Southern Africa could be facing a heightened risk of malaria this year, the World Health Organization warns.
The WHO has urged countries to hand out mosquito nets
The WHO says that the climate phenomenon La Nina has caused unusually wet conditions in the region, which could raise infection levels.
The WHO has urged countries to raise awareness and distribute anti-malaria drugs and insecticide-treated nets.
Malaria is one of the main causes of death in southern Africa, killing an average of 400,000 people each year.
"Malaria is a climate sensitive disease and for this time of the year we have experienced uncommonly heavy rainfall and flooding in parts of southern Africa," said Joaquim Da Silva, WHO's Malaria Epidemics & Emergency Officer in the region.
Further heavy rainfall has been forecast until February.
La Nina originates in the eastern Pacific Ocean, but its effects reach around the globe, making wet regions wetter and dry ones drier.
Mr Da Silva said the phenomenon could also raise the risk of flooding in river systems in Angola, Zambia, Zimbabwe, Mozambique, Namibia, Botswana and South Africa.