Vector resistance to insecticides is becoming a major obstacle to malaria prevention measures. A
baseline survey was carried out in Khartoum city, Sudan, during September–November 2007, to map the insecticide
susceptibility status of Anopheles arabiensis and to examine the correlation with insecticide usage in urban agriculture.
Susceptibility tests were conducted in 6 sentinel sites representing urban and periurban strata of the city. Mortality rates
and knockdown times were calculated for 8 insecticides on a total of 9820 specimens. An. arabiensis was susceptible
to bendiocarb (98.1%), propoxur (100%), fenitrothion (100%), deltamethrin (99.8%) and lambda-cyhalothrin (99.2%).
Susceptibility rates were significantly different between urban and periurban sites for malathion (80.8% vs 56.0%),
DDT (99.0% vs 95.0%) and permethrin (98.5% vs 96.3%). The 50% knockdown times were significantly higher in
periurban than urban populations of An. arabiensis for deltamethrin, lambda-cyhalothrin and malathion.