By: Alanna Shaikh
Mexico, Colombia, and Guatemala are making huge progress against river blindness, aka onchocerciasis. Colombia has eliminated river blindness from within its borders, the first country in Latin America to do so. Mexico and Guatemala have broken the cycle of transmission, and they’re ready to stop mass drug administration next year.
Elimination is a pretty clear term. It means that the disease, while still present on our planet, is down to zero in one particular region; in this case, Colombia. But what does it mean to break the cycle of transmission? Well, onchocerciasis is a tiny parasitic worm[1] that has a pretty complicated life cycle, and one particular kind of fly is essential to the survival of the disease. Without those flies, the disease is not transmitted and dies out.

Photo Credit: The Carter Center
To break the cycle of transmission, you spray insecticide in the areas of fast moving rivers where the flies breed. No more flies, no more onchocerciasis. According to the World Health Organization (WHO), it takes fourteen years of spraying to totally eliminate the reservoir of adult onchocerciasis worms and therefore make sure that the disease is gone. Once you’ve reached that point, it takes three more years of close monitoring to ensure that the disease really is gone. If there really are no cases in those three years, then, like Colombia, your country can be certified as having eliminated the disease. » Read more: Good News on River Blindness








