Corona viruses are a family of viruses that cause respiratory illness but also symptoms as mild as the common cold. This family of viruses includes Middle East Respiratory Syndrome, Severe Acute Respiratory Syndrome and most recently, COVID-19, which, when severe, also causes respiratory distress.
Coronavirus (COVID-19) was probably first detected in the city of Wuhan in China in late December 2019, possibly in a seafood market. This caused a cluster of cases of acute respiratory disease, that spread rapidly with major outbreaks in Brazil, Russia, India, Mexico, Peru, South Africa, Western Europe, and the United States. This was first declared a pandemic in March of 2020 and represented the most recent pandemic since the swine flu pandemic of 2009.
The reservoir of this particular virus is in horseshoe bats. COVID-19 may present with ocular symptoms including conjunctivitis, eyelid erythema and foreign body sensation. It also may produce anterior uveitis, optic neuritis, vasculitis or retinitis. The chance of spread from the tears is low and this virus is usually spread by aerosol inhalation. The details of ophthalmic involvement were noted by Li Wenliang, MD, a Chinese ophthalmologist who saw several patients, reported his concerns, for which he was censured, and then died from the disease. He was one of COVID-19’s first victims.
According to the World Health Organization (WHO), as of October 2022, there were at least 620 million people worldwide who had been infected with COVID-19, and approximately 6.5 million died. However, these numbers are likely underreported since testing has been a problem. Most patients die from hypoxia due to pulmonary involvement. Survival of the elderly, once intubated, is extremely low.
Fellow ophthalmologist, Li Wenliang, MD, who was the first to blow the whistle on the COVID-19 epidemic in China and later died from the disease.
Even in the modern era, the most important strategy in mitigating a pandemic is containment (isolation, quarantine, masks if aerosol spread as was recommended by the Red Cross in 1918. Going back centuries, plagues were thought to reflect the religious idea that it was the gods who made us sick. Plagues are a way that gods seek to get our attention about finitude and mortality.
Science only became involved in the history of medicine during the middle of the 19th century. Thus, we learned the importance of water-born dissemination from the Broad Street Pump during a cholera epidemic. It was really Louis Pasteur, however, who introduced the germ theory, suggesting that disease was caused by microorganisms. The initial presumption was that all diseases were due to bacteria, but it did not take long until it was recognized that there were other mechanisms.
One, as in the case of diphtheria, was that a toxin alone could do damage (noted by Emile Roux and Alexandre Yersin). Diphtheria toxin without diphtheria could produce the significant pathologic features. Antitoxins (initially by G.J. Hermann and Charles Reynolds) could save lives. Additional work by Emil von Behring showed that a mixture of diphtheria toxin and antitoxin could produce lasting protection from diphtheria (the first pharmaceutical cure). A diphtheria outbreak in Nome, Alaska led to the 800-plus mile importation of antitoxin by dog sled from Neanna to Nome. William Park, chief of the laboratory division of the New York Health Department and his deputy Ann Williams were able to produce an antitoxin that was 500 times as potent as the Europeans in 1894.
Population medicine also largely started in France with Pasteur (he created the first vaccine against rabies) and then was refined with experimental work in Germany. It is not surprising therefore that the advent of the medical school at Johns Hopkins significantly accelerated the acquisition of knowledge. William Welch (who had spent time in New York but had studied in Germany) had adopted the German approach to medicine. It was fortuitous that he was recruited to Johns Hopkins, a new medical school in Baltimore. Other developments were brought from Germany including the development of various dyes to stain microscopic specimens particularly in the study of Anthrax.
Lessons from Previous Pandemics
The 1918-20 influenza plague certainly provides important lessons for us today as we face the COVID-19 pandemic. Some of those lessons have been accepted but many have been ignored. In the absence of a specific treatment or vaccine we must fall back on the public health response which was lacking in 1918. If there is any chance to limit the geographical spread of the disease, officials must have the legal power to take quarantine measures. There was a waste of resources in 1918 in New York City as institutions worked in cross purpose to each other. The same applies today.
The World Health Organization has published documents for pandemic preparedness in 1999 (revised in 2005 and again in 2009). The Centers for Disease Control and Prevention also adopted a pandemic severity assistance framework in 2014 based particularly on fatalities although realizing that fatalities alone may not account for the full effect of a pandemic. They went on to analyze management being divided into containment and mitigation. Mitigation involves nonpharmaceutical means to limit spread and provides more time for developing vaccine and other treatments. Particularly for viruses spread as an aerosol, this includes antibacterial hand liquids, face masks, self-quarantine and community measures aimed at social distancing. In these days when development of vaccine seems to be accelerated, these means of mitigation are critical to reduce spread early on. This has been adopted in several locations including China.
Pandemics have been related to bacterial problems including bubonic plaque, mycobacterial problems including tuberculosis (which may affect one-fourth of the world’s population), parasites and viruses. DNA viruses include smallpox; RNA viruses produce yellow fever, Zika, measles, influenza, polio, AIDS, SARS, Ebola, and the current epidemic of COVID-19. Parasitic pandemics include malaria and toxoplasmosis. We now have new tools for investigating these pandemics, even in retrospect.
Johann Wolfgang von Goethe said, “We look for what we know, and we find what we look for.” Even without a specific vaccine there are measures which may mitigate disease by flattening the curve some of which were effective 100 years ago. In view of the propensity for RNA viruses to mutate, new vaccines may need to be given yearly. Unfortunately, it isn’t just the sick and dying that affect us; there are social and economic aspects that threaten us in this and future pandemics. We can be sure that COVID-19 will not be the last pandemic.
See previous articles in the series:
On Pandemics: Etiology of Pandemics – Part 1
On Pandemics: Historical Considerations of Pandemics – Part 2
On Pandemics: Viral Influenzas and the 1918 Great Influenza – Part 3