I was walking through the streets of Frederick, Maryland, yesterday when I came upon a small shop where the “Map Man” was sitting in a room full of maps. Now, when I write that the room was full of maps, I mean that the room was literally full of maps. He had maps from all sorts of sources and eras. There were maps as small as a postage stamp and as big as a wall.
As we talked, the topic of my work as an epidemiologist came up. I told him that we used map for much of our work in tracking diseases and their spread through the community. He was very intrigued to hear about John Snow’s cholera map from 1854. He told me he had some disease maps lying around and pulled out a map of Vermont from 1879. He said it was in an old publication he found while visiting Vermont. Whether it is an original map or a reproduction for a book printed later (which is most likely), is not known.
This made me curious about what happened then, so I searched in the database for The New York Times and found a small article from 1879 where a local report of diphtheria transmission was filed:
There is an article in the St. Albans Messenger, but it is behind a paywall. Nevertheless, something happened in that part of the United States regarding diphtheria and someone tried to use mapping to figure it out. As you can see, they even closed schools to prevent the spread of the disease. At this time in history, the germ theory of disease was not yet established as the paradigm for combating diseases, so there was probably nothing they could do but social distancing and hope for the best.
Today, there is a safe and effective vaccines against diphtheria. In the United States, it is given in combination with the tetanus and pertussis (whooping cough) vaccines during childhood. It’s been so effective that cases of diphtheria are almost unheard of in the United States. According to the Centers for Disease Control and Prevention:
“Diphtheria once was a major cause of illness and death among children. The United States recorded 206,000 cases of diphtheria in 1921, resulting in 15,520 deaths. Starting in the 1920s, diphtheria rates dropped quickly due to the widespread use of vaccines. Between 2004 and 2017, state health departments reported 2 cases of diphtheria in the United States. However, the disease continues to cause illness globally. In 2016, countries reported about 7,100 cases of diphtheria to the World Health Organization, but many more cases likely go unreported.
The case-fatality rate for diphtheria has changed very little during the last 50 years. The overall case-fatality rate for diphtheria is 5%–10%, with higher death rates (up to 20%) among persons younger than 5 and older than 40 years of age. Before there was treatment for diphtheria, the disease was fatal in up to half of cases.”