An evaluation of the pilot hydatid control project in northwestern Turkana district, Kenya
Hydatidosis (Hydatid disease) 1S a cyclozoonotic disease caused by the larval stages of Echinococcus granulosus. The disease is mainly transmitted between carnivores and herbivores. The most important cycle is the one which involves dogs and domestic livestock. A pilot hydatid control project was started in 1983 in the Northwestern part of Turkana District 1n Kenya (Macpherson et al., 1986). This area is known to have one of the highest prevalences and incidences of hydatidosis and echinococcosis in the world (French and Nelson, 1982). Since the pilot hydatid control project was initiated, no efforts had been made to assess the impact of the control measures effected against these diseases. This study was therefore initiated to assess whether the dog control measures undertaken in the Control area (Macpherson, 1986) had any impact Dn the prevalences of dog echinococcosis and human hydatidosis. In addition, this study tried to investigate whether the education measures undertaken alongside the dog control measures had been understood. The study region was divided into three areas namelYi the Control area where control measures were undertaken, an Intermediate area where little control measures were implemented and a Non control area where no measures against the disease were applied. In an effort to assess the effects of the control programme on the prevalence of echinococcosis in dogs, 808 dogs were killed and examined for the presence of Echinococcus granulosus worms. The results showed that Control area had a prevalence of 38.5%, the Intermediate area 41% and the Non-control area a 50.6%. Each of these was significantly different from the 63.5% recorded in Control area at the beginning of the programme. The presence or absence of Taenia hydatigena in dogs as an indicator of dogs being fed on raw offal was also examined. The highest prevalence (90.4%) was recorded in the Non-control area followed by 84.3% in the intermediate area and 64.7% in the Control area. This indicated that the Turkana people still fed dogs offal infected with hydatid cysts. During this study, 12,122 people were examined to determine the prevalence of human hydatidosis. A prevalence of 3.8% was obtained ln the whole study region. A prevalence of 3.7% was recorded in the Control area, 4.4~ in the Intermediate area and 4.2% in the Non control area. The significant risk factors for this disease and obtained were, sex, previous operation and settlement status. In the assessment of the knowledge on hydatid disease among the Turkana, 3,416 people were interviewed. One thousand five hundred and eighty four (1,584) people were from the Control area, 700 from the Intermediate area and 1,132 from the Non control area. The interviewees were classified into three categories namely; those with "complete" knowledge" . knowledge, "partial" knowledge and "no" Two thousand one hundred and fourty four (62.7%) of the people fell in the "partial" Knowledge group followed by 1151 (33.7%) who had "no" knowledge and 1121 (3.5%) who had "complete" knowledge. Out of 393 people who had obtained knowledge on hydatid di se'ase from African Medical and Research Foundation (AMREF), 316 (80.4%) were found in the Control area, 37 (9.4%) were found in the Intermediate area and 40 (10.2%) were from the Non control area. A similar trend was found in the school children, although a higher number 30 (9%) of school children had "complete" knowledge about the disease than adults who either had "partial" or "No" knowledge. In conclusion, the present study indicated that the prevalence of human hydatidosis had not significantly changed since the inception of the pilot Hydatid Control Project. The failure to achieve a significant decline in the prevalence of human hydatidosis could be due to the fact that the disease takes long to manifest itself, the recurrence of the disease and failure of the Turkana to seek medical attention in time. But the prevalence of dog echinococcosis had declined significantly. This decline could possibly be associated with the control measures undertaken against this disease. The high prevalences of T. hydatigena showed that dogs were still gaining access to offal infected with cysts. Considering that there had been no other control measures instituted before 1983, results from this study indicates that the control programme has had some positive effects on the knowledge of hydatid disease though not significant enough to alter the magnitude of this disease within a short time. There were various organisations involved in the dissemination of knowledge on hydatid disease not only in the Control area, but also in the other two study areas, but AMREF was more important in the dissemination of the knowledge. The other organisations were Turkana Rehabilitation Project (TRP) and the Catholic mission.