Tackling the unfolding Anopheles stephensi crisis in Africa: Minimise research and maximise action.

Abstract

When the Asian tiger mosquito (Aedes albopictus) was discovered in the EU for the first time, in a kindergarten in Genua (Italy) in 1990, it was followed initially by a call for action to stop its spread, but gradually turned into a 'study object', resulting in hundreds of research papers since, but very little action in terms of actually trying to eliminate it. Europe is now facing the grave consequences of this lack of action, with dengue, Chikungunya, and West Nile virus already creating problems around the Mediterranean, and aided by climate change both the mosquito and these diseases will move farther north in years to come, posing a risk to millions of people. This history is now repeating itself in the Horn of Africa. It's been thirteen years since Anopheles stephensi, an Asian malaria vector, invaded Djibouti, and has not had much going against it since. And like in Europe, stephensi has become 'the new kid on the block' for academics, and paper after paper (87 in the last 3 years) is coming online, always calling for action in the final paragraphs, but forgetting that mosquitoes don't care about papers and happily continue to conquer more terrain as we sit down to read another paper. Research should focus exclusively on four things: where is the mosquito (surveillance), what works to kill it (control), how do we free areas of it (implementation strategy) and how can we prevent re-invasion of cleared areas. In two of these areas we're almost clueless: strategic area-wide vector elimination and preventing re-invasion. Action in these areas is therefore critical if Africa is to prevent repeating Europe's mistake. And should start with garnering unwavering support and resources from governments of affected countries, regional organisations, and global players. The stephensi problem will not be solved with a dipper searching for larvae in the field. It should start by knocking on politicians' doors, intense lobbying, and succeeding in having the problem addressed with utmost priority. Only then will the means and resources become available to attempt elimination of this invasive vector. Critically, these resources should not affect any ongoing malaria control efforts but should be freed specifically for this purpose. On a more positive note, going aggressively after stephensi would concurrently teach us ways to go after indigenous African vectors in an area-wide fashion, notably through larval source management. Inertia will merely push us all decades backwards in terms of hoping to eliminate malaria in Africa one day.