Behavioural Surveillance Surveys - The Wisdom of Whores

It is not possible to validate data on sexual
practices by direct observation. It is, however,
possible to triangulate them with data from
other sources to see if the picture presented
is consistent and credible. An increasing
number of studies comparing self-reported
sexual behavior with biological markers of
sexual activity such as pregnancy, STIs and
HIV infection show that at an individual level
there is quite a good match between the
reported risk behavior and biological indicators
of risk.
Still, some misreporting of risk behavior
undoubtedly occurs, and true levels of risk
may well be underreported, especially by
women among whom extramarital sex is more
heavily stigmatized than it is among men.
Those tracking the HIV epidemic may, however,
be less concerned with the exact level of risk
behavior in a population than they are with
trends in those behaviors over time. Even
where there is misreporting, repeat behavioral
surveys will show changes in trends over time,
provided that the magnitude or direction of
misreporting do not change significantly.
Linking behavioral and serological data for
better explanatory power
In developing the framework for second
generation HIV surveillance, much discussion
went in to the issue of whether serological
and behavioral information could routinely be
collected from the same individuals. This is
a common practice in specialized research
studies. However it is logistically and ethically
complex. Generally, HIV surveillance is
conducted using blood left over from other
clinical procedures. It is stripped of all
identifying markers, so that a test result
can not be traced back to an individual.
This method allows blood to be tested without
the consent of the person it came from, so
eliminating refusal bias. Linking behavioral
data to HIV status changes that equation.
It may yield extra information about the
relationship between risk behavior and
infection, but since consent must be sought,
it also increases the likelihood that participants
will refuse to give blood. Those who refuse
may have different risk profiles from those
who accept — people who refuse are generally
thought to have higher risk profiles - and
the results of surveillance will be distorted. In
addition, there is an ethical obligation to offer
counseling and voluntary HIV testing to all
those in the sample. Because of this, it is not
generally recommended that HIV surveillance
and behavioral surveillance be conducted
using the same individuals.
Another consideration is that the populations
traditionallly used in sentinel surveillance for
HIV - pregnant women at antenatal clinics and
clients at STI clinics - have by definition had
unprotected sex in the recent past. If their risk
profile changes - they abstain or switch to
consistent condom use for example - they will
drop out of the population attending the
clinics. Trends in risk behavior among those
still attending the clinics will be virtually
impossible to interpret.
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C H A PTER 1 B EHAV I OR A L S U R V EI L L A NC E S U R V EY S