Parasites bared in Rattus norvegicus and Rattus tanezumi

This paper documents the richness of parasites inhabiting Rattus tanezumi and Rattus norvegicus. Rattusspp. revealed six ectoparasites, namely: mites genus Chirodiscoides,and Radfordiaensifera, Laelaps nutalli and Ornithonyssusbacoti, fleasXenopsyllacheopis, and licePolyplax spinulosa. While infestation with L. nutalliwas heavy in 15 (100%) and 13 (86.7%) R. norvegicusand R. tanezumi, respectively, only R. tanezumiharbored Chirodiscoides andP. spinulosaat80.0%. Endoparasites identified were two kinds of nematodes belonging to genus Nippostrongylus(Class Secernencea)and Capillaria hepatica (Class Adenophorea),and tapeworms identified as genus Raillietina, and Hymenolepis, and Taenia taeniaformis.Whileall 30 rats showed 100% parasitism with ecto-and endoparasites, Babesiainfection was detected only in eight rats (26.6%), with seven cases recorded in male rats.Most dominant endoparasites were Nippostrongylus in R. norvegicusat 73.3%, andR. tanezumiat 100.0%; while R. norvegicusandR. tanezumirevealed 86.6% and 66.6% prevalence with C. hepatica, respectively.Interestingly,Taenia taeniaformis andRaillietinawere detected only in R. norvegicusat 80.0% and20.0% infection, respectively. While both species of rats examined revealed susceptibility to different kinds of parasites, the heavier R. norvegicusseemed tonurture and support greater parasite species richness and density. In view of the argument of a clear accumulation of helminth diversity and species burden with increasing age of rat speciesand in the absence of information of the ages of rats used in the present survey, studies to cover an expanded rat population in the Philippines is recommended.