Show-Notes from our first podcast: Coronavirus Science and Contagion, from our new series “Coronavirus: Science and Prevention”
Coronaviruses have been present on humans and animals since science has studied these viruses. (HCoV-) 229E is the endemic human CV that causes common colds and is always present within a human population.
- In 2002, MERS-CoV appeared as the Middle Eastern Respiratory Syndrome. It was carried from bats to dromedary camels (Arabian single hump camels) and then to humans via camel milk.
- In 2003, SARS-CoV (Severe Acute Respiratory Syndrome) appeared in China and is believed to have been passed from bats to civets (raccoon-like animal) and then to humans.
- Today, SARS-CoV2 (COVID-19, novel coronavirus 2019-nCoV) is the 2020 pandemic that originated in China’s Wuhan province.
Why social distancing, shutdown of public events, travel restriction, and self-quarantine?
- The goal is Flattening the Curve to avoid overwhelming the healthcare systems. Anthony Fauci, MD, Director of the National Institute of Allergy and Infectious Diseases at the NIH described that well in the media.
- Example of overwhelmed healthcare system – Italy.
- Example of successful measures limiting the disease – Taiwan
- Taiwan was hit with the SARS-CoV and therefore well-prepared for the current pandemic by implementing full measures at the start.
March 14, 2020 COVID-19 Data
|S. Korea||51 million||8,086||72||1%|
Transmission: mostly via cough and sneezing within 6 feet – via inhalation, or touching contaminated surfaces then eyes or nose.
Incubation period: 5 days average, 2-12 days in 99% (rarely up to 24 days).
Week One– Prodrome (symptoms before clinical signs): myalgias (muscle aches), malaise, cough, low grade fevers, sore throat. Symptoms such as nasal symptoms, nausea and diarrhea occur in <5% and are not dominant.
Week Two– respiratory problems begin, average of 8 -9 days until development of severe trouble breathing and pneumonitis.
Counting the number of cases is like looking at the light from a star. (Dr Matthew McCarthy, Ass Prof of at Cornell Medical Center). The cases you see are from contagion 2 weeks prior.
Severe Acute Respiratory Syndrome
Occurs in 20-30% of patients, requiring supplemental oxygen. The fatality is 1% – 2.3%.
Treatment includes mostly supportive care.
China: lopinavir-ritonavir – however, the efficacy is questionable
United States: Remdesivir (from Gilead, anti-viral) – originally used for Ebola, effective against SARS-CoV-2 in cultured pulmonary cells, and mouse models.
Chloroquin (old anti-malarial)
Other medications are continuing to be developed
Vaccine under development – testing will start soon but will take several months to evaluate its efficacy
Viral Spread After Contraction
According to the CDC– Infected individuals spread the virus when they are the sickest, however, some may still spread the virus a few days before symptoms develop.
According to the Lancet Journal studying China cases- The virus spreads from 8 to 37 days after an individual starts showing symptoms and infected individuals can spread the virus up to 20 days after resolution.
Testing positive for COVD-19: South Korea’s positivity rate in only 3-4% of labs, United States’ positivity rate shows 1-2% in Quest and LabCorp tests. That means most people with symptoms who are tested have other viral infections.
The virus can be spread by asymptomatic individuals. Infected patients can show negative testing. There are few patients with incubation periods of up to 24 days.
Beware of the fomites!
Fomites are objects that can carry microbes.
Coronavirus can survive at room temperature for up to 9 days, with an average lifespan of 4-5 days.
- Coronavirus can survive on various surfaces from 2 hours to 9 days.
- Worse survival between 30 and 40 degree Celsius
- Better survival at 4 degree Celsius – 28 days
- Better survival at 50% humidity verse 30% humidity
- SARS-CoV is inactivated by UV-C 254 nm, heat 65 C, acidic pH <3, and alkaline pH >12
- Sensitivity to Heat and UV rays may account for the seasonality of some viral illnesses – less prevalent in warm climates.
The Bright Side of Things
The optimistic view is that the wave of infections should start to abate in 6-8 weeks.
The White House Press Conference Friday March 13 brought together business leaders and leaders of medicine
- Dr. Deborah Birx, Coordinator for Coronavirus Response in the White House, U.S. Global Aids Coordinator
- Anthony Fauci, MD, National Institute of Allergy and Infectious Diseases at the NIH
UV-C light is effective against SARS-CoV-2.