A 50-year-old woman from rural Cameroon presents with chronic itching and a papular rash. She has subcutaneous nodules over the greater trochanters. S...

Question

A 50-year-old woman from rural Cameroon presents with chronic itching and a papular rash. She has subcutaneous nodules over the greater trochanters. She has been on community-directed treatment with ivermectin (CDTI) annually for 10 years. Despite this, she continues to have active onchocerciasis symptoms. What is the limitation of ivermectin against Onchocerca volvulus?

Accepted Answer

Ivermectin is a potent microfilaricide but has limited macrofilaricidal activity; adult worms survive in nodules and continue producing microfilariae, requiring repeated treatment indefinitely

Answer

Ivermectin has no activity against O. volvulus

Answer

Ivermectin resistance has not been reported in O. volvulus

Answer

Ivermectin kills adult worms permanently after a single dose

Answer

Ivermectin only works against Loa loa, not Onchocerca

uk-dtmh MCQ (SBA): Ivermectin Limitation in Onchocerciasis