PARIS One or even two negative tests for the human
immunodeficiency virus (HIV) does not mean that infection --and the possibility
of developing AIDS--will not occur, according to recent findings from Dr.
Jean Jacques Lefrere, and his associates at Institut National de Transfusion
Sanguine, Saint Antoine Hospital.
The French researchers report the case of a woman who was negative for
HIV antibodies three times over a six month period. However, she began
to develop symptoms after the last test and when she was re-tested at eight
months, she was found to be HIV antibody positive. The 46 year old Algerian
woman, who worked as a cleaner in a hospital, accidentally picked up and
was pricked with an HIVcontaminated needle. By French law she was tested
at the time of the accident, and then again three and six months later.
She had none of the known risk factors for HIV infection.
The fact that she did not become HIV positive until eight months after
the accident suggests that the usual yardstick of two tests over a six
months period does not eliminate the possibility that infection has taken
place, Dr. Lefrere said:
" The possibility of a serologically silent window of more than
six months may have public health consequences. The underestimation of
the diagnosis of HIV infection may wrongly lead to reassurance of individuals
remaining negative six months after the potentially infectious accident
may contribute to further transmission.
" Indeed, infected persons may have a high level of viremia before
seroconversion and are likely to be highly infectious for their partners.
Moreover years could pass before the diagnosis of HIV infection and the
individual could miss opportunities for early treatment," he noted.
The French investigators suggests that the reason that it took so long
to detect HIV in the woman was that it may have been a weaker form of the
virus or because she received it in such a small dose that it took a longer
than usual time to build up in her body to the point where it became detectable.
They noted that although all of the tests commonly used to detect HIV,
including ELISA, Western blot and p24 antibody assays were consistently
negative within the first six months after the woman's accident, they subsequently
become strongly in the later tests. In addition, concentrations of the
CD4 T-lymphocytes used as a measure of infection rose steadily with subsequent
testing.
The case was reported in The Lancet, Vol., 345, June 24, 1955, pp. 1634-1635.
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