Impact of DDT re-introduction on malaria transmission in KwaZulu-Natal.
OBJECTIVE
To determine whether the re-introduction of DDT in KwaZulu-Natal had any effects on malaria transmission in the province.


METHODS
The 2000 malaria epidemic in KwaZulu-Natal has been attributed to pyrethroid-resistant anopheles mosquitoes in the area. Previous studies have shown that these mosquitoes are still susceptible to DDT. To determine whether DDT re-introduction had any impact on malaria transmission in KwaZulu-Natal, the following variables (pre- and post-epidemic) were investigated: (i) the number of reported cases; and (ii) the distribution of Anopheles funestus in relation to the insecticides sprayed.


METHODS
The notified malaria cases and the distribution of A. funestus were measured to determine the effects of DDT re-introduction on malaria transmission.


CONCLUSIONS
After DDT re-introduction, the number of malaria cases decreased to levels lower than those recorded before the epidemic. A. funestus appears to have been eradicated from the province. The combination of an effective insecticide and effective antimalarial drugs in KwaZulu-Natal has resulted in a 91% decline in the malaria incidence rate. Unfortunately the continued exclusive use of DDT within the malarious areas of the province is threatened by the emergence of insecticide resistance.
Maharaj
R
R
Malaria Research Programme, Medical Research Council, Durban, South Africa. rajendra.maharaj@mrc.ac.za
Mthembu
D J
DJ
Sharp
B L
BL
D000818:Animals; D000852:Anopheles; D003634:DDT; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D007303:Insect Vectors; D008288:Malaria / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D009032:Mosquito Control / Q000379:methods*; D010575:Pesticides; D013019:South Africa / Q000453:epidemiology
D010575:Pesticides; D003634:DDT