Today marks 5 months from the date China notified @WHO of an outbreaks of atypical pneumonia in Wuhan. Since then 6.2 M cases and > 300K deaths have been notified from 213 countries (US 1.8 M cases and 105K deaths). We have learned a lot about #COVID19 since then:

Transmission: this is a respiratory infection with most transmission occurring from close contact "person-to-person" through respiratory droplets when the person talks or coughs. Is 6 ft distance enough to prevent transmission? Probably not which is why masks are recommended.

Transmission through contaminated surfaces where a person touches and then touches their mouth, nose or eyes is possible. How long viable virus remains on surfaces depends on the type of surface,, the temperature and humidity. Cleaning and hand hygiene important for prevention.

Clinical: the spectrum goes from asymptomatic to ARDS and multisystem organ failure. ~ 3-5% remain truly asymptomatic but close to 80% have mild disease. Moderate to sever disease requiring hospitalization occurs on 15 - 20%. CFR is still to be define but likely ~ 1-2%.

Treatment: for most supportive care. No drug has proven to be of value in outpatients with mild disease. In moderate to severe disease remdesivir offers some benefits but not in those intubated or on ECMO.

Prevention: nonpharmacologic measures of social distancing, masking and hygiene continue to be our only tools but vaccines are now in development and at least 3 candidate vaccines are expected to enter clinical trials this Summer/Fall.

For more in depth discussion please read the most recent @JAMA_current VP that @PreetiNMalani and I wrote and published online last week https://jamanetwork.com/journals/jama/fullarticle/2766600