Cholera epidemics

Bacteria are smaller than protozoa and are responsible for many diseases, such as typhoid fever, cholera, diarrhea, and dysentery. Pathogenic bacteria range in size from 0.2 to 0.6 /tm, and a 0.2 /tm filter is necessary to prevent transmission. Contamination of water supplies by bacteria is blamed for the cholera epidemics, which devastate undeveloped countries from time to time. Even in the U.S., E. coli is frequently found to contaminated water supplies. Fortunately, E. coli is relatively harmless as pathogens go, and the problem isn t so much with E. coli found, but the fear that other bacteria may have contaminated the water as well. Never the less, dehydration from diarrhea caused by E. coli has resulted in fatalities. 

The cholera epidemic that reached Europe and North America in the early 1830s killed more than 20,000 people in England. It was during this epidemic that Queen Victoria s personal physician, Dr. John Snow, removed the handle from the polluted Broad Street pump in London in the first recorded, appropriate measure to prevent waterborne disease. 

Cholera is predominantly a disease of the poor. An official investigation of the 1832 cholera epidemic in Paris showed that up to 53 out of every 1000 inhabitants in the poorest neighborhoods died, compared to only 8 per 1000 in wealthy areas. The rich could flee, secure a supply of safe water, or, like the slave owners in New Orleans, drink claret even at breakfast. The poor drank from waterways that were their cesspools. 

Anderson C. Cholera epidemic traced to risk miscalculation. Nature 1991 354 255. 

Bacteria in water are usually thought of in terms of human disease. Indeed, until quite late in the nineteenth century, disastrous outbreaks of waterborne diseases such as cholera, dysentery, and typhoid fever were common in the major cities of the world. The last outbreak of typhoid in the United Kingdom occurred in Croydon in 1937. Serious cholera epidemics still occur in some parts of the world one that began in Peru in 1991 spread to several countries in the Americas, causing 391,000 cases of illness and 4000 deaths that year. 

An early report shows that cholera epidemics in Europe were effectively tackled by homeopathic medicines (Leary, 1994). The work refers to the epidemic in 1854. The results may not be reliable because modem diagnostic techniques were not available at that time and adequate placebo controls were not kept. Abrotanum D1 was tested on 27 dogs and 26 cats infected with intestinal nematodes in a Veterinary clinic of Germany and the results were positive (Krause, 1993). 

Chlorine Chlorine reacts with nearly all of the elements. Although chlorine is a deadly gas, compounds of chlorine have many uses, including some that can save lives. In 1848, a cholera epidemic began in London. About 25 000 people died during the epidemic, which was blamed on raw sewage flowing into the river Thames. In 1855, London became the first city to use chlorine compounds to disinfect sewage. 

The first known public water system in the United States was built in Philadelphia as early as 1799. Over 400 additional water systems had been built in major cities throughout the nation by 1860, and this increased to over 3000 by the early 1900s. With these systems came several major outbreaks of disease because when the supply water was contaminated, the system was an efficient way to spread the contamination throughout the community. In 1849, there were cholera epidemics in New York City that... 

C. Anderson, Cholera Epidemic Trace to Risk Miscalculation, Nature, 354, 255, Nov 28 (1991). 

Petrera, M. and Montoya, M. 1992. The economic impact of the cholera epidemic, Peru, 1991. Epidemiological Bulliten, PAHO 13 9-12. 

Anderson C. Cholera epidemic traced to risk miscalculation. Nature 1991 354 255. Tweats DJ. A review of the reduction and refinement of regulatory studies for pharmaceuticals. In Balls M, Van Zeller A-M, Haider M, eds. Proceedings of the Third World Congress on Alternatives and Animal Use in the Life Sciences. Progress in the Reduction, Refinement and Replacement of Animal Experimentation. Amsterdam Elsevier 2000 783-91. 

W. Cruickshank recommended use of CI2 as a disinfectant (widely used in hospitals by 1823 notably effective in the European cholera epidemic, 1831, and in the outbreak of puerperal fever, Vienna, 1845) Fluoride found in fossil ivory and teeth by D. P. Morichini (soon confirmed by J. J. Berzelius who found it also in bones)... 

This cruel experiment was unintentionally conducted in Peru in the 1980s. The result was a cholera epidemic affecting 300,000 people and causing 3,500 deaths. In the United States in 1994, problems in the water chlorination system of Milwaukee resulted in over a third of a million people being sickened by the protozoan, Cryptosporidium. Similarly, as discussed earlier in this book, the removal of DDT from Africa resulted in millions of deaths secondary to a resurgence of once-controlled malaria. The human trials have been done and, in retrospect, the benefit-to-risk ratio favors DDT and chlorine. Chlorine has not yet been banned. Why is there even any debate ... 

V. cholerae epidemics are associated with unsanitary conditions affecting the drinking water supply and are rare in the United States. However, these bacteria grow well under the alkaline conditions found in seawater and attach to chitin in shellfish. Thus, sporadic cases occur in the southeast United States associated with the ingestion of contaminated shellfish. 

The question whether cyanobacterial hepatotoxins constitute a human health risk is still debated and is not easy to answer since in comparison to other waterborne diseases, e.g., cholera epidemics, the number and severity of cyanotoxin related illnesses appears less dramatic. On the other hand, microcystins and cylindrospermopsins are potent toxins with LD50S similar to or even lower than that of some of the most notorious natural toxins, like a-amanitin (Amanita phalloides), strychnine (Strychnos nux-vomica), or aconitine (Aconitum sp.). Compared to these natural toxins, exposure to cyanobacterial toxins is much harder to avoid and the cyanotoxin-related epidemics indicate that potentially a large number of people can be affected when, for example, drinking water is contaminated. Among chemicals to which humans are exposed through water, cyanobacterial toxins probably occur most frequently in a global perspective. 

Chinese accusations that the United States started a cholera epidemic in Hong Kong in 1961 ... 

The least-controlled bacterial diseases in the world today are cholera, trachoma, leprosy, tuberculosis, brucellosis, urethritis, and the trepo-nematoses. Indonesia, North Africa, and (especially) the Indian subcontinent are the most severely afflicted with cholera, but thanks to the aeroplane, no part of the world is safe. Cholera is easily cured with tetracycline and intravenous saline. Cholera epidemics begin through poor hygiene, and spread explosively when the number of sufferers exceeds the nursing resources. Trachoma is an infection of the eyes by a minute, intracellular bacterium of the Chlamydia... 

As in many cities, the outbreak of typhoid fever and cholera, epidemics caused by contaminated drinking water, led to the erection of water treatment plants. 

Carnot s 118-page Reflections on the Motive Power of Fire received favorable reviews, then fell into obscurity. This was partly because the world was not ready to understand it, and partly because the theory s champion, Carnot, died in a cholera epidemic when he was 36 (and his personal effects, including many of his papers, were burned). And it was partly because the water analogy had limitations. 

In 1854, a cholera epidemic struck the Soho district of London. Physician John Snow traced the source of the disease to contaminated water being delivered through public pumps. His investigative methods led to the science of epidemiology. 

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