[1] Univ Manitoba, Dept Community Hlth Sci, Winnipeg, MB R3T 2N2, Canada
[2] London Sch Hyg & Trop Med, Dept Epidemiol & Populat Hlth, London WC1, England
[3] Ashodaya Samiti, Mysore, Karnataka, India
[4] Karnataka Hlth Promot Trust, Bangalore, Karnataka, India
[5] St Johns Med Coll & Hosp, Bangalore, Karnataka, India
[6] Univ Manitoba, Dept Med Microbiol, Winnipeg, MB, Canada
[7] Univ Manitoba, Dept Med, Winnipeg, MB, Canada