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

Abstract

Previous work done on the vaccination of village chickens in the communal areas of South Africa demonstrated that the Nobilis Inkukhu® commercial thermostable vaccine was able to protect chickens against virulent Newcastle disease challenge when applied by eye-drop, water or in-feed (cooked maize meal) application. In the initial trial work, University staff or graduate students, rather than poultry owners themselves prepared all vaccines. In order for vaccination of the village chickens to be carried out on a more extensive scale it is obviously necessary for a larger body of people to be enabled to vaccinate chickens. It was also felt by the researchers that once community members had to make an effort to get their chickens vaccinated, it would be possible to determine somewhat more accurately the real level of enthusiasm for vaccination of chickens among the community. The trial work was carried out in the village of Disaneng, which lies in the Northwest Province of South Africa. Visual and practical training material was prepared and presented to community-elected and volunteer “vaccinators”. Vaccinators were then required to register all the poultry owners in their ward who wished to have their chickens vaccinated. Once an indication of the number of chickens to be vaccinated had been made available, Inkukhu vaccine was supplied to vaccinators free of charge. Vaccinators were responsible for the organization of the vaccination campaign, including the storage and preparation of the vaccine for application. Vaccine application methods differed between wards. After a focus group discussion to select methods of vaccination only two of the three methods were chosen. A training session was arranged for training volunteer vaccinators in the method of vaccination i.e. water and in-feed administration All nine wards in the village were initially involved in the vaccination campaign with a total of 482 households owning 6 141 chickens participating. Detailed survey work carried out in three of the participating wards indicated that this represented slightly in excess of 60% of the chickens in the area. Involvement in a second round of vaccinations, one month later, was far poorer with only 211 households owning a total of 1 636 chickens participating. Approximately one month after each vaccination campaign, blood samples were collected from a random sample of about 150 chickens that had been vaccinated and tested for circulating antibodies to Newcastle disease, using the HI test. These results showed variable levels of protection achieved, but were influenced more by the area (vaccinator) from which they came, than the vaccine application method used. An investigation was done as to find the reasons for the sudden drop-off in community participation between vaccination campaigns as well as to obtain further information about vaccine handling and preparation by the community vaccinators. It was found that a concurrent disease outbreak causing the deaths of chickens and the attitude of the owners probably contributed to the demotivation of volunteers used as community vaccinators Another unexpected finding was the rate at which chicken flock numbers appeared to alter between vaccination campaigns. The reason for this is yet to be established but may indicate that chickens are moved between homesteads belonging to a single family, depending on what forage is available, or other unidentified disease problems. It was concluded that probably volunteers are not ideal for vaccination of community poultry. They are easily demotivated; do not keep good records and left the project when offered permanent employment.