Dr. Stuart Weiss: COVID-19 Update Tuesday 4-August-2020
Dr. Stuart Weiss, FACEP, FAAP, CBCP
August 4, 2020
Today’s topics: Good news for overall US case numbers, RT-PCR as the “gold standard”, when is a positive test not positive?
There will NOT be a Friday call this week.
| Good news for overall US Case Numbers The overall US average new case count for CoViD-19 has been down 9% this week over last week. Some of the hot spots from the last few weeks like Texas, Florida and Arizona have been on a down slope. Death rates are still increasing in those states but deaths lag behind new case rate by 6-8 weeks. So hopefully, over the next 4-5 weeks, we should start to see death rates in those states begin to decrease. While densely populated states have been the hotspots, virus is now spreading in less dense states and states like Nebraska, Montana, Wyoming and North Dakota are seeing increasing numbers of cases. In addition, test positivity is decreasing in the South indicating less community spread but increasing in the Midwest. According to the Johns Hopkins CoViD-19 tracker, the US continues to have the most cases and deaths in the world with 4,751,853 confirmed cases and 156,301 American deaths from CoViD-19. Is RT-PCR the “gold standard” test that we should be using? There was a study published today in Emerging Infectious Diseases journal that looked at patients with mild CoViD-19 disease and how long they were shedding virus. They found that actual virus and evidence of viral reproduction was rarely found after 8 days of illness even though viral genetic material could be found in some people for many weeks when they were tested by RT-PCR. And therein lies the potential problem. Are we using a test that is overly sensitive? From the viewpoint of controlling viral spread, all I care about is when someone is contagious. To be contagious you must be spreading live virus in your respiratory droplets. This study and other before it have shown that some people can be shedding viral remnants or pieces of virus that have been already killed for weeks after they recover. These pieces of viral genetic material (RNA) can be picked up on the PCR test since the test is very sensitive. The big question is do we care about that. My answer is that we don’t care if you are shedding pieces of dead virus. Rapid tests have been compared to the PCR test and have gotten some negative reporting because they aren’t as sensitive. I’m saying that perhaps we shouldn’t care if the rapid tests have a slightly lower sensitivity. When you look at the study comparing the Abbott ID Now to the RT-PCR, you can see at virus levels below the commonly believed infectious level (technically a CT level of 33 or above), the PCR test is positive when the rapid test can be negative. But, at viral levels where a person is infectious, the two tests are a perfect match. This is going to be even more important when the Lateral Flow Assay tests come out in a month or two. These low cost tests have a lower sensitivity then even the rapid tests but do well at viral levels where someone is infectious. And the benefit of testing frequently because the tests are cheap more than makes up for the lower sensitivity. As we learn more, we may decide that the “gold standard” test is too precise for our needs. When is a positive PCR not positive? I was awoken yesterday morning by a frantic call from one of our site managers. He was at a video shoot and 59% of the crew had CoViD-19 tests that came back positive. That was 3-4 times the rate in the local community and didn’t make sense to me. So I grabbed a cup of coffee and dug in to become a germ detective. I quickly reached out to the manager of the talent and asked about the people who had tested positive. Several were crew members who lived in the same hotel. So that was possible. Two were women coming off maternity leave who had stayed home with their newborns. One was a VIP who had flown home on a private jet and had been in his home for days. And the last person was my site manager who had previously been negative and was very careful about his exposure. This was making less sense to me. This group did not have a common exposure history and from an epidemiology standpoint, something was wrong. My next step was to speak with the lab medical director. We talked through the steps used to run the RT-PCR and talked about cross contamination that could happen when the samples were centrifuged. If the cap on the plate was not put on properly, then cross contamination could have occurred. The answer was to retest everyone. The site manager arranged with the lab to retest the entire crew and get quick results. The samples were taken and six hours later, all results were negative. The lesson to be learned from this is no lab is infallible. If you get a cluster of positive test results that don’t make sense, involve your medical director or medical team and do some basic epidemiologic investigation. If something doesn’t seem possible, then perhaps it actually isn’t possible. Don’t be afraid to ask questions if results don’t make sense. Be well and take care of yourself. There are storm clouds on the horizon. –Dr. Stu |
COVID-19 HEADLINES FOR TODAY
| Coronavirus update for August 4, 2020 World Wide Updates 2019 champion Rafael Nadal will not defend his US Open title in New York French gatherings of 5,000 or more to resume next month Kosovo prime minister tests positive for coronavirus Brazil’s health ministry says it is seeking alternatives if Oxford vaccine delayed Latin America and the Caribbean surpass 5 million Covid-19 cases Second Indian cabinet minister tests positive for Covid-19 Japan coronavirus total tops 40,000 as Okinawa confirms record number of cases Covid-19 cases nearly double in the Netherlands over the past week Poland contemplates imposing quarantine measures after largest virus outbreak yet French scientists warn of second wave in the fall as cases rise Iran reports 212 virus-related deaths in a day The US sent Brazil millions of hydroxychloroquine doses. Months later, they’re still in storage Germany already in second wave, says doctors’ association Londoners consider leaving the city as coronavirus leaves its mark Hong Kong confirms 80 new virus cases UN chief warns the world is facing a “generational catastrophe” on education Cricket Australia postpones T20 series against West Indies in October In Venezuelan state of Zulia, 22 doctors have died of coronavirus Vietnam reports 10 new cases of Covid-19 India reports more than 52,000 new coronavirus cases China reports 36 new coronavirus cases Australia to deploy 500 more soldiers to Victoria state to enforce stay-at-home order China and World Health Organizations discussing how to trace the origin of coronavirus Melbourne woman ‘smashed the head’ of female cop onto concrete after told to wear face mask Russia says it will produce a COVID-19 vaccine next month Turkey tightens containment measures after virus rebounds Ireland cancels plans to re-open pubs on Monday Greece reports 121 new coronavirus cases, highest number in weeks Danish state epidemiologist advises against lockdown easing Total Cases Worldwide: 18,649,725 Total Deaths Worldwide: 702,089 Total Recovered: 11,815,902 US Updates US stocks open lower Disney lost nearly $5 billion last quarter as Covid-19 hit its park and resort unit New York City reported no Covid-19 deaths for the 3rd straight day Mississippi governor orders statewide mask mandate Arkansas approaches 45,000 total Covid-19 cases Oklahoma’s Tulsa County reported more than 3,300 new Covid-19 cases in July Return to school will not look like business as usual, experts say Trump’s national security adviser returns to work after testing positive for Covid-19 Alaska Airlines has notified 4,200 employees that they could be furloughed this fall Ohio governor will issue order for children to wear masks in schools Governors from 6 states (Maryland, Louisiana, Massachusetts, Michigan, Ohio and Virginia) join to expand rapid antigen testing to slow Covid-19 spread Republican says Senate likely will be in session next week if stimulus deal isn’t reached Illinois reports nearly 1,500 new Covid-19 cases Indianapolis 500 will run without fans Group of House Democrats calls for mask-wearing provision in next Covid-19 stimulus package 5 people test positive after event attended by Florida governor Pennsylvania adds more than 800 new cases New York City health commissioner resigns Florida is reporting more than 5,000 new Covid-19 cases New Jersey adds Rhode Island to Covid-19 travel quarantine list, removes Delaware and Washington, DC 45 hospitals in Florida have reached ICU capacity — and show zero ICU beds available Nearly all of UCLA’s classes will shift online after Thanksgiving Corrections officer in Florida’s Miami-Dade dies from Covid-19 complications With NY eviction ban set to lift, resident of 14,000 city households at risk of eviction Radio City Christmas Spectacular canceled for first time ever, the latest casualty of COVID-19 Pennsylvania man arrested for shooting at store clerk who asked him to wear a mask Delta plane returns to gate after passengers refuse to wear face masks Georgia teen loses parents to COVID-19 four days apart Total US cases: 4,908,151 Total US deaths: 159,996 Total Recovered: 2,474,672 Total Tested in US: 57,543,852 Total cases in CA: 524,643 Total deaths in CA: 9,544 Total cases in FL: 497,330 Total deaths in FL: 7,402 Total cases in TX: 468,707 Total deaths in TX: 7,588 Total cases in NY: 446,467 Total deaths in NY: 32,798 Contact us |
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