For most of the December holidays, my home in Johannesburg has reeked of citronella oil in an attempt to ward off mosquitoes. Joburg is not a malaria area, so mosquitoes are just a nuisance. But imagine if that changed.

South Africa’s malaria areas are in Limpopo, KwaZulu-Natal and Mpumalanga near the borders with Zimbabwe and Mozambique. The map below from the Malaria Atlas Project showing malaria cases in 2022 in 5km x 5km blocks gives a good idea of where the malaria areas are.

South Africa aims to eradicate malaria by 2030. It appears to be making good progress as the number of reported cases have plunged from 64,622 in 2000 to 9,795 in 2023, according to Department of Health data.

But rising temperatures may make it harder to meet that target because temperature affects the growth cycle of the parasite that causes malaria (mostly Plasmodium falciparum in SA). At temperatures below 20°C it cannot complete its growth cycle in a mosquito, so malaria cannot spread. Areas higher than about 1,000m above sea level are also usually malaria free. Joburg is over 1,700m above sea level.

In many other African countries, thousands of people die a year from the disease. The Malaria Atlas Project, in a report entitled Climate Impacts on Malaria in Africa published in November 2024, predicts that thanks to climate change more people will die of malaria and notes that more investment is needed in the fight against the disease.