Ifakara Masterclass Edition 41 – The Invasion, Spread & Control of the Asian malaria Vector, An. stephensi in Africa

The 41st edition of the masterclass hosted by Fredros Okumu from Ifakara Health Institute (IHI) and Nana Aba Williams from MESA features Drs. Seth Irish, Fitsum G Tadesse, Abraham Mnzava, Bart G.J Knols, Eric Ochomo, Anne Wilson, Prof. Steve Lindsay and several experts from affected countries.

The discourse starts with a background on WHO vector alert on An. stephensi and recently launched WHO initiative against the spread of An. stephensi in Africa is pointed out with the objectives- information exchange, increase in collaboration, strengthening surveillance, prioritizing research and developing guidance. The introduction of An. stephensi to the African continent and its widespread existence in the Asian continent was delved upon. The detection of An. stephensi in Egypt in 1967 was touched upon briefly along with the need for differentiating invasive stephensi species with other was highlighted. The vector occurance in South Asia and the middle east was also discussed including the dwelling site and vector competence aspect of it, on which the spread depends upon. The recent detection of An. stephensi in Kenya and the need for sampling and surveillance was pointed out. Experts give a take on the genetic diversity of An. stephensi to gain insights into the pattern of spread via marine cargo ships. Also it was highlighted that the data on human and vector movement is being looked upon and analysed to identify the vulnerable sites in the African continent. Then, the convergence of threats like antimalarial drug resistance, reduced performance of mRDTs, emergence of An. stephensi and other epidemics was highlighted and a integrated holistic approach to deal with An. stephensi as a whole was stressed upon.

The discussion veers to the ecology, temperature, adapdability, resistance and parasite transmission capability of An. stephensi. Contribution of An. stephensi to the increasing malaria burden in Djibouti is touched upon. PMI action plan to respond to the threat of An. stephensi in Africa is elaborated in detail. Experts discuss the plans of East African countries to control and eliminate An. stephensi. Proven control measures and their application against An. stephensi was discussed bearing in mind the specifics of the vector and community it is spreading in. Also. experts explain social behavioural change strategy to respond to An. stephensi and the role it can play to contribute to vector control.