Unexpected infections in children, 1989-94: In a study of children with Kaposi’s sarcoma, 5 of 26 mothers of HIV-positive children tested HIV-negative. All children were less than 15 years old. Source: Zeigler JL, Katongole-Mbidde E. Kaposi’s sarcoma in childhood: an analysis of 100 cases from Uganda and relationship to HIV infection. Int J Cancer 1996, 65: 200-203. Abstract available at: http://www.ncbi.nlm.nih.gov/pubmed/8567117 (accessed 13 January 2012).
Unexpected infections in children, 1991-93: In 1991-93, WHO’s Global Programme on AIDS arranged for hospitals to test children aged 6-59 months (1/2 to 5 years old) admitted to pediatric care and their mothers in 4 cities in Africa: Kigali, Rwanda; Dar es Salaam, Tanzania; Kampala, Uganda; and Lusaka, Zambia. The studies tested 5,593 child-mother pairs, of which 61 (1.1% of 5,593) children were HIV-positive with HIV-negative mothers. The reports on this study do not give any breakdown by country. The authors conclude (incredibly!): “The risk of nosocomial and non-perinatally acquired HIV infection appears low among these populations.” This shows a double-standard for Africa; if 1% of inpatient Europeans had unexpected HIV infections, such a conclusion would be unacceptable. Source: Hitimana D, Luo-Mutti C, Madraa B, et al. A multicentre matched case control study of possible nosocomial HIV-1 transmission in infants and children in developing countries. 9th Int Conf AIDS, Berlin 6-11 June 1993. Abstract no. WS-C13-2. Available at: http://ww1.aegis.org/aidsline/1993/nov/M93B3075.html (accessed 31 August 2012).
Unexpected infections in children: A 2004-05 random sample national survey tested adults and children aged 0-5 years for HIV. Among all HIV-positive children, an estimated 13% had mothers who tested HIV-negative (7 of 55). The study was not able to test all mothers; among HIV-positive children with tested mothers, an estimated 16% of the mothers tested HIV-negative (7 of 44). These numbers are calcluated from reported data as follows: out of 364 children with HIV-positive mothers, 10.2%  tested HIV-positive; out of 6,671 children with HIV-negative mothers, 0.1% [= 7] were HIV-positive; and from 1,339 children with untested mothers, 0.8% [= 11] were HIV-positive. Source: Table 8.13 in: Ministry of Health, Uganda. Uganda HIV/AIDS Sero-Behavioural Survey 2004-05. Kampala: Ministry of Health 2006. Available at: http://www.measuredhs.com/pubs/pdf/AIS2/AIS2.pdf (accessed 5 January 2012).
Unexpected infections in adults: A study in Rakai, Uganda, in 2003-06 recruited HIV-negative men, circumcised some men but not others, and then followed them to see who got HIV. During the trial, 67 men got HIV at the rate of 1% per year (1 infection in 100 person-years). Among these 67 men with new infections, 6 reported no sex partners, and 10 reported always using condoms; these 16 men with unexpected HIV infections got HIV at the rate of 0.7% per year – almost as fast as all men in the trial. Source: Gray RH, Kigozi G, Serwadda D, et al. Male circumcision for HIV prevention in men in Rakai, Uganda: a randomized trial. Lancet 2007; 369: 657-666.