The first wave of cholera had broken unexpectedly over Europe, provoking at first reactions that were little more than the application of lessons learnt from past attacks of pestilential disease. Already during this first pandemic, however, it became clear that inherited quarantinist strategies would not necessarily prove effective this time. Examining their own experience and that of their predecessors, each nation underwent an epidemiological learning process that undercut the standing of quarantinism. In cholera's second phase, the half-century from the late 1830s up through Koch's discovery of the comma bacillus as the disease's cause and the gradual acceptance in official circles of its preventive implications during the late 1880s and early nineties, a similar process of experimentation, trial, error and the accumulation of experience continued. This increase in knowledge, though commonly shared among all nations, did not, however, lead in any automatic sense to uniform prophylactic strategies. States continued to take divergent approaches to cholera and other contagious diseases; indeed it may well have been that differences in national preventive tactics increased. Why, given a shared and increasingly accepted basis of knowledge, different tacks to a common problem persisted, is the question in need of an answer.

In the decades following the first epidemic, medical opinion remained largely unformed, while public health authorities continued the retreat from their initially strict quarantinism.