[Question #8111] HIV becoming more infectious
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48 months ago
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Thank you for taking my question. I read a Newsweek article from 2020 about how HIV in the US is becoming more infectious through natural selection and higher viral loads. Is this development something that would suggest the information about how HIV is spread and how easily it is spread is possibly no longer accurate? Would HIV be able to survive longer in an air exposed environment provided what is known from the study released?
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H. Hunter Handsfield, MD
48 months ago
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Welcome to the forum. Thank you for your confidence in our services.
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Both Dr. Hook and I are unaware of any scientific reports that suggest increasing transmissibility of HIV, or of improved survival of the virus in the environment, e.g. when secretions dry or are exposed to air. Indeed, we think it likely that overall HIV infection risks are decreasing in North America and Western Europe, and perhaps elsewhere as well -- the result of effective HIV treatment of infected persons and widespread use of anti-HIV drugs for pre- and post-exposure prophylaxis.
And what if sexual transmission risk were somewhat higher? Even if the risk were doubled, the average chance of infection of a male partner from unprotected vaginal sex with an infected woman would then be one in 1,125 instead of 1 in 2,500 -- still low on a per-exposure basis. And since HIV transmission virtually never occurs from non-personal exposure to the virus, e.g. in the environment or from contaminated surfaces etc, even a theoretical risk of such transmission doesn't seem worrisome.
I'll be happy to comment further if you could say more about the article you read, or perhaps a link to it. Until then, I really think this is nothing to be concerned about.
I hope these comments are helpful. Let me know if anything isn't clear.
HHH, MD
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48 months ago
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This was the article.
https://www.newsweek.com/hiv-getting-more-infectious-natural-selection-1481007
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H. Hunter Handsfield, MD
48 months ago
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Nothing posted.---
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48 months ago
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H. Hunter Handsfield, MD
48 months ago
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Thanks very much. I read the Newsweek article as well as the scientific paper on which it is based. Very interesting and sophisticated research by highly respected investigators from the University of California San Francisco and CDC's Division of HIV/AIDS Prevention. It's highly theoretical, but seems valid in concluding that, at a population level, the dominant HIV strains in the US may be evolving to be more transmissible and more virulent, i.e. more rapid disease progression in untreated infected persons. However, it says nothing about the mechanisms of increased transmission, nor the magnitude of the increase at a personal level, i.e. for individual sexual or blood exposures. Certainly nothing implies any change in the actual routes of transmission like particular sexual practices, or the amount of blood or sexual secretions needed for transmission. The results also do not imply increased survivability of the virus outside the body. And significantly, especially since the work comes in part from CDC, the study has not led to altered prevention advice or recommended strategies for HIV/AIDS control from CDC or other public health agencies. Finally, I'll add that the analysis is based on "large clusters" of HIV transmission -- which in the US almost certainly means mostly men who have sex with men; there are few sizable transmission clusters in risk groups other than MSM. So I would question the applicability of the study to heterosexual transmission or risks in injection drug users.
Accordingly, this does not alter my initial assumptions, or my initial advice above. I would not (yet) assume there has been any significant increase in the HIV transmission risk for any particular exposure; or if there is, it may be limited to the highest risk activities, like unprotected anal sex in men (which accounts for probably 80-90% of all HIV infections in the US and other industrialized countries). Perhaps that will come in the future if additional research addresses risks for particular kinds of exposure. For sure there is nothing that raises new concerns about virus survival outside the body or risks from environmental exposure to infected materials.
Thanks again. Let me know if you have any further comments or concerns.
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