Zika virus in the Americas: is it time to revisit mosquito elimination?

Author:Calder, Jennifer Ann Marie

In recent years, the Americas have experienced several emerging mosquito-borne diseases. Dengue virus first appeared in the Caribbean and Latin America in the 1980s; in 1999, West Nile virus was first recognized in New York City and is now endemic throughout the hemisphere (Komar & Clark, 2006). Malaria was eliminated from North America and most of the Caribbean; however, as a result of increased international travel and/or commerce, there have been travel-associated cases in nonendemic countries with an outbreak in 2006 in Jamaica that was linked to a single source introduction of the Haitian isolate (Webster-Kerr et al., 2011).

Since 2004, there have been an increasing number of persons traveling to the Americas from countries where mosquito-borne diseases exist in which humans play a role in the transmission. Thus, the risk for intercountry and intercontinental transmission has increased. Prior to the outbreak of chikungunya in the Caribbean, between October and December 2012, 84% of travellers from chikungunya-endemic countries to the Caribbean arrived from South Africa, India, China, the Philippines, and the French territory of Reunion--and the U.S. was the top destination from chikungunya-endemic areas of the Caribbean (Khan et al., 2014). In May 2015, the Pan America Health Organization announced the first case of Zika virus on Easter Island (Chile) and since then it has spread throughout parts of South America, Latin America, and the entire Caribbean with the exception of Cuba.

The Aedes aegypti mosquito is the main vector involved in the transmission of dengue fever, yellow fever, chikungunya fever, and Zika fever. In the mid-1980s, Aedes albopictus was imported into the U.S. from Asia; it is also capable of transmitting the viruses associated with the diseases listed above. Unlike A. aegypti, A. albopictus has been able to adapt to temperate climates, has shown a higher affinity for human blood, and in some instances has undergone genetic adaptation that enhances its ability to transmit select pathogens. For these reasons, the potential for disease transmission from A. albopictus is great.

To date, yellow fever and Japanese encephalitis are the only mosquito-borne diseases for which a human vaccine exists, and chemoprophylaxis exists only for malaria. While research continues to pursue developing effective vaccines and treatment modalities, mosquito elimination seems to be the most viable option at this time. Attempts to eliminate...

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