Inconspicuous Consumption

“The pandemic is over,” so we’ve heard. Yet, three years after the first cases appeared in North America covid continues to stalk us. Some jurisdictions (LA among them) consider reinstating mask mandates and other restrictions as new cases rise. I won’t discuss the merits or flaws of previous and current responses. Enough talking heads do that and, despite what they say, the argument is never entirely “about the science,” for even when people agree on the purely medical aspects of the disease, they still disagree on policy due to differing values of the tradeoffs involved. I won’t join the finger-wagging on any side. But I am reminded of another endemic scourge that in the 19^th century for a quarter of the population was (sooner or later) a cause of death: tuberculosis (TB for short) or “consumption” as they commonly called it then. I don’t know if it offers any lessons on covid, but it at least puts the matter in perspective.
 
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Symptoms include formation of tubercles, especially in the lungs, leading to coughing, fever, expectoration of (sometimes bloody) sputum, and difficulty breathing. It has been around throughout recorded history, and probably far into prehistory. Tuberculosis has been found in Egyptian mummies several thousand years old. It is described in ancient Indian and Chinese texts – and later in Greek and Roman ones. It is found in pre-Columbian Peruvian mummies, indicating it was carried across the Siberian land bridge 15,000 years ago (if not earlier). It remained widespread throughout ancient and medieval times. To this day about a third of the global population carries the latent infection asymptomatically. Those with weakened immune systems are most at risk of becoming symptomatic, but the disease can appear in an otherwise seemingly healthy person. Unlike covid, it hits the young harder than the old. Unhygienic conditions common in urban settings (especially before the 20^th century) tax immune systems, and so unsurprisingly are associated with a higher risk for the disease.
 
In his paper A New Theory of Consumption English doctor Benjamin Marten in 1720 conjectured that the disease was contagious even though it didn’t spread as rapidly and reliably as other plagues. He was proven correct in 1882 by Robert Koch who isolated the TB bacillus. The term tuberculosis had been invented by Johann Schoenlein in the mid-1800s, though the disease continued to be called consumption by much of the general public well into the 20^th century. 19^th century physicians developed a treatment for TB: rest, fresh air, and sunshine, preferably at high altitudes. (This isn’t far off from the prescription of Galen, the Roman medical author who was also the personal physician of emperor Marcus Aurelius: he recommended the fresh air and sunshine of a long sea voyage.) Sanatoria popped up in places like Colorado and Switzerland specifically to treat TB patients. This wasn’t really a cure. The patients remained infected. Many of them died in these facilities, but others did see their symptoms abate to the point where they could resume something close to normal lives.

Huts for TB patients in Colorado

It wasn’t until after World War 2 that TB cases began to plummet with the invention of effective antibiotic treatments, which not only cured the ill but thereby reduced transmission to others. (Those with latent infections do not transmit the disease.) By 1980 the chance of getting TB in North America and Europe had become small, but in that decade a spike occurred. Those with HIV were susceptible to TB as were those with diabetes and other stresses on the immune system. Worse, new strains of Mycobacterium tuberculosis appeared that were resistant to standard antibiotic treatment.
 
Today in the US the number of cases is still modest by historical standards but far from negligible. According the CDC there were 7,882 reported cases of TB in 2021, a rate of 2.4 per 100,000 (historical rates were orders of magnitude higher) though the agency acknowledges there probably is significant underreporting. Latent infections are estimated at 13,000,000, which is low by world standards but still a huge population in absolute terms.
 
The good news from this history is that it is indeed possible to reduce and control a longstanding dangerous endemic disease. The bad news is that it is nearly impossible (when not just plain impossible) to eliminate it. The bugs fight back. Sometimes all we can do (as individuals – I do not speak to public policy) is judge our risks and act as we see best.
 

Maria Muldaur – TB Blues