Study shows chikungunya mutation places several countries at risk of epidemic

June 18, 2014

In a study published in Nature Communications, University of Texas researchers predicted further adaptations of the mosquito-borne chikungunya virus that has recently spread from Africa to several continents. These adaptations may result in increased transmission and the infection of more people by this viral strain.

A key factor in a virus's potential to sustain its circulation and ultimately cause disease is its ability to adapt to new host environments. The number and complexity of these adaptations is shaped by how hospitable the new host is to a certain virus. Researchers had previously found that a recently emerged lineage strain of the chikungunya virus has adapted itself to be hosted not only by the Aedes aegypti mosquito, which lives mainly in the tropics, but also by the Asian tiger mosquito, A. albopictus, which can be found on all continents except Antarctica. This mutation in the Indian Ocean lineage occurred through a single adaptive change in the virus's genetic code that alters one protein in the envelope surrounding the virus.

The newest investigation analyzed recent events in chikungunya virus evolution that will aid in predicting future trends in transmission and circulation. The research team found that the initial adaptation provided the framework for a second wave of adaptations that can enable rapid diversification of viral strains and even more efficient transmission to people.

Meanwhile, authorities in 18 Caribbean countries or territories are reporting more than 100,000 confirmed or suspected cases. In the Dominican Republic, where health officials report more than 53,000 suspected cases, hospitals in hard-hit areas are treating hundreds of new patients daily. One Caribbean nation—Trinidad and Tobago—has avoided infection due to aggressive mosquito eradication efforts. In the United States, cases have been confirmed in North Carolina, Nebraska, Indiana, and Florida (some 25 in the Sunshine State). The CDC is advising travelers to Caribbean countries to take precautions against mosquito bites. Read more from a Trinidadian online news source.

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