The UNAIDS/WHO Working Group on Global HIV/AIDS

Quality of Surveillance Systems
The UNAIDS/WHO Working Group on Global HIV/AIDS and STI Surveillance has developed
coding schemes to represent four dimensions related to the quality of surveillance systems:1
• Frequency and timeliness of data collection;
• Appropriateness of populations under surveillance;
• Consistency of the sites/locations and groups measured over time; and
• Coverage/representativeness of the groups for the adult populations.
The coding schemes depend on the level of the HIV epidemic in a country. The levels are
defined as generalized, concentrated and low.2
Sub-Saharan Africa is the most affected region by the HIV/AIDS epidemic. Among the 44
countries scored, all but 4 have generalized epidemics. Surveillance systems in this region have
considerable variability in quality. Fifteen countries have systems that we categorized as being
fully implemented as of 2001. Fourteen countries do not have the most basic components for a
HIV/AIDS surveillance system. The remaining 11 countries have some or most of the
components of a fully implemented surveillance system in place, but have yet to build a system
that is capable of providing the data required to track the epidemic accurately. Fortunately, most
of the countries that are most affected by the epidemic also have the systems that are fully
implemented or have systems with some or most aspects implemented. Also, we are now
receiving information for the 2002 and 2003 rounds of surveillance and countries such as Angola
and Chad have expanded and improved their systems and if these stay in place will have higher
quality systems for tracking HIV.
Surveillance systems are improving
HIV surveillance in Africa has improved in recent years, notably in terms of coverage and
reporting of prevalence among young antenatal women. During 2002 approximately 220,000
pregnant women attending antenatal clinics were HIV tested for the purpose of surveillance.
These women attended about 625 antenatal clinics throughout the region, not including an
additional 400 clinics in the Republic of South Africa where antenatal clinics are selected
according to statistical sampling (FFFiiiggguuurrreee 111).