Changing temperature and rainfall across Africa could increase yellow fever deaths by up to 25 per cent by 2050. Scientists at the Imperial College London and the World Health Organisation (WHO) have attributed this to a new modelling of the burden of yellow fever.
The results of the modelling are published in the journal ‘eLife’. However, the scientists have similarly affairmed that future vaccine programmes would mitigate the impact of the yellow fever outbreaks. Going by the modelling, some East African countries including Ethiopia and Somalia may be increasingly impacted by yellow fever in the coming decades. On their part, West African countries currently have the highest yellow fever disease burden on the continent; so, although the study found there would be smaller proportional changes in the amount of yellow fever transmission, this would translate to large numbers of new deaths. The team however recommended the establishment of a programme of surveillance and appropriate mosquito control and vaccination to prevent this resulting in thousands more deaths.
Yellow fever is a viral infection causing 78,000 deaths per year in Africa. Despite an existing yellow fever vaccine, the disease is endemic in 34 countries in Sub-Saharan Africa, with serious outbreaks occurring in recent years. The virus can be transmitted by several mosquito species, or vectors, but the main vector in serious urban outbreaks is the mosquito species Aedes aegypti. To model the impact of climate change on yellow fever, the team built on an existing transmission model to include the sensitivity of A. aegypti and the virus to temperature and rainfall. Warmer temperatures can help the mosquitos emerge and mature faster leading to more mosquitos; however, too high a temperature can be fatal. Rainfall can also increase mosquito breeding by providing stagnant ponds for them to lay eggs in. Going by the findings, by 2050, the modelling showed that deaths could increase by around 11 per cent for the best-case scenario and up to 25 per cent for the worstcase scenario. “By 2070, these figures were projected to be 10 per cent and 40 per cent respectively,” the ‘Medical Xpress’ reported.