigt & Strobel, 1999). It affects approximately 180 million people, of whom 40,000 to 110,000 die each year (Pestehchian et al. , 2011). Entamoeba histolytica infections are worldwide, more common in the tropics and subtropics. Food and drink contaminated with faeces containing the cysts is a common source of infection. Most cases arise from human carriers, or cyst passers, who pass cysts in formed or semiformed stools. Natural infections with E. histolytica occur in monkeys, dogs, and possibly pigs, but these animals constitute, at the most, a minor source of human exposure compared with man himself (Beaver et al., 1984). The natural infection of wild rats with E. histolytica was first reported by Lynch (1915). Epstein & Awakian (1937) reported the discovery of wild rats harbouring E. histolytica. These naturally infected rats were restricted to a localized focus, in which cases of human amoebiasis were discovered, thus providing circumstantial evidence of the human origin of the infection, and throwing light on the possible role of rats as reservoir hosts (Neal, 1951). After 1951, many studies have been done on the prevalence of parasites among wild rats throughout the world including Sudan, Taiwan, USA, Egypt, Thailand, Australia and Korea (Singleton et al., 1991; Namue & Wongsawad, 1997; Easterbrook et al., 2008;