Evaluation of the application of a thermostable Newcastle disease vaccine by community volunteers in the North West Province of South Africa

摘要

Participatory research on vaccination of village poultry against Newcastle disease (ND) was carried out in the village of Disaneng, in the North West Province of South Africa. Three application methods for ND Inkukhu(R) vaccine were shown to induce sufficient levels of immunity in back-yard poultry when correctly administered. These are eye-droplet administration to individual fowls, in-feed and in-water administration to small flocks. After a community meeting and group discussion to select methods of vaccination, only 2 of the 3 methods were chosen; the individual administration of droplets into the eyes was considered to be too impractical because back-yard fowls are difficult to catch. Visual and practical training material was prepared and presented to volunteer vaccinators (n = 23). Vaccinators were then required to register all the poultry owners in their ward who wished to have poultry vaccinated. Once an indication of the number of chickens to be vaccinated had been made available, ND Nobilis Inkukhu(R) vaccine was supplied to vaccinators free of charge. Community vaccinators were responsible for the organisation of the vaccination campaign, including storage and preparation of vaccine for application. All 9 wards in the village were initially involved with a total of 482 households, owning 6141 chickens, participating. This represented slightly in excess of 60%of the fowls in the area. Involvement in a 2nd round of vaccinations, 1 month later, was far poorer with only 211 households owning a total of 1636 chickens participating. Serum samples were collected from vaccinated fowls using systematic random sampling and tested for circulating antibodies. The levels of protection varied, with no significant difference found between in-feed and in-water vaccine administration. Volunteer vaccinators were found to be unreliable, easily demotivated, did not keep good records and left the project when offered permanent employment. Contacting them to make arrangements for delivering vaccine was difficult and time consuming. Structured interviews indicated that deaths in poultry and the attitude of the owners probably contributed to the demotivation of the volunteers used as community vaccinators. It was concluded that volunteers are not the ideal choice for vaccination of village poultry against Newcastle disease.