geoffrey modest medical blogs

  A recent Swiss article compared SARS-Co V-2 viral load by PCR versus the quantitative measure of infectious virus by cell culture, finding among other things a very poor correlation between the two, in this preprint, pre-peer reviewed article (see  covid PCR viral load vs culture medrxiv2022  in dropbox, or  https://www.medrxiv.org/content/10.1101/2022.01.10.22269010v1.full.pdf ). thanks to Jon Pincus for bringing this to my attention   Details : -- 384 patients had nasopharyngeal swabs for SARS-CoV-2 daily during the first five symptomatic days of Covid-19. All had mildly symptomatic Covid infections      -- 118 unvaccinated individuals infected with pre-VOC SARS-CoV-2 ( pre-Variant-of-Concern,  i.e. basically the original, wild type virus)      -- 248 patients had the delta variant, 127 of whom were unvaccinated/121 had had two vaccinations at least 14 days prior and subsequent breakthrough infections   ...

  a recent mathematical modeling study suggested tweaking the current quarantine recommendations in the hopes of decreasing quarantine times by adding testing strategies, especially important with our current huge surge and more indoor exposure during  the upcoming holidays and prolonged winter,    (see  covid quarantine testing strategies medrxiv2020  in dropbox, or doi.org/10.1101/2020.10.27.20211631 )    Details:  -- the recommendation in general is to self-quarantine for 14 days after an exposure to someone who has Covid-19, per the CDC  -- the goal of this current mathematical modeling study is to blend the time of self-quarantine along with SARS-CoV-2 testing, to achieve optimal risk reduction for post quarantine transmission (PQT) of the virus  -- the current modeling assumes a one-day delay for testing results  -- they also assume that PCR specificity is 100% -- these models were based on clinical studies over time, fin...