Chikungunya Fever: Where Are We Today?

Abstract

Chikungunya fever is a mosquito-borne viral disease caused by Chikungunya virus. Chikungunya virus (CHIKV) is an RNA virus belonging to family Togaviridae. Mosquitoes primarily responsible for transmission of Chikungunya are Aedes aegypti, A. albopictus and A. polynesiensis, which breed in clean water collections like in tanks, disposable items and other scrap material from domestic and peri-domestic sites. It is a re-emerging viral disease characterized by sudden onset of fever with severe arthralgia followed by rash and constitutional symptoms lasting for 1–7 days. It is more or less a self-limiting disease, but long-term sequelae of the disease like persisting arthralgia/arthritis (arthralgia/joint stiffness plus joint swelling) are the most frequently encountered. In India several outbreaks were documented during 1963–1973. After then, no outbreak was reported between the period of 1973 and 2005 from most parts of the world, except for a few sporadic cases occurring in various parts of the world including India. After dormancy of almost three decades, Chikungunya virus re-emerged in India in the states of Karnataka, Andhra Pradesh, Maharashtra, Tamil Nadu and Madhya Pradesh since December 2005. Recently in 2016 a big upsurge due to Chikungunya was reported from all over India including the capital city of Delhi and other states and UTs. Mumbai reported a 12.5% seroprevalence rate in 2016. Laboratory diagnosis is very essential to validate the clinical diagnosis of suspected cases which can be done by virus isolation, serological tests and molecular methods by polymerase chain reaction. By establishing the exact diagnosis, specific public health measures can be initiated timely. Appropriate surveillance is, thus, compulsory to minimize re-emergence and in controlling the future outbreaks.