Mosquito-borne Infections

Mosquitoes are ubiquitous worldwide, found even in the Arctic. There are more than 3,000 species. The Aedes (Zika virus [ZIKV], dengue virus, Chikungunya virus [CHKV]), Anopheles (malaria), and Culex (West Nile virus) are the primary genera involved in human disease. Aedes aegypti, an aggressive daytime biting mosquito, is a particularly effective vector because it inhabits urban areas, feeds preferentially on human blood, and feeds multiple times in a breeding cycle. Aedes albopictus (Asian tiger mosquito) has spread worldwide through larva in recycled tires in the 1980s. This mosquito is more widely distributed than A aegypti, thrives in rural habitats, and can feed on other animals besides humans. Interestingly, this mosquito now vectors CHKV more efficiently due to a new adaptive mutation that occurred in the virus in 2005 or 2006, leading to reemergence of disease.

After a resoundingly successful mosquito control program in the 1940s and the decline of yellow fever in the 1960s, funding for mosquito control was cut. This has contributed to the dramatic resurgence of dengue, CHKV, and now ZIKV. Children are vulnerable to morbidity and mortality from these diseases.

ZIKV is a flavivirus that first was identified in Uganda in 1947. It emerged in Brazil in early 2015 and rapidly spread to most South American countries, with recent local transmission in the United States territories and the United States mainland. The most devastating effects have been neurotropic, with microcephaly in the newborns of infected mothers. This is the first time that a mosquito-borne disease has been linked with severe congenital malformation. Other neurologic complications such as Guillain-Barré syndrome can occur. Most infected …