ONCHOCERCIASIS IN ECUADOR - PREVALENCE OF INFECTION ON THE ECUADOR-COLOMBIA BORDER IN THE PROVINCE OF ESMERALDAS

The prevalence of onchocerciasis infection was determined in communiti es on 7 rivers located in the northern area of the canton San Lorenzo, province of Esmeraldas. Diagnosis of the infection was obtained by sk in biopsies and recombinant-antigen based-serology. No evidence of inf ection was detected in 9 communities studied along the Rio Mataje, whi ch forms the frontier between Ecuador and Colombia, nor in 10 adjacent communities located on 5 interior rivers. Evidence for Onchocerca vol vulus infection was found in 4 communities on the Rio Tululvi with the following prevalence: La Boca (3.5% by biopsy and 3.9% by serology), Guayabal (9.1% by both biopsy and serology). La Ceiva (51.5% by biopsy and 53% by serology), and Salidero (4% by biopsy and 7.7% by serology ). A few individuals in these communities were seropositive for O. vol vulus in the absence of detectable dermal microfilariae: these might h arbor very light or prepatent infections. No clinical disease attribut able to onchocerciasis was found. The infected communities will be inc luded in the ivermectin-based National Control Program for the disease with no evidence of the infection having extended north of the Ecuado rian-colombian border.