O ne noise that seems ubiquitous in Tanzania ’s villages is a revving motorbike, often making its way across a difficult dirt road while overloaded with farm produce to sell. A recent study found that nearly 90 per cent of vehicles on rural Tanzanian roads are motorcycles, or boda bodas , with their riders a critical part of the local economy. So when the motorbike mechanic in the village of Mwavi, in the Bagamoyo District of Tanzania, fell ill with malaria and died a few days later, a keystone of the community was gone. “He told us he had a terrible headache, so he went to the hospital, and they gave him some pills,” explains Mgeni, a mother of five who lives in Mwavi. “When he didn’t improve, he went back, but they told him it was too critical, so he was lost. It is very sad because he was such a big part of the community.” Tanzania is a country where the mosquito-borne disease remains endemic, with its population of 70 million accounting for roughly four per cent of global malaria deaths.…