Bancroftian filariasis in Kenya V. Mass treatment given by members of the local community

Abstract

Diethylcarbamazine citrate was given for a total of 13 days to all people above one year of age in the following areas: (1) Mambrui, a town with a population of about 1300; (2) Jaribuni, a rural area with a population of about 1500; (3) The towns and villages on the islands off the north coast of Kenya with a population of over 20 000.

The people were not weighed, but the daily dose was calculated according to age, being approximately 6 mg kg⁻¹; drug taking was not supervised.

The drug was mainly distributed by local people who also treated the side-effects; a doctor remained available in the background for consultation and advice.

In Mambrui and Jaribuni, where baseline data had been collected, the number of infective larvae per 1000 vector-mosquitoes had decreased by more than 90% in the six to 12 months period after the campaign. Two years after the campaign, the microfilaria rate in Mambrui had dropped by 75%; in Jaribuni, a reduction of 75% was recorded in men, but in women it was only 48%. The overall rates after the mass treatment were 5·3 and 9·3% in Mambrui and Jaribuni, respectively.

On the islands to the north, particularly good results were obtained in the village of Siyu, where the highest elephantiasis rate had been recorded; three years after the campaign, the microfilaria rate there had fallen to 3·6%, while none of 48 children under ten were found infected.

The spectacular results in Lamu town may have been partly due to excellent mosquito control in preceding years. However, no control was achieved on the remote island of Ndau, probably because the treatment team left before the side-effects had disappeared, causing many people to stop the course of tablets.

Thus, on the East African coast it is possible and cheap to control Bancroftian filariasis by mass treatment campaigns carried out by local, non-medical personnel.