Recent comments in /f/askscience

nicktheone t1_j3ggg4y wrote

Reply to comment by cristiano-potato in How long does HIV remain infectious outside the body? by Terradubia

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.

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QuietGanache t1_j3g6z4e wrote

Reply to comment by Dhonnan in How long does HIV remain infectious outside the body? by Terradubia

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.

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Faxon t1_j3g6z1p wrote

Reply to comment by Dhonnan in How long does HIV remain infectious outside the body? by Terradubia

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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