- Clinical epidemiology, not seroepidemiology is the
answer to Africa's AIDS problem -
Article by Konotey-Ahulu FID. BMJ 1987; 294: 1593-1594, with permission
from the BMJ Publishing Group. Copyright remains with the BMJ Publishing
If there is one thing veteran physicians, surgeons, public health experts,
and other health workers in Africa have been good at it is clinical epidemiology.
The work of Dr Cicely Williams (on kwashiorkor in west Africa)1
2, and Dr Denis Burkitt (on lymphoma in east Africa)3
4 is a prime example of what careful clinical and epidemiological
observation can produce. Some others who lived and worked in Africa and
emphasised this kind of approach in tropical medicine and health include
Shaper, Gelfand, Edington, Sai, Hutt, Lambo, Lucas, Morley, Gilles, Hendrickse,
Koinage, Osuntokun, and Bryceson, to mention but a sample. Now, suddenly,
with the acquired immune deficiency syndrome (AIDS), something called
seroepidemiology is being pushed - by people who have no knowledge of
tropical medicine - way above clinical epidemiology rather than being
made to work shoulder to shoulder with it. While travelling extensively
in sub-Saharan Africa recently I encountered great disquiet about this
approach. For example, Dr Miriam Duggan, the obstetrician-gynaecologist
medical superintendent of the large St Francis Hospital Nsambya, in Kampala,
was saddened by the way that external research agencies lost interest
whenever she mentioned the need for strengthening her clinical epidemiological
research base to enable her go round the villages to follow up and treat
patients with AIDS who had been discharged, and to measure longevity.
Research funds must never be for service ("that is the sole burden of
the Ugandan government"), she seems to have been told, but are for taking
the blood of as many people as possible to measure "seropositivity" and
T lymphocytes. These measurements are indeed important to indicate what
is happening in the population, but there must not be an "either research
or service" approach to health problems in the Third World. The greatest
contributions to medical knowledge in Africa by individuals (Cicely Williams,
Denis Burkitt, etc) or by agencies (the World Health Organisation, International
Atomic Energy Agency, etc) have been made when research was coupled with
service. For one thing, there is far more cooperation from the people
when problems are seen to be tackled. I had far more cooperation from
the prostitutes I met when I discussed their problems and fears about
AIDS (and in some cases future rehabilitation) than 1 would have got by
just distributing a questionnaire (unpublished findings).
If seroepidemiology had been consistently reliable in defining correctly
the seriousness of Africa's AIDS problem there would have been less disquiet
about it in the countries I visited. But Biggar et al described very high
rates of seropositivity in Kenya5 and eastern Zaire6,
only to remark a year later, "We now believe that the reactivity reported
was not specific" for human T cell lymphotropic virus type III (HTLV III)7-a
conclusion already arrived at by the more extensive investigations of
a team of German and British workers.8 9 Indeed,
using more than 6000 samples from African subjects, Wendler et al showed
"that fewer than one in a 1000 were seropositive for AIDS at the time
of sampling before 1985 and (the data) do not support the hypothesis of
the disease originating in Africa."9 This information
came too late to prevent extravagant projections of the AIDS problem in
Africa10 and to restore the confidence of Africans
in seroepidemiology. Investigators with a knowledge of tropical medicine
quite rightly observed that "associated with recurrent malaria and other
infectious diseases, excessively high rates of false-positivity with H9/HTV-11I
ELISA have led to a dichotomy between seroepidemiology and clinical epidemiology
in tropical Africa.11 In addition, "patients with
alcoholic liver disease have a high incidence of false positive results
on tests for HTI-V-III antibodies,"12 while acute
malaria infections have produced false positivity even with the Western
blot.13 When the conclusions of clinical epidemiology
differ from those of seroepidemiology clinicians should always believe
the former. Clinicians with considerable experience of Africa told Biggar
that if AIDS had existed there while they were practising they would have
recognised it, but he seemed to dismiss their conviction and described
"this type of evidence" as anecdotal.14 He came
to agree with them only after "reviews of the records of the Belgian and
French hospitals" at which Africans were treated, concluding that AIDS
became common only after 1980.14 During my travels
through sub-Saharan Africa I was heartened to observe that there are enough
trained health workers in post who can work out the clinical epidemiology
of AIDS a la Cicely Williams and Burkitt with a minimum of fuss. Granted,
seroepidemiology seems to be the more "scientific," but really it achieves
less and uses more resources. When Jonathan Mann wrote recently that "It
is difficult to gauge the spread and seriousness of AIDS in Africa. African
countries lack diagnostic equipment and testing facilities"15
he must have been referring to seroepidemiology. Primary health care in
Ghana, for instance, is so good that there is no difficulty in tracing
patients with AIDS and their relatives, and a field unit in south western
Uganda does not have to rely on seroepiderniology to gauge the spread
and seriousness of AIDS in Africa. I cannot, of course, speak for Zaire,
which was the only country that turned down my application for a visa
so that I could visit medical colleagues and discuss health problems.
to spend the money available
If funds were limited, as indeed they are in much of Africa, I would limit
serological work to
(1) assessing the specificity and sensitivity of the various kits
under African conditions (as researchers like Rosemary Mwendapole are
doing at Ndola in Zambia);
(2) screening all blood before transfusion starting from the cities
(as Kenya has begun to do); and
(3) serving as a back up procedure when clinical features are
not clear cut (as I saw being done in Dar es Salaam and Lusaka). I would
assume that prostitutes at ports and on trade routes, and the promiscuous,
were seropositive even if they were not and direct educational programmes
accordingly. I would not embark on an expensive wholesale screening for
AIDS. In my tribe, starting with those who have got AIDS, I would spend
the bulk of any available funds on answering the questions: How, when,
who, which, why, and where? The usual objection to this approach is that
"those who are sick with AIDS have no more people to infect so it is better
to identify the carriers and thereby stop the spread of the disease."
The answer to this is that I was unable to find a team in any of the countries
I visited whose policy was to inform all those with "positive serum" that
they had AIDS to make them behave appropriately. It was far easier to
advise everybody to behave appropriately rather than base caution on seropositivity.
For example, in Congo Brazzaville, a predominantly Roman Catholic community
though Marxist in it governmental politics, I asked what advice the doctors
gave to a married man with tuberculosis who was found to be seropositive
and they said: "Nothing." The patient was not even told that he might
have AIDS because the doctors, quite rightly, said that they had nothing
else to go on but seropositivity for human immuno deficiency virus as
assessed by ELISA and pulmonary tuberculosis. If it had been proved with
virus isolation studies, etc, that the man had AIDS would the doctor tell
him to protect his wife? The doctor pondered a little and then said that
there was little point in telling him about it: the recommendation to
use condoms was religiously unacceptable, and in any case "the man has
improved on anti- tuberculosis therapy and the wife is still seronegative."
This raises the question: Does seropositivity in a patient with tuberculosis
(or amoebiasis or strongyloides, for that matter) always mean AIDS? Only
clinical epidemiology can answer that question in Africa, and this is
why it is to be preferred.
that needs to be ascertained
Clinical epidemiological questions I should like health workers, patients,
and their relatives to tackle in my Krobo tribe in south eastern Ghana,
where there is only repatriation of people with AIDS are the following:
(1) Why of two girls who leave home on the same day for prostitution
in Abidjan does one return sick with AIDS and the other not?
(2) What type of "abnormal sex" did the one girl have and the
(3) Which clients did the one and not the other frequent?
(4) How was the prostitution organised: were the girls self employed
and regulated or did someone "own" them and pay them wages?
(5) Where did they carry on business: in brothels, in hotels,
on board ships, or in the homes of clients?
(6) When exactly did the girl with AIDS fall sick?
(7) Who treated the girls when they were ill (quacks?) and how
were they treated? And with dirty needles?
(8) What physical signs does the patient have in the perineum
(9) Have any of the returned patients (repatriated with AIDS from
Abidjan and Hamburg) improved after treatment with traditional herbal
(10) How long do the patients live?
(11) When will the first Krobo man develop the disease, and under
(12) Why do prostitutes return home with AIDS from the Ivory Coast
and not from Nigeria?
little more funds than are required to treat these patients a lot of data
can be collected. In other tribes in Africa where AIDS has proceeded from
the introduction phase to the propagation phase and men have developed
the disease data need to be collected on circumcision state (for men and
women); abnormal sex practices; longevity of men, women, and infants;
the phenomenon of the healthy infected mother (the "perpetual virus secreting
mother," who continues to conceive and to bear babies with AIDS); and
the most effective education slogans and posters, which will vary from
tribe to tribe. With pure clinical epidemiology (and without waiting for
a vaccine) a lot can be achieved in halting the march of AIDS in Africa,
especially if other public health measures for the communities are incorporated
in the procedures. As I pointed out previously in respect of another disease
in the Third World, "SERVICE, Education, research - in that order of priority
- will guarantee patients' co-operation, but reversing the order, as often
happens, to RESEARCH, Education, service succeeds in driving some away."16
thank the ministers of health, directors of medical services, and other
health workers who readily agreed to discuss AIDS with me in the context
of Africa's other problems
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