Epidemiology of Chikungunya Virus in Bahia, Brazil, 2014-2015

Article The Chikungunya virus (CHIKV) is an alphavirus that belongs to the Semliki Forest Virus antigenic complex1. Local outbreaks of CHIKV-like disease have been documented since the eighteenth century2 and the virus was discovered in 1952 in Tanzania3 . Over the last 50 years, CHIKV has spread beyond its African heartlands and caused explosive outbreaks comprising millions of cases in Indian Ocean islands and Asia.4The virus is mosquito-borne and transmission is associated with the vector species Aedes albopictus and Ae. aegypti, which are responsible for transmission cycles in urban and peri-urban environments5. Clinical symptoms include polyarthralgia, rash, high fever and severe headaches6 and outbreaks are often characterized by a rapid spread and high morbidity, resulting in losses in productivity7. To date, four distinct CHIKV genotypes have been identified. Two genotypes – the East-Central-South African (ECSA) and the West African genotypes – occupy a basal position in the phylogeny of CHIKV8 and are mostly enzootic in Africa. Of the remaining two genotypes, the Asian genotype is predominant in Southeast Asia, whilst the more recent Indian Ocean lineage spread from the Comoros islands in 2004 and caused a large outbreak in India and Southeast Asia in 2005-2008. In October 2013, the Asian genotype was first reported in the Americas, in the island of Saint Martin in the Caribbean9. By the end of December 2015, nearly 1 million cases had been notified i...
Source: PLOS Currents Outbreaks - Category: Epidemiology Authors: Source Type: research