[1] HOSP EVANDRO CHAGAS,INST OSWALDO CRUZ,DEPT VIROL,BR-21045900 RIO JANEIRO,BRAZIL
[2] FDN NACL SAUDE CE,BR-60150160 FORTALEZA,CEARA,BRAZIL
[3] LACEN CE,BR-60120002 FORTALEZA,CEARA,BRAZIL
[4] SESA CE,DEPT EPIDEMIOL,BR-60060440 FORTALEZA,CEARA,BRAZIL