What is the rationale behind PLACE?
1. Geographic Clustering of HIV
Geographic clustering of HIV transmission suggests that AIDS prevention programs should focus on preventing transmission in sexual and injecting drug use networks in geographic areas where HIV incidence is high.
Empiric evidence suggests that HIV incidence clusters geographically. Although maps showing differences in HIV prevalence among antenatal clinic patients (see maps below) must be interpreted with care, such surveillance data typically show that HIV prevalence is not uniform within a country.
In order to target resources effectively, AIDS prevention programs should focus on geographic areas where HIV incidence is highest. These areas have been dubbed "Priority Prevention Areas" or PPAs.
The clustering of HIV infection in a PPA reflects the size and characteristics of the underlying sexual and/or injection drug use networks. These networks are not directly observable. However, in most countries, knowledgeable local experts can identify PPAs using available demographic, epidemiologic, and contextual data. In sub-Saharan Africa, for example, there has been a pattern of geographical clustering of HIV/AIDS infection by level of urbanization and population density2,3,4,5,6 (see map of Kenya). The intersection of alcohol consumption, short-term migration and commercial activity (e.g., along transport routes, in port cities, and in mining towns) may signal a PPA.7 Other factors possibly associated with HIV incidence include poverty, rapid growth, poor access to health services, a high male-to-female ratio, and high unemployment.
Source of Maps: UNAIDS Epidemiology FACT Sheets on Kenya and Thailand.