HISTORY OF CHIKUNGUNYA OUTBREAK

Chikungunya occurs in Africa, Asia and the Indian subcontinent. Human infections in Africa have been at relatively low levels for a number of years, but in 1999–2000 there was a large outbreak in the Democratic Republic of the Congo, and in 2007 there was an outbreak in Gabon.

Starting in February 2005, a major outbreak of chikungunya occurred in islands of the Indian Ocean. A large number of imported cases in Europe were associated with this outbreak, mostly in 2006 when the Indian Ocean epidemic was at its peak. A large outbreak of chikungunya in India occurred in 2006 and 2007. Several other countries in South-East Asia were also affected. Since 2005, India, Indonesia, Maldives, Myanmar and Thailand have reported over 1.9 million cases. In 2007 transmission was reported for the first time in Europe, in a localized outbreak in north-eastern Italy. There were 197 cases recorded during this outbreak and it confirmed that mosquito-borne outbreaks by Ae. Albopictus are plausible in Europe.

In December 2013, France reported 2 laboratory-confirmed autochthonous cases in the French part of the Caribbean island of St. Martin. Since then, local transmission has been confirmed in over 43 countries and territories in the WHO Region of the Americas. This is the first documented outbreak of chikungunya with autochthonous transmission in the Americas. As of April 2015, over 1 379 788 suspected cases of Chikungunya have been recorded in the Caribbean islands, Latin American countries, and the United States of America. 191 deaths have also been attributed to this disease during the same period. Canada, Mexico and USA have also recorded imported cases.

On 21st October 2014, France confirmed 4 cases of locally-acquired chikungunya infection in Montpellier, France. In late 2014, outbreaks were reported in the Pacific islands. Currently chikungunya outbreak is ongoing in Cook Islands and Marshall Islands, while the number of cases in American Samoa, French Polynesia, Kiribati and Samoa has reduced. WHO responded to small outbreaks of chikungunya in late 2015 in the city of Dakar, Senegal, and the state of Punjab, India.
In the Americas in 2015, 693 489 suspected cases and 37480 confirmed cases of chikungunya were reportedto the Pan American Health Organization (PAHO) regional office, of which Colombia bore the biggest burden with 356,079 suspected cases. This was less than in 2014 when more than 1 million suspected cases were reported in the same region.

The decreasing trend continues in 2016, with about 31,000 cases reported to PAHO as of 18 March 2016, representing a 5-fold decrease compared to the same period in 2015. Despite this trend, chikungunya remains a threat for the region with Argentina recently reporting its first chikungunya outbreak.