Emerg Infect DisEmerging Infect. DisEIDEmerging Infectious Diseases1080-60401080-6059Centers for Disease Control and Prevention22000396331068511-077610.3201/eid1710.110776Letters to the EditorLetterDengue Virus Serotype 4, Roraima State, BrazilReemergence of Dengue 4 in Roraima, BrazilAcostaPablo Oscar AmézagaMaitoRodrigo MeloGranjaFabianaCordeiroJoel da SilvaSiqueiraThalitaCardosoMayara NunesCoradoAndré de LimaBarletta-NavecaRaphaela HonoratoNavecaFelipe GomesAuthor affiliations: Universidade Federal de Roraima, Boa Vista, Brazil (P.A. Amézaga Acosta, F. Granja, J. da Silva Cordeiro, T. Siqueira, M. Nunes Cardoso, A. de Lima Corado);Laboratório Central de Roraima, Boa Vista (R. Melo Maito);Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil (R.H. Barletta-Naveca);Instituto Leônidas e Maria Deane, Fiocruz, Brazil (F. Gomes Naveca)Address for correspondence: Pablo Oscar Amézaga Acosta, Universidade Federal de Roraima–Biologia, Campus Paricarana, Av. Cap. Enê Garcêz, no. 2413, Bairro Aeroporto, Boa Vista, Roraima 69301-000, Brazil; amezaga@osite.com.br102011171019791981Keywords: Dengue virus type 4Brazilphylogenyvirusesletter

To the Editor: Temporão et al. recently reported the detection and characterization of dengue virus serotype 4 (DENV-4) in Boa Vista, Roraima, Brazil (1). To date, 4 subtypes of DENV-4 have been recognized: genotype I, which comprises Asian strains (e.g., Thailand-1978-U18441); genotype II, which has been detected since the early 1980s in the Americas (e.g., Brazil-1982-U18425); genotype III, which comprises recently emerged Thai strains (GenBank accession no. AY618989); and genotype IV, which comprises sylvatic strains (GenBank accession no. EF457906) (2).

Temporão et al. conducted phylogenetic analysis of envelope gene sequences and concluded that 3 samples of DENV from Roraima in 2010 were DENV-4, genotype I (1). Unfortunately, the authors mistakenly labeled Asian strains (Thailand-1978 and -1985) as genotype II, and American strains (e.g., Brazil-1982) as genotype I. Those DENV-4 strains isolated in Roraima in 2010 in fact belong to genotype II (2,3). We had previously analyzed 2 samples isolated from Roraima in 2010 by using C/prM nucleotide sequencing and maximum-likelihood phylogenetic reconstruction. Our results, presented at the XXI National Meeting of Brazilian Society for Virology in October 2010, show that both isolates are indeed genotype II (3). Nucleotide sequences are available in GenBank under accession nos. HQ822125 and HQ822126.

Temporão et al. also concluded that because only genotype II (reported as genotype I) was identified in their samples, “[it] excludes the possibility that Asian genotypes previously circulated in Brazil.” Beyond its obviously flawed logic, we believe that this statement lacks scientific support; DENV-4 genotype I, closely related to Chinese and Philippine strains, has in fact been shown to occur in the city of Manaus, ≈800 km south of Boa Vista, as reported in 2 recent articles (4,5). Circulation of DENV-4 genotype I in northern Brazil, probably related to increasingly intense trade with Asian countries, may be sporadic and geographically limited as yet (5), but ignoring this evidence can hardly be helpful for dengue surveillance and control.

Suggested citation for this article: Amézaga Acosta PO, Melo Maito R, Granja F, da Silva Cordeiro J, Siqueira T, Nunes Cardoso M, et al. Dengue virus serotype 4, Roraima State, Brazil [letter]. Emerg Infect Dis [serial on the Internet]. 2011 Oct [date cited]. http://dx.doi.org/10.3201/eid1710.110776

ReferencesTemporão JG, Penna GO, Carmo EH, Coelho GE, do Socorro Silva Azevedo R, Nunes MR, Dengue virus serotype 4, Roraima State, Brazil [letter] Emerg Infect Dis. 2011;17:938–4021529421Vasilakis N, Weaver SC The history and evolution of human dengue emergence. Adv Virus Res. 2008;72:1–76 10.1016/S0065-3527(08)00401-619081488Naveca FG, Figueiredo RM, Barletta-Naveca RH, Almeida TA, Mourão MP, Maito RM, Two genotypes of dengue virus serotype 4 in northern Brazil. In: Abstracts of the XXI National Meeting of Brazilian Society for Virology; Gramado (Rio Grande do Sul State); 2010 Oct 17–20. Abstract no. 00858–00001.Figueiredo RM, Naveca FG, Bastos MS, Melo MN, Viana SS, Mourão MPG, Dengue virus type 4, Manaus, Brazil. Emerg Infect Dis. 2008;14:667–9 10.3201/eid1404.07118518394292de Melo FL, Romano CM, Zanotto PM Introduction of dengue virus 4 (DENV-4) genotype I into Brazil from Asia? PLoS Negl Trop Dis. 2009;3:e390 10.1371/journal.pntd.000039019399169Emerg Infect DisEmerging Infect. DisEIDEmerging Infectious Diseases1080-60401080-6059Centers for Disease Control and Prevention DOI: 10.3201/eid1710.110927 ArticleVasconcelosPedro F.C.NunesMárcio R.T.Author affiliation: Evandro Chagas Institute, Ananindeua, BrazilAddress for correspondence: Pedro F. C. Vasconcelos, Instituto Evandro Chagas, Ministério da Saúde, Rodovia BR-316, Km 7, 67030–000, Ananindeua, Pará State, Brazil; email: pedrovasconcelos@iec.pa.gov.br

In Response: With regard to their comment on our letter, Dengue Virus Serotype 4, Roraima State, Brazil (1), Amézaga Acosta et al. correctly refer to an erroneous correlation between genotype I and American strains and between genotype II and Asian strains (2). That was a typographic error in the text and figure. Our Figure shows the correct association.

Phylogenetic tree demonstrating the 2 clusters of dengue virus serotype 4 correctly associated with corresponding genotypes: genotype II, American strains, including strains isolated in Roraima in 2010; and genotype I, 2 Asian strains. Boldface indicates strains isolated in Roraima. Scale bar indicates 1% nucleotide sequence divergence.

Amézaga Acosta et al. also suggested a scientific inconsistency, that our results exclude circulation of previous Asian strains in Brazil, and argue that Figueiredo et al. (3) published a letter on the introduction of DENV-4 in Manaus. However, Amézaga Acosta et al. probably do not know that the article by Figueiredo et al. has been contested by the Brazilian Ministry of Health for failing to demonstrate any irrefutable scientific result, including the virus isolation. Our statement was logically based on strong epidemiologic surveillance, virus isolation, serologic evidence (hemagglutination inhibition assay and immunoglobulin ELISA), and clinical aspects.

Regarding circulation of 2 genotypes in Brazil, when the article was written, epidemiologic and molecular evidence supported the hypothesis of circulation of only the American genotype (II) in northern Brazil and not the Asian (I) and American (II) genotypes at the same time (1,2,4). More specifically to the Manaus finding, no virus was isolated and no strong serologic evidence (in the lack of virus isolation) was provided, and the Ministry of Health considers this article a mistake, probably caused by laboratory contamination with Asian genotype I.

Possible introduction and detection of Asian DENV-4 strains in Brazil should not be ignored because the possibility of multiple introduction events in the country resulting from intense transit of people and commercial activities across Brazil from the Caribbean and Asian regions poses a real risk. However, at this time, only genotype II has been isolated and genetically characterized (1). The previously published articles lack strong and reliable scientific evidence.

Suggested citation for this article: Vasconcelos PFC, Nunes MRT. Dengue virus serotype 4, Roraima State, Brazil [letter]. Emerg Infect Dis [serial on the Internet]. 2011 Oct [date cited]. http://dx.doi.org/10.3201/eid1710.110927

ReferencesTemporão JG, Penna GO, Carmo EH, Coelho GE, do Socorro Silva Azevedo R, Nunes MR, Dengue virus serotype 4, Roraima State, Brazil [letter] [PubMed] Emerg Infect Dis. 2011;17:938–4021529421Amézaga Acosta PO, Melo Maito R, Granja F, da Silva Cordeiro J, Siqueira T, Nunes Cardoso M, Dengue virus serotype 4, Roraima State, Brazil [letter] Emerg Infect Dis. 2011;17:1979–8022000396Figueiredo RM, Naveca FG, Bastos MS, Melo MN, Viana SS, Mourão MPG, Dengue virus type 4, Manaus, Brazil. Emerg Infect Dis. 2008;14:667–9 10.3201/eid1404.07118518394292Melo FL, Romano CM, Zanotto PM Introduction of dengue virus 4 (DENV-4) genotype I into Brazil from Asia? PLoS Negl Trop Dis. 2009;3:e390 10.1371/journal.pntd.000039019399169