HIV Highly Contagious Before Symptoms Show: Study

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HIV Highly Contagious Before Symptoms Show: Study

Thursday October 18 1:23 PM ET

NEW YORK (Reuters Health)- HIV may be highly transmissible before an

infected person has the first, flu-like symptoms or before HIV tests

can pick up the virus--underscoring the importance of consistent safe

sex in preventing the spread of AIDS, researchers report.

The investigators studied five couples in whom HIV transmission

occurred soon after one partner contracted the virus--and as early as

one week before the partner developed the flu-like symptoms

characteristic of early HIV infection.

``The main thing that's new is that we've shown for the first time

that sexual transmission can happen readily and very soon after

exposure,'' Dr. D. Pilcher of the University of North

Carolina at Chapel Hill said in a statement.

Researchers have suspected as much, but no one had documented it,

according to Pilcher. He and his colleagues report their findings in

the October 10th issue of The Journal of the American Medical

Association.

The period shortly after transmission is known as primary HIV

infection, a time when virus levels in the blood soar and short-lived

symptoms including fever, fatigue and swollen glands may set in. At

this point, the immune system has not yet produced antibodies to the

infection, so standard tests that detect HIV antibodies cannot pick

up the infection.

In addition, researchers have theorized that during this window of

time, high amounts of the virus are ``shed'' into the genital tract,

making it a highly infectious time period. The current study suggests

that is the case--highlighting, according to Pilcher, how vital it is

to avoid unsafe sex practices.

``If you engage in unsafe sex,'' he said, ``you cannot assume that

you are not infected or infectious just because you had a negative

antibody test for HIV. The most commonly used tests can't show HIV

for several weeks.''

Pilcher's team came to their conclusions by taking the couples'

sexual histories and genetically analyzing the HIV in their blood

samples. All transmissions had been suspected of occurring when one

partner had a documented primary HIV infection.

The researchers conclude that each case of a documented primary

infection presents a ``unique public health opportunity'' to track

down that person's recent sexual contacts and prevent the further

spread of HIV.

SOURCE: The Journal of the American Medical Association 2001;286:1713-

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