Mayaro virus: imported cases of human infection in São Paulo State, Brazil.
Mayaro virus (MAYV) is an arbovirus (Togaviridae: Alphavirus) enzootic in tropical South America and maintained in a sylvan cycle involving wild vertebrates and Haemagogus mosquitoes. MAYV cases occur sporadically in persons with a history of recent activities inside or around forests. This paper reports three cases of MAYV fever detected in men infected in Camapuã, MS, Brazil. Serum samples collected at four days and two months after the onset of the symptoms and examined by hemagglutination inhibition test, revealed monotypic seroconversion to MAYV. Isolation of the virus was obtained from one of the samples by inoculation of the first blood samples into newborn mice. A suspension of the infected mouse brain was inoculated into C6/36 cells culture and the virus was identified by indirect immunofluorescent assay with alphavirus polyclonal antibodies. RT-PCR, performed with RNA extracted from the supernatant of C6/36 infected cells in the presence of alphavirus generic primers as well as specific MAYV primers, confirmed these results. The reported cases illustrate the importance of laboratory confirmation in establishing a correct diagnosis. Clinical symptoms are not always indicative of a disease caused by an arbovirus. Also MAYV causes febrile illness, which may be mistaken for dengue.
Coimbra
Terezinha Lisieux M
TL
Seção de Vírus Transmitidos por Artrópodos, Instituto Adolfo Lutz, São Paulo, SP, Brasil. licoimbra@ial.sp.gov.br
Santos
Cecília L S
CL
Suzuki
Akemi
A
Petrella
Selma M C
SM
Bisordi
Ivani
I
Nagamori
Adélia H
AH
Marti
Antonia T
AT
Santos
Raimundo N
RN
Fialho
Danya M
DM
Lavigne
Shirlene
S
Buzzar
Marcia R
MR
Rocco
Iray M
IM
D000328:Adult; D000368:Aged; D000524:Alphavirus / Q000235:genetics / Q000276:immunology; D018354:Alphavirus Infections / Q000175:diagnosis / Q000821:virology*; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001938:Brazil; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction