AFRICAN AIDS: TRUE OR FALSE?
By Neville Hodgkinson, Zambia
The Sunday Times (London) 5 Sept. 1993
Zambian doctors, faced with an enormous gap between reports of people
testing HIV positive and the number of people falling ill with AIDS, are
calling for a reappraisal of the idea that a positive test means a person
is liable to develop the disease.
They say that different HIV test procedures in Africa produce such widely
differing results that their use should be re-examined. Yet at present
some people are being "frightened to death" by a positive diagnosis.
By the end of last year, the National AIDS Prevention and Control Programme
had received a cumulative total of 7,124 reports of full-blown AIDS since
the first cases were recorded in 1985. That represents fewer than a thousand
a year, relatively few in a nation of 8m people.
But, according to screening surveys conducted late last year, as many
as four out of 10 sexually active people are now testing HIV positive,
and a million Zambians could be infected with the virus. Those findings
have horrified most politicians and AIDS workers, and spurred the government
into launching a new anti-AIDS campaign.
Guy Scott, an MP and former cabinet minister, says the disease threatens
to orphan 2m children, and to take the lives of large numbers of staff
in companies, public utilities and government. "It is ripping through
the system. It is an absolute disaster," he said.
But Dr Francis Kasolo, head of virology at the University Teaching Hospital
in Lusaka, said work in his department suggests the HIV figures cannot
be taken at face value.
"We have found a big problem with false positives. When we repeat
the tests, there are a lot of disparities in the results. A test kit from
one manufacturer behaves differently from another's." The conclusion,
he said, was that "most of our results are more or less compromised".
Most of the country's 80 testing centres were unable to afford a more
expensive, confirmatory procedure after an initial positive test. Even
that second test, known as Western Blot, produced widely differing results.
A third, rapid test, still in use at some clinics, had been shown to
produce up to 40% false positive results in patients infected with malaria.
Blood "stickyness" of patients, unrelated to HIV, also produced
Dr Wilfred Boayue, the World Health Organisation's representative in
Zambia, says the recent surveys show such a big increase in positive results
compared with six to seven years ago, when the proportion was only about
5 to 8%, that he shares concern that the country is in the grip of an HIV
Kasolo, however, believes changes in the type of test kit used may contribute
to the changing picture. He says international aid for the developing countries
is often tied to use of materials provided by the donor nation.
"Most of the kits are supplied by the donors. If one decides not
to provide funds any more, we move to another who will, and the kits come
from that country instead. So the kits vary a lot: reporting can be high
or low, depending on the kit.
"We have had individuals tested in one laboratory, and told they
are positive, who move onto another, where they are negative."
Kasolo said the picture had been further confused by a phenomenon called
"transient antibody to HIV" reported at a recent international
meeting. A Uganda-based professor of virology had seen that some HIV positive
patients subsequently tested negative.
Kasolo agreed with a recent call by scientists in Australia for use
of HIV test kits to be reappraised, in the light of evidence that many
conditions apart from HIV infection such as TB, malaria, malnutrition and
multiple infections can cause a person to test positive.
"It is important that we address the whole issue of HIV in Africa
scientifically," Kasolo said. "There is something going on that
we do not understand."
Dr Sitali Maswenyeho, a paediatrician at the University Teaching Hospital
and former fellow in AIDS research at the University of Miami, said he
had long argued against the HIV test. "It's non specific," he
said. "The test itself is killing a lot of people here. The stigma
is doing the damage.
"We have malnutrition, bad water, poor sanitation; and when on
top of that you are told you have an incurable disease, that really cuts
off people's lives."
Despite concerns on the tests' validity, the presence of a severe form
of immune system failure, affecting mainly sexually active people, is generally
There is argument, however, over its causes. Kasolo questions the "new
virus" theory maintaining that a variety of sexually transmitted infections
might be responsible. This view is shared by many older Zambians.
David Chipanta, 22, an HIV positive man helping with the work of an
AIDS education and counselling organisation, says: "People in the
villages tell us it is not new, but that it has become worse because of
Chipanta disagrees, arguing that even in the past, people were promiscuous.
But he supports the challenge to HIV testing. *