Daily COVID-19 Briefing: 3/21/20

  1. New York tops 10,000 cases. Major national disaster is declared
    Multiple news organizations report on the dire situation in New York state where confirmed COVID-19 cases now top 10,000 with 6,211 cases in New York City alone. The federal government declared New York a major disaster on Friday, making the state eligible for Federal Emergency Management Agency (FEMA) aid. Gov. Cuomo said the state anticipates that between 40 and 80 percent of New Yorkers will be infected with SARS-CoV-2, the virus that causes COVID-19.
    What does this mean? The goal for New York (and all other U.S. states) must be to flatten-the-curve so that the burden of disease can be spread out over time to avoid overwhelming hospitals, something that is already happening in this, the hardest hit state.
  2. Viral mutation, everyone’s talking about it
    Public discourse and social media are filled with conjectures about how the SARS-CoV-2 virus might have, or might in the future mutate into something more dangerous. I am not a virologist, but I listen to what they say. Mutation is one of those scary words that has gone, well, viral! The reality is that all viruses mutate randomly all the time. That is because the replication process for an RNA virus is very prone to error. As a result, the SARS-CoV-2 virus, like all viruses is constantly mutating. There is no surprise in that. In fact, within one infected person, there will be countless different “versions” of the virus in circulation, like documents spewing from an old broken Xerox machine. All viruses mutate; those mutations rarely make any meaningful difference in how the virus works or how it spreads. The vast majority of mutations are just genetic noise; they don’t take hold and change the behavior of the pathogen because they don’t produce a meaningful survival advantage. Big changes do occur in viruses, but not generally on the time-scale of a specific outbreak. We do know that one such big change occurred when this coronavirus ‘spilled over’ from it’s natural host to people (possibly though an as yet unknown intermediate host).
    What does this mean? In science fiction, viruses (like superheroes) mutate suddenly and acquire extraordinary capabilities. In real life, meaningful mutations that matter are rare, unlikely and impossible to predict. That doesn’t mean that a qualitative change in the disease due to a mutation is impossible. But, we now have more tools than ever in human history to monitor this pathogen in real time, to watch for mutations that change the infectivity, transmissibility or lethality of the disease. That usually doesn’t happen. Nature is more complex. Yes, the virus is always mutating. That’s all part of what experts described in a comment in Nature Microbiology as the “…humdrum aspect of life for an RNA virus”. Most mutations don’t matter.
  3. U.S. cases doubling every day, deaths doubling every 3 days
    If you follow my blog you are used to seeing a graph showing growth in cases. We are all trying to get our heads around the reality of exponential change. Below is a look at what is going on with deaths in the U.S. using data collated daily by Wikipedia. The bad news is that deaths are starting to escalate in a similar exponential way. The good news, if you want to call it that, is that deaths are doubling more slowly than cases.
    What does it mean? The fact that deaths are rising exponentially is not surprising. It is important though because deaths are a more reliable gauge of the actual epidemic (as opposed to being a measure of how much testing we are doing). We expect deaths to continue to rise. It’s too early to say when these numbers will peak.
  1. Emerging evidence suggests that up to half of infections are covert cases
    According to a March 20 article in Nature News, The first evidence is now coming together to show that up to half of all infections of COVID-19 are covert cases, meaning they are infections in people with mild symptoms or no symptoms at all. This is important because it is widely believed that some covert cases have the potential to spread the disease to others. Because people with mild or no symptoms are much less likely to seek medical treatment and are not being tested, they may be driving the epidemic.
    What does this mean? We know that this novel coronavirus is more contagious than the flu. A big reason why is that people are out and about and spreading the disease without being tested or knowing that they are sick. That’s why the R0, or basic rate of reproduction continues to be around 2 or higher (meaning that every sick person transmits the illness to 2 other people). This is why it is so critical to continue to enact social distancing measures. It makes good sense that states are asking people to stay home.

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