Malaria occurs mainly in tropical developing countries in sub-Saharan Africa, Central and South America, Asia and Oceania. Through effective malaria control measures, malaria transmission has been limited to the north-eastern part of South Africa, mainly in the low altitude (below 1000 m) areas of Limpopo, Mpumalanga and northern KwaZulu-Natal provinces. Limited focal transmission may occasionally occur in the North West and Northern Cape provinces along the Molopo and Orange rivers. Malaria is distinctly seasonal in South Africa, with the highest risk being during the wet summer months (September to May).
All of South Africa’s neighbouring countries, with the exception of Lesotho, have malaria transmission. Most imported malaria in South Africa is acquired in Mozambique, because of its high prevalence there and the large cross-border movement of people. Swaziland, Botswana, Namibia and Zimbabwe have more limited risk areas for malaria transmission.