Here are three new things on Covid-19.
- Congratulations to Jim Berg! Jim was found to have positive antibodies to Covid -19 several months after getting sick while skiing in Colorado in early March. Jim has been donating plasma which is being used to treat critically ill patients. If you want to have your antibodies checked, South Tissue Blood Bank and Tissue Center will check you for antibodies to Covid-19 if you donate blood. They use the Abbott machine which is one of the most reliable. Also, for those positive, they send the serum to Austin to be checked to see if the antibodies are specific for Covid-19. Exposure to other coronaviruses (there are 7 of them) might cause a false positive test. The lab in Austin is able to differentiate antibodies to the different antibodies. Here is the information on donating: http://South Texas Blood and Tissue Center <STBTC@mail111.connectingdonors.org>
Benefits of physical distancing: A study in The Lancet Infectious Diseases offers additional evidence that physical distancing can slow the spread of COVID-19. Researchers used mobility data from cell phones to estimate movement patterns across the U.S. from January through mid-April. They found that decreases in mobility were strongly associated with decreases in COVID-19 case growth. The effect was not seen until at least 9–12 days after mobility decreased, which aligns with the virus’s incubation period. The researchers write, “This study strongly supports a role of social distancing as an effective way to mitigate COVID-19 transmission in the USA. Until a COVID-19 vaccine is widely available, social distancing will remain one of the primary measures to combat disease spread.”https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30553-3/fulltext
Antibody test accuracy: Lateral flow immunoassays (LFIAs) — antibody assays potentially used as point-of-care tests — have the lowest sensitivity of SARS-CoV-2 antibody tests studied, according to a meta-analysis in The BMJ. Researchers examined 40 studies that evaluated the accuracy of antibody tests with RT-PCR as the reference standard (half the studies were not peer-reviewed). Overall, the sensitivity of chemiluminescent immunoassays (CLIAs) for IgG or IgM was roughly 98%; enzyme-linked immunosorbent assays (ELISAs), 84%; and LFIAs, 66%. Test sensitivity was highest 3 or more weeks after symptom onset. The researchers note that the data were “characterized by high risks of bias, heterogeneity, and limited generalizability to point-of-care testing and to outpatient populations.” They add that “the available evidence does not support the continued use of existing point-of-care serological tests.” So if someone offers to prick your finger to tell you if you have Covid-19, keep walking.https://www.bmj.com/content/370/bmj.m2516