1. Retrovirus Laboratory, Virology Service, Adolfo Lutz Institute, São Paulo, Brazil.
2. Brazilian AIDS Program, Federal District, Brasília, Brazil.
3. Emilio Ribas Institute, São Paulo, Brazil.
4. DST/HIV/Aids Reference Center, Municipal Secretary of Health, Ubatuba, São Paulo, Brazil.
5. DST/HIV/Aids Reference and Training Center, São Paulo, Brazil.
6. São Paulo State Secretary of Health, São Paulo, Brazil.