Tuesday, April 2, 2024

Reviewing the CDC’s Respiratory Virus Guidance with Regard to Covid

The document, Respiratory Virus Guidance is available at https://www.cdc.gov/respiratory-viruses/guidance/respiratory-virus-guidance.html. Background information on the Guidance, explaining the reasoning that underpins it is at https://www.cdc.gov/respiratory-viruses/background/index.html.

To my surprise, I found there is a great deal to like in it, though also some considerable problems. I wish it were stronger and compliance is, to put it mildly, poor, but it seems to be the first attempt to provide unified national public health advice on respiratory viruses and there is some good advice here. It is still limited, however, and especially poor on control of covid.

The CDC does not have the authority to enforce public health measures on state and local jurisdictions, which means that while the CDC may make recommendations, it may not enforce them. I plan separate discussions of the CDC Backgrounder and of the legal issues of public health in the USA; this post is a response to the main CDC Respiratory Virus Guidance.

General Problematic Areas

Minimizing the Unique Character of Covid

Covid is a respiratory virus only in the sense that it usually infects the respiratory tract first, and responding to it as though it is only a respiratory virus will fail.

Covid is an extraordinarily contagious airborne disease caused by a quick-mutating RNA virus. Reinfection is common and infection often leads to serious sequelae and disability. It is only partly seasonal; unlike flu and RSV there is a baseline rate of infection in all seasons. As Dr. Peter Hotez observes on X, “Covid is not the same [as flu] due to its cardiovascular and thromboembolic effects leading to stroke, [heart attack], long covid.”

Covid has become endemic, killing elders and other vulnerable people, causing disabilities among younger people, and being a massively expensive economic drag. It would be best if covid were made rare, yet the Guidance treats it in the same way as colds and flu. Currently the Guidance only provides general advice, and so far only specific situational advice on covid in healthcare settings, not schools, workplaces, or homes, and that is not going to make covid rare.

The Risks Of Covid Are Downplayed

The Guidance discusses preventative measures, but there is little (in some cases no) warning about why these measures are important. People simply are not told how dangerous covid can be, that stroke and heart attack are potential sequelae, especially in people over 50, that covid is dangerous to pregnant people and interferes with fetal development, and so on through the by now extensively documented sequelae.

Protection For Vulnerable Groups Is Inadequate

There is a section entitled Risk Factors for Severe Illness from Respiratory Viruses but the advice is inadequate, and puts the onus for prevention almost entirely on vulnerable people. There is no emphasis on protecting grandparents and they do not actually say that risks of severe illness increase starting at age 50; one has to go to the Backgrounder to see that.

Monitoring

The efficacy of many of the CDC respiratory guidance measures depends on monitoring, knowing when exposure is a risk. This is especially the case for indoor air quality, where knowing that a disease is spreading allows additional precautions to be taken. That, unfortunately, doesn’t seem to be discussed or addressed. Even if it were addressed, the CDC does not have the broad enforcement authority required to madate it.

Comments on specific sections

Hygiene

There are generally good remarks on hand-washing, which is useful for controllying colds, flu, and RSV, but this section also states this will help control covid, which is nonsense.

Steps for cleaner air

The insights of ASHRAE 241, Control of Infectious Aerosols are not incorporated into the advice. (To read the standard, go here and scroll down; ASHRAE strictly controls the distribution of its standards.) There is too much concentration on outside air and air changes. Opening doors and windows is not practical in poor weather, when people have allergies, or when outdoor air is not healthy. They do discuss filtration (some) but they also use air changes per hour, which are not a reliable way of preventing the spread of airborne pathogens, rather than clean air delivery rates, which are.

Preventing Spread of Respiratory Viruses When You’re Sick

It is in two parts: the first says that one can resume normal activities under fairly liberal conditions; the second says take added precautions for five days. The first has often been quoted without the second, and is by itself inadequate, and that has been the source of a great deal of anger. Here’s the full advice. If actually implemented, five days of precautions would make the advice considerably better, but infectious covid can persist for more than five days, so testing ought to be required. In any event, the likelihood of this actually being implemented for many workers is poor.

  • You can go back to your normal activities when, for at least 24 hours, both are true:
    • Your symptoms are getting better overall, and
    • You have not had a fever (and are not using fever-reducing medication).
  • When you go back to your normal activities, take added precaution over the next 5 days, such as taking additional steps for cleaner air, hygiene, masks, physical distancing, and/or testing when you will be around other people indoors.
    • Keep in mind that you may still be able to spread the virus that made you sick, even if you are feeling better. You are likely to be less contagious at this time, depending on factors like how long you were sick or how sick you were.
    • If you develop a fever or you start to feel worse after you have gone back to normal activities, stay home and away from others again until, for at least 24 hours, both are true: your symptoms are improving overall, and you have not had a fever (and are not using fever-reducing medication). Then take added precaution for the next 5 days.

Masks and Respiratory Viruses Prevention

This is called an “additional strategy,” not something that is central to prevention, but it is here. There is even a discussion of wearing N95s and how to do a seal check.

Conclusions

This is a beginning, but it minimizes covid and some of it is out of date or simply wrong. It is not going to control endemic covid. The disease is going to continue to rip through homes, schools and workplaces. It is going to continue to kill elders and other vulnerable people.

The CDC is getting something of a bum rap here; many things it is asked to do are beyond its authority, but, also, the CDC is minimizing the impact of covid; if one digs into the Backgrounder, one finds many things that the CDC has left out of the general Guidance, so there is no way to say that the CDC is unaware of the issues.

This is going to be a long struggle.

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