How do we know that Person B was infected by Person A, unless Person B went into quarantine directly after interacting with Person A? If they don’t go into quarantine, how do we know that a random Person C didn’t interact with them and cause the infection?
And for the vast majority of infections that can’t be contact traced like the example above, how do we determine the date they were actually infected if the disease can be transmitted asymptomatically?
In: Biology
Here’s the World Health Organization [basic explanation article](https://www.who.int/news-room/q-a-detail/q-a-coronaviruses). Covid19 is the same type of virus as SARS and MERS, so they have *some* experience with how it behaves and the typical incubation period.
Otherwise, we don’t know “for sure” that any individual person may or may not have been infected at a particular moment in time. It’s all statistical chances and probabilities, and the CDC / WHO and doctors in general have procedures that keep that in mind. They won’t test just persons A B and C, for example, but any others who have come into “close contact” with them, based on how the infection spreads (water droplets from coughing and sneezing, contact surfaces).
[The advice here](https://www.cdc.gov/coronavirus/2019-ncov/about/prevention.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fabout%2Fprevention-treatment.html) is actually what’s effective at stopping the spread and protecting you and everyone’s health. That page isn’t “opinions”, it’s *medical advice*. The doctors and health officials are taking it seriously, they’re not joking with it, they’re not cutting corners or holding back advice or instructions that could help.
Latest Answers