Scientists and medical authorities agree
that HIV does not survive well outside the body, making the possibility
of environmental transmission remote. HIV is found in varying concentrations
or amounts in blood, semen, vaginal fluid, breast milk, saliva, and
tears. To obtain data on the survival of HIV, laboratory studies have
required the use of artificially high concentrations of laboratory-grown
virus. Although these unnatural concentrations of HIV can be kept alive
for days or even weeks under precisely controlled and limited laboratory
conditions, CDC studies have shown that drying of even these high concentrations
of HIV reduces the amount of infectious virus by 90 to 99 percent within
several hours. Since the HIV concentrations used in laboratory studies
are much higher than those actually found in blood or other specimens,
drying of HIV-infected human blood or other body fluids reduces the
theoretical risk of environmental transmission to that which has been
observed–essentially zero. Incorrect interpretations of conclusions
drawn from laboratory studies have in some instances caused unnecessary alarm.

Results from laboratory studies should not be used to assess
specific personal risk of infection because (1) the amount of virus
studied
is not found in human specimens or elsewhere in nature, and (2) no
one has been identified as infected with HIV due to contact with
an environmental surface. Additionally, HIV is unable to reproduce
outside
its living host (unlike many bacteria or fungi, which may do so under
suitable conditions), except under laboratory conditions; therefore, it does not spread or maintain infectiousness outside its host.