- MONTPELLIER, France (AFP)
- French and African researchers said Friday that strains of the AIDS virus
were mutating, a development with potentially alarming repercussions on
testing and treatment for the infection.
- Scientists at the Research Institute for Development
(IRD) in Montpellier said they had found that two strains of the Type 1
human immunodeficiency virus (HIV), previously thought to be genetically
far apart, had combined together.
- There are two main types of HIV virus, the precursor
to acquired immune deficiency syndrome (AIDS).
- HIV-1, the most widespread, has three strains -- M, N
and O -- that each have different characteristics.
- Until now, conventional thinking was that these groups
were so divergent -- genetically more than 50 percent dissimilar -- that
there was no risk of recombination between them.
- But researchers at the IRD's retrovirus laboratory, working
with counterparts in the West African country of Cameroon, said they had
isolated and identified a live strain that had combined from group M and
- "We found a patient in Cameroon who had been infected
by the two strains and, against all our expectations, we found that the
two strains had merged, forming a new variant," the head of the team,
Martine Peeters, told AFP.
- "This supposes that even viruses which are genetically
far apart can mix and form a completely new variant."
- The discovery, reported in a US publication, the Journal
of Virology, could have grave implications in how the AIDS virus is spread,
as well as the conventional methods for testing and treating it, she said.
- "At the moment, group O is rare. But the fact that
it can recombine with another virus may change its characteristics and
make it more virulent," she said.
- Another problem is screening. Because O is rare, viruses
in this group sometimes cannot be detected using commercially-available
test kits, and they are resistant to certain anti-retroviral treatments.
- Cameroon has been the theatre of a previous landmark
discovery in AIDS research.
- It was there that a French researcher, Francois Simon,
first identified the group N strain in September 1998.
- Group N is genetically close to a virus that prevails
in chimpanzees, leading to speculation that humans contracted it from eating
ape meat. The HIV strain that is most prevalent in western countries is
- The other type of AIDS virus, HIV-2, is mainly prevalent
in Africa's Great Lakes region.
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