[Question #2110] HIV infectiousness

45 months ago

Dr. Hook or Dr. Handsfield,

I attempted to use the search function to find an answer to my question but was unable to locate any question related to my concern. Let me briefly provide you some context and then get to my question. I have been diagnosed with OCD (after being previously diagnosed with another anxiety disorder). In the course of my treatment, which has used primarily cognitive-behavioral work and self-acceptance, I have seen tremendous improvement. One feature of my previous work (when I was handwashing) was detailed information about the uncommonness of the bacteria I feared. As I am certain you doctors can imagine, this information did not end my washing behavior. But it did dramatically reduce it and my anxious distress. I am hoping information you can provide me will be similar.


While my bacteria fears have decreased (along with my washing!) another fear has taken its place. My psychologist told me this is not uncommon and we will continue to identify thoughts and behaviors worth challenging. An ascendant fear is of contracting HIV via a needle stick. I check objects constantly and no longer wear flip-flops because of a fear of a needle stick I do not notice. I read elsewhere that the chances of being infected with HIV through a needle stick is one in three hundred. This one in three hundred number is comforting. And at the same time, I would like to see if I can get that risk any lower. What I mean is that I also read elsewhere that when HIV is outside of the body it becomes less infectious. I understand there are probably no studies with the precise measurements of the relationship between time and infectiousness, but I was hoping you could give me a general estimate of how long HIV might remain infectious in a needle I may encounter in a public setting such as a road, sidewalk, office building, or bathroom. Do you suspect HIV blood may be infectious within a needle for hours, days, weeks, or months? As stated, I now I cannot be certain. But if my past experience applies here, a better understanding of my risk has the potential to greatly reduce my distressful anxiety and problematic behavior.

Edward W. Hook M.D.
Edward W. Hook M.D.
45 months ago
Welcome to our Forum.  I'll try to help.  As you point out, context is important.  The 1 in 300 Infection rate you quote is the estimate of infection risk for health care associated needle sticks in which a used needle from an infected person sticks someone almost immediately after it is taken our of the infected person, I.e. The blood in the needle is "fresh".  With environmental needle sticks of the sort you mention you  should understand that not all needles contain HIV and that with time, the infectivity of the virus steadily declines over time.  As you suggest, there are no studies that I am aware of to provide a precise answer but, given that the virus becomes non-infectious almost immediately on direct environmental exposure, I would exppect virus in blood within the lumen of an infected needle to be non-infectious I hours.  I should add that while many of our clients worry about such exposures, I have never seen a patient acquire infection in this way.

I hope this comment is helpful.  EWH
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45 months ago
Thanks Dr. Hook. I suspected more or less what you pointed out, but it's reassuring to hear it from you. A follow up along similar lines: were I to be stuck with a needle, do you believe it's safe to say that any needle stick that poses a risk of infecting me with HIV would bleed? Or at least would bleed a few drops? I get worried about feelings and sensations on my skin. Thanks again.
45 months ago
Dr. Hook, I'd also like to obtain some general risk//advice from you. Sometimes while I'm at work or playing, I cut myself or scrape myself. Usually, I will use some hand sanitizer to disinfect my wound. If I cut myself am I at risk from HIV secretions? For instance, if someone used the hand sanitizer before me and got blood on the bottle, would I then be at risk for blood getting into my cuts or scrapes? When I write this, what I realize I am looking for is a risk assessment I can keep in mind in day to day activities about how I can be sure of my safety even if I have cuts or scrapes or come into contact with HIV secretions. Thanks for your help. I already feel much better regarding your initial answer.
Edward W. Hook M.D.
Edward W. Hook M.D.
45 months ago
Yes, I would say that for HIV transmission to occur, the needle would need to puncture the skin and draw blood.

Superficial scrapes and abrasions are listed as theoretical risk factors for HIV but this is overly conservative. Most people have scrapes and abrasions (and hangnails) which have never been shown to be risk factors for acquisition of HIV.  Your day-to-day activities should not put you at risk for HIV.  EWH
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45 months ago
Thanks Dr. Hook. Another clarification, in response to my initial question, one thing you wrote was, "I would exppect virus in blood within the lumen of an infected needle to be non-infectious I hours."

I think by "I" you meant "In" but I wanted to be sure. And by hours, am I correct in understanding that, although there are no studies so you cannot be sure, you suspect that blood in a needle would likely not be infectious after 24 hours? Or would you say even less? Thanks again.
Edward W. Hook M.D.
Edward W. Hook M.D.
45 months ago
Sorry for the typo.  You are correct, I meant to write "in" rather than "I".  My (educated) guess I that such blood in a needle would most often no longer be infectious at 24 hours but I emphasize that this is agues, nothing more.

As this question related to my typo I will not yet close the thread but gently pointing out that this in part related to your OCD, I will permit one more follow-up/clarification, then the thread will be closed.  EWH
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