A bacterial infection. I hadn’t thought of a bacterial infection. I was sure, with my internet medical degree, that I had a viral infection, the flu or Covid. My symptoms were a low-grade fever and fatigue, and occasionally, when I would cough, a short-lived headache. All the things I had when I had Covid…so I was sure it was viral.

Many things cause what we think of as a “disease”. You have protozoa such as worms and amoeba. You can get ill from fungus, and of course, you have bacteria and viruses. Before we knew of all these “pathogens” the general idea was that disease was caused by “miasma”, or bad air. This belief was based upon the healer Galen in the first century A.D. He wrote about it and his medical book survived the Crusades and was considered the final authority on all things medical in Renaissance Europe.

The first idea that “germs” caused disease came from German scientist, Athanasis Kircher, who thought he could see little things in the blood of plague victims. We don’t know what he saw, but his microscope was not very good, and it is probable he saw white blood cells. The first to actually see protozoa, which he called “animalcules”, and bacteria, was Anton van Leeuwenhoek in 1674.

While aware that these microscopic “things” existed, most biologists and physicians still didn’t believe they were pathogens until Louis Pasteur showed that they didn’t spontaneously generate in rotting materials, but instead, they were the agents responsible for causing things to rot. Why not diseases? Thus, he proposed the Germ Theory of Disease. Based upon that Theory, in 1884 Robert Koch developed Koch’s Postulates, a series of steps to determine if microscopic creatures were the cause of a disease. The disease Koch worked with was anthrax, thus it became the first known bacterial disease.

Bacteria are relatively large…compared to viruses. It was found that you could filter all the bacteria from fluids and yet the fluid could still cause the disease. Dmitry Ivanovsky was the first to discover that. He was studying tobacco mosaic, a plant disease, and he found that even after filtering the fluid from one infected plant, the left-over fluid still held a poison… which he named “virus”. James Carroll, working with Walter Reed on the Yellow Fever Commission, showed that a filterable “virus”, or poison, could transmit yellow fever, the first human viral disease identified.

Most know the story of Alexander Fleming and the discovery of antibiotics (one of which I am presently taking). Fleming’s first discovery was not penicillin, however, it was lysozyme. He was working with bacterial cultures and had a cold. Snot dripped from his nose onto a bacterial culture. He didn’t clean it up and later discovered that the bacteria near the snot had died. He determined the bacteria killing ingredient in the snot, lysozyme, was also in tears and for the next six weeks he paid lab assistants to suck on lemons in order to produce tears which he harvested for his work. Unfortunately the lysozyme in tears wasn’t strong enough to be made into a medicine.

Next came the story of rotting orange peels and the fungus Penicillium, which also killed bacteria. Ten years later two English scientists purified and stabilized penicillin, the chemical produced by the fungus, and the first antibiotic was available just in time for World War II.

Which - protozoan, bacterial, or viral are the worst diseases? One disease caused by a protozoan, malaria, has probably killed more people than any other disease. The Black Plague, killed one third of Europe and cholera is the cause for all the graves along the Oregon Trail. They are bacterial in nature. We have smallpox, yellow fever, and the flu, which are all viral and they have killed millions.

But, which is the worse? My guess is you would say the one you have at the time and at present, apparently, I have a bacterial infection and it is worse than the viral Covid infection I had last year! But thanks to Sir Alexander and his rotting oranges, I’ll soon be over it!