STUDIES ON HELMINTH PARASITES OF COMMENSAL AND FIELD RATS IN KARACHI AND SOME DISTRICTS OF SINDH.

Studies on helminth parasites of rats are important from the view point that these are known to cause diseases of extreme importance to man, domestic and wild animals and livestock. The public and Zoonotic importance of parasitic infection specially by rats continues due to their prevalence, vitality, global distribution and their effects on both nutritional and immune status of populations particularly those living in the tropics and subtropics. Therefore present investigations were taken.A total of 448 small mammals belonging to the orders rodentia, insectivore and families Muridae, cricetidae, soricidae, trapped from Agricultural fields and urban areas of some districts of Sindh, were examined in the laboratory for Helminth Parasitic Infections during 1990 to 1993 and 1996. A record of connection, including name of host, locality, location etc. was kept regularly for reference. The highest infection encountered was of Nematodes, followed by Cestodes and Trematodes.A total of 19 different Helminth parasites including Nematodes, Cestodes and Trematodes are described and figured in detail. These includes 10 species and 1 subspecies and description of two subgenera of Nematodes, 5 species and a new combination of Cestodes and 2 species of Trematodes. Out of the ten species of Nematodes reported, five are described as new species including a new subspecies.The new species are Trichuris taterii, from the host Tatera indica (Hardwicke, 1807) and Rattus rattus (Linnaeus, 1758), Haemonchus indicus, from the host Tatera indica. Syphacia pakistanica, from the host Rattus rattus,Protospirura unidentata, from the host Rattus norvegicus (Berkenhout, 1769), Seuratum bilqeesae from the host Tatera indica and Syphacia pakistanica sub.sp.n. from the host Nesokia indica (Gray and Hardwicke, 1832). Subspiculuris and Aspiculuris are the two subgenera of Aspiculuris recorded for the first time from Pakistan. Physaloptera qadrii, Pseudo physaloptera petaloidi, Pterygodermatites variabilis are redescribed and Streptopharagus kuntzi is a new record from the host Tatera indica from Pakistan.Out of five species of cestodes described two species i.e. Hymenolepis karachiensis from the host Tatera indica L., and Catenotaenia qadrii from the host Mus musculus (Linnaeus, 1758) are. regarded new species. Hymenolepis murini is new combination, which was previously described as vampirolepis murini Noor et al., 1995. Vampirolepis sp., is presently retained upto generic level and discussed in detail from the host Tatera indica. Mathevotaenia symmetrica (Baylis, 1927) Akhumian, 1946 is described with a new host and locality from Sindh Province. Cysticercus/ Strobilocercus larva belongs to taenidae family; it is occasionally found encysted in the liver of Rattus norvegicus and Rattus rattus.Catatropis pakistanensis Shafi et al., 1982 and Echinostoma bengalensis Shafi et al., 1986 arc the redecorations of two Trematode species from the field rats in Sindh.Scanning electron micrographs of some Nematodes were prepared, in order to observe detail morphology, these include: Trichuris taterii sp.n., Protospirura unidentata sp.n., Physaloptera qadrii Ghazi et al., 1987; Pterygodermatites variabilis Ghazi et al., 1991; Streptopharagus kuntzi (Mayer's, 1954) Lewis and Ashour, 1983.</p><p>In general commensal rats were found to be more infected with parasites as compared to the field rats. Tatera indica was found to be richly infected with Nematodes and Cestodes. Present work gives an idea about the parasites commonly found in field and commensal rats and Insectivores of Sindh. The 19 species of helminthes parasites reported herein constitute one of the extensive report from field and commensal rats of Sindh, Pakistan