[1] Yale Univ, Sch Publ Hlth, Dept Epidemiol Microbial Dis, New Haven, CT 06510 USA
[2] Yale Univ, Sch Med, AIDS Program, Dept Internal Med,Sect Infect Dis, New Haven, CT 06510 USA
[3] Univ Malaya, Fac Med, Ctr Excellence Res AIDS CERiA, Kuala Lumpur, Malaysia
[4] Univ Malaya, Fac Med, Infect Dis Unit, Kuala Lumpur 50603, Malaysia