Expert: Terry B - 5/6/2007

Question
I noticed there was no direct answer for the following question you received on 1/02/07...

[Does HIV survive if frozen....I had someone helping me put packages of
frozen meat in the freezer, when he sliced his hand on a cardboard box.  
Do I need to be careful of any of the blood that may have gotten on the
packages placed in the freezer?]

If a small amount of blood was transferred to a frozen food, like the box in the example above, and the food was then consumed while frozen (ice cream, frozen grapes, cookie dough, etc.) would there be a risk for HIV/AIDS transmission, assuming the blood was infected, once the "thawing" takes place inside the body?

This question sounds strange but there's a real world incident behind it.  Thanks!

Answer
Dear Donovan:

Peace.  

I did not receive nor answer the earlier question, and as a health professional with experience in infection control, one should be careful about exposure to human blood.  HIV can survive freezing in blood and plasma; in transfusion medicine, blood is routinely tested for antibodies to HIV and other diseases.

As for a second question, which appears to be "What is the relative risk of HIV infection from ingesting small amounts of HIV infected blood?", I can give you a partial answer and also recommend you review answers here and go to a website (http://www.cdc.gov/hiv/) that has a wealth of information.

One reason that (had you asked me,) I would not have been able to give you a direct answer:  I know of no study where human beings ingested small amounts of HIV infected blood to measure the rate at which this causes HIV infection.  As you can guess, such a study would be highly unethical because it would place subjects at tremendous risk.

Data about HIV infection is usually retrospective; asking about risk behaviors after a person is discovered to be infected.  If, for example, a person has engaged in fluid exchange without barrier protection, it would be assumed that this (being a known high-risk activity) is likely the behavior that placed her/him at risk and how transmission occurred.  Persons who report that their only known risk is performing oral sex make up only a portion of the cases of known HIV/AIDS.  In reports surveying woman who became infected while nursing their infants, about 22% (Nairobi) passed the virus to their children.  This means that 78% of infants who took in HIV infected breast milk on a regular basis every day did not become infected.   This does not mean that ingesting blood, semen, vaginal secretions, and/or breast milk from an infected person is a safe activity.  

It does mean that one should examine the factors that contribute to an exposure becoming a transmission, including Route, Amount, Area, Duration, Frequency of Exposures.

I hope this helps.

Terry