47 - What makes a particular species of mosquito a competent vector?

Abstract: Mosquitoes are responsible for the transmission of numerous human-pathogenic viruses and parasites of global health significance. The term “vector competence” describes the intrinsic ability of an arthropod vector to transmit an infectious agent. While transmission events by blood-feeding mosquitoes may seem straightforward conceptually, the mosquito itself presents a complex and hostile environment through which the infectious agent must transit to ensure the propagation, sometimes development, and transmission of itself to the next host. Viruses imbibed in an infectious blood meal must pass into and out of the mosquito midgut, traffic through the body cavity or hemocoel, invade the salivary glands, and be expelled with the saliva when the vector takes a subsequent blood meal. Parasitic nematodes also utilize different organs as developmental sites, such as the Malpighian tubules or thoracic flight muscles. For both viruses and parasites, physical, cellular, microbial, and immunological barriers are encountered during this journey, which is also influenced by the genetic background of the mosquito vector as well as environmental conditions. This presentation will provide an overview of the current state of the field in understanding the mosquito-specific factors that underpin mosquito vector competence, and ultimately what makes a particular mosquito species a competent vector.