2.1 Threats to public health from urbanisation and industrialisation
The public health movement began in England in the nineteenth century in response to the huge toll of deaths from infectious disease in the urban slums and overcrowded tenement buildings that sprang up to house the influx of workers during the Industrial Revolution. An inspirational group of philanthropists founded the ‘sanitary movement’ or ‘sanitarianism’, with the aim of protecting the public health from sickness, which they recognised arose primarily from the polluted urban environment of the period.
The term ‘public’ encapsulates their focus on protecting the health of the population as a whole, rather than on treating or preventing disease in its individual members, and this emphasis characterises the public health approach today.
Quarantine is a period of enforced isolation or restriction of travel or activity. It is one of the oldest forms of public health intervention, pre-dating the germ theory of disease. In the nineteenth and early twentieth centuries, ‘fever’ hospitals and TB sanitariums were built outside major centres of population in Europe and the USA, to quarantine their patients away from the rest of society. This approach is still being applied in modern times: for example, in 2003, an isolation hospital was constructed in Southern China to quarantine people infected with the severe acute respiratory syndrome (SARS) virus.
From its earliest period, the advocates of public health strategies for tackling infectious disease promoted an evidence-based approach, collecting systematic data on the incidence and prevalence of disease, the geographical location, socio-economic circumstances and behaviour of cases, and the impact of interventions on subsequent disease rates. The insistence on evidence led to the gradual development of a new academic discipline – epidemiology – the collection, analysis and interpretation of data on the occurrence, distribution, potential causes and control of diseases, disorders, disabilities and deaths in populations.
Epidemiology remains central to modern public health in the twenty-first century, but the methods of data collection now involve global monitoring and surveillance networks and huge online databases.