Echinococcus Infections in Man and Animals in Kenya

1. Hydatid cysts are found in more than 30 per cent of all cattle, sheep and goats in Kenya, but the disease is prevalent in man only in the semi-desert area of Turkana. Up to the time of the present investigation the life-cycle of the parasite in East Africa had not been studied, but it was suggested that wild carnivores, such as hyenas and jackals, might be the main hosts of the adult worms. 2. One hundred and forty-three carnivores, representing 23 species, have been examined. Echinococcus adults were found in 27 out of 43 domestic dogs (Canis familiaris), in three out of four hunting dogs (Lycaon pictus), in one out of nine jackals (Thos mesomelas), and in three out of 19 hyaenas (Crocuta crocuta). 3. A detailed morphological study was made of the Kenya material. After comparison with specimens from other parts of the world, it was concluded that the only species occurring in Kenya was E. granulosus, but it is possible that the minor morphological and biological differences are evidence of distinct strains. Further laboratory studies are necessary to compare the parasite from man and animals in different parts of Kenya with material from elsewhere. 4. A search was made for larval hydatids in 92 ungulates representing 18 species, and in a miscellaneous collection of nearly 2,000 rodents and primates representing a further 31 species. Only one animal was positive, a wildebeest (Gorgon taurinus). 5. The infections in the wild carnivores were all very light; only domestic dogs were heavily infected. It is concluded that the main cycle of transmission in Kenya is between dogs and domestic livestock. 6. Turkana tribesmen are the most heavily infected people in Kenya, either because the strain of parasite is more pathogenic to man in that area, or, more probably, because of the intimate contact between children and the large number of infected dogs. A particularly dangerous custom in the area is the use of dogs to clean the face and anal regions of babies when they vomit or have diarrhea. No satisfactory explanation can be given for the rarity of the disease in man in many of the other areas of Kenya where hydatids are very common in domestic animals. 7. The control of the disease will depend upon an active health-education campaign, together with the destruction of all unregistered dogs and improvement in meat hygiene.

Opening Comments Before Master Conservationist Presentations

It is a real pleasure to participate in this recognition program honoring the 2004 Master-Conservationists. We are grateful for the partnership with the Omaha World Herald in this unique program. In an effort to keep the program in tune with current developments in soil and waster conservation, a special committee is considering the idea of including conservation easements in the 2005 program. Some members of the committee are in the audience tonight. We appreciate the efforts of members of the Omaha World Herald, Natural Resources Districts, the USDA Natural-Resources Conservation Service and the Institute of Agriculture and Natural Resources in carrying out this program.

COMMENSAL RODENT CONTROL

SUMMARY: Federal Urban Rat Control Program grants were awarded to cities in different areas of the United States. Severe problems of rat infestations have been detected in many of the cities by the Environmental Health Service. Approximately 20% of 3.8 million people in the project areas were occupying homes infested with rats. Control operations are now in effect in all cities, and the living conditions of the people have been substantially improved. An increase in interest in rodent control also is evident in countries outside of the United States. The Technical Development Laboratories of the National Communicable Disease Center are participating in the World Health Organization program of research on new rodenticides. The evaluation program involves five steps which carry a candidate toxi¬cant from laboratory phase through field testing. Acceptability and suitable concentrations of both acute and accumulative rodenticides are determined. Observations are made on the hazard of the compound to pets and to other nontarget vertebrates. Laboratory and field studies have been completed on a new, promising stabilized scilliroside glycoside which has given excellent control of the Norway rat in 16 out of 19 premises. Another new coded compound has shown a unique specificity for roof rats as compared to Norway rats. Although anticoagulant resistant rat populations have occurred in several countries in Europe, as yet no evidence has been noted of such resistance in rats in the United States.