DENV-3 genotype III circulating in São Paulo, Brazil,from 2003 to 2008 is not associated with dengue haemorrhagic fever/dengue shock syndrome.

ABSTRACT

Dengue viruses (DENV) are the most important arboviruses of public health significance, and compriseof four distinct antigenic serotypes (DENV-1 to 4) that show substantial genetic diversity. These virusesusually cause dengue fever (DF) but some patients progress to a more severe form of the illness, i.e.dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). The first reports of DENV-3 cases inBrazil occurred in the year 2000 with co-circulation of DENV-1 and 2. Thereafter, DENV-3 spreadthroughout the country. DENV-3 phylogenetic analysis has revealed the existence of four to five DENV-3 genotypes. Genotype III of DENV-3 has been the main genotype circulating in Brazil, but recent studieshave indicated that DENV-3 genotype I and genotype V are also circulating in some states of Brazil. Inorder to evaluate DENV-3 genotypes circulating in São Paulo state from 2003 through 2008 we analyzedthe NS1 region of DENV-3 isolated from patients residing in Ribeirão Preto and presenting with differentclinical manifestations of dengue disease. Nucleotide sequences from 31 viruses were obtained andcompared to 105 DENV-3 corresponding sequences retrieved from GenBank. Phylogenetic analysisshowed that São Paulo DENV-3 sequences belong to genotype III and that Puerto Rico strains are closelyrelated to South American strains. There was no association between DENV-3 genotype and DHF/DSS.