Chikungunya: an overview

Chikungunya (CHIK), a mosquito borne debilitating disease, is caused by CHIK virus, an alphavirus belonging to the family Togaviridae. The sudden onset of very high fever along with rash, and severe arthralgia especially in the small joints of hands and toes are the characteristics of the disease. It was first reported from Tanzania in 1952-53 and spread subsequently to sub-Saharan Africa, South East Asia and Pacific causing large epidemics. The virus exists in three genotypes, the Asian, West African and East Central South African that are responsible for outbreaks in the respective areas. The first outbreak in Asia was in Bangkok in 1958 followed by other Asian countries. India experienced massive outbreaks of CHIK in the 1960s and early 70s mainly in cities. After a gap of 32 years an explosive outbreak of CHIK devastated the country affecting more than 1.4 million people in 13 states. The epidemic also witnessed many unusual clinico-pathological complications including CHIK associated deaths and mother to child transmission. High morbidity with severe arthralgia persisted for several months made the people mentally and physically weak. This review describes CHIK in general and highlights the various clinico-pathological aspects observed during the recent outbreak.