Dysentery epidemic killed many in the 1700s-1800s

Dysentery, or rödsot as it used to be called in Swedish, remains a major problem in developing countries. In the Western world, however, the disease is almost gone. Yet prior to the decline in infectious diseases among causes of death in the 1800s, Sweden was at times struck very hard by the disease, with catastrophic consequences.

'The disease had detrimental effects, but the geographical differences were significant. For example, 90 percent of all deaths in a parish could be due to dysentery in some years, while nearby parishes were left practically unaffected,' says the author of the thesis, Helene Castenbrandt.

Castenbrandt studied how the disease struck Sweden during the period 1750-1900, with a focus on changes over time as well as regional and local differences. Jönköping County was used as a case study. Besides demographic data, she also used parish registers, maps, newspapers, reports from medical district officers and other information written down by doctors.

Many historians have described dysentery as a regularly recurring and not very serious disease. Cholera and smallpox are often described as the most devastating epidemic diseases of that era. But Castenbrandt's results beg to differ.

'My study points to dysentery as very epidemic in nature. The disease struck communities extremely hard at times. It flared up quite irregularly and the patterns of transmission differed from one outbreak to the next.'

Using Jönköping County as an example, the study clearly shows the vast differences in dysentery mortality within the same county. The pattern of transmission for the three most severe outbreaks in 1773, 1808 and 1857 shows that although the disease spread across almost the entire county, there were some clusters with extremely high mortality. However, the hardest hit parts of the county varied.

The thesis also analyses the reasons behind the presence and disappearance of the disease. The results point to complex links between possible explanations such as sanitary conditions and population concentrations for example in connection with wars.

'It is likely that many factors interacted, which makes it difficult to identify one single reason why dysentery emerged and disappeared. I hope future studies will be able to explore these links,' says Castenbrandt.