A 2-year study was conducted in Haiti to determine the effect of the residual fumigant technique on Anopheles albimanus and on malaria transmission.
From 4,618 to 5,760 houses in the Commune of Arcahaie were treated with dichlorvos-wax dispensers at 3- to 4-month intervals and at a rate of one unit per 165 to 300 cubic feet of space. Twelve-hour exposure tests with caged A. albimanus females showed that the treatment gave average kills of 90 percent for approximately 12 weeks. Although malaria incidence declined, transmission was not interrupted, a result considered to reflect the tendency of A. albimanus to bits out-of-doors.
Behavior studies indicated that 75 to 80 percent of the human biting occurred outside of the house. Half of this feeding was between 5:30 and 7:30 p.m. during a period when the human population normally was outside of the house. These habits of A. albimanus also preclude the successful use of other types of residual house treatments in inter-rupting transmission. This study was a cooperative endeavor of the Agency for International Development, Pan American Health Organization, Communicable Disease Center, and the Government of Haiti.
Biology/Chemistry Section, Technology Branch, Communicable Disease Center, Public Health Service, U. S. Department of Health, Education, and Welfare, Savannah, Georgia.
Agency for International Development, Portau-Prince, Haiti.
Present address: Fly Control Research, Orange County Health Department, Santa Ana, California.
Present address: Research and Training Grants Branch, Office of Resource Development, Environmental Health, BSS, PHS, DHEW, Washington, D. C.