STATS SA RESPONDS TO MRC'S HIV/AIDS REPORT
By Statistics South Africa
10 Oct. 2001
STATEMENT BY STATISTICS SOUTH AFRICA ON MEDICAL RESEARCH COUNCIL'S HIV/AIDS
Statistics South Africa has difficulties with the Medical Research Council's
findings that 40% of adult deaths are the result of HIV/AIDS.
There are many questions about HIV/AIDS that we in South Africa cannot
adequately answer at present. For example, we do not have sufficient
information about the probability of transmission of the disease for
different groups of people in the country.
There is a wide range of reasons, which explains our present lack of
knowledge. For example, HIV/AIDS is not a notifiable disease. Therefore, it
is difficult to trace the disease and its manifestations from its sources of
origin. We have incomplete registration of births and deaths in the country,
particularly in rural areas. Death data are essential for monitoring the
extent of the epidemic. We also need information on the sero-prevalence rate
in the country as a whole. At present, this rate for the country is
calculated from women attending public antenatal clinics, which is not
necessarily a representative sample.
The only recourse we have at present regarding estimating the extent of the
epidemic is through demographic modelling. This is why we welcome the
Medical Research Council's report. It contributes to the debate on both the
changing profile of the disease and causes of deaths in South Africa.
But this type of model has its own built-in risks.
* It may be based on incomplete and possibly inaccurate or unrepresentative
* Each model is based on certain underlying assumptions, which are sometimes
difficult to test.
* Demographic modelling could over- or under-estimate the extent of a
phenomenon such as an epidemic, depending on these assumptions.
* Assumptions about the probability of transmission of a disease may make
the model unstable.
* Projections of mortality from a possibly inaccurate base (for example the
1985 base used in the MRC model) against which to compare changes in
mortality over time is also open to question.
Stats SA therefore believe that at present it is difficult to model the
HIV/AIDS epidemic adequately or accurately, since the country requires much
better empirical data.
Stats SA would like to initiate such empirical studies be undertaken in the
country which links life circumstances and living conditions of households,
and attitudes and behavioural practices within them, to the prevalence of
The only way in which such a study can be undertaken is through bringing the
household survey expertise of Stats SA together with the expertise of other
bodies. For example, nurses in the Department of Health could draw blood or
saliva samples from selected households for testing, the MRC could give
conceptual and methodological inputs, and the expertise of the SAIMR or
other bodies could be used for blood or saliva testing.
After wide consultation with relevant stakeholders, a questionnaire could be
developed, which covers living conditions and life circumstances of South
Africans, with particular emphasis on those circumstances that may place
certain people at higher risk than others regarding contracting the disease.
The survey could also ask questions on knowledge, attitudes and behavioural
practices in relation to the transmission of the disease.
This questionnaire could be administered to a representative selection of
households throughout the country. The size of the sample would depend on
funds available, but it should be a large one (at least 60 000 households),
since larger samples are required to measure the extent of less common
Following on questionnaire administration, a sample of blood could be drawn
from members of the household, or a sample of saliva extracted. This sample
could be sent for HIV/AIDS testing. The data from the results of the tests
could be linked to the questionnaire information. Analysis of the importance
of each risk factor could then be undertaken, in relation to the presence or
absence of HIV/AIDS.
There are indeed certain issues that would need to be addressed before such
a study could be undertaken, for example, having the issue of the ethics of
this type of research debated in public and through an ethics committee.
Another issue could be how to test, for example, whether to embark on
confidential, or anonymous testing, as against giving people information and
counselling about their HIV status. The blood testing among pregnant women
is done anonymously. Ongoing confidentially, for example throughout the
linking process of questionnaire completion and the results of blood or
saliva testing, would need to be guaranteed. Respondents would need to be
assured on the issue very safe testing procedures.
In spite of these issues, such studies have been successfully undertaken in
other developing countries such as Zambia. It is the only scientific way to
determine the size of the epidemic.
Dr Sulaiman Bah at (012) 310 8678 or 083 305 5781
Dr Ros Hirschowitz at (012) 310 8955 or 082 454 6209