On: COVID-19 (Continued)
Date: March 2020
Background: Scientist, pediatrician, and advocate in the fields of global health, vaccinology, and neglected tropical disease control.
- No real sense of actual number of cases (% of population infected).
- Geographical distribution of cases (density) probably more important than absolute number of nationwide cases.
- Multiple of actual to confirmed cases could be about 10-20x (estimate as of March 20).
- Based on estimated days to mortality and mortality rate.
- Means there could be about 100-200k cases in the US, spread over various centers.
- US hospitals starting to become overwhelmed.
- Lack of state/federal coordination.
- Healthcare professionals are getting sick.
- Shortage of equipment.
- Inconsistency in age range of infections across countries.
- About 1/3 of US hospital cases is 20-40 year age range, about 50% under 54.
- Different from China.
- Fatality rate not as high in lower age group, but still fairly severe symptoms and perhaps long-term implications.
- Reasons not clear: vaping? [or, as per Comments below, high blood sugar may be a relevant underlying symptom that is more prevalent in the US?]
- Potential treatment options.
- Plasma from recovered patients.
- Repurposed drugs, such as:
- Chloroquine (cheap malaria drug).
- Remdesvir (ebola).
- ARBs (angiotensin-receptor blockers).
- Vaccine: takes time.
- Toxic mix ensures rapid transmission and high number of fatalities.
- Rate of transmission (fairly high).
- Rate of fatality (fairly high).
- Asymptomatic individuals (not all cases are immediately symptomatic).
- Excellent video explanation of ACE-2 receptors, Ace-inhibitors and ARBs here.
- Some related points from a Twitter thread by David Sinclair, biologist, genetics professor:
- SARS-CoV2 attacks pneumocytes in the lungs, intestine, heart and the cells lining blood vessels.
- In the lungs, CoV2:
- Prevents cells from making biological detergents to keep lung passages open.
- Acute respiratory distress follows.
- Oxygen levels fall.
- There may be a dangerous underlying process.
- COVID-19 may also involve abnormal blood production.
- CoV genes may interfere with heme, the red compound in blood, by kicking out the iron.
- This would explain why chloroquine seems effective as a treatment.
- Chloroquine prevents the attack on heme.
- This may also explain why diabetics and elderly are more susceptible.
- Blood sugar levels usually increase as we get older.
- This increases the amount of glycated hemoglobin (HbA1c).
- The virus may more easily disrupt the heme in red blood cells.
- If so, the virus:
- Destroys the lung so patients can’t take up oxygen, AND
- Reduces the body’s ability to carry oxygen.