Malaria, one of the world’s major health problems, could be changing its geographical pattern because of climate change. A new study suggests that rising temperatures are gradually shifting malaria risk away from parts of West and Central Africa toward regions in eastern and southern Africa.
Malaria is caused by a parasite that is spread to people through the bites of infected mosquitoes. For many years, West and Central Africa have recorded some of the highest levels of malaria because the region has generally provided suitable temperatures and rainfall for both mosquitoes and the parasite.
However, scientists say climate change is beginning to change these conditions. As temperatures rise, some areas that were previously suitable for malaria transmission may become less favourable for mosquitoes. At the same time, warmer conditions could make some areas farther east and south more suitable.
Researchers studied data covering more than a century to understand how climate conditions may have affected malaria cases across Africa. Climate scientists used information from blood samples and developed models that connected malaria levels with factors such as temperature and rainfall.
The researchers then compared the results with a model showing what malaria patterns might have looked like in a world without human-caused climate change. This comparison helped them estimate the possible influence of global warming on the spread of the disease.
The study found that between 1901 and 2014, climate change likely caused a small overall increase in malaria cases across Africa. However, the impact was not the same everywhere. Some parts of East and southern Africa experienced greater increases, while some areas in West Africa saw malaria risk decline.
Ethiopia, for example, was among the areas where malaria cases increased as conditions became more suitable for transmission. In contrast, some parts of West Africa may have become less suitable for the mosquitoes and parasites because of changing temperatures.
The researchers also looked ahead to the end of this century. Under a moderate level of global warming, their models suggest that malaria rates across sub-Saharan Africa could fall by around 2% by 2100. However, this overall decline does not mean that every country or region will experience less malaria.
The findings show that climate change can produce very different health effects in different parts of the same continent. Some communities could face a lower risk of malaria, while others may experience an increase as mosquitoes and malaria parasites move into new areas.
The changing pattern could create new challenges for health authorities. Areas that have historically experienced lower levels of malaria may need to prepare for a greater risk if environmental conditions become more suitable for transmission.
At the same time, malaria control programs will continue to be important in regions where the disease remains common. Measures such as mosquito control, bed nets, early diagnosis and effective treatment can help reduce the impact of malaria.
The study highlights that climate change is not simply making the planet warmer. It is also changing environmental conditions that affect diseases and the people who are exposed to them.
Overall, the research suggests that global warming is reshaping the distribution of malaria across Africa. While the total number of cases may change only slightly under some future climate scenarios, the movement of malaria risk between regions could have major consequences for millions of people and public health systems across the continent.