An epidemiological study on zoonoses in Korea

Abstract

Helminthic zoonoses are of significant importance to the public health and to the socioeconomic consequences especially in lost-meat, animal products and animal labor. For past several decades in Korea, it has been recognized that endoparasitic infections among domestic animals are extremely common and many of the helminth parasites of man have been acquired from, or are shared with domestic animals. However, there has been no survey of a nationwide scale on the prevalence of animal helminthiasis; and control measures are also not satisfactory. Furthermore, because of the remarkable increase in demand, the number of domestic animals and pets is rapidly increasing. Therefore, an extensive study on zoonotic helminths was carried out from July 1980 throughout August 1981 to clarify the present status and parasite-host relationship from the epidemiological veiwpoint. 13,685 fecal specimens of cattle, sheep, pigs, dogs and cats were collected from 26 localities in the country, and examined by formalin-ether centrifugal sedimentation technique. Of the 13,685 specimens examined, 9,808 (71.7%) were positive for helminth parasites. The positive rates were 99.0% in cattle, 86.5% in sheep, 85.4% in pigs, 35.4% in dogs, 15.1% in cats. Single infection showed the highest rate (60.0%) and double infection (27.5%), followed by triple (8.1%), quadruple (2.8%), quintuple (1.5%) and hexad (0.1%) in decreasing order. In the present study, 18 species zoonotic helminths were found: 11 nematodes, 6 trematodes and 1 cestode. According to province, Cheju revealed the highest rate 84.8%, then Kyungnam 77.5%, Jeonnam 75.6%, Jeonpuk 75.4%, Kyonggi 75.2%, Chungnam 71.7%, Chungpuk 70.6% and Kangwon 64.2% were in decreasing order and Busan and Seoul showed 70.4% and 58.1%, respectively. Rural areas showed a slightly higher rate (74.7%) than urban areas (68.5%), and rates of infestation in mountainous areas (70.4%) and plains (71.1%) are very similar. Among cattle 6 nematodes and 3 trematodes were found. Strongyles was found in 26.4%, Neoascaris vitulorum in 24.1%, Trichuris ovis in 12.0%, Nematodirus sp. in 6.3%, Strongyloides papillosus in 5.1%, Capillaria bovis in 0.02%, Paramphistomum sp. in 41.5%, Fasciola hepatica in 33.2% and Eurytrema pancreaticum in 29.7%. In sheep 3 nematodes and 2 trematodes were found: Strongyles in 33.0%, S. papillosus 26.9%, Nematodirus sp. 14.6%, F. hepatica 31.7% and E. pancreaticum 19.6%. In pigs there were 5 nematodes and 2 trematodes: Strongyles in 43.1%, Ascaris suum 29.0%, Metastrongylus apri 20.3%, Trichuris suis 14.0%, Strongyloides ransomi 12.1%, Clonorchis sinensis 1.4% and Paragonimus westermani 0.9%. Among dogs 4 nematodes, 3 trematodes and 1 cestode were noted as follows: Toxocara canis in 14.4%, Trichuris vulpis 9.5%, Ancylostoma caninum 8.0%, Toxascaris leonina 4.0%, C. sinensis 2.4%, Metagonimus yokogawai 1.3%, P. westermani 0.8% and Spirometra sp. 0.9%. In cats 2 nematodes, 3 trematodes and 1 cestode were found including: Toxocara cati in 7.7%, Ancylostoma tubaeforme 3.1%, C. sinensis 1.9%, P. westermani 1.4%, M. yokogawai 1.2% and Spirometra sp. 0.7%.