Tag Archives: Viral Transmission

Mask Truths and Signals

26 Tuesday Oct 2021

Posted by in Coronavirus, Public Health

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It’s been clear since the beginning of the pandemic that your chance of getting infected with COVID outside is close to zero. (Also see here). Yet I still see a few masked people on the beach, in the park, on balconies, and walking in the neighborhood. Given the negligible risk of contracting COVID outdoors, the marginal benefit of masking outdoors is infinitesimal. Likewise, the benefit of a mask to the sole occupant of a vehicle is about zilch. Okay, some individuals might forget to remove their masks after leaving a “high-risk” environment. Sure, maybe, but cloth masks really don’t stop the dispersion of fine aerosols anywhere, indoors or outdoors. Of course, the immune-compromised have a reasonable excuse to apply the precautionary principle, but generally not outside with good air quality.

The following link provides a list of mask studies, and meta-studies. Several describe randomized control trials (RCTs). They vary in context, but all of them reject the hypothesis that masks are protective. Positive evidence on mask efficacy is lacking in health care settings, in community settings, and in school settings, and the evidence shows that masks create “pronounced difficulties” for young children and “emotional interference” for school children of all ages. Here’s another article containing links to more studies demonstrating the inefficacy of masks. Also see here. And this article is not only an excellent summary of the research, but it also highlights the hypocrisy of the “follow the science” public health establishment with respect to RCTs. Compliance is not even at issue in many of these studies, though if you think masks matter, it is always an issue in practice. Even studies claiming that cloth masks of the type normally worn by the public are “effective” usually concede that a large percentage of fine aerosols get through the masks… containing millions of tiny particles. In indoor environments with poor ventilation, those aerosols remain suspended in the air for periods long enough to be inhaled by others. That, in fact, is why masks are ineffective at preventing transmission.

Another dubious claim is that masks are responsible for virtually eliminating cases of influenza in 2020 and 2021. Again, to be charitable, masks are of very limited effectiveness in stopping viral transmission. Moreover, compliance has been weak at best, and areas without mask mandates have experienced the same plunge in flu cases as areas with mandates. A far more compelling explanation is that viral interference caused the steep reduction in flu incidence. The chance of being infected with more than one virus at a time is almost nil. Simply put, COVID outcompeted the flu.

Again, I grant that there are studies (though only a single randomized control trial out of India of which I’m aware) that have demonstrated significant protective effects. Even then, however, the mixed nature of this body of research does not support intrusive masking requirements.

Nevertheless, masks are still mandated in some jurisdictions. Those mandates usually don’t apply outdoors, however, and not in your own damn car! Mask mandates contribute to the general climate of fear surrounding COVID, which is wholly unjustified for most children and healthy working-age people. Public health messaging should focus on high-risk individuals: the elderly, the obese, and those having so-called comorbidities and compromised immune systems. Those groups have obvious reasons to be concerned about the virus. They have excuses to be germaphobic! Still, they are at little risk outdoors, the value of masks is doubtful, and breathing deep of fresh air is good for you in any case!

The incidence of COVID has declined substantially in many areas since early September, but the virus is now almost certainly endemic and is likely to return in seasonal waves. However, the Delta wave was far less deadly than earlier variants, a favorable trend many believe will continue. These charts from the UK posted by Michael Levitt demonstrate the improvement vividly. Perhaps the mask craze will fade away as the evidence accumulates.

The pandemic has been a moment of redemption for germaphobes, but no reasonable assessment of risk mitigation relative to the cost, inconvenience, discomfort, and psychological debasement of face jackets can prove their worth outdoors. Their value indoors is nearly as questionable. Yet there remains a stubborn reluctance by public health authorities to lift mask mandates. There are far too many individuals masking outdoors, and to be nice, perhaps it’s mere ignorance. But there are still a few would-be tyrants on Twitter presuming to shame others into joining this pathetic bit of theatre. I believe Anne Wheeler nailed it with this recent tweet:

“This is one of the first things you learn in OCD therapy – you don’t get to make people participate in your compulsions in order to lesson your own anxiety. It’s bizarre that it’s been turned into a virtue.”

There’s also no question that masks are still in vogue as a virtue signal in some circles, but a mask outdoors, especially, is increasingly viewed as a stupid-signal, and for good reason. I’ll continue to marvel at the irrationality of these masked alarmists, who just don’t understand how foolish they look. Give yourself permission to get some fresh air!

Cases Climb, Most Patients Faring Better

30 Tuesday Jun 2020

Posted by in Pandemic, Public Health

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There’s been much speculation about whether recent increases in confirmed cases of COVID-19 (first chart above) will lead to a dramatic increase in fatalities (second chart). More generally, there is curiosity or perhaps hope as to whether the virus is not as dangerous to these new patients as it was early in the pandemic. I have discussed this point in several posts, most recently here. Based on the national data (above), we’re at the point at which an upturn in deaths might be expected. Based on the experience of many individual states, however, deaths should have trended upward by now, but they haven’t done so. Cases are generally less severe and are resolving more quickly.

Of course, more testing produces more cases (though there has been a mild uptick in test positivity over the past two weeks), but that doesn’t really explain the entire increase in cases over the past few weeks. In particular, why are so many new cases in the south? After all, there is evidence that the virus doesn’t survive well in warm, humid climates with more direct sunlight.

As I have mentioned several times, heavy use of air-conditioning in the south may have contributed to the increase. Nate Silver speculates that this is the case. The weather warmed up in late May and especially June, and many southerners retreated indoors where the air is cool, dry, and the virus thrives. Managers of public buildings should avoid blasting the AC, and you might do well to heed the same advice if you live with others in a busy household. In fact, nearly all transmission is likely occurring indoors, as has been the case throughout the pandemic. At the same time, however, with the early reopening of many southern states, younger people flocked to gyms, bars and other venues, largely abandoning any pretense of social distancing. So it’s possible that these effects have combined to produce the spike in new cases.

Some contend that the protests following George Floyd’s murder precipitated the jump in confirmed cases. Perhaps they played a role, but I’m somewhat skeptical. Yes, these could have become so-called super-spreader events; there are certain cities in which the jump in cases lagged the protests by a few weeks, such as Austin, Houston, and Miami, and where some cases were confirmed to be among those who protested. But if the protests contributed much to the jump, why hasn’t New York City seen a corresponding increase? Not only that, but the protests were outside, and the protests dissuaded many others from going out at all!

The trend in coronavirus fatalities remains more favorable, despite the increase in daily confirmed cases. One exception is New Jersey, which decided to reclassify 1,800 deaths as “probable” COVID deaths about six days ago. You can see the spike caused by that decision in the second chart above. Reclassifications like that arouse my suspicion, especially when federal hospital reimbursements are tied to COVID cases, and in view of this description from Bloomberg (my emphasis):

“… those whose negative test results were considered unreliable; who were linked to known outbreaks and showed symptoms; or whose death certificates strongly suggested a coronavirus link.”

Deaths necessarily lag new cases by anywhere from a few days to several weeks, depending on the stage at the time of diagnosis and delays in test results. The lag between diagnosis and death seems to center on about 12 – 14 days. Thus far, there doesn’t appear to be an upward shift in the trend of fatal cases, but the big updraft in cases nationally only started about two weeks ago. More on that below.

Importantly, a larger share of new cases is now among a younger age cohort, for whom the virus is much less threatening. The most vulnerable people are probably taking more precautions than early in the pandemic, and shocking as might seem, there is probably some buildup in immunity in the surviving nursing home population at this point. We are also better at treatment, and there is generally plenty of hospital capacity. And to the extent that the surge in new cases is concentrated in the south, fewer patients are likely to have Vitamin D deficiencies, which is increasingly mentioned as a contributor to the severity of coronavirus infections.

I decided to make some casual comparisons of new cases versus COVID deaths on a state-by-state basis, but I got a little carried away. Using the COVID Time Series web site, I started by checking some of the southern states with recent large increases in case counts. I ended up looking at 15 states in the south and west, and I added Missouri and Minnesota as well. I passed over a few others because their trends were basically flat. The 17 states all had upward trends in new cases over the past one to two months, or they had an increase in new cases more recently. However, only four of those states experienced any discernible increase in daily deaths over the corresponding time frames. These are Arizona, Arkansas, Tennessee, and Texas, and their increases are so modest they might be statistical noise.

Again, deaths tend to lag new cases by a couple of weeks, so the timing of the increase in case counts matters. Five of the states were trending upward beginning in May or even earlier, and 13 of the states saw an acceleration or a shift to an upward trend in new cases after Memorial Day, in late May or June. Of those 13, the changes in trend occurred between one and five weeks ago. Six states, including Texas, had a shift within the past two weeks. It’s probably too early to draw conclusions for those six states, but in general there is little to suggest that fatal cases will soar like they did early in the pandemic. Case fatality rates are likely to remain at much lower levels.

We’ll know much more within a week or two. It’s very encouraging that the upward trend in new cases hasn’t resulted in more deaths thus far, especially at the state level, as many states have had case counts drift upward for over a month. If it’s going to occur, it should be well underway within a week or so. Much also depends on whether new cases continue to climb in July, in which case we’ll be waiting in trepidation for whether more deaths transpire.

Lockdown Illusions

16 Thursday Apr 2020

Posted by in Federalism, Liberty, Pandemic

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Analytical sins have occurred with great regularity in popular discussions of the Covid-19 pandemic and even in more scholarly quarters. Among my pet peeves are cavalier statements about the number of cases or deaths in one country or state versus another without adjusting for population. Some of this week’s foibles also deal comparisons of the pandemic and public policy across jurisdictions, but they ignore important distinctions.

No matter how you weigh the benefits and costs of lockdowns or stay-at-home orders, there is no question that maximizing social distance can reduce the spread of the virus. But stories like this one from Kansas dispute even that straightforward conclusion. As evidence, the author presents the following table:

Now, I fully support the authority of states or local areas to make their own decisions, but this table does not constitute valid evidence that stay-at-home orders don’t reduce transmission. There are at least three reasons why the comparisons made in the table are invalid:

  1. The onset of coronavirus in these states lagged the coastal states, primarily because…
  2. These are all interior states with few direct arrivals of international travelers;
  3. These states are all more or less rural with relatively low population densities, ranking 40, 41, 42, 46, 48, 49, 52, 53, and 55 in density among all states and territories.

All of these factors lead to lower concentrations of confirmed cases and Covid deaths (though the first applies only on the front-end of the epidemic). The last two points provide strong rationale for less restrictive measures to control the spread of the virus. In fact, population density bears a close association with the incidence of Covid-19, as the table at the top of this post shows. Even within low-density states, residents of urban areas are at greater risk. That also weighs heavily against one-size-fits-all approaches to enforced distancing. But instead, the authors fall over themselves in a clumsy attempt to prove a falsehood.

Even highly-educated researchers can race to wholly unjustified conclusions, sometimes fooled by their own clever devices and personal mood affiliation. This recent study directly controls for the timing of stay-at-home orders at the county level. The researchers attempt to control for inherent differences in county transmission and other factors via “fixed effects” on case growth (which are not reported). This is an excuse for “assuming away” important marginal effects that local features and conditions might play in driving the contagion. The authors conclude that stay-at-home orders are effective in reducing the spread of coronavirus, which is fine as far as it goes. But they also leap to the conclusion that a uniform, mandatory, nationwide lockdown is the wisest course. Not only does this neglect to measure the differential impact of lockdowns by easily measured differences across counties, it also assumes that the benefits of lockdowns always exceed costs, regardless of density, demographics, and industrial composition; and that a central authority is always the best judge as to the timing and severity of a mandate.

The national crisis engendered by the coronavirus pandemic required action at all levels of government and by private institutions, not a uniform set of rules enforced by federal police power. State and local police power is dangerous enough, but better to have decisions made by local authorities who are more immediately accountable to citizens. Government certainly has a legitimate role to play in mitigating behaviors that might impose external costs on others. Providing good information about the risks of a virus might be a pivotal role for government, though governments have not acquitted themselves well in this regard during the Covid crisis.

It’s also important for federal, state and local authorities to remember that private governance is often more powerful in achieving social goals than public rule-making. People make innumerable decisions every day that weigh benefits against risks, but public authorities are prone to nudging or pushing private agents into over-precautionary states of being. It’s about time to start easing up.