Transmission potential ofRickettsia felisinfection byAnopheles gambiaemosquitoes

A growing number of recent reports have implicatedRickettsia felisas a human pathogen, paralleling the increasing detection ofR. felisin arthropod hosts across the globe, primarily in fleas. HereAnopheles gambiaemosquitoes, the primary malarial vectors in sub- Saharan Africa, were fed with either blood meal infected withR. felisor infected cellular media administered in membrane feeding systems. In addition, a group of mosquitoes was fed onR. felis-infected BALB/c mice. The acquisition and persistence ofR. felisin mosquitoes was demonstrated by quantitative PCR detection of the bacteria up to day 15 postinfection.R. feliswas detected in mosquito feces up to day 14. Furthermore,R. feliswas visualized by immunofluorescence in salivary glands, in and around the gut, and in the ovaries, although no vertical transmission was observed.R. feliswas also found in the cotton used for sucrose feeding after the mosquitoes were fed infected blood. Natural bites fromR. felis-infectedAn. gambiaewere able to cause transient rickettsemias in mice, indicating that this mosquito species has the potential to be a vector ofR. felisinfection. This is particularly important given the recent report of high prevalence ofR. felisinfection in patients with “fever of unknown origin” in malaria-endemic areas.