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
There are techniques using genetic sequencing that can be used as viruses mutates very fast. So if the genes of the virus in person A and B is very similar then they got it from each other. However this is not used for fast spreading infections as this is costly and time consuming. Instead what is being done is just a simple assumption after an investigation. We can not know for sure but we can come up with some good assumptions if we know who have been in contact with who and when the people involved developed symptoms.
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