Contamination Risk

[strangeproblems]

Hello Doc,

My question is in regards to a contamination risk.

If an environmental surface (ie. a countertop) contaminated with blood was BRIEFLY wiped down with an isopropyl 70% soaked prep swab and left to dry for a few minutes, could that surface still contaminate other objects with either HIV or Hepatitis C?  For example, if a sterile needle was placed on that surface after the brief isopropyl wipe down, no visible blood was left present, and it had been left to dry completely, is it possible that that needle could be contaminated with enough HIV or Hepatitis C to cause infection if the needle was used?

Thanks

[Edward W Hook, MD]

Sorry, this is a "what if question" which has no context.  There is no way to anwer it.  It suggests however that you are having trouble moving on.  Please try. No further questins please, I answered the question.  EWH

[strangeproblems]

Thanks for your answer Doc!

Just a follow-up question;

Can microscopic amounts of blood infect someone with HIV?

[Edward W Hook, MD]

Such cleaning would assure you that HIV would not be transmissible from this surface.  There are several factors that contribute to this.  First the virus does not survive well in the environment.  It is susceptible to decreased temperature such as room temperature and to drying.  Second, the isopropyl alcohol is toxic to the virus.  Third, the act of rubbing with a paper towel, sponge or other removes the virus.  

Concerns about getting HIV or hepatitis from a contaminated surface are ill-founded.  No one has ever been infected in this way.  It is not something to worry about.  EWH