High Prevalence of Rickettsia bellii in Mosquitoes From Eastern China

Mosquitoes are the most important vectors carrying significant numbers of human pathogens. Recent studies implicated that mosquitoes play an important role in circulation and transmission of multiple Rickettsia species. In this study, Rickettsia bellii was identified in four mosquito species (Culex pipiens, C. tritaeniorhynchus, Aedes albopictus, and Anopheles sinensis) collected from three Eastern China provinces during 2019-2020. Rickettsia bellii was detected in 37.50 and 26.32% of the C. pipiens pools from Beijing and Jiangsu province, respectively. In C. tritaeniorhynchus and An. sinensis from Shandong, the infection rate is 20.00 and 6.25%, respectively. Additionally, three Ae. albopictus pools (3/42, 7.14%) from Beijing were also detected positive for R. bellii. Genetic and phylogenetic analysis on 16S, gltA, and groEL genes indicates that sequences from all these strains are highly homologous and closely related to other R. belliistrains.This is the first report that Ae. albopictus and C. tritaeniorhynchus harbor R. bellii.The wide host range and high infection rate in certain areas may dramatically increase the exposure of R. bellii to human and other vertebrates.The role of mosquitoes in transmission of rickettsiosis and its potential risk to public health should be further considered.

Automated summary

Mosquitoes are important vectors carrying various human pathogens, including Rickettsia bellii, which was found in multiple mosquito species in Eastern China. The high infection rates in certain areas may increase the risk of exposure to R. bellii for humans and other vertebrates, emphasizing the need for further consideration of mosquitoes in the transmission of rickettsiosi and their potential impact on public health.