Re: How long can HIV survive in a vacutainer collection tube of blood.

There are two answers here, really depending on what you mean by "survive".  
First, relating to the question of infectivity, i.e. how long should such a 
tube of blood be considered infectious and capable of transmitting HIV to a 
person, the answer is FOREVER.  The information in the following paragraph 
should not lead one to believe that HIV-contaminated blood has necessarily 
lost its ability to transmit the disease after a certain amount of time.  
As an example of this, I would point out that before testing was available, 
HIV was clearly transmitted by blood products that had been stored for a 
considerable time.

The second answer relates more to the question of viral assays, i.e. how 
many viral particles can we detect after a period of storage of blood.  
This is not necessarily the same thing as infectivity!  Various studies 
have specifically addressed this question, as it is important when we 
consider the modes of specimen handling in clinical trials, and so on.  
Representative examples are:

J Clin Microbiol 1998 Feb;36(2):493-498 
J Clin Microbiol 1997 Nov;35(11):2886-2893 
J Clin Microbiol 1996 Sep;34(9):2312-2315 
J Infect Dis 1993 Nov;168(5):1269-1272 
J Infect Dis 1993 Jan;167(1):210-212 
(You can find abstracts for these articles on Medline at:http://www4.ncbi.nlm.nih.gov/PubMed/

The message in general is that efficient culture of HIV from blood is 
impaired after only a few hours at room temperature, although "complete" 
decay of the virus was not seen even after 7 days in one study.  Storage in 
the refrigerator definitely helps maintain the virus, since it is in fact 
being actively degraded in the blood (activities inhibited by the cold).  
Storage in the freezer after separation of the plasma is best of all.  When 
the assay measures the viral nucleic acid (which does not require viable 
virus) there seems to be a greater stability, such that virus can be 
detected fairly reliably after even a few days at room temperature.  Even 
for these assays, though, most reliable and stable results are obtained 
with specimens kept cold and separated soon after collection.

There are definitely other factors that effect the stability of virus 
during storage.  For example, the lower the white blood cell count, the 
longer the virus survives.  Thus, I am reluctant to give a simple number to 
describe how long the virus survives in blood.  If the above comments are 
not enough information, please consult the references listed, as well as 
others therein.  And again, it is important to remember that you must 
consider any HIV-infected blood to be infectious no matter how long it has 
been stored!

Tom Wilson MD PhD