Tag: coronavirus

The Lasting Effects of the 1918 Influenza Pandemic

[I’ve never put a trigger warning on a post before but given the current situation the information here is potential upsetting to anyone expecting a child. I do not think that the current pandemic will be as bad as the 1918. I am also hopeful that the weather will work in our favor and that, as Tyler argued, America will start to work. Do also read my post, What Worked in 1918-1919 for a more positive message.]

The 1918 influenza pandemic struck the United States with most ferocity in October of 1918 and then over the next four months killed more people than all the US combat deaths of the 20th century. The sudden nature of the pandemic meant that children born just months apart experienced very different conditions in utero. In particular, children born in 1919 were much more exposed to influenza in utero than children born in 1918 or 1920. The sudden differential to the 1918 flu lets Douglas Almond test for long-term effects in Is the 1918 Influenza Pandemic Over?

Almond finds large effects many decades after exposure.

Fetal health is found to affect nearly every socioeconomic outcome recorded in the 1960, 1970, and 1980 Censuses. Men and women show large and discontinuous reductions in educational attainment if they had been in utero during the pandemic. The children of infected mothers were up to 15 percent less likely to graduate from high school. Wages of men were 5–9 percent lower because of infection. Socioeconomic status…was substantially reduced, and the likelihood of being poor rose as much as 15 percent compared with other cohorts. Public entitlement spending was also increased.

At right, for example, are male disability rates in 1980, i.e. for males around the age of 60, by year and quarter of birth. Cohorts born between January and September of 1919 “were in utero at the height of the pandemic and are estimated to have 20 percent higher disability rates at age 61…”.

Figure 3 at right shows average years of schooling in 1960; once again the decline is clear for those born in 1918 and note that not all pregnant women contracted influenza so the actual effects of influenza exposure are larger, about a 5 month decline in education, mostly coming through lower graduate rates.

Higher disability and lower education translate into greater government payments as show in the final figure below. Almond labels these welfare payments which might be slightly misleading–these are Social Security Disability payments in 1970. Here’s Almond:

Average payments to women and nonwhites in 1970 are plotted in figure 8. The average welfare payment was 12 percent higher for both women and nonwhites born in 1919, or approximately one-third higher for children of mothers who contracted influenza. When we focus on quarter of birth, it is apparent that these increased payments are generated by high payments to those born between April and June of 1919.

Note that men and women who were especially disabled could have died before 1970 and so these are lower bounds on the disability impact.

Fetal exposure seems to be the key as Almond tests for and rejects other possibilities. The 1918 kids, for example, seem about the same as the 1920 kids so it’s not that the flu killed off the weak kids in 1918.

Almond was interested in the 1918 pandemic not simply as a historical episode but to make the case that infant health and infant health programs have high benefit to cost ratios, a still relevant lesson.

Hat tip: Wojtek Kopczuk.

What Worked in 1918-1919?

The influenza pandemic of 1918 was the most contagious calamity in human history. Approximately 40 million individuals died worldwide, including 550 000 individuals in the United States...[C]an lessons from the 1918-1919 pandemic be applied to contemporary pandemic planning efforts to maximize public health benefit while minimizing the disruptive social consequences of the pandemic as well as those accompanying public health response measures?

That’s the question Markel et al. analyzed in 2007 by gathering historical data on outcomes and what 43 US cities, covering about 20% of the US population, did to combat influenza in 1918-1919.

Nonpharmaceutical interventions were considered either activated (“on”) or deactivated (“off”), according to data culled from the historical record and daily newspaper accounts. Specifically, these nonpharmaceutical interventions were legally enforced and affected large segments of the city’s population. [1] Isolation of ill persons and quarantine of those suspected of having contact with ill persons refers only to mandatory orders as opposed to voluntary quarantines being discussed in our present era. [2] School closure was considered activated when the city officials closed public schools (grade school through high school); in most, but not all cases, private and parochial schools followed suit. [3] Public gathering bans typically meant the closure of saloons, public entertainment venues, sporting events, and indoor gatherings were banned or moved outdoors; outdoor gatherings were not always canceled during this period (eg, Liberty bond parades); there were no recorded bans on shopping in grocery and drug stores.

The authors define “public health response time” as the number of days from the day the excess death rate was double baseline to the day that at least one of their three key public health measures was implemented. Cities that responded very early have a negative public health response time. The basic result is shown in the figure below. The longer the public health response time the greater the total excess deaths (the arrow is my least squares eyeball).

Moreover, although it’s difficult to control for other factors, cities that combined school closures, isolation and quarantining, and public gathering bans tended to do better. Some cities let up on their public health interventions and these cities seem to correlate well with bi-modal distributions in excess death rates, i.e. the death rate increased. Denver was an example where the public gathering ban was dropped and the school ban was lifted temporarily and the excess death rate rose after having fallen.

The authors conclude:

…the US urban experience with nonpharmaceutical interventions during the 1918-1919 pandemic constitutes one of the largest data sets of its kind ever assembled in the modern, post germ theory era.

…Although these urban communities had neither effective vaccines nor antivirals, cities that were able to organize and execute a suite of classic public health interventions before the pandemic swept fully through the city appeared to have an associated mitigated epidemic experience. Our study suggests that nonpharmaceutical interventions can play a critical role in mitigating the consequences of future severe influenza pandemics (category 4 and 5) and should be considered for inclusion in contemporary planning efforts as companion measures to developing effective vaccines and medications for prophylaxis and treatment. The history of US epidemics also cautions that the public’s acceptance of these health measures is enhanced when guided by ethical and humane principles.

Addendum: Another way of putting this is that China has largely followed the US model. Can the US do the same?