There was a sudden onset of apprehension, followed by potentially violent cold shivers, headache, body pains and exhaustion. Then, after a few hours, there was profuse sweat followed by heat, headache, delirium, rapid pulse with heart pain and palpitations, intense thirst and in many cases, death within 24 hours.

The English sweat (AKA sweating sickness) was a deadly epidemic disease in England in the 1500s around the time of Henry VIII. I became interested in this after I saw it in The Tudors (A semi-historic series about Henry VIII). I wasn’t familiar with the disease, so I thought it might make a good topic for this blog. The disease is distinct from the plague (Yersinia pestis) and based on the descriptions, it was devastating, but not of the same magnitude as the plague. There were several outbreaks of the Sweating Sickness during the first half of the 1500s. The disease, as it was described, has never been seen since in the form of an outbreak or epidemic and, consequently, the cause remains a mystery. Using the symptoms and circumstances surrounding the outbreak, some scientists and historians have speculated about the cause of the disease. At first, the possibilities seem limited, as there are few diseases today that strike populations with the same severity among so many people especially in the northern latitudes of Europe. Hantavirus, Louse borne typhus, relapsing fever, influenza and even chronic fatigue syndrome have been suggested in the medical/history literature based on symptoms and infection patterns.

How could a disease like sweating sickness appear in a population, infect many individuals with devastating results, reappear again a few times over the course of several decades, and then vanish? There is little information available in the scientific literature other than historic accounts and speculation but I think that the following three scenarios are plausible:

1. Perhaps the sweating sickness was not one disease but several more common diseases that were confused by the poor science and medicine of the time (e.g. Brucellosis, Malaria, Typhoid fever). In other words, there was no real single disease epidemic.

2. Perhaps the few epidemics were sparked from chance encounter with an exotic/tropical virus that was able to gain only a temporary foothold and make a few rounds in Europe before fizzling out during the 16^th century. Possibly, this could have been aided by unusually warm weather.

3. It is possible that the agent of the disease emerged within Europe through the transformation of a more harmless common microbe into a killer. After making a few rounds, the disease induced broad immunity in the population preventing further epidemics of such large magnitudes. It could still be around today.

Immortal cells and transmissible cancers

Although Henrietta Lacks died of cancer almost 60 years ago, in a way, she still lives on. Prior to her death in the early 1950s, her cancer cells were collected by her doctor and grown outside of her body in a laboratory. Over the years, HeLa cells (as they were called to protect her identity) have been used for many experiments resulting in some very important scientific breakthroughs, such as development of a polio vaccine. These cells are special because, unlike most human cells, they are immortal. They have no limit (Hayflick limit) to cell division. Consequently, they reproduce and multiply is such a way that makes them relatively easy to grow in a tissue culture. They have evolved into what some consider a new species with an erie independence that can, at times, even be disruptive to researchers. HeLa cells have been known to contaminate other cell lines and grow "wild" within laboratories. While normal human cells have 46 chromosomes (23 pairs), HeLa cells have 76-80 chromosomes. When planted into animal tissue, HeLa cells can grow and produce a tumor, demonstrating that cancers can be transmissible. In general, other types of cancer cells share this pervasive behavior and immortality with HeLa cells. This has tragically been observed when human cancers are accidentally passed on to others from transplanted organs. While HeLa cells and other human cancers are transmissible only by artificial means (as far as we know), Devil facial tumor disease (DFTD) is an example of transmissible cancer that occurs in nature. This transmissible cancer of the grumbly little marsupials down under known as the Tasmanian Devil may severely imperil their populations. When devils bite each other, they pass on these cancer cells, which are derived from Schwann cells that normally support nerve cells. The devil's tumor cells have fewer chromosomes than the normal cells (13 instead of 14). Dogs also suffer from a form of transmissible cancer call Canine Transmissible Venereal Tumor (CTVT). Unlike devils, this cancer is sexually transmissible between dogs. Of course, the transmissibility of cancer agents is well known and widespread and not new. Viruses such as Hepatitis B, Hepatitis C, HPV and many others are known to cause cancer. However, this is quite different from transmissible cancers where the cancer cells themselves (rather than a virus) are passed on from one body to the next and continue dividing uncontrollably.