In response to the detection of yellow fever cases in Douala, Cameroon, a collaborative effort involving the Eliminate Yellow Fever Epidemics (EYE) Secretariat in WHO, WHO representation in Cameroon, and TDR (the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases) aims to strengthen the capacity of Douala communities to reduce the transmission of the yellow fever virus by managing aquatic mosquito habitats such as discarded tires and drinking troughs. Epidemics and outbreaks are one of the four global health challenges TDR focuses on as outlined in the TDR Strategy 2024-2029.
In urban settings, the yellow fever virus is transmitted by Aedes aegypti mosquitoes. By controlling this mosquito vector, transmission of the virus can be significantly reduced. While vaccination is the primary method of controlling yellow fever outbreaks, vector control can reduce the risk of infection in urban settings and can be implemented early before full protection from vaccination is achieved.
A recent analysis conducted in March 2024 in Douala focused on surveillance and control of Aedes aegypti mosquitoes. The findings revealed that all aquatic habitats of Aedes mosquito larvae in Douala were generated by communities.
These habitats included discarded tires, storage containers, drinking troughs, sheet metal, and even discarded shoes. This underscores the critical role of community engagement in managing Aedes larval sources to reduce the risk of infection.
As many community leaders were unaware of the link between Aedes mosquitoes and the transmission of yellow fever virus, TDR, the EYE Secretariat, and WHO Cameroon conducted a workshop to train community leaders on managing Aedes habitats.
More than 50 participants, including community leaders, communication professionals, and health area heads from all nine health districts in Douala, took part. The training covered topics such as the role of Aedes mosquitoes in the transmission of yellow fever virus, the role of the community in Aedes habitats, Aedes larval source management, and community engagement strategies. Participants also observed Aedes mosquito larvae and pupae during the session.
Training of trainers session in Douala, Cameroon, April 2024
Credit: TDR / A. Gildas Yahouedo
Dr Raymond Tabue, Head of the Integrated Vector Control Unit at National Malaria Control Programme of Cameroon, emphasized the importance of this training effort in addressing yellow fever risk in Douala. “The training of community leaders in Douala for managing Aedes aquatic habitats is an unprecedented and pioneering effort in controlling yellow fever in Douala,” he said.
Following the training, several priority actions were identified, including training of community members by community leaders, cleaning of gutters and drains to prevent water stagnation, educating the public and allocation of resources for field investigations. WHO Cameroon will closely monitor these actions in collaboration with national authorities. Urban yellow fever outbreaks remain the biggest threat to global health security, and the EYE Secretariat in WHO and TDR will continue to develop effective strategies, with community engagement playing a pivotal role.
For further information, please contact Dr Corinne Merle and Dr Marie-Eve Raguenaud.