What comes to mind when you think of the most dangerous animals? Sharks? Tigers? …How about mosquitoes? Mosquito bites are responsible for the deaths of around 400,000 people every year. The largest single cause of these deaths is malaria – which can be a severe disease, caused by a tiny parasite carried by some mosquitoes. The current vaccine against malaria is only partially effective and not yet widely used so prevention mainly comes down to mosquito control (getting rid of mosquitoes from populated areas or preventing them from biting people). Another method for prevention being tried out in some places is to give drugs that kill the malaria parasite to large numbers of people. This technique is known as mass drug administration, shortened to ‘MDA’.
Using mathematical models we wanted to find out when and where MDA works well. Our four models each predicted different levels of effectiveness for MDA, but overall we discovered the important factors that made MDA work better. Although MDA can be useful in malaria control programmes it still needs to be combined with good mosquito control.