Thursday 7 January 2016

Faecal-oral paradigm: part 1

The Broad Street pump, London, was pivotal in 
John Snows identification of the faecal-oral paradigm.
Source:  (Secret cities, 2015).

Despite the groundbreaking identification of John Snow, Sutherland and others in the 19th century Britain of the link between cholera and many other diarrhoeal diseases to the consumption of faecal matter through water,  faecal-oral transmission and consumption still remains significant in disease incidence throughout urban areas with poor urban water and sanitation within Africa. 

This four part mini-blog series aims to revisit Snow et al. fundamental contributions to the faecal-oral paradigm as well as look at the range of arguments now within academic literature as to what factors primarily restricts faecal-oral transmission, thus preventing disease incidence.

The first officially recorded case of cholera in 19th century Britain occurred in 1831 in Sunderland. Over the proceeding 30 years,  Britain suffered four pandemics with the most serious occurring in 1849 with 53,000 registered deaths for England and Wales (Snow, 2002). The fear created by cholera led to over 700 individual works on its cause and transmission published between 1841 and 1856. Snow (2002), (not John Snow!) highlights how miasmatic theories, whereby disease was thought to be caused by 'bad air', were central to debates surrounding the causes and transmission of Cholera. Prevention took the form of sanitary improvements and this was echoed in the Board of Health's report on the 1849 cholera outbreak which argued that the best approaches to tackling cholera revolved around cleaning up the physical environment including air purification and waste disposal

In an independent report by John Sutherland, who also worked for the Board of Health, he recognised whilst still affirming the importance of sanitary improvements,  water as a predisposing  and casual factor (but not a primary cause) in relation to cholera epidemics. He used statistical evidence to show that cholera cases occurred in houses using a contaminated pump in Hope street, Sutherland (Snow, 2002). However, John Snow was the first to suggest that contaminated water was in fact instrumental in the spread of cholera and not just disposing using the infamous outbreak in Broad/Broadwick street and on differing suppies of water to south London . Snow argued that cholera was introduced into the alimentary canal though swallowing of cholera poison, when cholera faeces entered the public water supply 'either by permeating the ground and getting into well, or by running long channels and sewers into the rivers' (John Snow in Snow (2002). The preventative measures suggested focus on thorough personal hygiene (doctors rarely rarely were infected by patients) and the controlling of disease though its environment (in line with the Board of Health's core responses). It is interesting to note that these suggestions are still central to arguments as to what factors restrict faecal-oral transmission today (see part 3).

Despite John Snow publishing his findings on cholera in 1849, as Smith (2002) argues in a commentary on mid 19th century epidemiology, success in fighting cholera must be 'judged against the fact that cholera is still an endemic disease in in many poor parts of the word. Knowledge of how to prevent cholera has not been translated into action'. Smith also highlights how in the mid-19th century links between cholera and poverty were being made with calls for the rich to act to help the poor. William Bud in 1848 argued that 'we are all more nearly related here than we are apt to think...he that was never yet connected with his poorer neighborhoods by deeds of charity or love, may one day find, when it is too late, that he is connected with him by a bond which may bring them both, at once, to a common grave' (Bud in Smith (2002). Smith suggests that this has a close resemblance to some arguments on the role of income inequality in health today with arguments that higher levels of inequality is associated with worse health among the poor but also for the rich.

The key findings of the 2015 Joint Monitoring Program for water supply and sanitation demonstrated that 2.4 billion people still lack access to improved sanitation facilities further showing how despite the faecal-oral paradigm being discovered in the mid-19th century sanitation improvements are still not sufficient.  Within this context, part 2 of this blog outlines the current global situation with regards the faecal-oral paradigm.

For part 2 click here.

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