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 a Quick summary of covid literature so far by two HIV clinical fellows at Boston hospitals have recorded a biweekly deep dive into the most compelling COVID-19 data. this is snapshot as at may 18 2020 this is page 3 so there is more -- move left at bottom of page

https://www.medscape.com/viewarticle/930588#vp_3

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Here are some key points from our first three presentations that are still valid.Viral Shedding: Key Points

• Nasopharyngeal viral load peaks around 1 day prior to symptom onset, correlating to peak time of infectiousness.
• Saliva may become an important sampling site for diagnosis.
• SARS-CoV-2 is a descending infection; in later disease, viral loads are higher in the lower respiratory tract (especially in severe/critical illness).
• In mild cases, live virus is isolated up to day 8 after symptom onset.
• There can be prolonged shedding of viral RNA lasting many weeks, particularly after critical illness. Correlation with infectiousness is unknown.
• Studies differ on whether severity of illness correlates with viral load.
• In some cases, viral RNA has also been identified in the stool, blood, conjunctiva, urine, cerebrospinal fluid, and pleural fluid.

SARS-CoV-2 Seroprevalence

• Studies with (near) universal screening of various populations are increasingly available, finding a wide range of asymptomatic people with positive RT-PCR tests.
   
  • Pregnant women in NYC: 13.5% (87% of total infections)
  • Homeless shelter in Boston: 36% (great majority of infections)
  • Town in Italy: < 1% (41% of total infections)
  • Iceland: < 1% (43% of total infections)
  • Diamond Princess cruise ship: 9% (46% of total infections)
• Varying rates relate to local stage of epidemic, population and sampling, and mitigation strategies in place.
• Some asymptomatic people are likely to be presymptomatic given the variable and sometimes lengthy incubation period.

Viral Entry: Key Points

• ACE2 is an important receptor for viral cellular entry.
• TMPRSS2 primes the S protein and allows for efficient cellular entry.
• An interaction between SARS-CoV-2 and CD147 may facilitate invasion.
• Many unresolved questions remain regarding the exact role of CD147 in viral entry. Does it directly interact with the S protein or is the interaction mediated by CypA and the N protein, as was found for SARS-CoV?

What Else Have We Learned?Key observations from our first three updates that are still relevant:

• Peak infectiousness is probably 1 day prior to symptom onset.
• In the absence of therapy/vaccine, intermittent social distancing is likely to be needed for years to avoid overwhelming critical care capacity.
• Emerging pathologic correlates of clinical presentations:
   
  • Multiple mechanisms of cardiac injury
  • Virus can cause systemic infection
  • Viral endotheliitis and possible complement activation as cause of micro/macro thromboses
• Obesity is a risk factor for severity of disease.
• Hypercoagulability is a key feature of the disease.
• Age-based sheltering is unlikely to be effective without social distancing.
• Epidemic control is feasible with contact tracing if minimal delay is achieved.
• Asymptomatic/presymptomatic transmission is substantial.
• The incubation period is highly variable (median, 5 days).

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here is the table key findings in mode of transport, and the clinical course

all taken from the summary link in main post