Introduction: An Overview of the PLACE Method

The AIDS epidemic is a global tragedy. In the past 20 years, countries have seen their workforce diminish, their children orphaned, and the unbearable suffering of millions. Every day, another 12,000 people age 15 and older become newly infected with the virus that causes AIDS. Of these, almost 50% are women and about 50% are aged 15 to 24 years. Why are so many new infections occurring daily when most people know how to prevent transmission of HIV? There are no easy answers to this question, but conquering the global pandemic will not be accomplished solely by global efforts. Conquering the AIDS pandemic will require action at the local level in the thousands of resource-poor communities and districts where transmission is most likely to occur. There is surely a global HIV epidemic, but it is comprised of thousands of local HIV epidemics.

Preventing HIV transmission at the local level is a challenge. Local HIV epidemics are as varied as the populations and cultures they inhabit. Valid information on local epidemics is rarely available. There are many reasons why little is known about local HIV epidemics. First, HIV surveillance systems are usually national in scope and do not provide information about local epidemics. Second, newly infected people rarely know they are infected, making the local pattern of new infections almost impossible to detect. Finally, there is often a lack of capacity at the local level to collect the information necessary to target interventions and monitor prevention efforts.

The lack of information about local epidemics stymies national efforts to target AIDS prevention strategies and scale up effective programs. In what part of the country is HIV incidence highest? Who is most likely to become infected in that area? Where is the epidemic likely to spread next? Where should prevention program managers focus their efforts? These questions often go unanswered. These are the questions that PLACE addresses.

In sum, the problem addressed by the PLACE method is the need for rapidly available information to target and monitor local AIDS prevention efforts strategically.

Notes

1Weir SS, Pailman C, Mahlalela X, Coetzee N, Meidany F, Boerma JT. From people to places: focusing AIDS prevention efforts where it matters most. AIDS. 2003;17(6):895-903.

2Boerma JT, Urassa M, Klokke AH, Senkoro KP, Ng'weshemi JZL. Spread of HIV/AIDS in a rural area in Tanzania. AIDS. 1999;13(10):1233-1240;

3Carael M. Urban-rural differentials in HIV/AIDS/STDs and sexual behaviour. In: Herdt G, ed. Sexual Cultures and Migration in the Era of AIDS: Anthropological and Demographic Perspectives. Oxford: Oxford University Press; 1997:107-126;

4Barongo LR, Borgdorff MW, Mosha F, et al. The epidemiology of HIV/AIDS-1 infection in urban areas, roadside settlements and rural villages in Mwanza Regon, Tanzania. AIDS. 1992;6:1521-1528;

5Wawer M, Serwadda D, Musgrave SD, Konde-Lule JK, Musagara M, Sewankambo NK: Dynamics of the spread of HIV/AIDS-1 infection in a rural district of Uganda. BMJ. 1991;303:1301-1306;

6Anderson RM, May RM, Boily MC, Garnett GP, Rowley JT. The spread of HIV/AIDS1 in Africa: sexual contact patterns and the predicted demographic impact of AIDS. Nature. 1991;352(6336):581-9.

7 Boerma T, Urassa M. Situation analysis for a district HIV/AIDS/AIDS programme. In: HIV/AIDS Prevention and Care in Africa: A District Level Approach. Amsterdam: Royal Tropical Institute, 1997:39-50.

8 Boerma T, Weir S. Integrating demographic and epidemiologic approaches to research on HIV/AIDS: the proximate determinants framework, In Press, Jour Inf Dis.

9 Garnett GP, Anderson RM. Sexually transmitted diseases and sexual behavior: insights from mathematical models. J Infect Dis. 1996;174(Suppl 2):S150-S161.

10 Yorke JA, Hethcote HW, Nold. A. Dynamics and control of the transmission of gonorrhea. Sex Transm Dis. 1978;5:51-57.

11 Wasserheit JN, Aral SO. The dynamic topology of sexually transmitted disease epidemics: implications for prevention strategies. J Infect Dis. 1996;174(Suppl 2):S201-S213.

12 In countries with low-level or concentrated epidemics, where HIV prevalence is low among the general population but occurs at higher rates among subgroups such as sex workers, injecting drug users, or men who have sex with men, HIV prevalence is more difficult to measure. In these areas, ANC prevalence data may not be as useful a proxy measure. For further discussion of the estimation of HIV/AIDS prevalence, see the supplementary issue of Sexually Transmitted Infections on "Methods and tools for HIV/AIDS estimates and projections". Also see Walker, N, KA Stanecki, T Brown, J Stover, S Lazzari, JM Garcia-Calleja, B Schwartlander and PD Ghys. Methods and procedures for estimating HIV/AIDS and its impact: the UNAIDS/WHO estimates for the end of 2001. AIDS 17(15):2215-2225. (http://www.ncbi.nlm.nih.gov/ent...) and UNAIDS resources on estimation (http://www.unaids.org/Unaids/EN/Resource...).