Chikungunya is a mosquito transmitted viral infection that, up until about a decade ago, was a little known outside of Africa. It was first described in Tanganyika in the early 1950s, and for the next five decades it was sporadically seen across eastern and central Africa.
That is, until 2005, when Chikungunya made a surprise jump to the Indian Ocean island of Réunion. There, it infected nearly 1/3rd of the island’s 770,000 residents (see 2006 EID article Chikungunya Disease Outbreak, Reunion Island) in just a matter of months.
Chikungunya – while rarely fatal - produces a fever, severe muscle and joint pain, and headaches. The symptoms usually go away after a few weeks, but some patients can sustain permanent disability, and some deaths have been reported. In the eight years since the jump to Réunion Island, `Chik’ has spread further across the Indian Ocean, Southeast Asia, and even briefly into northern Italy.
I wrote about that story several years ago in It's A Smaller World After All, but the short version is that a traveler, returning from India, brought the virus to Italy in 2007 which led to more than 290 cases reported in the province of Ravenna, which is in northeast Italy.
While Chik is still geographically fairly limited, the breeds of mosquito that can transmit this virus (Aedes aegypti & Aedes albopictus) can be found across many areas of the globe, making its importation via infected (viremic) travelers a concern both in Europe, North & South American, and the Caribbean.
Aedes albopictus (Asian Tiger) Mosquito - Wikipedia
Dark blue: Native range
Dark green: introduced (as of December 2007)
The risk is considered great enough that early last year, the CDC and PAHO (Pan American Health Organization) put together a 161-page guide on preparing for the arrival of Chikungunya to the Americas (see Preparedness and Response for Chikungunya Virus Introduction in the Americas).
As anticipated by that report, Chikungunya has now been identified on the Caribbean Island of St. Martins. This from the World Health Organization.
Disease outbreak news
10 December 2013
On 6 December 2013, WHO was notified of two laboratory confirmed cases of locally acquired chikungunya disease in the French part of the Caribbean isle of Saint Martin. The other part of the isle is a country that is part of the Kingdom of the Netherlands (Sint Maarten). These two cases were confirmed by polymerase chain reaction (PCR) test performed by the French National Reference Centre for arboviruses in Marseille.
There has been an outbreak of dengue fever on St Martin / Sint Maarten since January 2013. Chikungunya disease was detected during an investigation following the notification of five cases with joint pains and fever on 18 November 2013, for whom the diagnosis of dengue was excluded. The onset of symptoms of the five cases occurred between 12 October and 15 November 2013.
As of 10 December 2013, altogether two confirmed, four probable and twenty suspected cases of chikungunya infection have been reported.
Chikungunya is a viral disease that is rarely fatal and is transmitted to humans by infected mosquitoes. Symptoms of chikungunya include high fever and headache, with significant pains in the joints (ankles, wrists), which can persist for several weeks. The symptoms appear between 4 and 7 days after the patient has been bitten by an infected mosquito. The name, chikungunya derives from a word in Makonde language roughly meaning “that which bends up”, reflecting the physique of a person suffering from the disease.
In the absence of specific treatment and an effective human vaccine, preventive measures are based on a dual strategy:
- raising awareness of the risk factors for chikungunya infection as well as the protective measures individuals can take to prevent mosquito bites;
- stopping the proliferation of mosquitoes by reducing their breeding grounds.
This is the first time that locally acquired transmission of chikungunya has been detected in the WHO Americas Region.
The health authorities on both the French and the Dutch side of the island are cooperating closely to respond to this outbreak, in close coordination with public health authorities in France and the Netherlands. Actions implemented by local authorities to-date include:
- Epidemiological surveillance including syndromic surveillance and surveillance of severe cases.
- Vector control activities have been implemented in the affected area and will rapidly be extended to the entire island, including around airports, schools, day nurseries, hospitals.
- Communication and social mobilization: information is being disseminated to health professionals, to the public (on individual protection, how to eliminate the larvae breeding ground) and to the travelers by specific information in the airports.
WHO does not advise special screening at points of entry with regard to this event nor does it currently recommend the application of any travel or trade restrictions.