Submitted by Terradubia t3_1065u1q in askscience
How long does HIV remain infectious in blood or semen, once it has left the body? Because some sources state that the virus is inactivated within minutes, while others state that HIV remains active for days (not only in syringes). Do you know the answer? I would appreciate your input!
Yeah, somehow all the quick internet answers are normally “it dies very quickly outside the body” but research indicated otherwise
Do not compare laboratory data with real life data. Just because a virus "survives" in a lab setting for weeks it does not mean that on a real life surface it will do the same.
We also saw this with the pandemic. Lab data showed survival on surfaces up to 3 months but not in real world setting.
Why not in real world setting?
Because the real world is far less sterile than in a laboratory. People come and go, UV exposure is a factor if outdoors (this was shown to play a huge role in rendering the virus inert, which is what fueled the outdoor dining surge during the height of the pandemic), and there are all kinds of surfaces that have some amount of anti-microbial properties as well. It's why doorknobs in hospitals were historically all made with brass (and many still are), because the copper content helps kill germs that get transferred to the knob as people open and close the door. The same goes for push plates on doors without knobs, railings in bathrooms and stairwells, and other common surfaces like cabinet handles. Stainless steel has taken over due to being cheap and easy to clean, but it's not the same in terms of killing stuff that's living on it the way bronze does. That said, there's research being done on ways to passivate steel (inhibit corrosion) using copper containing ions, to such a degree that it transfers this capability to the steel. Copper is already used in some bluing solutions for steel, but you'd probably need to use a lot more applications of it than you would just to blue the steel properly.
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From looking about articles on it seems that the virus doesn't survive for that long normally and the main form of transmission is from aerosolised droplets. The labs used unrealistic amounts of virus compared to real world settings
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the real world generally doesn't have surfaces that don't move and have a constant temp.
A glass dish in a temp controlled lab in a windproof box vs. a sneezed upon lamppost for example.
There's a range of factors that could create a gulf between detecting a viable virus in the laboratory and a real-world risk of infection. For degradation, the environment is likely to be much more tightly controlled in the laboratory (low UV, reduced airflow, ect.). For exposure, a hand briefly touching a surface is very different from doing an intensive swab. For viability, the virus may be encapsulated in the fomite in such a way that it doesn't release back into the body in a viable form.
the test was done in serum, unless you're storing bodily fluids it's not really the same.
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I don't think there is any known episode of surface transmission even documented for COVID. That doesn't mean it doesn't happen but it's exceedingly rare if it does.
Which makes all the wiping down and sanitizing people still do hygiene theater.
ETA lol people hate it when you tell the truth, and tell them their hand sanitizer and bleach wipe theater has no bearing whatsoever on covid risk. At some point ubiquitous dispensers of hand sanitizer became a performative way of saying "this business cares about your health," with little to no actual value except in a hospital or food service setting. Like so much else in our culture it's virtue signaling. If your business rally cared about Covid you'd have a masking requirement at all times for all people in the building, vehicle, or whatever. I laugh at people who don't bother to wear a mask but sanitize their hands a lot. There are other diseases that can help prevent, but not Covid. There's not one shred of evidence it helps.
Also gonna ruin your day: the dirtiest surface many of us touch every day is the top push button on a public hand sanitizer bottle. Think about it.if you really care about hand hygiene, soap and hot water are far more effective anyway. And any man could tell you how many fellow men don't wash their hands at all leaving a restroom.
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Survival doesn't mean it is likely to infect. Even if you can demonstrate that the virus stays intact in a dried blood stain, it is extremely unlikely to make it's way into your circulation from there. Since if you touch the dried stain, not much material will stick on your hands, and even if you managed to bring a few virus particles to your mouth by accident, it is not very contagious via the oral route (compared to direct blood contact or vaginal or anal intercourse).
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My understanding is that it is not even common to pass it on sexually. Perhaps there is more recent info but I recall reading research before that transmission from an infected person to a non-infected person was 1% or less (though this number varied based on the type of sex and who the infectious one was) per sexual encounter.
To be clear, if the HIV+ person is under treatment and is "Undetectable", there have been no cases of transmission -- none, never, even with unprotected sex.
Although since medicine never says never, it is still recommended to use condoms.
I have no idea of the transmission rate between an HIV+ person and an as-yet infected person, such research would be unethical in the extreme. But it would depend on the viral load of the infected person, the type of sex, etc. Many factors.
The question of the virus living outside the body is anything from minutes to days (is the area in full sun, is it subjected to temperature differences/extremes, is the area being cleaned at all, etc.). Many factors. One thing would be difficult though is having the virus get from this point into a mucosal lining of another human.
Anyway, I am sure there is context to the question being asked that would allow for a more scientific answer.
Yeah, it's pretty low, especially for a male having vaginal sex with an infected female.
What was really shocking to me is that when I was growing up just as the AIDS epidemic really took off in the 80s, I was under the impression that heterosexual transmission was extremely high, to the point where if you had sex with an infected person it was basically a death sentence. When I read actual transmission statistics decades later I was surprised that they're actually that low, relatively speaking to what I thought they were before.
IIRC a lot of this came from men infected with HIV that wanted to keep the fact they have sex with other men secret, so they attributed catching it to some unnamed female prostitute, and this skewed transmission statistics in M-F sex.
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If it's so low, why is it still here?
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Because as stated in the research above it was kept in serum. I don't know about you but the environment i live in has very little human cell compatible serum
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Lab environment isn't the same as in the world. There can be many factors that contribute to the inactivation of microbes: from the antimicrobial properties of some materials to the UV radiation of sunlight there's a huge difference in survivability when compared to a sterile and controlled environment like a lab.
General answers and advice is less restrictive than what is technically possible. I'll give a personal example. I have HSV2, but orally not on my genitals. Was trying to figure out the risk of spreading it oral to oral. General advice is not unless outbreak, but technically possible since research shows can have virus present without outbreak. Notably with oral HSV2 another outbreak is almost guaranteed not to happen (and I've never had one since and it's been about 10yrs).
In any event, I wasn't satisfied with the potential discrepancy and actually emailed researchers listed on papers and was pleasantly surprised by most responding. My take away was that while none wanted to give me advice beyond referring to official sources (which for HSV2 is generally limited to genital contact), because can't rule out oral to oral happening. But they did note that if I ever thought I spread it via oral-to-oral to reach out to them because it would be a case they'd like to look into...
So outlier risk they can't rule out, but one that people shouldn't factor into their ordinary lives. So I have disclosed to all sexual partners (in certain cases preempting their status as a sexual partner, lol), but not a risk I consider otherwise with caveat of anyone I think may be immunocompromised.
It’s notoriously fragile outside in vivo. The chances of transmission from blood/bodily fluid outside body is <1/1000. Even a blood needle sticks are ~.5%, or 1/200
Regarding "sufficient number".
Please excuse my very lame question, but i am genuinely interested.
If there is an ideal infection event but number of virus particles is small.
Does it mean the immune system can deal with them?
sometimes! i don’t know specifically for HIV how many particles are needed to infect. but i know for norovirus it’s something wild like only 10 viral particles need to enter the body to cause infection. this is the same for shigella, about 10ish bacterial cells. comparing to salmonella which is like thousands of cells (different sources say different numbers but on average about 10^5 or 10^6 cells: 100,000 or 1,000,000). in the case of these 3 pathogens it’s different because they’re gastrointestinal & i think the number of cells has to do with survival in stomach acid (part of your immune system, called the innate part) but my point for saying all of this is that yes, at some point for all pathogens your immune system will kill all of the particles but the issue is when there are too many particles at once for it to kill. 1 particle of a pathogen, yeah you got this. 2 particles? probably. 100 particles? not so sure. because another factor that comes into play is how good the pathogen is at evading the immune system. for the example i used above, shigella isn’t as affected by stomach acid as salmonella is, so shigella can “evade” by surviving and entering your intestine which is why only small numbers are needed to infect. on the other hand salmonella isn’t so good at evading the immune system/the stomach acid, so you need like a hundred thousand cells because sooo many of them are going to be killed by the stomach acid that with a higher number of cells, there are higher odds that a few cells will survive and make it through to your intestine. with lower numbers of cells entering the stomach, the odds are higher that the stomach acid will destroy all the cells and none will make it to your intestine, therefore you do not get sick bc your immune system/stomach acid worked!
i hope this helps explain the general concept even though i could not focus on HIV specifically. feel free to ask me any more questions (even if you think they’re lame - they’re not!! i love explaining and talking about micro stuff!!) and if there is something specific you really want to know i can help you find good sources that explain it
EDIT: i also forgot to add because i haven’t seen it really spelled out in the few comments i’ve read. but for pathogens living on surfaces, if the surface is “clean” it’s generally harder for a bug to survive a long time (“long time” being different for each pathogen) but if a surface is “dirty” it is generally easier. so by dirty, i mean if there is actual dirt or biological material, like dried blood or body fluids. so to help you picture it, at home let’s say you want to disinfect your stove top but there is dried food all crusted on. that is a “dirty” surface because of the dry food. and in order to disinfect, you need to first clean the surface to remove all crusty food & once you do that it is a “clean” surface. then you can disinfect properly. the reason you can’t disinfect straight away on a dirty surface is that whatever Stuff is on there can provide some sort of environment or nutrient etc to pathogens and it’s hard to penetrate the Stuff with disinfectant, so you first need to clean to remove the Stuff which removes a safe spot for the pathogen, and then when you disinfect there is no Stuff to penetrate and you can ensure disinfectant remains on the surface for the given contact time
Thank you so much for your time and explanation!
Not a lame question at all! It’s astute. Viruses differ in the amount of virions necessary to cause infection because the immune system sometimes does have the ability to fight a particular virus before you get symptoms.
In the case of HIV, HIV positive people on Prep or other drug therapy AND with a very very low titer have been shown to not transmit the virus to intimate partners.
Measles requires a very low amount of virus to cause illness while a fairly large dose of rhinovirus can be handled by the immune system without causing symptoms.
Viruses and our immune systems are fascinating and I could go on all day! Lol
Thank you for very valuable answer!
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How fast or slow has the "virus" been shown to move on the surface? What happens if the "virus" come in contact with blood on tbe surface? Does the "virus" cause the blood to attack it? Or will the virus overcome and replicate in the pool of drying blood?
One statement that comes to mind in regards to your last paragraph is that HIV is an opportunistic virus.
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Ive heard by many nurses that sex within the hospital campus amongst hospital staff (ie nurses, doctors, cnas, food service workers) is a widely known phenomenon
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This article and the references listed on the bottom should help you get started. The answer seems to be “it depends”. Dried body fluids loose infectiousness quickly, but the virus can survive for weeks under the right conditions.
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You guys didn't receive any help or guidance with this from police/emt?
This was a public safety hazard. Crazy and sorry you had to see that.
Did that catch the killer?
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HIV, the virus that causes AIDS, is a fragile virus that does not survive long outside the body. HIV is transmitted through certain body fluids, including blood, semen, vaginal secretions, and breast milk. HIV is not transmitted through casual contact, such as shaking hands or sharing food.
In general, HIV is not considered infectious outside the body. HIV does not survive well in the environment and is quickly destroyed by exposure to air, heat, and sunlight. HIV is also easily killed by most household disinfectants and cannot be transmitted through food or water.
It is important to note that HIV can be transmitted through the sharing of needles or other injection drug equipment, as well as through sexual contact. It is important to use proper precautions and to engage in safer behaviors to reduce the risk of HIV transmission.
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1UpQuark t1_j3f8w3p wrote
In summary -HIV can survive on surfaces for extended periods, especially if associated with cells (blood, sperm). A consideration is how much HIV is present -low tiger or high titer. See This link is to a review (1991) of survival in various environments (including whole blood). (The link title is wrong but the link is good) https://www.researchgate.net/profile/Syed-Sattar/publication16877227_Rotavirus_inactivation_by_chemical_disinfectants_and_antiseptics_used_in_hospitals/links/59df5783aca27258f7d77fb6/Rotavirus-inactivation-by-chemical-disinfectants-and-antiseptics-used-in-hospitals.pdf
This from a primary journal article: Journal of clinical microbiology 32 (2), 571-574, 1994 Cell-free and cell-associated human immunodeficiency virus cultures suspended in 10% serum remained infectious for several weeks at room temperature. The stability was further increased when cell-associated virus was suspended in neat serum. When dried onto a glass coverslip, virus remained infectious for several days, although cell-associated virus lost infectivity more rapidly than cell-free virus.
Happily-no evidence of transmission via a surface in non-healthcare related situations has been shown. A few cases of “mystery” transmission in healthcare settings were noted. Don’t forget-the dried material would have to contact mucosal membranes, open wounds, or genital mucosal linings if sufficient amount to causes infection.
Hope this helps.