Is the Oriental House Rat (Rattus tanezumi) a Potential Reservoir for Trypanosoma evansi in Thailand?

Abstract

ABSTRACT:Trypanosoma evansi is a protozoan blood parasite and etiologic agent of ''surra,'' a disease affecting a wide range of domestic and wild mammals, some identified as potential reservoirs. Although T. evansi has been detected in several small wild rodent species, their role in the epidemiology of surra is unclear.There is molecular evidence of T. evansi in wild rodents in Asia, but it is not known whether they can carry the parasite for sufficient time to significantly contribute to the epidemiology of surra. We assessed the susceptibility of the Oriental house rat (OHR; Rattus tanezumi) to T. evansi infection. Five adult male OHRs trapped in Bangkhen district, Bangkok, Thailand, and five laboratory Wistar rats (Rattus norvegicus) as positive controls, were experimentally infected with a local strain of T. evansi. The five controls and three of the five OHRs were highly susceptible and rapidly exhibited the high levels of parasitemia usually observed in Wistar rats. They died or were euthanized just prior to expected death. Two OHRs presented fluctuating levels of parasitemia, without obvious clinical signs, throughout 40 d of monitoring. These results highlight the moderate susceptibility of some OHRs and their ability to carry the infection over time. Along with the molecular evidence of T. evansi in captured OHRs (demonstrated elsewhere), our results bring new information on the potential role of OHRs in the complex epidemiology of surra.

The animal trypanosomiases and their chemotherapy: a review

“…Trypanosoma b. evansi can parasitize a wide range of wild and domestic animal hosts, but the infection is particularly pathogenic in horses, camels and Asian water buffaloes (Desquesnes et al 2013 b ). There is increasing evidence that common rodents are an important reservoir host for T. b. evansi and other trypanosomes (Jittapalapong et al 2008; Maia da Silva et al 2010; Kocher et al 2015; Pumhom et al 2015), such as T. lewisi , a parasite of rats also found in atypical human infections (Howie et al 2006; Sarataphan et al 2007). These findings revive the important question of rodents as reservoirs of other T. brucei species.…”

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

“…Furthermore, the abundance of a synanthropic rodent species is consistent for one highly adaptable species in particular, the oriental house rat (OHR: Rattus tanezumi ) ( Heaney and Molur, 2016 ), which results in its being typically found around residential areas and agricultural fields. This rat can expose and harbor multiple pathogens, particularly numerous helminth species, Trypanosoma spp., Leptospira spp., Bartonella spp., Hantaviruses ( Chaisiri et al, 2015 ; Johansson et al, 2010 ; Kocher et al, 2015 ; Loan et al, 2015 ; Plyusnina et al, 2009 ), and a further high diversity of arthropod ectoparasites, some of which play the role of vector for rickettsial diseases ( Huang et al, 2013 ). Knowledge about the exposure of the OHR to typhus-causing Rickettsia in different environments will improve the understanding of the epidemiology of these typhi and generate baseline information that can be used for disease management and prevention.…”

Surra: Trypanosomiasis in Livestock is Potential as Zoonotic Disease

“…Walaupun sejauh ini belum ada laporan yang menyebutkan bahwa tikus sebagai faktor utama terjadinya wabah Surra pada ternak, tetapi keberadaannya perlu diwaspadai (Rodríguez et al 2010). Kocher et al (2015) berpendapat bahwa tikus rumah (Rattus tanezumi) sebagai reservoir T. evansi yang berpotensi memfasilitasi penyebaran Surra pada manusia dan harus mendapatkan perhatian yang serius. Pernyataan ini telah dibuktikan melalui sebuah penelitian pada skala laboratorium.…”

“…Tikus dalam kondisi seperti ini menjadi lebih berbahaya karena parasit tetap berkembang dalam tubuh tikus dan menjadi ancaman bagi kesehatan manusia. Hasil penelitian Kocher et al (2015) memberikan peringatan dini untuk lebih meningkatkan kewaspadaan terhadap penyebaran Surra yang mungkin diperantarai oleh tikus rumah.…”