HIV does not spread in a uniform pattern. The diversity of HIV epidemics around the world is becoming ever more apparent. Because of this diversity, existing HIV surveillance systems are ill-equipped to capture outbreak patterns, or to explain changes over time in mature epidemics. Efforts are now being made to build on existing systems, strengthening their explanatory power and making better use of the information they generate.
Strengthened systems, dubbed "second generation surveillance systems",
aim to concentrate resources where they will yield information that is most useful in reducing the spread of HIV and in providing care for those affected. Each country will need to tailor its surveillance systems to the pattern of the epidemic in that country. Data collection must be concentrated in the populations most at risk of becoming newly infected with HIV. This means populations with high levels of risk behaviour or young people at the start of their sexual lives. It means comparing information on HIV prevalence and on the behaviours that spread it and to then build up an informative picture of changes in the epidemic over time. It also means making best use of other sources of informationócommunicable disease surveillance, reproductive health surveys, etc.óto increase understanding of the HIV epidemic and the behaviours that spread it.
The Joint United Nations Program On HIV/AIDS (UNAIDS) has released a guideline document that suggests classifying the epidemic into different statesólow-level, concentrated and generalizedódepending on the prevalence of the virus in various population sub-groups. The most efficient mix of data collection for surveillance will depend on the epidemic state in a country. The recommended choice of populations among whom data are collected will vary from epidemic to epidemic; so will the mix of behavioural and bio-medical surveillance.
Data use will also vary according to the epidemic state. Where HIV is
uncommon, biomedical surveillance and especially behavioural data can provide early warning of a possible epidemic. Where it is concentrated in sub-populations with high-risk behaviour it can provide invaluable information for designing focused interventions. In generalized epidemics it can help indicate the success of the response and provide information essential for planning care and support. In all epidemic states, surveillance systems aim to provide information that will increase and improve the response to the HIV epidemic.
Vidyya has obtained a copy of the guideline. This document provides an overview of the principal issues which need to be considered in strengthening surveillance systems and increasing their utility. It also suggests priority approaches for the various epidemic states.
You may download a PDF of the document--Second generation
surveillance for HIV: The next decade. This guideline document is used with permission. However it may not be redistributed for commercial purposes and should be used for educational purposes only.