Saturday, May 2, 2020
COVID 19 Update
*As always, I will try to be fact based to the best of my knowledge. Any opinions I express here do not necessarily reflect those of the leadership of my practice group or profession.
There is a lot of happy talk out there right now about COVID 19. While the situation indeed does not seem quite as dire as it did a few weeks ago amid horrific pictures and stories coming out of New York City and it may be appropriate to reassess some of the "lockdown" rules, the same virus is still out there and it's as deadly as ever. Here's some numbers to meditate on(approximate numbers):
Worldwide: Cases- 3.3 Million. Deaths- 240, 000. Case-Fatality Rate- 7%.
United States: Cases- 1.1 Million. Deaths- 64, 000. Case-Fatality Rate- 5.8%
California: Cases- 52,180. Deaths- 2136. Case-Fatality Rate- 4%.
San Bernardino County(CA): Cases- 2113. Deaths- 94. Case-Fatality Rate- 4.4%.
The rates of new cases and deaths have leveled off, almost certainly due to mitigation efforts through both voluntary individual action and government mandates, but they also are not dropping significantly over the past 2-3 weeks. There were 30,000 new cases and 1829 new deaths reported in the U.S. yesterday. Over the past 3 days, there have been 5926 new cases and 282 new deaths reported in California, 266 new cases and 9 new deaths in San Bernardino County. Those rates are as high as they have ever been for those areas.
OK, so prevalence studies strongly suggest there are many more asymptomatic or minimally symptomatic cases which are not being counted in the denominators of those Case-Fatality Rates. That is true, but the stubbornness of those rates as case numbers steadily climb should be cause for considerable alarm. What we can say with a reasonable degree of confidence is if you are infected and become sick enough to seek medical attention and get tested, you have approximately a 5% chance of dying. If you don't find that fact terrifying, you are a stronger person than I.
While true case-fatality ratios may well be much lower(Anthony Fauci continues to use 1% as his estimate-still a frighteningly high number), true death rates are likely also significantly higher than reported. When comparing reported COVID numbers with seasonal influenza, it is important to remember that these COVID numbers are generated from confirmed diagnoses and death certificates while seasonal influenza deaths are calculated from excess overall death rated above baseline. Preliminary studies using influenza methodology strongly suggest comparable death rates from COVID may be as much as 1.5 times those currently reported.
So, where are we in the pandemic and where are we headed? Based on antibody testing, which is itself quite problematic, prevalence rates range from 4% in Santa Clara and Los Angeles counties to between 15 and 25% in New York. When a pandemic like this follows its natural course, total number infected is generally 50-70%, at least in the first wave. The model California Governor Gavin Newsom used in his decisionmaking was 56%(not sure where the precision of that number came from, but it still is on the low side in my opinion). Full "herd immunity" requires closer to 85 to 90% of population with antibodies through infection or vaccination. What this means is even in New York, we are still far from even the halfway point in the natural history of the COVID pandemic.
Just for rough estimate purposes, let's say the prevalence for infections across the country is 7%, an estimate that is probably on the high side. That has generated roughly 65, 000 known deaths. Multiply that by 10 to get to 70% which is the likely end point for the first wave of a pandemic that is twice as contagious as seasonal influenza, you get 650, 000 total deaths across the country. A more pessimistic way of looking at it would be 70% of 320 Million is about 220 Million. 1% of that is 2.2 Million as in total deaths from the COVID 19 pandemic in the U.S alone.
So, I am not aware of any new data from the last 6 weeks that substantially changes my original estimates for the natural history of the pandemic. I can think of only 3 ways to substantially alter these dire projections: 1. Vaccine. 2. Effective treatment. 3. Effective mitigation with transition to containment.
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I plan to write future posts on a variety of COVID related subjects including containment vs mitigation, testing and consequences to society.
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Thanks for the update Doc, the data is sobering but that's reality these days. You've confirmed what I've heard from our political leaders and health professionals here. We won't be out of the woods from covid-19 until a vaccine is developed. Regarding a 2nd wave of the pandemic, we are in a marathon not a sprint, We have a ways to go getting this under control. Stay safe everyone.
ReplyDeleteAppreciate the info.
ReplyDeleteStay vigilant.
With people retesting positive after recovering, is herd immunity even possible?
ReplyDeleteThe answer is we don't know for sure. My semi-educated guess is we will see varying degrees of immunity with some people having close to full immunity others partial immunity and perhaps some who have little or no immunity even after infection. The same will likely be true of any vaccines.
DeleteA similar situation is seen in yearly flu shots where "effectiveness ranges from 20-70% from year to year, but we think even if recipients don't completely prevent the flu, they are more likely to get a less severe case.
Errr....even if recipients aren't completely protected from the flu......
DeleteCovid-19 is not an equal opportunity killer.
ReplyDeleteDeaths estimated:
13.4% of patients 80 and older (I live here)
8.6% of those in their 70s (my wife is here)
4% of those in their 60s
1.25% of those in their 50s
0.3% of those in their 40s
Overall,
1.4% is the fatality rate among people with confirmed disease (although I think this is contradicted if asymptomatic cases are included).
Data is from:
https://www.statnews.com/2020/03/30/what-explains-coronavirus-lethality-for-elderly/
I am in the first group with an underlying condition (hypertension, mild and controlled by medication). I don't leave the house except to walk, alone. I have a 19-month old granddaughter living in Chico whom I haven't seen for nearly 2 months. I would like to survive for her to know a grandfather, I am the only one she has.
It seems to me that if the elderly and those with "conditions" are sheltered, the rest of the population that so-wanted could go at it without worse complications than the flu which hits the under 40.
There is a significant cost in health to letting the economy "go to hell" which seems to be OK with the governor.
People with incomes seem less anxious to battle it out in the open, but I think there is an accommodation to be reached.
You raise some interesting points. I am not sure where the 1.4% Case-Fatality Rate comes from because every data source I can find shows an overall Case-Fatality Rate ranging from around 4-7% for confirmed cases. True CFR is likely less due to large numbers of unreported cases, but there are also large numbers of unreported deaths.
DeleteI also am very skeptical that it is possible to turn whole age groups loose and expect they won't become a reservoir that transmits it to more vulnerable populations. We have already seen transmission from young, healthy caregivers to vulnerable older adults living in care facilities. Having large numbers of infected people running around will increase risk to hospital workers and to people like store clerks and vulnerable people who shop at stores for food.
The 1.4% Case-Fatality Rate referenced above comes from
Delete"https://www.statnews.com/2020/03/16/lower-coronavirus-death-rate-estimates/"
which is arguably not a good source!
The first paragraph reads:
"In a rare piece of good news about Covid-19, a team of infectious disease experts calculates that the fatality rate in people who have symptoms of the disease caused by the new coronavirus is about 1.4%. Although that estimate applies specifically to WUHAN, the Chinese city where the outbreak began, and is based on data from there, it offers a guide to the rest of the world, where many countries might see even lower death rates."
The US rate which includes the disaster in the northeastern states and other over-impacted states such as Louisiana (Mardi Gras) & Michigan (Detroit) is 5.8% in-line with your number.
If only the 25 least affected states (which includes the 3 largest by population: California, Texas, and Florida), the CFR reduces to 3.3%, which is still big.
If the 3 "biggies" are taken out of the "lesser half" the CFR is reduced to 2.9%, quite cherry-picked but still 120,000+ cases.
California CFR is 4%, pulled up by Los Angeles Santa Clara, and San Bernardino.
Taking a supreme cherry-pick for California, the least affected 27 counties (half of 54 counties in the state), including a few big ones like San Francisco (1.8%) and Orange (1.9%), the CFR for more than half of California by physical area is only 1.5%!
California should not be treated as one state: the 50,000 square miles north of Sacramento -- a huge area -- is unaffected!
The state data above is from an excellent website:
Deletehttps://www.worldometers.info/coronavirus/country/us/