Epidemiological Explanations

Ballard’s first two categories offer a host of ecological factors that he believed influenced the prevalence of summer diarrhea from year to year and city to city. Among the “general” ecological conditions Ballard studied, he theorized that both atmospheric and surface temperature (measured at a depth of four feet below the surface) contributed to diarrheal mortality rates, but that surface temperature, which declined much more slowly than atmospheric temperatures, had a more significant impact. He observed that when average subsurface temperature exceeded 56°F diarrheal mortality was more likely to surge. In addition, he proposed that lower annual rainfall and a quiet windy season tended to contribute to a higher diarrheal mortality rate. Ballard also observed that regions of lower elevation often experienced higher infant mortality. Soil quality also mattered. Ballard believed that solid, impermeable rock reduced the frequency of diarrhea. Loose soil allowed more air and water in, which was favorable for bacterial growth. He further theorized that annual rainfall mattered as well – excess rainfall cleansed the soil of fouling bacterial growth.1Supplement in Continuation of the Report of the Report of the Medical Officer for 1887: Diarrhoea and Diphtheria, 2–4.

Local (especially urban) ecologies further influenced the ebb and flow of cases of summer diarrhea from year to year. Higher population density, Ballard argued, increased diarrheal mortality rates, because “dispersion over area disfavours diarrhoeal mortality” and “impediments to the free circulation of air promote diarrhoeal mortality.”2Supplement in Continuation of the Report of the Report of the Medical Officer for 1887: Diarrhoea and Diphtheria, 4. He observed that general dirtiness often went hand in hand with poor ventilation in crowded, poorer parts of large cities. He suggested that urban pollutants, including emanations from sewers, cesspools, or chemical works frequently compromised infant health in poorly ventilated homes. He argued that the accumulation of filth in the form of organic rotting waste kept in or near the home “where the free movement of air is impeded” resulted in a fouling of the air, which further contributed to a rise in cases of diarrheal mortality.3Supplement in Continuation of the Report of the Report of the Medical Officer for 1887: Diarrhoea and Diphtheria, 4–5. Given the nature of working-class housing, which was often comprised of densely occupied, ill-ventilated “back-to-back” housing, it is unsurprising that cases of summer diarrhea were most common among working-class children.

In his third category of causation (social conditions), Ballard introduced human agency into the equation. Unsurprisingly, since he associated the disease with filth, Ballard claimed that diarrhea was less common “among the well-to-do portion of the community, and comparatively great among families of the lower social grades.”4Supplement in Continuation of the Report of the Report of the Medical Officer for 1887: Diarrhoea and Diphtheria, 6. In part, he attributed this to diet. Ballard rejected a commonly held belief that indigestible food was a leading cause of diarrhea, and instead argued that “some extraneous substance in the food” was more likely to cause the malady. He applauded Medical Officers of Health, such as E.W. Hope, then Assistant Medical Officer of Health in Liverpool, who had found that infants fed at the breast were “remarkably exempt from diarrhea” compared to those fed with a bottle (later in this chapter I will contend that feeding, or at least the goal of keeping the baby’s food protected from emanations from filth, would become a centerpiece of the public health strategies intended to mitigate summer diarrhea). Finally, Ballard argued that maternal care or neglect played a major role in the frequency of diarrheal mortality. He suggested that illegitimate children, who disproportionately suffered from higher rates of maternal neglect, tended to suffer from higher rates of diarrheal deaths.5Supplement in Continuation of the Report of the Report of the Medical Officer for 1887: Diarrhoea and Diphtheria, 6–7.

Ballard’s study is just one example that highlights how contemporary physicians understood the epidemiology of summer diarrhea in late Victorian medical discourse. These ongoing epidemiological investigations were not exclusive to Britain. For example, W.S. Christopher, Professor of Diseases of Childhood at the Chicago Policlinic, also studied the causes of summer diarrhea and concluded that it resulted from a poison in the bowels that also caused constipation, fevers, kidney disorders, and, in some cases, even comas. Like Ballard, Christopher believed that the disease most often afflicted children between six months and one year of age. This was the point in an infant’s development when they were just beginning to start eating animal foods (such as cow’s milk) to aid in their rapid growth. Christopher argued that these foodstuffs, while easily digestible by adults, were also excellent hosts for microorganisms that could poison the intestines of infants, whose developing tissues easily absorbed both healthy nutrients and harmful, poisonous microbes. According to Christopher, unsanitary surroundings or alterations in temperature could also contaminate food.6Christopher, Summer Complaint and Infant Feeding, 30. As a result, Christopher argued, if a child was breastfed until at least six months of age (if not longer), they were at a much lower risk of microbial poisons compared to infants who were consuming (potentially contaminated) animal foodstuffs.7Christopher, Summer Complaint and Infant Feeding, 24–26. In 1897, German-Austrian pediatrician Theodor Escherich offered a similar etiological origin. He proposed that infant diarrhea was often caused by milk contaminated with streptococci bacteria from a cow’s uterus.8Dwork, “The Milk Option,” 57–58.

These international theories offer a sense of the bacteriological thinking about summer diarrhea in the late Victorian era. These are select examples of the literature that the Medical Officers of Health were immersed in – a literature which urged them to pay particular attention to the relationship between summer diarrhea, the environment, and diet as they began to expand the purview of public health. Based on a careful reading of their annual reports, I argue that the Medical Officers of Health, at least in Birmingham, Liverpool, and Manchester, were highly aware that the ecological conditions – both environmental and socially created – increased children’s susceptibility to summer diarrhea. In turn, the Medical Officers of Health took significant steps to reduce the threat of this deadly disease whenever they could.