Before the first round of MDA is implemented in the Implementation Unit (IU), the sentinel sites for that IU need to be identified. These sites will be used to ascertain the baseline indicators (parasitological and clinical signs) and the progress indicators and will make it possible to carry out periodic evaluation of the parasitological indicators.
The greater the number of sentinel sites, the more data will be available. However, as surveys in the sentinel sites require resources, it is necessary to strike a balance between the resources available and the number of sentinel sites. It is recommended that two sentinel sites should be identified for every IU and each sentinel site should have a minimum population of 500 persons. When the IU is very large or has a population of over 1 million, more sentinel sites to be chosen at the rate of at least two sentinel sites per million population or one for every 500,000 people.
Click here for the WHO guideline for programme managers: Preparing and implementing a national plan to eliminate filariasis in countries where onchocerciasis is not co-endemic.
Click here for the WHO guideline for programme managers: Preparing and implementing a national plan to eliminate filariasis in countries where onchocerciasis is co-endemic