Fifteen years of annual mass treatment of onchocerciasis with ivermectin have not interrupted transmission in the west region of cameroon.

We followed up the 1996 baseline parasitological and entomological studies on onchocerciasis transmission in eleven health districts in West Region, Cameroon. Annual mass ivermectin treatment had been provided for 15 years. Follow-up assessments which took place in 2005, 2006, and 2011 consisted of skin snips for microfilariae (mf) and palpation examinations for nodules.

After a decade of annual dose mass ivermectin treatment in Cameroon and Uganda, onchocerciasis transmission continues.

Objective: To evaluate the effectiveness of 10 years' annual single dose ivermectin treatment on onchocerciasis transmission in hyperendemic areas of Cameroon and Uganda.

Methods: Baseline nodule and microfilaria ('skin snip') prevalence data were available from 10 hyperendemic sentinel communities in Cameroon (from 1996) and hyperendemic 20 sentinel communities in Uganda (from 1993). We returned to these villages in 2005, 10 months after the last annual ivermectin distribution, to repeat the cross-sectional surveys.