[1] UNIV PERUANA CAYETANO HEREDIA,INST MED TROP ALEXANDER VONHUMBOLDT,POB 5045,LIMA 100,PERU
[2] UNIV PERUANA CAYETANO HEREDIA,DEPT BIOL,LIMA,PERU
[3] INST NACL SALUD,CTR INVEST HUGO LUMBERAS CRUZ,LIMA,PERU
[4] UNIV PERUANA CAYETANO HEREDIA,DEPT BIOCHEM,LIMA,PERU
[5] UNIV LONDON LONDON SCH HYG & TROP MED,DEPT MED PARASITOL,LONDON WC1E 7HT,ENGLAND