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Second Generation Surveillance for HIV/AIDS

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What it is

Second generation surveillance for HIV/AIDS is the regular, systematic collection, analysis and interpretation of information for use in tracking and describing changes in the HIV/AIDS epidemic over time. Second generation surveillance for HIV/AIDS also gathers information on risk behaviours, using them to warn of or explain changes in levels of infection. As such, second generation surveillance includes, in addition to HIV surveillance and AIDS case reporting, STI surveillance to monitor the spread of STI in populations at risk of HIV and behavioural surveillance to monitor trends in risk behaviours over time. These different components achieve greater or lesser significance depending of the surveillance needs of a country, determined by the level of the epidemic it is facing: low level, concentrated or generalized.

Why it is Important

All countries affected by the HIV epidemic need information about their epidemic in order to combat its spread. Information about trends in the spread of HIV —whether and by how much the rates are increasing or decreasing and which populations are affected—can help countries monitor the epidemic and provide information to improve planning and evaluation of prevention activities.

How it is Done

  • In generalized epidemics where HIV is over one percent in the general population, surveillance systems concentrate on monitoring HIV infection and risk behaviour in the general population. This usually includes HIV sentinel surveillance among pregnant women in antenatal care.
  • In concentrated epidemics where HIV is over five percent in any sub-population at higher risk of infection (such as drug injectors, sex workers, men who have sex with men), surveillance systems monitor infection in those groups and pay particular attention to behavioural links between members of those groups and the general population. Surveillance systems also monitor the general population, especially young people, for high-risk sexual behaviour that might lead to rapid spread of the virus if it were introduced and trends in STI.
  • In low-level epidemics where relatively little HIV is measured in any group, surveillance systems focus largely on high-risk behaviours, looking for changes in behaviour which may foster a rapid spread of infection.

Human resources, infrastructure and supplies needed

Surveillance activities should be conducted according to a well-developed plan that specifies how trends in different parts of a country or in different population groups are going to be measured over time. The coordinating unit for surveillance should be located in the Ministry of Health. The coordinator for surveillance should have a background in epidemiology and additional expertise is needed in the fields of laboratory, sampling, database management and social sciences. Such expertise could be located in the unit or be derived by linking with institutions in the country. For instance, a university or the national statistical office may be able to provide expertise on behavioural monitoring or sampling and data processing. Training and supervision of the staff in the sentinel sites and of the staff conducting surveillance in special population groups is essential and resources need to be set aside to allow the central unit to provide such support.

Cost Information

Costs will vary according to the size of the country and types of monitoring and evaluation being undertaken. In order to minimize cost and promote an integrated and sustainable approach, monitoring and evaluation activities should be integrated with surveillance activities of the National Strategic Plans. It has been estimated that the cost of M&E activities, with surveillance activities included, would be in between 5 to 10% of the National AIDS budget.

Key References

The three main sources for materials listed here are WHO, UNAIDS, Family Health International. They can be found here.

1. World Health Organization and UNAIDS. Second generation surveillance for HIV: compilation of basic materials. CD-ROM. Geneva, World Health Organization (WHO/HIV/2002.07).2002
2. World Health Organization and UNAIDS.Initiating Second Generation HIV Surveillance Systems: Practical Guidelines. Geneva, World Health Organization (WHO/HIV/2002.17). 2002
3. World Health Organization and UNAIDS. Guidelines for Second Generation HIV Surveillance for HIV:The Next Decade. Geneva, World Health Organization (WHO/CDS/EDC/2000.05). 2000
4. World Health Organization and UNAIDS. AIDS Epidemic Update: December 2002. Geneva, World Health Organization(ISBN 9291732532). December 2002.
5. World Health Organization and UNAIDS. Report on the Global HIV/AIDS Epidemic 2002. Geneva, World Health Organization (ISBN 9219731854). July 2002.
6. UNAIDS Best Practice Collection.Trends in HIV Incidence and Prevalence: Natural Course of the Epidemic or Results of Behavioural Change? Geneva, UNAIDS (UNAIDS 99.12e). June 1999.
7. UNAIDS Best Practice Collection.Connecting Lower HIV Infection Rates with Changes in Sexual Behaviour in Thailand: Data Collection and Comparison. Geneva, UNAIDS (UNAIDS 98.15). June 1998.
8. UNAIDS Best Practice Collection. A Measure of Success in Uganda: the Value of Monitoring both HIV Prevalence and Sexual Behaviour. Geneva, UNAIDS (UNAIDS 98.8). May 1998.

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