- NEW YORK (Reuters Health) - Spraying insecticide to control fly populations
can reduce rates of blindness and diarrhea in the developing world, concludes
a study published in the April 24th issue of The Lancet.
- According to researchers, "fly control
resulted in 75% fewer new cases" of trachoma, an eye infection estimated
to be the leading cause of preventable blindness in the world.
- Flies are a prime means of transmission
for a number of infections prevalent throughout the developing world, including
trachoma (caused by Chlamydia trachomatis bacteria) and diarrhea, which
kills more than 3.3 million children each year.
- Researchers led by Dr. Paul Emerson of
the Medical Research Council in Banjul, The Gambia, sought to determine
the impact of fly-control insecticide programs on rates of fly-borne infection.
They sprayed two Gambian villages with insecticide during the wet or dry
season, and compared subsequent rates of trachoma and diarrhea rates to
those of villages without these interventions.
- "Fly control resulted in 75% fewer
new cases of trachoma in intervention villages than in (unsprayed) villages,"
the authors report, as well as up to a 26% decline in cases of childhood
- However, the researchers believe that
rural spray programs are "unlikely to be a sustainable routine public-health
measure" for resource-poor nations in Africa and elsewhere in the
- The study findings do point out the importance
of fly control in reducing risks for trachoma and diarrhea. In a commentary,
Dr. Chandler Dawson of the University of California, San Francisco, points
out that "other measures of integrated pest management, such as the
availability of covered latrines to limit fly breeding sites, can substantially
reduce the population of eye-seeking flies."
- The Lancet 1999;353:1376-1377,1401-1403.