Impact of single-dose ivermectin on community microfilaria load in bancroftian filariasis infection: two years post treatment.

The concept of annual single-dose treatment for the control and possible interruption of transmission of lymphatic filariasis has brought much hope to the previously hopeless disease. The logistics for implementing this enormous public health intervention have wide ramifications and will depend on the efficiency of drug delivery and distribution at various levels of the health system. In sub-Saharan Africa, where the public health services are inadequate, this becomes even more important. Six communities in southern Ghana known to be endemic for filariasis were treated with single-dose ivermectin in January/February 1997 as part of pilot programme activities. The 1998 treatment could not take place because of unavailability of the drug. The 1999 community microfilaraemia prevalence and intensity were reduced by only 25.5% and 39.5% of pre-treatment levels, respectively. The implications of any shortfalls on the drug delivery system on the goal of elimination of lymphatic filariasis are discussed.