The burden of yellow fever in any given area is known to be heavily dependent on climate, particularly rainfall and temperature which can impact both mosquito life cycle and viral replication. Now, researchers from Imperial College London and the World Health Organization (WHO) have developed a new model to quantify yellow fever dynamics across Africa using not only annual averages of these climatic measures but seasonal dynamics.
The new model integrated the effects of temperature on mosquito behavior and virus transmission and looked at monthly variation in temperature, rainfall, and vegetation throughout the year across Africa. The model confirmed and quantified that, even in areas with high transmission potential for yellow fever, the risk varies throughout the year.
This finding, in conjunction with forecasted data, could highlight areas of increased transmission and provide insights into the occurrence of large outbreaks. When used in conjunction with forecasted data, the model predictions could be useful for focusing both surveillance efforts, and the pre-positioning of material and equipment in areas and periods of, particularly high risk. This would allow the facilitation of early interventions in emerging yellow fever outbreaks — which is key to prevent large-scale outbreaks
Yellow fever is an acute viral hemorrhagic disease transmitted by the Aedes and Haemogogus mosquitoes. It is not always easy to diagnose, especially at the beginning, since its symptoms can often be confused with those of malaria, dengue fever, or other hemorrhagic fever. However, some patients will suffer from jaundice specific to the disease, which explains why the term “yellow” is used.
To date, there is no treatment for yellow fever. Water and medicines can be given to target the symptoms, such as fever or dehydration. Vaccination is the best option to prevent outbreaks of the disease and to protect people against it.
Other strategies to combat the disease include mosquito population control, with the large-scale use of pesticides and mosquito nets, as well as the treatment of stagnant water sources.