(Left) Cell user in Kenya (via Konrad Glogowski & PBS) (Right) Malaria outbreaks in Kenya (via MARA ARMA)
The African continent has long endured a battle with Malaria. Groups like the World Health Organization have been able to reduce the number of deaths by 33% since 2000. In 2010, about 600,000 people were killed in Africa by the mosquito-borne infection, mostly children. Many measures and programs have been enacted to attempt to eradicate the disease, but until this point, the spread of the infection has been difficult to understand as Malaria is capable of spreading to uninfected insects through infected people and then spread further through these newly-infected bugs. New research done by a team from the Carnegie Mellon University in Pittsburgh is shedding new light on how we can better combat malaria, specifically in Kenya.
Amy Wesolowski and her team used the fact that 14,816,521 Kenyans have cell phones (of a population of about 40 million). From June 2008 to June 2009, the team collected anonymous information, from 11,920 cell towers, as to how individuals traveled and compared this data with maps provided by the Kenya Medical Research Institute and the Malaria Atlas Project that show where malaria has broken out. The Carnegie Mellon team then looked at Kenyans, within the areas being studied, and calculated the probability of an individual to become infected based on where they were on the map and if they traveled through the high risk regions. The team then made new maps that, for the first time ever, that correlated travelers to the spread of the disease. It showed “source” areas that originally emitted the disease and “sink” areas or places where malaria was brought in.
Within the 692 locations watched, the study found that most of the malaria was imported or brought into areas by infected travelers where there was no malaria to begin with. Many times these carriers do not show any symptoms. The 10% of areas with the highest risk of becoming infected were found to make 9 trips more per year than the other 90% (29 to 20). Kenya’s western highlands and suburbs of Nairobi are known to be malaria hotspots but have low populations of infected mosquitoes, however they receive lots of traffic from the coast of Lake Victoria, which has the highest population of infected mosquitoes. This means that localized treatment in some areas will always be ineffective and more efforts should be put in screening, treating and informing travelers in certain high-traffic routes.
Team member, Caroline Buckee of the Harvard School of Public Health in Boston summarized the teams findings, "To eliminate malaria, we've got to start thinking about transmission. There's a big danger of people damaging control programs by traveling and bringing parasites in with them."