Another battle in the fight against neglected tropical diseases (NTDs) has been won in Guatemala, where onchocerciaisis transmission has been eliminated in Huehuetenango.
A recent article in the Journal of Parasitology Research evaluated onchocerciasis transmission in the department of Huehuetenango in western Guatemala after 22 rounds of mass drug administration (MDA) over 13 years. In 2007-2008, prevalence of infection was determined to be zero percent through eye examinations of residents, antibody detection in school children and parasite detection in black flies. Following the results of this evaluation, mass treatment was halted in 2009 and post treatment surveillance of parasite prevalence in black flies was conducted from 2009-2011. Infection remained at zero percent, validating that transmission had been eliminated in the area.
Onchocerciasis, also known as river blindness, is caused by the parasite Onchocerca volvulus and is transmitted to humans by the bite of black flies. Infection with the parasite can produce nodules, inflammation, discoloration and itching of the skin, as well as lesions that can lead to blindness. Onchocerciasis is found in 37 countries across the world.
The Onchocerciasis Elimination Program of the Americas, or OEPA, was established in 1992 with the goal of supporting national programs in LAC countries to provide twice yearly MDA of ivermectin to a minimum of 85 percent of the eligible population at risk. The Guatemala Ministry of Public Health, with the assistance from OEPA, began MDA for onchocerciasis in 1996, and since 2002 has reached the targeted coverage of the eligible population through twice-yearly MDA. There were four endemic foci for onchocerciasis in Guatemala. Before this study, transmission in two of the four foci had already been declared eliminated. With this recent evidence of elimination in Huehuetenango and with post treatment surveillance being conducted in the fourth foci, Guatemala is well on its way to request the WHO certification of nation-wide elimination in 2015.