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How did it become accepted that Cholera was spread by ingesting infected water?

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Presentation on theme: "How did it become accepted that Cholera was spread by ingesting infected water?"— Presentation transcript:

1 How did it become accepted that Cholera was spread by ingesting infected water?

2 Explain how miasmic theorists came to accept that Cholera was spread by consuming infected water…

3 Miasmatists… Edwin Chadwick Poor Law Commission Secretary John Simon London Medical Officer William Farr Chief statistician in marriages and deaths Never changed his mind! Changed his mind by 1870 Changed his mind by 1866

4 Original arguments by Miasmatists ‘diseases are caused by dirty air produced by rotting animals and vegetables.’ ‘all smell is disease’ Times Newspaper 1853 Chadwick ‘the poison of cholera is an emanation from the earth.’ Florence Nightingale Criticised building of drains under houses as it could spread miasma causing smallpox and scarlet fever Dr Duncan (firsts medical officer ever) ‘air below three feet is unsuitable for respiration.’ THE WATER LOOKED CLEAN – NASTY SMELLS WERE EVERYWHERE!

5 John Snow helped to convert some Miasmatists… 1849 – On the mode of Communication of Cholera – water infected by sewage may cause cholera to spread 1854 Cholera epidemic – Snow produces ‘cholera map’ showing links between deaths and the Broad Street Pump Snow, ‘-the water propagates the disease and stops it from dying out through not reaching fresh victims.’ Pump handle removed from Broad Street!

6 Snow produced further evidence of infected water causing Cholera 1853/54 – Snow compared mortality rates of people who drank from different water companies but lived in the same area Vauxhall Water Company had few deaths Southwark Water Company had many more deaths Water was spreading disease not infected air! Snow said water should be boiled and/or filtered

7 Some Miasmatists still refused to change their minds… John Simon was still more concerned with removing smells than improving water supply e.g. passed drainage reforms to ‘remove smells.’ ‘This disease mist is like an angel of death that has hovered over London for centuries.’ Elevation in feetCholera deaths per 10,000 0137 1550 2540 3525 4520 5513 6536 (included level of Broad St Pump) 7519

8 Committee for Scientific Enquiry into the Recent Cholera Epidemic (1854) Farr, Simon, Arnott ‘If the Broad Street Pump did actually become a source of disease – it was not because it contained choleriac elements but because it added to the atmospheric infection of the district. The spread of cholera is less to do with water than the air.’ ‘We see no reason to accept Snow’s findings.’ John Snow suddenly died in 1858 – very few people had realised his genius

9 The East London Cholera epidemic and the conversion of William Farr… Bazalgette had almost completed his system of intercepting sewers beneath London. Most London water companies had built filter beds for their reservoirs…except East London Water Company 27 th June – Mr and Mrs Hedges died of cholera The Cholera spread quickly through the families nearby… all got their water from East London Water Company 1866…

10 Times Newspaper 1 st August 1866 THE RETURN OF CHOLERA 924 PEOPLE DEAD! ALL GET WATER FROM EAST LONDON COMPANY! By the end of August 1866 it was estimated that 3,797 deaths out of 4,363 had happened in areas supplied by East London Water Company! Farr changed his mind!

11 ‘An indifferent person would have breathed the air without any apprehension. But only a very robust scientist would have dared to drink a glass of water from East London Water Company!’

12 ‘Dr Farr has now also agreed; the conclusions made by John Snow in regard to the influence of the water supply in causing disease are irresistible.’ August 1866

13 The Conversion of John Simon After William Farr had at last accepted that Miasmic Theory was incorrect, John Simon was soon to follow suit. In 1870 he wrote… ‘It is now certain that the water supply of a town may be the essential cause of the most terrible epidemic outbreaks of cholera, typhoid fever and dysentery’ ‘Dr Snow in 1849 was not able to prove his theory. However, new evidence has established as almost certain that he had been correct.’

14 In the following years, John Simon and William Farr pushed for further measures to improve the cleanliness of the London Water… Bazalgette completed his intercepting sewer system All Water Companies had to have filter beds in their reservoirs Pumping stations were built to improve the efficiency of removing sewage Farr declared that 1867 was the healthiest year for London since 1860, judged by the death rate. London Death Rate in 1872 21.5 per 10,000 people A lower rate than Paris, Vienna, Berlin, Brussels, Rome or any other major European, American or Indian city, despite having a population of 3.3million

15 London Death Rate in 1872 21.5 per 10,000 people A lower rate than Paris, Vienna, Berlin, Brussels, Rome or any other major European, American or Indian city, despite having a population of 3.3million By 1896 Cholera was so scarce in England that it was labelled an ‘exotic disease’ The 1875 Public Health Act forced other cities in Britain to adopt similar measures to improve the water supply A CHOLERA EPIDEMIC HAS NOT RETURNED TO BRITAIN SINCE 1866


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