Controlling Airborne Diseases: Tuberculosis and Covid

Another airborne disease, tuberculosis, was suppressed during the 20^th century. Could we do the same with covid?

Comparison

Overview

	Tuberculosis	Covid
Infectious agent	Mycobacterium tuberculosis bacillus	SARS-2 RNA virus
Transmission	Airborne aerosols, persistent indoors 4-6 hours. Direct sunlight kills the bacillus; outdoor transmission is less likely but does occur. Warm damp air maintains the bacillus.	Airborne aerosols, persistent indoors several hours. Denatured by direct sunlight; outdoor transmission is possible but less common.
Infectiousness	Modest but it was nonetheless widespread. Adequate methods to control the spread of the disease only emerged as its mechanism of transmission was discovered in the 20th century.	High. The disease is easily transmitted indoors unless precautions are taken.
Mutation rate	Slow. Antibiotic resistant strains have emerged over a period of years.	Fast. Resistant strains emerge within months.
Vaccines	Attenuated strain of Mycobacterium bovis, a bovine variant. The vaccine is most effective given in childhood and perhaps 50% effective overall.	Two mRNA vaccines, 95% effective, denatured partial SARS-2 virus protein vaccine, 90% effective.
Public health measures	Testing, vaccination, masking, quarantine. Ventilation, disinfection of contaminated air.	Testing, vaccination, masking, quarantine. Ventilation, disinfection of contaminated air.
Treatment	4-6 month course of antibiotics. In resistant cases, surgery	Antivirals, becoming increasingly less effective as resistant strains develop. Management of sequelae. Vaccination after infection sometimes effective against sequelae.

Course of disease

Tuberculosis

Most initial infections are asymptomatic, leading to a latent form. The latent form of tuberculosis is not contagious but can be detected with antigen tests. The latent form never entirely goes away without treatment. Immune suppression, as with HIV/AIDS, predisposing factors like diabetes, or just bad luck can lead to the disease becoming active. Once active, signs of lung infection appear and a general weakness overtakes the patient. Active tuberculosis can spread to other organs; the bacillus can infect multiple body systems. Unless treated, active tuberculosis is invariably fatal over a period of months or years; it is the canonical wasting disease and has been given many names over the centuries – phthisis, the white plague, consumption, … It is estimated that prior to the 19^th century 1 in 7 deaths were caused by tuberculosis.

Covid-19

Initial infection is not symptomatic but highly contagious. Sometimes an infection does not become symptomatic. Like tuberculosis, the disease is exceptionally dangerous to immune-compromised patients. The symptomatic form is initially an upper respiratory tract infection like a cold, but the disease can infect multiple body systems. Moderately severe cases can emerge as a disabling lung infection that typically lasts one or two weeks, followed by some weeks of recovery. Extremely severe cases require hospitalization. In perhaps 20% of infections, the acute phase is followed by long-term symptoms (“long covid” or “PASC” – post-acute sequelae of covid) of varying severity. In some cases, long covid is severely disabling or even lethal. The quick mutation rate of the virus, combined with the large number of infected patients, is troublesome; as with the common cold (and, I believe, most RNA viruses) infection by one variant does not provide immunity to others. Vaccines must be routinely updated and recent variants have become resistant to all previously effective antivirals.

Prospect

Covid can be controlled with the same methods that have dramatically reduced the spread of tuberculosis. So far, however, the will to do so is lacking. Tuberculosis has long been known as one of the great scourges of humanity and, because of this, rigorous measures to control tuberculosis were accepted when introduced. The dramatic efficacy of antibiotics against the disease helped acceptance by increasing the sense of control over the disease – it is unfortunately true that people are much less scared of a danger they feel they can control.

So far, there is much desperate denial of the dangers of covid. In high-income nations, the scourge of tuberculosis is two generations in the past, and it is hard, even, for people educated after tuberculosis was controlled to grasp how much of a scourge it was, and how willing people were to adopt rigorous measures to control it. The general human failure of risk assessment plays into this. Many cultures encourage risk-taking on the part of men and boys and so ignoring the real dangers of the disease has become part of masculinity. And yet men are higher risk and the odds of disability from covid infection are probably worse than that of death in Russian roulette.

At the 2023 World Economic Forum in Davos, an annual gathering of business and political leaders, rigorous measures to control the spread of covid were taken – all support personnel were masked, they tested every member when they arrived and shut them out if they were positive, there were air filters everywhere, people were wearing coats indoors indicating extensive ventilation. Bruce Y. Lee, author in the article I linked above, comments, “It is interesting to see the contrast between what’s being implemented at the WEF versus what you see in places around you and hear from the political and business leaders.” As there is an elite faction which has for over a century opposed making good medical care available to the masses, there is apparently one which would prefer that their inferiors be unhealthy, while protecting themselves.

I would like to end this on a positive note, but the history of public health doesn’t give me much reason for hope of a quick resolution. Over time, probably, anti-covid measures will be adopted but that could be a generation; that is about what it took seatbelts to be adopted. We do not yet know what the long-term dangers of covid infection are. The epidemic is only three years old. At this point, most children have been infected, and I fear we will see a rise in unexpected death and disability when they grow up. It will continue to kill the elderly, and the number of those deaths will be increased by the elder care facilities which refuse to mandate masking or vaccination.

So we blunder on, as the disease mows us down…unnecessarily.