WEBVTT - How Long Can Viruses Last on Surfaces? 0:00:01.920 --> 0:00:06.480 Welcome to brain Stuff production of I Heart Radio. Hey 0:00:06.559 --> 0:00:09.879 brain Stuff, Lauren Bogle Bomb here Today we're kicking off 0:00:10.000 --> 0:00:13.480 mini series of health and safety topics surrounding the novel 0:00:13.520 --> 0:00:18.200 type of coronavirus identified in which causes what's therefore being 0:00:18.239 --> 0:00:22.240 called COVID nineteen. Because everything is a little less scary 0:00:22.320 --> 0:00:26.920 when you understand it better. So first up, let's talk 0:00:26.960 --> 0:00:31.280 about how long viruses can live on surfaces. Because between 0:00:31.320 --> 0:00:34.400 all those door handles, credit card keypads, and even our 0:00:34.440 --> 0:00:37.760 own cell phones, we interact with so many surfaces daily. 0:00:38.280 --> 0:00:40.239 I mean, even if you don't hand your phone over 0:00:40.280 --> 0:00:43.080 to everyone you meet, you probably put it down on, say, 0:00:43.159 --> 0:00:45.839 a table that other people have touched. And that's a 0:00:45.920 --> 0:00:49.919 fact of life. But some of what we colloquially call germs, 0:00:50.120 --> 0:00:53.280 that is viruses, bacteria, and other microbes that can cause 0:00:53.320 --> 0:00:57.600 infections in our bodies, some germs can survive on surfaces 0:00:57.600 --> 0:00:59.920 outside of our bodies long enough to spread from one 0:01:00.120 --> 0:01:04.679 person to another. There's unfortunately no hard and fast rule 0:01:04.800 --> 0:01:08.360 for how long viruses in general can live on surfaces. 0:01:08.880 --> 0:01:11.640 Part of the uncertainty is because viruses are diverse and 0:01:11.680 --> 0:01:15.440 have a variety of surface survival rates. The type of surface, 0:01:15.440 --> 0:01:18.680 and environmental temperature and humidity all come into play too, 0:01:19.360 --> 0:01:22.720 so which surfaces are safe to touch and how often 0:01:22.840 --> 0:01:26.360 do we need to disinfect them? But wait, let's back 0:01:26.440 --> 0:01:29.600 up a step. What are viruses and are they even 0:01:29.640 --> 0:01:33.720 alive in the first place. Things that we generally consider 0:01:33.800 --> 0:01:36.960 to be living have the more or less standalone ability 0:01:37.000 --> 0:01:41.800 to eat, grow, and reproduce. A single celled bacterium or fungi, 0:01:41.920 --> 0:01:44.000 or even a cell from your body can do all 0:01:44.040 --> 0:01:47.520 those things because they contain the genetic instructions to do so, 0:01:47.800 --> 0:01:52.639 plus the enzymes to carry out those instructions. But viruses don't. 0:01:53.320 --> 0:01:56.600 They have the genetic instructions the DNA or RNA, but 0:01:56.640 --> 0:01:59.280 they don't have the right enzymes to create the chemical 0:01:59.400 --> 0:02:04.840 reactions necessary for reproduction. Instead, viruses need a host cell, 0:02:05.160 --> 0:02:08.440 which can be bacteria, fungi, or a planter animal including 0:02:08.440 --> 0:02:11.920 a human. Virus will attack a host cell and release 0:02:11.960 --> 0:02:15.680 its genetic instructions, which hijack the host cells enzymes to 0:02:15.880 --> 0:02:19.280 make new viruses. That's good for the virus but generally 0:02:19.320 --> 0:02:22.760 bad for the host. Without a host cell, a virus 0:02:22.840 --> 0:02:26.320 can't survive long term. However, it does have a short 0:02:26.360 --> 0:02:28.960 window of time during which it can stay functional in 0:02:29.080 --> 0:02:31.600 hopes of infecting a new host and attaching to a 0:02:31.680 --> 0:02:35.880 host cell. Outside of a host, viruses can either stay 0:02:35.919 --> 0:02:39.360 intact and remain infectious, or they can degrade to the 0:02:39.360 --> 0:02:42.799 point that they're merely identifiable, which means that you'll still 0:02:42.800 --> 0:02:45.480 be able to identify them from their genetic material, but 0:02:45.560 --> 0:02:49.000 they won't be capable of seeking out and attacking host cells. 0:02:49.760 --> 0:02:51.520 At the point that a virus on a surface is 0:02:51.520 --> 0:02:55.600 only identifiable, it won't be able to cause harm. The 0:02:55.720 --> 0:02:58.680 length of time that viruses can remain infectious on surfaces 0:02:58.800 --> 0:03:04.680 varies greatly. There are baseline differences between viruses. For example, rhinoviruses, 0:03:04.800 --> 0:03:07.640 the viruses that are mostly responsible for the common cold, 0:03:07.840 --> 0:03:11.399 will last for less than an hour on surfaces. Others, 0:03:11.440 --> 0:03:13.960 such as the norovirus, which is a virus that can 0:03:14.000 --> 0:03:17.480 cause vomiting and diarrhea, can last for weeks, which is 0:03:17.480 --> 0:03:21.040 why noravirus can easily spread both through infected people and 0:03:21.120 --> 0:03:27.040 through contaminated foods and surfaces. There are several types of coronaviruses. 0:03:27.480 --> 0:03:31.280 Most cause mild symptoms and are responsible, along with rhinoviruses, 0:03:31.400 --> 0:03:34.120 for the common cold, but three types are known for 0:03:34.160 --> 0:03:39.120 causing more serious diseases mers, SARS and COVID nineteen, and 0:03:39.480 --> 0:03:43.480 because the coronavirus that causes COVID nineteen is novel, the 0:03:43.560 --> 0:03:46.320 research into how long it can last on surfaces is 0:03:46.440 --> 0:03:52.440 new and ongoing. A study published online on marcht by 0:03:52.520 --> 0:03:55.760 researchers at the National Institutes of Health, the US Centers 0:03:55.760 --> 0:03:59.600 for Disease Control and Prevention, and multiple universities compared the 0:03:59.640 --> 0:04:03.680 novel coronavirus with the coronavirus that causes severe acute respiratory 0:04:03.720 --> 0:04:08.120 syndrome or STARS. This is the most closely related human 0:04:08.120 --> 0:04:11.600 coronavirus to COVID nineteen and was responsible for the two 0:04:11.600 --> 0:04:15.520 thousand three epidemic. This study, which has not been peer 0:04:15.520 --> 0:04:18.599 reviewed as of this recording, found that the two viruses 0:04:18.680 --> 0:04:22.040 have similar viability in the environment, which is to say, 0:04:22.240 --> 0:04:26.640 not a whole whole lot something between rhinovirus and neurovirus. 0:04:28.040 --> 0:04:31.159 The study determined that novel coronavirus could remain infectious for 0:04:31.279 --> 0:04:34.880 up to three days on stainless steel and plastic surfaces, 0:04:34.920 --> 0:04:38.240 but survival on other surfaces was lower, just one day 0:04:38.240 --> 0:04:41.200 on cardboard and four hours on copper, and it was 0:04:41.279 --> 0:04:44.120 lowest of all in the air just up to three hours, 0:04:44.839 --> 0:04:47.280 but keep in mind that these numbers are the maximum 0:04:47.320 --> 0:04:50.400 for the viability of the virus. Viruses start to degrade 0:04:50.480 --> 0:04:53.560 pretty immediately when they're not in a host. The longer 0:04:53.600 --> 0:04:56.880 they're in the air or on a surface, exponentially fewer 0:04:56.920 --> 0:05:00.320 of them will remain infectious. And if your imman system 0:05:00.360 --> 0:05:03.320 is working okay, a lot of individual viruses need to 0:05:03.320 --> 0:05:06.120 get into your body, either via your mucous membranes like 0:05:06.200 --> 0:05:08.560 your eyes, nose, and mouth, or via cuts in your 0:05:08.560 --> 0:05:11.640 skin in order for you to get infected. That's why 0:05:11.720 --> 0:05:14.760 direct person to person contact is still the easiest way 0:05:14.800 --> 0:05:17.880 for coronavirus to spread, and why everyone's telling you to 0:05:17.920 --> 0:05:21.240 wash your hands before touching your face. It's also why 0:05:21.279 --> 0:05:24.360 we don't have more precise numbers for how long coronavirus, 0:05:24.440 --> 0:05:26.600 or any virus for that matter, no matter how long 0:05:26.640 --> 0:05:31.280 they've been studied, can last on surfaces. We spoke via 0:05:31.320 --> 0:05:35.440 email with Dr Alicia Kray, postdoctoral fellow in epidemiology at 0:05:35.480 --> 0:05:40.520 Emory University. She said, generally, survival of pathogens on famites, 0:05:40.640 --> 0:05:43.800 which are objects or materials likely to carry infection, is 0:05:43.880 --> 0:05:46.920 determined by inoculating a surface with a known quantity of 0:05:47.000 --> 0:05:50.280 virus and then sampling at various time intervals to determine 0:05:50.320 --> 0:05:54.240 the amount recovered. Scientists use this information to estimate a 0:05:54.279 --> 0:05:57.440 decay curve for the pathogen on the particular surface, which 0:05:57.480 --> 0:06:02.520 can be extrapolated to longer time in vals. The NIH 0:06:02.640 --> 0:06:06.200 and CDC team that studied surface variation for coronavirus is 0:06:06.240 --> 0:06:10.960 still researching. They're looking into coronavirus viability from snott versus 0:06:11.000 --> 0:06:15.159 flegm versus poop, as well as in varying environmental conditions. 0:06:15.880 --> 0:06:19.919 Because although viruses have differing baseline rates of survival on surfaces, 0:06:20.160 --> 0:06:23.360 additional factors affect their ability to endure outside of a host, 0:06:23.520 --> 0:06:28.400 like temperature, humidity, and properties of the surface itself, Cray said. 0:06:28.839 --> 0:06:33.080 In general, viruses survive longest at lower temperatures, higher humidity, 0:06:33.120 --> 0:06:37.000 and on non porous surfaces like stainless steel. However, some 0:06:37.080 --> 0:06:40.960 viruses do well at low humidity. There have been a 0:06:41.000 --> 0:06:44.160 lot of theories about whether coronavirus will lessen during warmer 0:06:44.160 --> 0:06:47.560 months because dry, cold air like in the winter tends 0:06:47.560 --> 0:06:51.480 to provide favorable conditions for flu transmission, but we simply 0:06:51.520 --> 0:06:55.440 don't know yet. Dr Anthony Fossey, Director of the National 0:06:55.480 --> 0:06:59.600 Institute of Allergy and Infectious Diseases explained during the March thirteen, 0:06:59.720 --> 0:07:03.880 twenty c in Facebook Global Coronavirus town Hall that when 0:07:04.000 --> 0:07:08.000 considering the viability of a virus on various substances, it's 0:07:08.040 --> 0:07:11.880 probably measured in a couple hours. While he recommends wiping 0:07:11.880 --> 0:07:14.800 down surfaces like door knobs and cell phone screens when 0:07:14.840 --> 0:07:18.280 you can, he cautioned against worrying about things like money 0:07:18.360 --> 0:07:22.400 and mail in the end. Despite the differences in viability 0:07:22.480 --> 0:07:26.840 on surfaces among pathogens, fomites, and contexts, the number one 0:07:26.840 --> 0:07:30.600 recommendation for preventing the spread of viruses is standard if 0:07:30.640 --> 0:07:33.280 you've touched a shared surface, wash your hands before you 0:07:33.320 --> 0:07:35.240 touch your face or any part of your body that 0:07:35.360 --> 0:07:38.440 might have a cut or other skin abrasion. The human 0:07:38.480 --> 0:07:41.040 skin is great at keeping out cold and flu viruses 0:07:41.440 --> 0:07:44.080 thanks to its pH and porous nature. They survive for 0:07:44.160 --> 0:07:52.120 only about twenty minutes on our hands. Today's episode was 0:07:52.120 --> 0:07:54.960 written by Carrie Whitney, PhD and produced by Tyler Clang. 0:07:55.280 --> 0:07:57.040 For more on this and lots of other topics, visit 0:07:57.080 --> 0:07:59.520 how stuff works dot com. Brain Stuff is production of 0:07:59.560 --> 0:08:01.880 I heart Rate Dio. For more podcasts. For my heart Radio, 0:08:01.960 --> 0:08:04.520 visit the heart Radio app, Apple podcasts, or wherever you 0:08:04.520 --> 0:08:05.720 listen to your favorite shows.