The most devastating disease during the second half of the war was bubonic plague, which is often simply called “the plague.” There are three forms of the disease:
Bubonic itself, the most common form, is not usually transmitted from one person to another, and is frequently fatal;
Septicemic, which is usually quickly fatal, often before plague symptoms even show, and is easily spread if it reaches the lungs;
Pneumonic, in which the infection starts in the lungs and spreads to anyone breathing nearby. This version is almost always fatal, the sort of thing that gives Dr. James Nichols nightmares in the series.
Plague is caused by the Yersinia pestis bacterium. It is usually spread by fleas, especially those found on rats. Plague can be treated by many antibiotics, including sulfa drugs, but it is not affected by penicillin. Modern vaccines are good for only about six months. (It is interesting to note a recent discovery that a genetic mutation in some people that makes them resistant to plague also makes them resistant to AIDS.)
Prior to 1630, the most devastating disease during the Thirty Years War was probably typhus, also called “gaol fever,” “camp fever,” and “the Hungarian disease.” Typhus was spread from person to person by body lice, common especially with armies. The disease probably caused far more deaths during the Thirty Years War than the armies caused directly in the course of fighting battles. It devastated many German cities.
Typhus is caused by a rickettsiae, a small kind of bacteria, with the specific name Rickettsia prowazekii. It is fatal about one-third of the time, and more so in the sick and elderly. It is rapidly and effectively treated by the antibiotics tetracycline or chloramphenicol, but not penicillin or sulfa drugs. It can be prevented by getting rid of body lice, i.e., by sterilizing clothes, using insecticides, and bathing.
Smallpox was also endemic during this time period. It is caused by the Variola virus, and is spread only by breath at close contact. It did not tend to spread as rapidly as the plague or typhus. Still, it was frequently fatal, with no known treatment until Edward Jenner discovered that vaccinating with cowpox, a very mild infection caused by the Vaccinia virus, prevented the spread of the disease. It is not treatable by antibiotics. Many of the people in Grantville who are over the age of forty will have some resistance to smallpox due to childhood vaccination. They probably won’t have enough resistance to prevent the disease, but are likely to have enough to reduce its severity.
Syphilis was apparently a much more lethal disease several centuries ago than it is today. Spread mainly by sexual contact, it killed half its victims after several years, many of them going insane before they died. Syphilis is treatable at an early stage with penicillin and other antibiotics, but not sulfa drugs. The first effective drug was called salvarsan, a fairly toxic mercury-based compound.
Tuberculosis, commonly referred to today as TB, is an infection that usually starts in the lungs. It is bacterial in nature, and the airborne version mainly infects those who are sick or elderly. A different version is spread from unpasteurized milk, and effects mostly children. Also called consumption, it weakens its victims over time before often killing them. It is difficult to treat, but can be treated with streptomycin, as well as some TB-specific drugs, such as isonazid.
Fortunately, the childhood version of the disease can be prevented by pasteurizing milk, a process which will be rather quickly available in the 1632 context given the modern knowledge of the characters. But an even simpler method which can be applied immediately is just to boil milk before using it. This is one of those diseases which can be prevented by the application of simple prophylactic measures known to modern medical science.
Staphylococcal bacteria often caused infections in wounds, as well as food poisoning. They are usually treatable with antibiotics. Streptococcal bacteria cause strep throat, as well as scarlet fever, in which the infection reaches the blood stream and often infects the heart. It is also treatable by antibiotics.
Antibiotics
Today, there are a large number of antibiotics available to treat various kinds of infections. The reason so many different antibiotics are needed is that the bacteria that cause the diseases mutate, or change, to better survive in their environment. So while in the 1950s there were originally only half a dozen different kinds—such as penicillin, tetracycline, and streptomycin—now there are many dozens, some of which are no longer used because they don’t work as well against today’s mutated versions.