The US becomes the nation with the most COVID-19 infections Yesterday, according to data from the Johns Hopkins Center for Systems Science and Engineering (CSSE) the United States passed China for top spot in total COVID-19 cases. At this moment, the US has more than 83,000 cases compared to 81,782 cases in China and 80,589 in Italy. The epidemic is surging in the US as a function both of increases in testing and because the SARS-CoV-2 virus is highly contagious and humans do not have immunity to it. The daily epidemic curve below shows the shape of the outbreak in the U.S. indicating that the epidemic is accelerating due to exponential growth in cases. What does it mean? While the numbers are surging, the overall attack rate (infections per 100,000 persons) remains low. The epidemic is just getting started here and we expect to continue to see large and increasing daily jumps in cases. It is clear that the United States is following a path illustrated by Italy and that the outbreak will not be over in the next few weeks as some have hoped. In my opinion, what we see in New York state will occur in other states unless intensive counter-measured are put in place immediately.
Rise in deaths lags behind cases but will catch up Yesterday, the total number of Americans who have died rose to 1,295 according to Worldometer. That included a record high 100 deaths in New York state. This trend will no doubt continue as rises in deaths will be following in the footprints left by the exponential rise in cases. What does this mean? As epidemiologists, we pay attention to the numbers of deaths, but also the rate. The death rate is much better for comparing to other populations and for providing clues about the nature of the epidemic. Also, the case-fatality rate is of vital importance in monitoring how well we are doing as a nation in responding to the pandemic. It also allows us to make predictions about how many deaths we can expect. Right now, deaths are occurring in about 1.5% of confirmed cases. This is not a true estimate of the overall CFR because we are still so far behind in testing that the lion’s share of cases remains undetected (or covert). However, just using that rate tells us a lot. The rate of deaths per confirmed case (1.5% in the U.S.) is way lower than what is seen in Italy (10.2%), China (4%) and Spain (7.7%). This is mostly because we are earlier in the process than other countries. Germany is an especially fascinating case, where >49,000 cases have occurred but only 304 deaths, a mortality rate of only 0.6%. According to a story on NPR by Rob Schmitz, the Germans started testing early and often; they have done significantly better so far than most countries in identifying and isolating cases before they can spread the illness to high risk groups.
The U.S. is ramping up testing, but remains way behind the curve In terms of COVID-19 testing, the U.S. continues to make strides as early road blocks are starting to be cleared away. However, as the figure below shows, while we are doing lots of tests, the U.S. remains near the bottom in our testing rate (tests done per 100,000 people). Spain has tested 6 times as many of its citizens in comparison; Italy has tested nearly 4 times the number. Iceland continues to outpace other nations testing about 3,100 per 100,000, with only 648 total positive tests. There is still a long way to go on testing in the U.S., especially in some states. According to data from OurWorldInData, several states and territories have still yet to complete the first 1,000 including Arizona, Delaware, Maryland, Missouri, and Puerto Rico.
Based on previous research, stopping social distancing before Easter could result in more death and suffering Today’s top pick is an article in Vox about why easing social distance measures too soon risks causing a spike in cases and deaths. The article reports on a study published in JAMA in 2007 that looked at epidemic curves from the 1918 Spanish flu pandemic in various U.S. cities. The figure below comes from that paper. I added some annotations in blue to explain things. It shows that when St. Louis MO reopened schools and stopped banning public gatherings in late November, cases doubled in December, forcing officials to re-instate control measures. It wasn’t just St. Louis, they studied 43 cities and found that places that instituted social distancing measures early had fewer deaths. Cities that stuck with it longer also had fewer deaths. Why this matters? President Trump has told the nation that he wants America to be open for business and back in church by Easter. I have not heard a single public health expert say that this is a good idea. We are not yet near the peak of cases in the U.S.. Easing social distancing measures will cause death and suffering. This epidemic is being driven by covert cases. Therefore, sending people back to work, school and church will do nothing but reignite the epidemic just as these important measures are starting to work.
U.S. cases rise by 23% on Wednesday, while deaths are doubling every two days Despite some evidence of a slowing pace of epidemic spread in Tuesday’s data, the Wednesday numbers show 12,209 new cases (another new high) and 225 deaths. I don’t tally today’s numbers until mid-night, but it’s clear that Thursday will be as bad or worse. Regionally, 62% of cases are now in the Northeast, due to the fact that New York has been so badly impacted, but fast moving brushfires are arising all over the country. Significant hot-spots were seen (in hot places by the way) including Texas, which added 564 new cases overnight (a rise of 138%). Texas has already added over 400 cases on Thursday, so this is no fluke. Other hard hit states include Louisiana (+407), Massachusetts (+679), Florida (+565), and Michigan (+501). What does this mean? Hopes we were nearing peak were misplaced. What looked like a slow down in new cases is most likely a back-log of testing as the nation’s labratory bandwidth starts to get stretched.
Many COVID-19 patients don’t fit the symptom profile I have returned to this topic on several occasions, but I remain very concerned about a disconnect between our case definition of COVID-19 and the reality that is being seen in hospitals. For a powerful example, read the account of a 38 year-old history professor who was infected with COVID-19 but did not self-isolate because he had symptoms that didn’t match what he had heard (VICE, March 25, by Jordan Davidson). Craig Hollandar had no cough and no breathing or respiratory issues. What he had was fatigue, a loss of appetite and diarrhea. His doctor’s told him he didn’t have the right symptoms and had not traveled so he didn’t have COVID-19. But he did. A new study online at the American Journal of Gastroenterology tracked 200+ patients treated at Wuhan hospitals and found that nearly showed up with digestive problems like loss of appetite or diarrhea as the main problem, not respiratory symptoms. Why this matters? Until we know more, everyone must recognize that this disease shows up in different forms in different places. Those who experience stomach problems, tiredness and loss of appetite may have COVID-19, even if they don’t have a cough, and should consider themselves a presumptive case. If this sounds like you, stay home and call your doctor.