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The Centers for Disease Control and Prevention on Wednesday expanded how it defines a “close contact” of someone with Covid-19 as it released new evidence showing the coronavirus can be passed during relatively brief interactions.

Previously, the CDC described a close contact as someone who spent 15 minutes or more within six feet of someone who was infectious. Now, the agency says it’s someone who spent a cumulative 15 minutes or more within six feet of someone who was infectious over 24 hours, even if the time isn’t consecutive, according to an agency spokesperson.

Close contacts are those who are tracked down during contact tracing and are recommended to quarantine.

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The announcement from the CDC comes as scientists described in a new study how a correctional officer in Vermont appears to have contracted the coronavirus during “multiple brief encounters” with six incarcerated people who had Covid-19. The infected people were awaiting the results of their Covid-19 tests while the interactions happened.

In the study, the authors — including officials from the CDC and Vermont’s health and corrections departments — noted that the data for defining a close contact have been limited. “A primary purpose of contact tracing is to identify persons with higher risk exposures and therefore higher probabilities of developing infection, which can guide decisions on quarantining and work restrictions,” they wrote, adding that “public health officials should consider transmission-risk implications of cumulative exposure time within such settings.”

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Experts have long noted that the 15-minute, within-six-feet rule was not some sort of threshold that needed to be hit for transmission to occur. So much about whether spread happens depends on how infectious a person is, how well-ventilated the room that people are in is, how the virus might move through the air in a particular setting, whether people are wearing masks, and more. The 15-minute window had just been used as a benchmark to prioritize who should be followed up with for contact tracing and quarantine.

One reason why the length of interactions might matter, experts think, is because people need to be exposed to a certain level of virus if they’re going to get infected. Researchers still aren’t sure what that “infectious dose” is — and if a higher dose corresponds to how sick people are likely to get — but the thought is that the longer someone is around someone else who is infectious, the higher level of virus they will be subjected to, and the more likely they are to get Covid-19.

After the officer was diagnosed with Covid-19 in August, health officials and staff at the correctional facility reviewed surveillance footage of his interactions with the six incarcerated people. Though he never spent 15 straight minutes within six feet of any one of them, he was within six feet of them at least 22 times during one eight-hour shift, totaling at least 17 minutes of exposure. During their interactions, the incarcerated people were wearing masks most, but not all, of the time, while the officer always had a microfiber cloth mask, gown, and eye protection on.

The correctional officer had no known contact with anyone else with Covid-19 and coronavirus cases were low in his home county and in the rest of the correctional facility at the time, leading researchers to rule that his case most likely came over the brief encounters.

The new study “adds to the scientific knowledge of the risk to contacts of those with Covid-19 and highlights again the importance of wearing face masks to prevent transmission,” the CDC spokesperson said.

This story has been updated with more details about the CDC’s announcement.

  • Masks protect other people by preventing the moisture in your breath – and the germs sticking to it – from shooting out in all directions. My mask protects you, your mask protects me (and my elderly clients), but only if you wear it right! If you’re feeling air around the sides or top of your mask, try again.

  • There is nothing in this study that supports wearing a face mask. This was an investigation of the behaviors of the guard. There was no control group without masks to even begin to say masks are helpful.

    • Answer this…how are cold and flu transmitted? By coughing, sneezing, and touching objects. It stands to reason Covid is transmitted the same but is worse. So if you don’t want to wear a mask, then use one properly now so we can all do our part in getting back to a normal way of life.

  • I cant believe nobody thinks they can catch the virus getting gas ,shopping for food or touching things without GLOVES ON ?

    • Gloves only work when they’re changed or properly washed after an item is touched. Every. Single. Item.

  • It’s always some new thing. They change their minds constantly. Just shut everything down a few weeks, just social distance, keep our elderly locked up and away from their loved ones, give our children health problems and anxiety by sending them back to school with mask mandates, just another month….and on and on it goes never ending. People speak up take a stand – this is not just about protecting each other anymore ( not they it ever was)

    • They’re not “changing their minds”.
      They are gaining new information, and adjusting prior understanding.
      It’s called learning from new information (instead of having a mind that is closed to new input).

    • Please, please understand that it isn’t them changing their minds, but rather as they see and observe different aspects in just how this virus manages to infect, that is helping us in learning more and more about it! We do not live in a vacuum as you are aware. Therefore, organisms (all organisms) move. Therefore, when coming upon a new and deadly organism such as this novel corona-type virus is, we observe more about it. Unfortunately, except for vaccine trials, we only have the public and medical personnel who contract it, in order to “trace” how it was contracted. We are not gods, the CDC is not god, the WHO aren’t god-people. They are scientists observing and noting what is happening. How is this not understandable?

    • I fail to see how this actually helps the argument for masks. If the CO had a eye covering, mask and gown while he was dealing with inmates who almost all wore masks how was he able to get covid so quickly. He probably got it from a touching his mask, eyewear etc.

  • Here we go again. Moving the goal post to fit their need. Data shows that 99.9% of people ages 0- 19 will survive the Wuhan flu. 99.8% ages 20 – 39 survive. 99.5% ages 40-59 survive and so on. Yet we ar all told to shut up…put your mask on…You have no first amendment. The Constitution is a living document that can and will be interpreted the way the libtards want so long as it supports their adgenda, which is to destroy free will and thinking in the USA. Give me a break. Give me the data and let me decide how to best live my life. I swore an oath to defend the constitution of the United States against ALL enemies, both foreign and domestic. Well we can clearly see who the domestic threat is. Re-elect Donald Trump and let’s all MAGA.

  • Researchers aren’t sure. They think. The thought is that….
    The officer had a positive test. Didn’t say whether he was actually sick. He wore a mask the whole time and the others did almost the whole time yet he still has a positive test. How does this support mask wearing?
    This whole thing is utter nonsense and beds to stop. Journalists, quit fear mongering!

  • Listen. The CDC is getting pretty ballsy with their “suggestions”. They have “suggested” MANY things over the last several months and NONE of it is based in general reality. They are under controlled conditions and reflect nothing about the true nature of this nonsense. You wanna talk about “misinformation”… reporting information being derived from the CDC is hearsay at best. They have failed to deliver accurate information and in any reasonable amount of time, with any consistency. It’s just WE who have believed their dribble and ignored the failures OVER and OVER and OVER cause “CDC”. F##K that noise.

  • I just don’t get how couples who sleep in the same bed can have one get the Chinese virus and the other doesn’t. I have known three such couples. The fear mongering continues.

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