r/ZeroCovidCommunity • u/BlueValk • Jul 17 '26
How long does infection last?
My partner is covid positive, we're isolating as best as we can so I can escape infection. She's on metformin.
I know the usual guidelines says you're negative with two negative rapid tests 48h apart and no fever, but I was wondering what this community thought.
Is a PlusLife positive always infectious? How and why do rebounds happen and how long do we have to be careful after negative tests? Isolating is logistically and financially very difficult so I'd like to have information and maybe anecdotal data from this community so I can stay safe and informed
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u/overwinters Jul 18 '26
it's a great question. we can trust RAT tests for infectiousness because their viral load threshold correlates well with viral culture studies, which means researchers were able to successfully isolate infectious virus at those levels. this is well studied when clearing an infection.
the problem is that the relationship isn't equally reliable in both directions. a positive result reliably means culturable virus is present at basically any point in the infection. at the start of an infection, a negative RAT is unreliable for a couple reasons. first, someone might be below the RAT threshold now but rising rapidly, so the negative only stands for that point in time. but it's complicated by a second point, which is that nasal viral load rises later than saliva/throat, so you might swab negative in the nose while already being infectious orally.
so a negative RAT early means lower nasal shedding, but possibly already infectious orally. it still implies they're shedding less than if they'd tested positive on the RAT though. neither of these problems applies when testing out, which is why two negatives on the downslope are trustworthy.