[1] Natl Canc Registry, Natl Hlth Lab Sci, 1 Modderfontein Rd, ZA-2192 Johannesburg, South Africa
[2] Univ Bern, Grad Sch Cellular & Biomed Sci, Uni Mittelstr,Mittelstr 43, CH-3012 Bern, Switzerland
[3] Swiss Trop & Publ Hlth Inst, Kreuzstr 2, CH-4123 Allschwil, Basel Land, Switzerland
[4] Univ Basel, Peterspl 1, CH-4001 Basel, Switzerland
[5] Univ Bern, Inst Social & Prevent Med, Mittelstr 43, CH-3012 Bern, Switzerland
[6] Univ Witwatersrand, Sch Publ Hlth, 27 St Andrews Rd, ZA-2193 Johannesburg, South Africa
[7] Univ Bristol, Bristol Med Sch, Populat Hlth Sci, Beacon House,Queens Rd, Bristol BS8 1QU, Avon, England
[8] Univ Cape Town, Ctr Infect Dis Epidemiol & Res CIDER, Sch Publ Hlth & Family Med, Falmouth Rd, ZA-7925 Cape Town, South Africa
[9] Univ KwaZulu Natal, Coll Hlth Sci, Sch Nursing & Publ Hlth, Dept Publ Hlth Med, Howard Coll Campus,George Campbell Bldg,2nd Floor, ZA-4041 Durban, South Africa
[10] IARC WHO, Int Agcy Res Canc, Infect & Canc Epidemiol Grp, 150 Cours Albert Thomas, F-69372 Lyon 08, France
[11] Stellenbosch Univ, South African DSI NRF Ctr Excellence Epidemiol Mo, 19 Jonkershoek Rd, ZA-7600 Stellenbosch, South Africa