HIV survival outside the body
To the editor:
A news article in the 10 March issue of BMJ quotes Daniel Halperin to say
that “The HIV virus is extremely fragile, dying easily and quickly once
exposed to air.” This statement contradicts all available evidence from
relevant laboratory studies reported in peer-reviewed journals.
In 1985, Barre-Sinoussi and colleagues reported HIV’s “unusual stability”
at room temperatures. Dried preparations of concentrated HIV retained
some infectious virus after 4 and 7 days. In 1986, Resnick and colleagues
reported HIV surviving for more than 15 days in wet conditions and up to 3
days after drying. These experiments, which began with concentrated HIV,
showed that a 1 log reduction in infectivity after drying required hours.
In 1987, CDC reported, without describing details of their procedures,
that “drying HIV causes a rapid (within several hours) 1-2 log (90%-99%)
reduction in HIV concentration.” This vaguely worded report is consistent
with other evidence that 10% of dry HIV survives for several hours.
In an experiment reported in 1994, Van Bueren and colleagues dried cell
free and cell-associated HIV mixed with 10% or 100% fetal calf serum,
placed the solutions on glass slides, and allowed them to dry. During
drying, which took about 2.5 hours, the loss of infectious titer “was
never more than 1 log TCID50/ml.” After storing the glass slides for
various numbers of days at room temperature, they tested the dried HIV to
see how much of it was still able to infect cells. From these experiments,
they estimated that 10% of HIV survives from 17.5 hours to several days
after drying, and that it takes 5 days or more to inactivate all HIV.
Dried HIV survived longer in preparations with more protein and with cell-
free vs. cell-associated HIV.
A review published in 2006 states that HIV survives more than 7 days on
dry surfaces. In wet conditions, such as in a used syringe or needle,
research published in 1999 showed that HIV can survive for weeks at room
Misinformation about HIV survival is widespread and dangerous. For
example, in 2005, I sat with sex workers in India who reported standing in
line for tattoos administered to client after client with the same needle
and inkpot. They thought that getting a tattoo under such circumstances
was not a risk for HIV infection, because they had been told that HIV dies
quickly outside the body.
David Gisselquist, independent consultant
Competing interests: No competing interests