Rise in Ebola Outbreaks in Africa Linked to Climate Change

World health officials are linking a significant rise in African Ebola outbreaks in this century to climate change.

Uganda’s September 20 Ebola outbreak is just the latest in a growing number of eruptions of this deadly hemorrhagic disease in Africa. Since 2000, the World Health Organization has reported 32 outbreaks of Ebola, 19 in the last decade compared to 13 in the preceding one.

Ebola is one of a range of zoonotic diseases — infections originating in animals and jumping to humans. A WHO analysis finds Ebola and other viral hemorrhagic fevers constitute nearly 70% of these outbreaks. The remaining 30% include dengue fever, anthrax, plague, and monkeypox.

WHO Africa incident manager for the Ebola outbreak in Uganda, Patrick Otim, says the number of zoonotic diseases occurring in the region in the last decade has increased by more than 63%.

“There have been a couple of researchers that have shown a possible link between the climatic changes that we are seeing and the increase in zoonotic diseases, and for this particular case for Ebola, for instance,” he said.

Otim said diseases are caused by several factors. Ebola, he said, is strongly influenced by the human factor. As populations increase and people encroach on wildlife habitats, interaction with animals increases. This, he said, increases the spread of disease to humans.

Otim said temperature and climatic changes also spur migration and movement of some Ebola virus hosts.

“For the Ebola virus, we know that the bats and other animals are hosts of this particular virus,” he said. So, when they move from areas where, for instance, there is drought or whether areas that are no longer conducive for them and they move to favorable areas, they may move into an area where the human population is inhabiting and therefore the interaction between the humans increases.”

WHO says Ebola now has spread to seven districts in Uganda beyond the original epicenter in the Mubende district. The latest reports put the number of cases at 131, including 48 deaths.

The current Ebola outbreak in Uganda has been triggered by the so-called Sudan strain for which there is no vaccine. WHO said several promising candidate vaccines soon will undergo clinical trials to evaluate their potential against Ebola.