Re-defining the extent of malaria transmission in South Africa: implications for chemoprophylaxis.

BACKGROUND Malaria case numbers reported in South Africa have reduced considerably over the last decade, necessitating a revision of the national risk map to guide malaria prevention, including the use of chemoprophylaxis. OBJECTIVES To update the national malaria risk map based on recent case data and to consider the implications of the new transmission profile for guiding prophylaxis. METHODS The geographical distribution of confirmed malaria cases detected both passively and actively over the last six malaria seasons was used to redefine the geographic distribution and intensity of malaria transmission in the country. RESULTS The national risk map was revised to reflect zones of transmission reduced both in their extent and their intensity. Most notably, the area of risk has been reduced in the north-western parts of Limpopo Province and is limited to the extreme northern reaches of KwaZulu-Natal Province. Areas previously considered to be of high risk are now regarded to be of moderate risk. CONCLUSION Chemoprophylaxis is now only recommended from September to May in the north-eastern areas of Limpopo and Mpumalanga Provinces. The recommended options for chemoprophylaxis have not changed from mefloquine, doxycycline or atovaquone-proguanil.