⚠️Exciting - SEROLOGY (ANTIBODY) STUDIES BEGINNING: @CDCgov has begun preliminary studies to try to determine how many Americans have already been infected w/ #SARSCoV2, the virus that causes #Covid19. Serology also reveals immunity! This holds promise🧵
statnews.com/2020/04/04/cdc…
statnews.com/2020/04/04/cdc…
2) the CDC hopes to flesh out the portion of cases that have evaded detection using three related studies: 📌The first, already begun, will look at blood samples from people never diagnosed as a case in #Covid19 hot spots, to see how widely virus circulated.
3) 📌a national survey, using samples from different parts of US, will be conducted. 📌A third will look at special populations — HCWs top priority — to see how widely virus has spread within HCW. CDC hopes to start national survey in summer; no timeline for HCW study.” #COVID19
4) These sero-surveys involve drawing blood from people never diagnosed as a case to look for antibodies to virus. They are conducted by taking a representative sample of people in a city, for instance, ensuring people from diff age groups are included. #COVID19
5) It’s known that many people have mild infections when they contract #Covid19. Data from China and elsewhere suggests about 80% of people confirmed to have the infection have mild or moderate symptoms. But it is also assumed that figure may in fact be low...
6) ...that more people may have already encountered and fended off the virus than have been detected. There have been reports, for instance, from the Diamond Princess cruise ship involving people who tested positive who recounted having no symptoms at all. #COVID19
8) Getting a sense of how many mild and asymptomatic cases there are helps plan for future responses to #Covid19. If a high %people were likely infected when 🦠 moved through during its first wave, response to reappearance later might be tailored to protect only high-risk people
9) This work is part of ramped-up #COVID19 surveillance at the CDC. The agency has been adapting a number of surveillance systems used to record the toll of seasonal flu in the United States to get a near-real-time picture of SARS-CoV-2’s march across the country.
10) On Friday, CDC published the first of what will be a weekly #Covid19 surveillance report, based on the model of its longtime influenza report, FluView. report is based on data from the last week of March. It showed that in that week, nearly 11,000, or 14.5%, tested positive.
11) It also showed that pneumonia and influenza deaths, which would normally be falling at this time of year as flu season starts to abate, are increasing. Pneumonia deaths have been rising sharply since the end of February — because of #Covid19.
12) The new surveillance systems will allow the CDC to add context to the daily reports of #Covid19 cases and deaths. It will help the agency determine who is contracting the virus and being hospitalized because of Covid-19 infections, and who is dying from the disease.
13) BOTTOMLINE: these #COVID19 “census” blood surveys by CDC will give us critical insights into how bad the infection has been, how often HCW are infected, and who’s being hospitalized. (Also side bonus will be assessing potential immunity prevalence). Let’s start these soon!🙏
