Assessing the Origin of and Potential for International Spread of Chikungunya Virus from the Caribbean

Abstract

Background: For the first time, an outbreak of chikungunya has been reported in the Americas. Locally acquired infections have been confirmed in fourteen Caribbean countries and dependent territories, Guyana and French Guiana, in which a large number of North American travelers vacation. Should some travelers become infected with chikungunya virus, they could potentially introduce it into the United States, where there are competent Aedes mosquito vectors, with the possibility of local transmission. Methods: We analyzed historical data on airline travelers departing areas of the Caribbean and South America, where locally acquired cases of chikungunya have been confirmed as of May 12th, 2014. The final destinations of travelers departing these areas between May and July 2012 were determined and overlaid on maps of the reported distribution of Aedes aeygpti and albopictus mosquitoes in the United States, to identify potential areas at risk of autochthonous transmission. Results: The United States alone accounted for 52.1% of the final destinations of all international travelers departing chikungunya indigenous areas of the Caribbean between May and July 2012. Cities in the United States with the highest volume of air travelers were New York City, Miami and San Juan (Puerto Rico). Miami and San Juan were high travel-volume cities where Aedes aeygpti or albopictus are reported and where climatic conditions could be suitable for autochthonous transmission. Conclusion: The rapidly evolving outbreak of chikungunya in the Caribbean poses a growing risk to countries and areas linked by air travel, including the United States where competent Aedes mosquitoes exist. The risk of chikungunya importation into the United States may be elevated following key travel periods in the spring, when large numbers of North American travelers typically vacation in the Caribbean.

Arboviral infections diagnosed in a European area colonized by Aedes albopictus (2009–2013, Catalonia, Spain)

“…More thorough investigation is warranted, particularly on the role of unapparent or mild dengue infections in promoting virus spread [17]. When bearing in mind the 2008 chikungunya outbreak in Italy, which was originated from a single imported case from Asia [18], or the 2014 Caribbean explosive outbreak [19], it is obvious that a carefully planned official and public-funded program of surveillance must be strongly encouraged.…”

Control of immunopathology during chikungunya virus infection

“…On the contrary, a modern lifestyle might amplify an epidemic through travel, and the prevalence of underlying medical conditions might increase the frequency of severe infections. 84 Third, occurrence of CHIKV infections fluctuates with climate. CHIKV appears seasonally in highly endemic areas, and climate changes seem to be of critical importance for the survival and spread of Aedes species mosquitoes, as well as the biting rate and incubation time within these vectors of disease.…”

Measuring Haitian children's exposure to chikungunya, dengue and malaria

“…albopictus occur in Haiti, chikungunya virus was expected to arrive in the country and to be disseminated rapidly 9 , 10 . In December 2013, the World Health Organization (WHO) reported the local spread of the virus in nearby Saint Martin – another overseas department of France 11 . On 6 June 2014, the United States Centers for Disease Control and Prevention (CDC) reported 6318 chikungunya cases in Haiti and, by the end of 2014, transmission of chikungunya virus had been reported throughout the Caribbean basin 12 , 13 …”