Ricardo -> RE: COVID-19 start of a new era (Feb. 27 2020 11:31:44)
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From a Doctor friend of mine: <Quite a few people have asked me for an update to my previously posted thoughts about the Covid19 outbreaks. A few hours ago something happened that is worth an update: Today, the first community-acquired case of Covid19 was confirmed inside the United States. In this context, "community-acquired" means that the affected patient had not travelled outside the US and had no identifiable contact with any known potential foreign source of infection. That means Covid19 is now loose in the US, and has very likely already spread into communities all across the country. The same situation now exists in several European countries as well. In my opinion this is now a pandemic, and I believe the CDC and WHO will soon make an announcement to that effect. There is no longer any possibility of containment, and despite all the messaging by public authorities, there is no known effective way to avoid eventual exposure to this virus. Masks and other personal protective equipment (PPE) are effective when used properly to avoid transmission from a small number of known and contained cases. Unfortunately, even trained professionals often are infected due to brief or unrecognized violations of PPE protocol. Now we are no longer dealing with a small number of quarantined cases: we are facing a pandemic. Masks and other protective gear have never been effective to prevent ultimate exposure in a pandemic respiratory illness. During the 1918-1919 flu pandemic, for example, virtually everybody in the world was eventually exposed regardless of how careful people tried to be. Vaccine development is underway, but there is no existing mechanism by which a vaccine for the general population could be developed, manufactured, and distributed in quantity during this season of the pandemic. Once infected, there is no proven effective treatment. We are going to have to cope with this as best we can. How bad will it be? Nobody has a definitive answer for that question. We don't know the true death rate because there is one big piece of data missing: we have absolutely no idea how many people have been infected and had only minimal or mild symptoms. We have never systematically tested exposed but asymptomatic patients, or those with mild symptoms but no fever at the time of presentation. There aren't enough tests available to do so, and the tests have too many false positives and false negatives to be used for screening of asymptomatic people. We've learned that it's possible to test negative for several weeks (possibly up to 4 weeks) before becoming symptomatic and testing positive. We have quite a bit of data but we still don't know the true mortality rate. My personal guess is that the true mortality rate will be on the order of 0.1% - 0.5%. This estimate is based on public and private reports from China and elsewhere, and on published data from the "natural experiment" that occurred on the cruise ship Diamond Princess. This estimate makes sense to me in the context of my general knowledge as a physician and a biophysicist, and of the special knowledge I gained while working for a time in the area of preparedness for bioterrorism and emerging diseases. Estimates released by public officials may be based on different assumptions or may reflect different scenarios. This is just my own best guess based on what I know at this time. To understand my estimate, consider the Diamond Princess cruise ship experience: The ship carried roughly 3700 passengers and crew. There is evidence to support a belief that 100% of these were exposed during their time aboard. Roughly 700 people have become noticeably sick and have tested positive, and thus far 5 of those have died. No doubt more will become ill and more will die, but we are many weeks from the initial exposures and the current numbers are at least a starting point. What we see is that about 20% of those exposed have become significantly sick and a little less than 1% of the sick ones have already died. The overall death rate among those exposed is currently 5/3700 (0.14%, or roughly 1 in 740). If another 5 to 10 people die (this would match the China experience in which 2% to 3% of the identifiably sick patients died) the *overall* mortality rate would be something on the order of 0.4%, or roughly 1 in 250. This is significantly worse than the seasonal flu but it's not as bad as the initial estimates of 2% - 3% mortality and nowhere near the 1918 flu pandemic, in which 1 out of 6 people died, often within a few hours of symptom onset. To reiterate, I think the 2% mortality estimates we've been hearing are high because they are based on counts of people with test-proven disease, and nobody got the test unless they were significantly sick. All mild cases and asymptomatic patients were excluded from the denominator. The Diamond Princess gives us our best estimate because we know the total number of people who were placed at risk. It's worth noting that at any mortality rate, disruption to our social and economic order could potentially do as much harm as the virus itself. For example, many people live paycheck to paycheck, so if their work is shut down they'll have no money to buy food or medicine, or pay rent. If schools are closed, as they surely will be, many households will be financially strained. And for anybody who ends up in the ICU with Covid19, the medical bills could be crippling. A public health problem of this magnitude that affects us all certainly puts "Healthcare for all" into a different perspective. In some epidemics the supply chain is disrupted and critical infrastructure may collapse. This pandemic likely will not be severe enough to cause such a collapse in and of itself, but public mismanagement, antisocial behavior, and panic could combine to make things much worse. We will need to pull together to get through this. We need to keep the system working. We can't afford to treat each other badly. Nobody is going to be able to hide long enough to avoid exposure, especially since a doorknob or a perfectly healthy-seeming person may be a vector. Now is also the time to make contingency plans. The vast majority of us will survive, but now would still be a good time to write or update wills, and to make sure children won't be left without a designated guardian in the event of unexpected death of a parent. Of course all of this may change as new data becomes available. Things should get better as we get past the traditional flu season. Next year we will likely have a vaccine and possibly even a proven therapy. Under normal circumstances we expect a virus of this general type to circle the globe for a year or two, until the number of susceptible hosts becomes too low to sustain it. At that point the original virus typically dies away or mutates to behave quite differently. Sometimes a virus mutates significantly once it begins propagating outside its population of origin. If that happens, everything could change fairly quickly. Wishing the best for everybody.>
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