APPENDIX 29
Letter from the Chief Medical Officer,
Sir Liam Donaldson, Department of Health to the Chairman of the
Committee (5H 1B)
RE: HIV VIRAL
LOAD AND
THE RISK
OF HIV TRANSMISSION
At the Health Select Committee evidence hearing
on 10 February on New Developments in HIV/AIDs and Sexual Health
Policy, Melanie Johnson suggested that I write to clarify some
of the issues around HIV viral load and the risk of HIV transmission.
Highly active antiretroviral therapy (HAART)
where effective can significantly reduce HIV viral load (ie amount
of HIV virus in a sample). An undetectable HIV viral-load is the
goal of anti-HIV treatment. But as Melanie Johnson indicated,
a reduced or undetectable viral load does not mean that a person
is not infectious. The patient information booklet HIV and Sex
produced by the National AIDS Manual provides a useful summary
on this issue. It states that although many people with undetectable
viral load in their blood also have an undetectable viral load
in their sexual fluids, this is not always the case. Some people
with undetectable viral load in their blood have quite high viral
load in their sexual fluids which could be high enough to infect
someone.
The NAM booklet also indicates that studies
conducted in men have found that having an untreated sexually
transmitted infection, particularly gonorrhoea, increases the
chance that viral load will be detectable in semen. HIV can also
be present in cells and these could transmit HIV even when a person
has an undetectable viral load.
Through its national health promotion work the
Department funds, amongst others, the Terrence Higgins Trust and
the African HIV Policy Network to produce information resources
which also address the needs of people living with HIV. These
include messages on the importance of using a condom, not only
to prevent further transmission but also to avoid the transmission
of other STIs and drug-resistant HIV.
February 2005
| 
