2019-01-112019-01-112012-11-24FELIX, Alvina Clara et. al. Low sensitivity of NS1 protein tests evidenced during a dengue type 2 virus outbreak in Santos, Brazil, in 2010. Clinical and Vaccine Immunology, Washington, v. 19, n. 12, p. 1972-1976, 2012.1556-6811e-1556-679Xhttp://repositorio.bc.ufg.br/handle/ri/16707In 2010, a large outbreak of dengue occurred in Santos, Brazil. The detection of the NS1 antigen was used for diagnosis in addi-tion to the detection of IgG, IgM, and RNA. A large number of NS1 false-negative results were obtained. A total of 379 RNA-posi-tive samples were selected for thorough evaluation. NS1 was reactive in 37.7% of cases. Most of the cases were characterized as a secondary infection by dengue 2 virus. Sequencing of NS1 positive and negative isolates did not reveal any mutation that could justify the diagnostic failure. Use of existing NS1 tests in the Brazilian population may present a low negative predictive value, and they should be used with caution, preferentially after performing a validation with samples freshly obtained during the on-going epidemic.engAcesso AbertoArtigo10.1128/CVI.00535-12