Abstract:
Studies of human malaria infections with multiple, genetically distinct parasites have illuminated mechanisms
of malaria transmission. However, few studies have used the genetic diversity in mosquito infections to
understand how transmission is sustained. We identified likely human sources of mosquito infections from a
longitudinal cohort in Western Kenya based on genetic similarity between parasites and the timing of
infections. We found that several human infections were required to reconstitute each mosquito infection and
that multiple parasite clones were likely transmitted from infected humans to mosquitoes in each bite,
suggesting that superinfection and co-transmission occur simultaneously and are important mechanisms of
transmission. We further investigated this using an individual human and mosquito simulation model and found
that co-transmission alone was unlikely to reproduce the high complexity of mosquito infections. We concluded
that the superinfection of mosquitoes likely plays an important, but under studied, role in sustaining moderate
to high malaria transmission.
