Measles in the European Past: Outbreak of Severe Measles in an Isolated German Village, 1861

Abstract

Background: In 1861, Hagelloch, an isolated village in Germany, experienced a measles epidemic, which affected nearly all children under 14 years of age. We examined determinants of severe measles. Methods: A contemporary medical thesis by Albert Pfeilsticker had sufficient information on timing of measles cases within all households in the village to make it possible to determine who were index cases, infected outside the household, and who were secondary cases, infected after exposure in the household. Results: The measles case fatality ratio (CFR) was 6.4% (12/187); 10.0% (7/70) for children under five years of age. The youngest class in the local school was the epicentre of the epidemic; all children aged 7-9 years contracted measles at school and became index cases in their own families. The frequency of secondary cases was higher among younger and older children. Overall 44% (82/187) of the children were secondary cases. Secondary cases tended to have higher CFR than index cases (RR=3.03 (95% confidence interval: 0.91-10.07)), whereas there was less difference in the risk of complications (RR=1.34 (0.78-2.28)). The CFR was higher for boys than girls (4.46 (1.03-19.22)), and boys were more likely to suffer severe complications than girls (RR=1.73 (0.97-3.08)). Boys who were infected by a girl had higher CFR than boys infected by other boys (RR=6.30 (1.18-85.64)). Children under five years of age, who survived measles infection, did not have higher mortality in 1862; the 11 children who had not had measles in 1861 had a RR of dying in 1862 of 4.17 (1.22-14.28) compared with those who had measles in 1861. Conclusion: When measles was severe in Europe, the determinants of fatal infection were similar to those observed more recently in low-income countries. Changes in intensity of exposure within the home, due to smaller family size, better housing, and more public childcare, may have been major causes of the mortality decline in the industrialized countries during the 19th and the early 20th centuries. Funding: PA has received support from the Danish Council for Development Research, the Danish Medical Research Council, the Danish National Research Foundation and the Novo Nordisk Foundation. Declaration of Interest: None to declare.