Coprological survey of alimentary tract parasites in dogs from Zambia and evaluation of a coproantigen assay for canine echinococcosis

Abstract

Faecal samples were collected from the rectum of 540 domestic dogs from four districts (Lusaka, Katete, Petauke and Luangwa) in Zambia between 2005 and 2006 and prevalences of canine alimentary tract parasites were determined by coprological examination. Thirteen different ova and parasites including strongyle (43·3%), Spirocerca lupi (18·7%), taeniid (13·1%), Toxocara canis (7·6%), Sarcocystis sp.* (7·5%), Isospora sp.* (5·7%), Physaloptera sp.* (4·6%), Capillaria sp.* (2·8%), Dipylidium caninum (2·2%), Mesocestoides sp.* (2·0%), Ascaris sp.* (1·7%), Trichuris vulpis* (0·4%) and Schistosoma mansoni* (0·4%) were detected, Ascaris and Schistosoma probably originating from coprophagy. The species with asterisks and later-described Taenia multiceps are for the first time reported from dogs in Zambia. A coproantigen enzyme-linked immunosorbent assay (CoproAg-ELISA) developed for Echinococcus spp. revealed 43 positive dogs and 37 of these harboured taeniid eggs. From 63 of the 71 taeniid egg-positive samples, eggs and DNA thereof were isolated and subjected to a multiplex polymerase chain reaction for differentiating E. granulosus sensu lato, E. multilocularis and Taenia spp. Amplicons indicative for Taenia spp. were obtained from 60 samples. Sequencing of amplicons spanning part of the mitochondrial cytochrome c oxidase subunit 1 gene, which was possible with 38 samples, revealed 35 infections with T. hydatigena and 3 with T. multiceps. Therefore, the CoproAg-ELISA showed some positives, but concrete evidence for the existence of canine E. granulosus infection could not be established. Comparison of the results of the CoproAg-ELISA and Taenia species identification indicated that the CoproAg-ELISA cross-reacts with patent infections of T. hydatigena (57%) and T. multiceps (33%).

We thank Professor Yoshimitsu Maede for his valuable support for this survey. We are grateful to the staff of the Laboratory of Parasitology, Graduate School of Veterinary Medicine, Hokkaido University, and the staff of Laboratory of Helminthology, Samora Machel School of Veterinary Medicine, University of Zambia, for their valuable support. We also thank local veterinary officers and veterinary assistants in the surveyed area in Zambia for their support in the survey. This work was supported by Twenty-first Century COE Program ‘Program of Excellence for Zoonosis Control’, MEXT, by the Japan Society for the Promotion of Science (grant no. 15380205) and by the Ministry of Health, Labor and Welfare, Japan (grant for ‘The control of emerging and reemerging diseases in Japan’).