Guidelines for second generation HIV surveillance - World Health ...

3.1.4. Understand mortality trends in surveillance
While designing a comprehensive surveillance system, remember that understanding trends in mortality
can be critical to interpreting changes in incidence. Mortality surveillance is an important indicator of
survival among people who are infected and an important descriptor of the epidemic.
Mortality records among HIV-positive people come from two main sources:
• Vital registration
• Antiretroviral therapy registers.
The relative importance of each source depends on two things:
• How complete are the vital registration records are in your country
• What proportion of people diagnosed with HIV is receiving antiretroviral therapy
Evaluating a National Surveillance System
In countries with strong vital registration systems, all deaths are reported centrally including the primary
cause of death. If your country has a high burden of disease, try to have algorithms for attributing and
coding deaths due to AIDS morbidity incorporated into the system.
Many countries have weak vital registration systems. Listing AIDS as a cause of death is still stigmatizing.
This leads to underreporting of AIDS-related deaths in the vital registration systems.
People who are registered or start antiretroviral therapy should be followed until death or till they drop out.
It may be difficult for an antiretroviral therapy centre to determine why a patient has stopped coming to the
centre. The patient needs to be contacted in their communities if they stop coming to the clinic and this is
often logistically difficult. Individuals who have died versus individuals who have dropped out should be
accounted for in the interpretation of results from this data source.
In addition to these more routine forms of AIDS death reporting, some countries have undertaken more
proactive studies of mortality. Some countries have returned to households that reported a recent death to
conduct a verbal autopsy to determine the cause of death. Other countries have used innovative methods
for reviewing cases of death to determine what proportion of deaths in an area is AIDS-related (19).
More technical details for measuring mortality due to HIV infection are in preparation.
3.1.5. Review the design of your surveillance system regularly
A good time to review the design is before or during an annual planning cycle for the next round of
surveillance. Ideally, this review and planning process should closely follow the analysis and interpretation
of data from the previous round. This ensures that the field experience of collecting and analysing the data
is fresh in the minds of planners and contributes to planning the next round.
New information from surveillance activities may also influence adjustments to the design of the second
generation surveillance system. For example:
• mapping efforts may identify a new pocket or population with high-risk behaviours, which should be
included in the next round of surveys
• an unusual spike in AIDS case reporting in an area may trigger more extensive mapping of key
populations at higher risk in the next round.
The process of review of your surveillance system may also enrich the analysis and interpretation of
surveillance data as it focuses attention on the epidemic from a geographical perspective, combining
multiple sources of data together (Figure 3.3).
Surveillance activities such as surveys or mapping exercises may take place in a staggered fashion over a
long timeframe rather than during a discrete period. The system will benefit from the practice of spending
time at the end of each round of surveillance activities:
• to review field experience
• to document problematic areas that need more resources or technical support
• to identify best practices
• to share lessons learned.
These process evaluations can inform a more comprehensive review of system design.
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