Impact of delayed introduction of sulfadoxine-pyrimethamine and arthemeter-lumefantrine on malaria epidemiology in KwaZulu-Natal, South Africa.

ABSTRACT

OBJECTIVE: To investigate how delayed introduction of sulfadoxine-pyrimethamine (Fansidar) and arthemeter-lumefantrine (Coartem) as first-line drugs for malaria in KwaZulu-Natal contributed to the reported epidemics of 1985-1988 and 1997-2001. METHODS: Ecological study assessing the association between malaria incidence and the emergence and degree of resistance to chloroquine from 1982 to 1988 and to sulfadoxine-pyrimethamine from 1991 to 2001, when each was the first-line malaria treatment. RESULTS: The relative risk for malaria infection after the level of drug resistance reached 10% was 4.5 (95% CI 4.0-5.2) in the chloroquine period and 5.9 (95% CI 5.7-6.1) in the sulfadoxine-pyrimethamine period. In the chloroquine period, the relative risk of death from malaria was tenfold (95% CI 1.3-78.1) and the case fatality doubled after drug resistance had reached 10%. The risk of death during the sulfadoxine-pyrimethamine period was 10.8 (95% CI 5.9-19.2) and case fatality 1.8 times higher after drug resistance had reached 10%, than before. CONCLUSION: Malaria epidemics in KwaZulu-Natal, South Africa have been exacerbated by failing drug regimens. The establishment of sentinel sites for monitoring drug failure and the prompt adoption of guidelines based on World Health Organization standards in drug resistance should improve malaria control.