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 https://t.co/QKhTqtwJBD

— Eric Feigl-Ding (@DrEricDing) April 5, 2020

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.

— Eric Feigl-Ding (@DrEricDing) April 5, 2020

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

— Eric Feigl-Ding (@DrEricDing) April 5, 2020

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

— Eric Feigl-Ding (@DrEricDing) April 5, 2020

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...

— Eric Feigl-Ding (@DrEricDing) April 5, 2020

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

— Eric Feigl-Ding (@DrEricDing) April 5, 2020

7) The was the first of several cruise ships on which the virus circulated widely; nearly 20% of passengers and crew on the ship eventually tested positive for the #SARSCoV2 virus. #COVID19

— Eric Feigl-Ding (@DrEricDing) April 5, 2020

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

— Eric Feigl-Ding (@DrEricDing) April 5, 2020

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.

— Eric Feigl-Ding (@DrEricDing) April 5, 2020