Here are a couple of news summaries from different news releases from the Center for Disease Control plus a statement by the Methodist Healthcare System on Covid-19 antibody testing.
The first is good news. It’s tough to get the coronavirus from a contaminated surface. If someone coughs on a table and you wipe your hand on it and then touch your face, you might get it. Otherwise, these “deep cleans” are probably not worth it. Likewise, adding ultraviolet lights or ultraviolet filters to your air conditioning is of doubtful utility.
CDC: Coronavirus “does not spread easily” via touching surfaces, objects
USA Today (5/20, Flores) reports recently updated Centers for Disease Control and Prevention guidelines say that the novel coronavirus “does not spread easily” by touching contaminated surfaces or objects, by animal-to-human contact, or vice versa. However, the agency warned that transmission via such routes “may be possible.” Meanwhile the CDC continues to warn “that the main way the virus is spread is through person-to-person contact, even among those who are not showing any symptoms,” and that “the main way to prevent infection” is social distancing, hand washing with soap, and “cleaning and disinfecting frequently-touched areas.”
The second is the CDC’s estimate of how many Covid-19 cases are asymptomatic. I have read in other articles estimates of 10-80% with 20% being the most widely quoted percentage. This estimate is 35%. I think it will be awhile before we know who is truly asymptomatic versus minimally symptomatic and pre symptomatic. Of course, this is the reason for social distancing and facemasks. We want to avoid spreading it if we have the virus and don’t know it. For those who want to delve into the 5 different scenarios that the CDC used to come up with this number, I’m including the link. I tried to wade through it last night but kept nodding off.
Estimates That About One-Third Of Coronavirus Patients Don’t Have Symptoms
CNN (5/22, Azad) reports that in its “new guidance for mathematical modelers and public health officials,” the CDC “is estimating that about a third of coronavirus infections are asymptomatic.” The agency also “says its ‘best estimate’ is that 0.4% of people who show symptoms and have [COVID-19] will die, and the agency estimates that 40% of coronavirus transmission is occurring before people feel sick.” The CDC “cautions that those numbers are subject to change as more is learned about [COVID-19], and it warns that the information is intended for planning purposes.”
Finally, this from the Methodist Healthcare System on antibody testing:
Date: May 20, 2020
Subject: COVID-19 Update
To: Methodist Healthcare Medical Staff
From: Paul Hancock, MD, Chief Medical Officer
Methodist Healthcare has 26 known COVID-19 positive patients under our care.
- COVID Antibody Testing
Given the current science of SAR-CoV-2 antibodies, the only viable question which can be answered by a COVID antibody test is: Has this patient been exposed to SARS-CoV-2? It is not known if any particular level of antibodies indicates immunity. A recent study in JAMA showed that IgM and IgG antibodies peak mid-way into the third week after the onset of symptoms. Thus, IgM does not likely serve as an early marker of infection.
Clinical management decisions based on COVID antibody testing is still strongly discouraged by the data, public health officials, the FDA and the CDC. Instead, clinicians should continue to base clinical management decisions on COVID PCR testing, which is the only acceptable testing modality for such decisions. MHS does not offer COVID Antibody testing at this time. In addition, Point of Care and in-office modalities continue to fail validation and, therefore, have not been approved for use. Commercial labs, including Quest and LabCorp are now offering antibody tests but these are not available through MHS facility labs.