Figure 3. Annual number of new adult HIV infections and AIDS deaths, 1980–2007. doi:10.1371/journal.pone.0003729.g003 number of AIDS deaths by half and, as a consequence, also cutting in half the number of new orphans each year. The high coverage of adult ART has also contributed to a reduction in mother-to- child transmission of HIV. Due to the high number of new infections in the past 24,000 adults progress to eligibility for ART each year. As a result, the need for adult ART will increase by nearly 60% by 2016. This presents a major challenge to maintain the current levels of high coverage. References 1. UNAIDS/WHO (2006) 2006 Report on the global AIDS epidemic, UNAIDS/ WHO, May 2006. 2. National AIDS Coordinating Agency (2008) October to December 2007 National AIDS Council Report, BHRIMS February 2008. 3. Abt Associates South Africa Inc. (2000) An Impact Assessment of HIV/AIDS on Current and Future Population Characteristics and Demographics in Botswana. Gaborone, Botswana: Coordinated by the Ministry of Finance and Development Planning in collaboration with UNDP and the Ministry of Health. 4. Dorrington RE, Moultrie TA, Daniel T (2006) The Demographic Impact of HIV/AIDS in Botswana. Gaborone: UNDP and NACA: Botswana. 5. Ministry of Health (2005) Botswana Second Generation HIV/AIDS Surveillance, 2005. Gaborone, Department of HIV/AIDS Prevention and Care. 6. National AIDS Coordinating Agency (NACA), CSO and Other Development Partners (2005) Botswana AIDS Impact Survey II: Statistical Report. Gaborone: National AIDS Coordinating Agency. 7. Brown T, Grassly NC, Garnett G, Stanecki K (2005) ‘‘Improving projections at the country level: the UNAIDS Estimation and Projection Package 2005.’’ Sex Trans Inf 2006 82: 34–30. HIV in Botswana The PMTCT program represents a major success with over 90% of HIV-positive women receiving antiretrovirals to prevent trans- mission of HIV to their children. The program has averted an estimated 10,000 child infections since its inception. The combined effects of the PMTCT program and the child treatment program have averted an estimated 11,000 child AIDS deaths. With fewer new child infections the need for child treatment is also be reduced. Unfortunately similar progress has not been made in reducing the number of new adult infections (Figure 3). Some prevention programs have been expanded to scale. Condom use in Botswana is among the highest anywhere in the world. High coverage has been achieved for voluntary counseling and testing and AIDS education in the schools. But these programs have not been enough to make a significant difference. The proportion of adults with more than one sexual partner remains very high. A high level of partner concurrency contributes to rapid reproduction of new infections. New approaches are urgently needed. At the current rate of new infections prevalence will remain at very high levels and the burden to expand treatment programs in the future will continue to grow. Author Contributions Conceived and designed the experiments: BF TM GM. Analyzed the data: JS BF TM. Wrote the paper: JS BF BCM TM GM. 8. Stover J (2008) AIM: A Computer Program for Making HIV/AIDS Projections and Examining the Demographic and Social Impacts of AIDS. Washington, DC, USAID | Health Policy Initiative, January 2008. 9. Todd J, Glynn J, Marston M, Rangsin R, Lutalo T, et al. (2007) ‘‘Time from HIV sero-conversion to death prior to ART: a collaborative analysis of eight studies in six developing countries.’’ AIDS vol 21 sup 6: S55–S63. 10. Stover J, Johnson P, Zaba B, Zwahlen M, Dabis F, Ekpini R (2008) ‘‘The Spectrum projection package: improvements in estimating mortality, ART needs, PMTCT impact and uncertainty bounds.’’ Sex. Transm. Inf. 84: i24–30. 11. Marston M, Zaba B, Solomon JA, et al. (2005) ‘‘Estimating the net effect of HIV on child mortality in African populations affected by generalized HIV epidemics.’’ J Acquir Immune Defic Syndr 38: 219–27. 12. National AIDS Coordinating Agency (2007) 2008 Progress Report of the National Response to the UNGASS Declaration of Commitment on HIV/ AIDS, Ministry of State President, National AIDS Coordinating Agency, December 2007. 13. Tlale J, Keapoletswe K, Anderson MG, Gomez FdlH, Mmelesi M, Seipone K (2008) Mother-to-child transmission rate in Botswana–analysis of dried blood spot (DBS) results from the national PMTCT programme, Abstract presented at the International AIDS Conference, Mexico City, August 2008. PLoS ONE | www.plosone.org 4 November 2008 | Volume 3 | Issue 11 | e3729