Genome-scale phylogenetic analyses of Chikungunya virus reveal independent emergences of recent epidemics and various evolutionary rates
Autor(es): Volk Sara M, Chen Rubing, Tsetsarkin Konstantin A, Adams A Paige, Garcia Tzintzuni I, Sall Amadou A, Nasar Farooq, Schuh Amy J, Holmes Edward C, Higgs Stephen, Maharaj Payal D, Brault Aaron C, Weaver Scott C
Resumo: Chikungunya virus (CHIKV), a mosquito-borne alphavirus, has traditionally circulated in Africa - Asia, causing human febrile illness accompanied by severe, chronic joint pain. In Africa, epidemic emergence of CHIKV involves the transition from an enzootic, sylvatic cycle involving arboreal mosquito vectors - nonhuman primates, into an urban cycle where peridomestic mosquitoes transmit among humans. In Asia, however, CHIKV appears to circulate only in the endemic, urban cycle. Recently, CHIKV emerged into the Indian Ocean - the Indian subcontinent to cause major epidemics. To examine patterns of CHIKV evolution - the origins of these outbreaks, as well as to examine whether evolutionary rates that vary between enzootic - epidemic transmission, we sequenced the genomes of 40 CHIKV strains - performed a phylogenetic analysis representing the most comprehensive study of its kind to date. We inferred that extant CHIKV strains evolved from an ancestor that existed within the last 500 years - that some geographic overlap exists between two main enzootic lineages previously thought to be geographically separated within Africa. We estimated that CHIKV was introduced from Africa into Asia 70 to 90 years ago. The recent Indian Ocean - Indian subcontinent epidemics appear to have emerged independently from the mainl- of East Africa. This finding underscores the importance of surveillance to rapidly detect - control African outbreaks before exportation can occur. Significantly higher rates of nucleotide substitution appear to occur during urban than during enzootic transmission. These results suggest fundamental differences in transmission modes -/or dynamics in these two transmission cycles.
Imprenta: Journal of Virology, v. 84, n. 13, p. 6497-6504, 2010
Identificador do objeto digital: 10.1128/JVI.01603-09
Descritores: Chikungunya virus - Biochemistry ; Chikungunya virus - DNA ; Chikungunya virus - Genome ; Chikungunya virus - Pathogenesis ; Chikungunya virus - RNA ; Chikungunya virus - Viral infections ; Chikungunya Virus - Virus ; Chikungunya virus - Transmission ; Chikungunya virus - Epidemic ; Chikungunya virus - Epidemiology ; Chikungunya virus - Public health
Data de publicação: 2010
