Malaria control--two years' use of insecticide-treated bednets compared with insecticide house spraying in KwaZulu-Natal.
OBJECTIVE
The objective of this study was to produce data indicating whether insecticide-treated bednets should replace insecticide house spraying as a malaria control method in South Africa. We report 2 years of preliminary data on malaria incidence comparing areas receiving insecticide-treated bednets and those subjected to house spraying in northern KwaZulu-Natal.


METHODS
In order to measure significant reductions in malaria incidence between the two interventions, a geographical information system (GIS) was used to identify and create seven pairs of geographical blocks (areas) in the malaria high-risk areas of Ndumu and Makanis in Ingwavuma magisterial district, KwaZulu-Natal. Individual blocks were then randomly allocated to either insecticide-treated bednets or house spraying with deltamethrin. Malaria cases were either routinely recorded by surveillance agents at home or were reported to the nearest health facility.


CONCLUSIONS
The results show that 2 years' use of insecticide-treated bednets by communities in Ndumu and Makanis, KwaZulu-Natal, significantly reduced the malaria incidence both in 1997 (rate ratio (RR) = 0.879, 95% confidence interval (CI) 0.80-0.95, P = 0.04) and in 1998 (RR = 0.667, CI 0.61-0.72, P = 0.0001). Using a t-test, these significant reductions were further confirmed by an assessment of the rate of change between 1996 and 1998, showing a 16% reduction in malaria incidence in blocks using treated bednets and an increase of 45% in sprayed areas (t = 2.534, P = 0.026 (12 df)). In order to decide whether bednets should replace house spraying in South Africa, we need more data on the efficacy of treated bednets, their long-term acceptability and the cost of the two interventions.
Mnzava
A E
AE
Malaria Research Lead Programme, South African Medical Research Council, Durban.
Sharp
B L
BL
Mthembu
D J
DJ
le Sueur
D
D
Dlamini
S S
SS
Gumede
J K
JK
Kleinschmidt
I
I
D000336:Aerosols / Q000191:economics / Q000627:therapeutic use*; D000818:Animals; D001512:Bedding and Linens; D009033:Culicidae / Q000187:drug effects; D006801:Humans; D015994:Incidence; D007306:Insecticides / Q000191:economics / Q000627:therapeutic use*; D008288:Malaria / Q000191:economics / Q000453:epidemiology / Q000517:prevention & control*; D009032:Mosquito Control / Q000191:economics; D012111:Residence Characteristics; D013019:South Africa / Q000453:epidemiology; D013997:Time Factors
D000336:Aerosols; D007306:Insecticides