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{{Cholera}}
{{Cholera}}
{{CMG}}; '''Associate Editors-In-Chief:''' [[Priyamvada Singh|Priyamvada Singh, MBBS]] [mailto:psingh13579@gmail.com]
{{CMG}}; '''Associate Editors-In-Chief:''' {{SaraM}}, {{TarekNafee}}, [[Priyamvada Singh|Priyamvada Singh, MBBS]] [mailto:psingh13579@gmail.com]{{AY}}
==Overview==
==Overview==
Cholera affects an estimated 3-5&nbsp;million people worldwide, and causes 100,000-130,000&nbsp;deaths a year as of 2010. This occurs mainly in the [[developing world]].<ref>{{cite journal |author=Reidl J, Klose KE |title=Vibrio cholerae and cholera: out of the water and into the host |journal=FEMS Microbiol. Rev. |volume=26 |issue=2 |pages=125–39 |year=2002 |month=June |pmid=12069878 |doi= 10.1111/j.1574-6976.2002.tb00605.x|url=}}</ref> In the early 1980s, death rates are believed to have been greater than 3 million a year. It is difficult to calculate exact numbers of cases, as many go unreported due to concerns that an outbreak may have a negative impact on the tourism of a country.<ref name=NEJM2006>{{cite journal |author=Sack DA, Sack RB, Chaignat CL |title=Getting serious about cholera |journal=N. Engl. J. Med. |volume=355 |issue=7 |pages=649–51 |year=2006 |month=August |pmid=16914700 |doi=10.1056/NEJMp068144 |url=}}</ref> Cholera remains both [[epidemic]] and endemic in many areas of the world.
In 2015, 172,454 cases and 1,304 deaths of cholera were reported to [[WHO]] worldwide. Outbreaks continued to affect several countries.
Although much is known about the mechanisms behind the spread of cholera, this has not led to a full understanding of what makes cholera outbreaks happen some places and not others. Lack of treatment of human [[feces]] and lack of treatment of drinking water greatly facilitate its spread, but bodies of water can serve as a [[Natural reservoir|reservoir]], and seafood shipped long distances can spread the disease. Cholera was not known in the [[Americas]] for most of the 20th century, but it reappeared towards the end of that century and seems likely to persist.<ref>{{Cite journal | last1 = Blake | first1 = PA | title = Epidemiology of cholera in the Americas | journal = Gastroenterology clinics of North America | volume = 22 | issue = 3 | pages = 639–60 | year = 1993 | pmid = 7691740 }}</ref>
Overall, 41% of cases were reported from Africa, 37% from Asia, and 21% from the Americas.<ref name="WHO-epi2">World Health Organization. Global Health Observatory (GHO) data. http://www.who.int/gho/epidemic_diseases/cholera/en/ Accessed on October 5th, 2016</ref> In the early 1980s, mortality rates are believed to exceeded 3 million deaths a year. It is difficult to calculate exact numbers of cases, as many go unreported due to concerns that an outbreak may have a negative impact on the tourism of a country.<ref name="NEJM2006">{{cite journal |author=Sack DA, Sack RB, Chaignat CL |title=Getting serious about cholera |journal=N. Engl. J. Med. |volume=355 |issue=7 |pages=649–51 |year=2006 |month=August |pmid=16914700 |doi=10.1056/NEJMp068144 |url=}}</ref> Cholera remains both [[epidemic]] and [[endemic]] in many areas of the world.
Although much is known about the mechanisms behind the spread of cholera, this has not led to a full understanding of what makes cholera outbreaks happen some places but not others. Lack of adequate treatment of human [[feces]] and/or drinking water greatly facilitates the spread of cholera. Bodies of water can serve as a [[Natural reservoir|reservoir]] of the disease. Seafood shipped over long distances can also spread the disease. Cases of cholera were not observed in the [[Americas]] for most of the 20th century, thought the disease reappeared towards the end of that century and seems likely to persist.<ref>{{Cite journal | last1 = Blake | first1 = PA | title = Epidemiology of cholera in the Americas | journal = Gastroenterology clinics of North America | volume = 22 | issue = 3 | pages = 639–60 | year = 1993 | pmid = 7691740 }}</ref>
 
==2017 Yemen outbreak==
 
{| style="border: 0px; margin: 5px;" width="1000px"
| style="background:#4479BA; padding: 10px 10px;" align="center" |{{fontcolor|#FFF|'''Date'''}}
| style="background:#4479BA; padding: 5px 5px;" align="center" |{{fontcolor|#FFF|'''Cases''' (confirmed and suspected)}}
| style="background:#4479BA; padding: 5px 5px;" align="center" |{{fontcolor|#FFF|'''Deaths'''}}
| style="background:#4479BA; padding: 5px 5px;" align="center" |{{fontcolor|#FFF|'''More details'''}}
|-
| style="padding: 5px 5px; background: #EBEBEB;" |June 11th, 2017|| style="padding: 5px 5px; background: #F2F2F2;" |101,820|| style="padding: 5px 5px; background: #F2F2F2;" |791 (0.7%)
| style="padding: 5px 5px; background: #F2F2F2;" |
*Since the [[outbreak]] started in April 27, 2017, a total of 101,820 cases  were suspected from which 791 died.<ref name="urlWHO | Number of suspected cholera cases reaches 100 000 in Yemen">{{cite web |url=http://www.who.int/mediacentre/news/releases/2017/suspected-cholera-yemen/en/ |title=WHO &#124; Number of suspected cholera cases reaches 100 000 in Yemen |format= |work= |accessdate=}}</ref>
*Most of the fatalities are children below 15 years (46% of cases) and elderly over 60 years (33% of cases).
*The disease is spreading in 19 out of 23 governorates in the country that is war torn.<ref name="urlYemen cholera cases pass the 100,000 mark: WHO | Reuters">{{cite web |url=http://in.reuters.com/article/us-yemen-cholera-idINKBN18Z17N?feedType=RSS&feedName=health&utm_source=Twitter&utm_medium=Social&utm_campaign=Feed:+reuters%2FINhealth+%28News+%2F+IN+%2F+Health%29 |title=Yemen cholera cases pass the 100,000 mark: WHO &#124; Reuters |format= |work= |accessdate=}}</ref>
*The health system in the country is nearly destroyed which makes the mission to control the disease even harder. After 2 years of conflict, less than half of the healthcare centers are working. Medical supplies are entering Yemen in a rate that is third of what it used to be before the conflict. Moreover, infrastructure is terribly damaged preventing 14.5 million people from having access to clean water and sanitation.
*Efforts by [[WHO]] and UNICEF are made to control the outbreak especially in the “hotspots” or the most affected areas.
*66.7 million US dollars are invested in the fight against the outbreak. Till the moment, 3.5 million people have been reached through disinfecting water tanks, chlorination of water and distributing hygiene kits.<ref name="urlWHO | Number of suspected cholera cases reaches 100 000 in Yemen" />
|-
| style="padding: 5px 5px; background: #EBEBEB;" |June 25th, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |200,000
| style="padding: 5px 5px; background: #F2F2F2;" |1300 (0.65%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* Number of suspected cases has doubled so has the number of dead, making it the worst cholera outbreak in the recent history.<ref name="urlWHO | Statement from UNICEF Executive Director Anthony Lake and WHO Director-General Margaret Chan on the cholera outbreak in Yemen as suspected cases exceed 200,000">{{cite web |url=http://www.who.int/mediacentre/news/statements/2017/Cholera-Yemen/en/ |title=WHO &#124; Statement from UNICEF Executive Director Anthony Lake and WHO Director-General Margaret Chan on the cholera outbreak in Yemen as suspected cases exceed 200,000 |format= |work= |accessdate=}}</ref>
* Numbers are expected to rise in the next few weeks.
* WHO and UNICEF are scaling up their efforts to contain the outbreak.
* Rapid response teams are going from house to house educating people about the effective measures for [[Primary prevention|primary]] and [[secondary prevention]].
* Local health workers (estimated 30,000 of them) have not been paid for 10 months due to the ongoing conflict and economic crisis, making the efforts to contain the infection more difficult.<ref name="urlWHO | Statement from UNICEF Executive Director Anthony Lake and WHO Director-General Margaret Chan on the cholera outbreak in Yemen as suspected cases exceed 200,000">{{cite web |url=http://www.who.int/mediacentre/news/statements/2017/Cholera-Yemen/en/ |title=WHO &#124; Statement from UNICEF Executive Director Anthony Lake and WHO Director-General Margaret Chan on the cholera outbreak in Yemen as suspected cases exceed 200,000 |format= |work= |accessdate=}}</ref>
|-
| style="padding: 5px 5px; background: #EBEBEB;" |July 2nd, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |246,000
| style="padding: 5px 5px; background: #F2F2F2;" |1500 (0.6%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* WHO is paying incentives to the local health workers who have not been paid for 10 months.
* WHO is setting up treatment centers in 10 governorates with the capacity of 50 each. Centers will be working around the clock in the efforts to fight the [[epidemic]].
|-
| style="padding: 5px 5px; background: #EBEBEB;" |July 10th, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |297,438
| style="padding: 5px 5px; background: #F2F2F2;" |1706 (0.57%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* After 10 weeks of the [[outbreak]], the international committee of the red cross has declared that the recent outbreak is a disaster added to the economic collapse and the near famine in  Yemen.
* The daily growth of the cases has decreased to 2%. However, new outbreak hotspots are discovered.
* The west region is the area most affected by the outbreak and that is due to the continuous war there.
* The spread of the disease is thought to be limited due to acquistion of “[[herd immunity]]” by the population from surviving patients.
*The [[mortality rate]] is controlled due to the early catching of the disease and the abundant network of rehydration points.
|-
| style="padding: 5px 5px; background: #EBEBEB;" |July 16th, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |326,082
| style="padding: 5px 5px; background: #F2F2F2;" |1,743 (0.53%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* The [[outbreak]] has spread to 91% of the yemeni governorates.
* The plans to deploy [[Vaccines|cholera vaccines]] were suspended.
* According to WHO spokesperson, priority now comes to the measures to stop the progress of the [[outbreak]] such as ensuring clean water supply and treating patients.
* Up till now, about 2300 diarrhea treatment centers and 700 oral rehydration facilities were set up in the efforts to stop the spread of the [[outbreak]].
* The limited numbers of [[vaccine]] doses can not cover the whole country and can cause more disputes between different regions of the country. This was another reason to suspend the plans to deploy the vaccines.
* Up till now, 42% of the infected population are children below 15 years and 32% of the deaths are 60 years or above.
|-
| style="padding: 5px 5px; background: #EBEBEB;" |July 22nd, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |462, 545
| style="padding: 5px 5px; background: #F2F2F2;" |1817 (0.39%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* Cholera cases is now over 360,000 cases  in three months only. The epidemic is declared the worst (in terms of the cases per one year) since the start of the modern recording system (highest number was in Haiti in 2011 and it recorded 340, 311 cases/year).<ref name="urlYemens cholera epidemic is worst on record: Oxfam | Yemen News | Al Jazeera">{{cite web |url=http://www.aljazeera.com/news/2017/07/yemen-cholera-epidemic-worst-record-oxfam-170721081529026.html |title=Yemen's cholera epidemic is worst on record: Oxfam &#124; Yemen News &#124; Al Jazeera |format= |work= |accessdate=}}</ref><ref name="urlWHO | Yemen crisis">{{cite web |url=http://www.who.int/emergencies/yemen/en/ |title=WHO &#124; Yemen crisis |format= |work= |accessdate=}}</ref>
* Oxfam estimates that the number of cases might rise above 600,000 cases making it the worst epidemic since 1949.
* Unicef states that most of the children do not have access to clean water or the proper medical care and that 17 million Yemenis do not know from where they are getting their next meal.
 
[[Image:Cholera.PNG|center|400px|thumb|Distribution of cholera cases per 1000 people on July 17 - Source: http://www.who.int/en/]]
|-
| style="padding: 5px 5px; background: #EBEBEB;" |July 29th, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |408,583
| style="padding: 5px 5px; background: #F2F2F2;" |1,885 (0.46%)
| style="padding: 5px 5px; background: #F2F2F2;" |
*The rate of daily infected cases is now dropping and so is the case fatality rate.
*The outbreak is thought to have peaked 3 weeks ago.
*Despite the slowing of the spread, the number of daily cases remains high (5,000 to 6,000 cases per day) and the outbreak remains one of the worst in the recent history.
*The WHO is preparing for a massive campaign of vaccination in 2018 using 500,000 doses of oral cholera vaccine. WHO is targeting not only Yemen, but also Somalia, Kenya, Congo, Nigeria, Tanzania and South Sudan where cholera remains a concern.
|-
| style="padding: 5px 5px; background: #EBEBEB;" |August 5th, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |453,175
| style="padding: 5px 5px; background: #F2F2F2;" |1,930 (0.42%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* Estimates that one million children are acutely malnourished with one fifth of them has severe malnutrition.<ref name="urlYemen cholera toll rises to 1,992: WHO | Business Standard News">{{cite web |url=http://www.business-standard.com/article/news-ians/yemen-cholera-toll-rises-to-1-992-who-117073000045_1.html |title=Yemen cholera toll rises to 1,992: WHO &#124; Business Standard News |format= |work= |accessdate=}}</ref>
* Malnourished children are three times more at risk to contract the infection because of the reduced immunity.
* Children below 15 years account for 44% of the new cases and 32% of the deaths.<ref name="urlWHO | Statement by UNICEF Executive Director, Anthony Lake, WFP Executive Director, David Beasley and WHO Director-General, Dr Tedros Adhanom Ghebreyesus, following their joint visit to Yemen">{{cite web |url=http://www.who.int/mediacentre/news/statements/2017/joint-visit-yemen/en/ |title=WHO &#124; Statement by UNICEF Executive Director, Anthony Lake, WFP Executive Director, David Beasley and WHO Director-General, Dr Tedros Adhanom Ghebreyesus, following their joint visit to Yemen |format= |work= |accessdate=}}</ref>
 
[[Image:DGIG4TSXkAEzKdv.jpg|center|500px|thumb|Source: http://www.who.int/en/]]
|-
| style="padding: 5px 5px; background: #EBEBEB;" |August 12th, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |473,701
| style="padding: 5px 5px; background: #F2F2F2;" |1,953 (0.41%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* The outbreak is now affecting 96% (22/23) governorates and 89% (297/333) districts.<ref name="urlWHO EMRO | Situation reports | Yemen-infocus | Yemen, WHO EMRO | Situation reports | Yemen-infocus | Yemen">{{cite web |url=http://www.emro.who.int/yem/yemeninfocus/situation-reports.html |title=WHO EMRO &#124; Situation reports &#124; Yemen-infocus &#124; Yemen, WHO EMRO &#124; Situation reports &#124; Yemen-infocus &#124; Yemen |format= |work= |accessdate=}}</ref>
* Seventy Percent of Yemen’s 28 million population live in these affected areas.<ref name="urlYemens civil war turns country into cholera breeding ground - ABC News">{{cite web |url=http://abcnews.go.com/Health/wireStory/yemens-civil-war-turns-country-cholera-breeding-ground-49129085 |title=Yemen's civil war turns country into cholera breeding ground - ABC News |format= |work= |accessdate=}}</ref>
* The overall number of suspected cases have been declining in the past five weeks, however, it has reached a plateau stage in the top 4 governorates affected.
 
[[Image:Epidemic curve.JPG|center|500px|thumb|An epidemic curve showing the weekly number of cases during the first wave (in 2016) and the second wave (in 2017) of the outbreak - Source: http://www.who.int/en/]]
 
[[Image:02 outcome.JPG|center|500px|thumb|The figures show the distribution of cases by age and sex. The right most figure shows the percentage of the different outcomes of suspected cases -Source: http://www.who.int/en/]]
 
[[Image:03 Attack rate.JPG|center|500px|thumb|The map on the left shows the total number of cases in the different governorates while the map on the right shows the attack rate per 10,000 people in the same governorates - Source: http://www.who.int/en/]]
|-
| style="padding: 5px 5px; background: #EBEBEB;" |September 5th, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |607,065<ref name="urlWHO EMRO | Situation reports | Yemen-infocus | Yemen, WHO EMRO | Situation reports | Yemen-infocus | Yemen">{{cite web |url=http://www.emro.who.int/yem/yemeninfocus/situation-reports.html |title=WHO EMRO &#124; Situation reports &#124; Yemen-infocus &#124; Yemen, WHO EMRO &#124; Situation reports &#124; Yemen-infocus &#124; Yemen |format= |work= |accessdate=}}</ref>
| style="padding: 5px 5px; background: #F2F2F2;" |2,047 (0.34%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* The number of cases hit the 600,000 mark. This is the double of the [[WHO]] estimates for the worst case scenario in April.
* The number of cases has been falling in August but some districts report sharp increase in the number of suspected cases for the past two weeks.<ref name="urlYemens cholera epidemic hits 600,000, confounding expectations | Reuters">{{cite web |url=https://www.reuters.com/article/us-yemen-cholera/yemens-cholera-epidemic-hits-600000-confounding-expectations-idUSKCN1BG158 |title=Yemen's cholera epidemic hits 600,000, confounding expectations &#124; Reuters |format= |work= |accessdate=}}</ref>
* [[WHO]] investigates if the new rise of cases is due to cholera or due to another [[Diarrhea|diarrheal illness]].
* With the continuation of civil war, nearly 16 million Yemenis are deprived of clean water and proper sanitation.
|-
| style="padding: 5px 5px; background: #EBEBEB;" |September 29th, 2017
| style="padding: 5px 5px; background: #F2F2F2;" |754,373<ref name="urlWHO EMRO | Situation reports | Yemen-infocus | Yemen, WHO EMRO | Situation reports | Yemen-infocus | Yemen">{{cite web |url=http://www.emro.who.int/yem/yemeninfocus/situation-reports.html |title=WHO EMRO &#124; Situation reports &#124; Yemen-infocus &#124; Yemen, WHO EMRO &#124; Situation reports &#124; Yemen-infocus &#124; Yemen |format= |work= |accessdate=}}</ref>
| style="padding: 5px 5px; background: #F2F2F2;" |2,119 (0.28%)
| style="padding: 5px 5px; background: #F2F2F2;" |
* The outbreak is declared as the worst recorded cholera outbreak after the number of suspected cases exceeded the Haiti outbreak of 2010.<ref name="urlYemen cholera outbreak set to be worst on record | The Independent">{{cite web |url=http://www.independent.co.uk/news/world/middle-east/yemen-cholera-outbreak-worst-on-record-health-middle-east-a7973726.html |title=Yemen cholera outbreak set to be worst on record &#124; The Independent |format= |work= |accessdate=}}</ref>
* There number of cases are expected to reach one million by November this year.<ref name="urlYemen cholera cases could hit 1 million by year-end: Red Cross | Reuters">{{cite web |url=http://www.reuters.com/article/us-yemen-security-redcross/yemen-cholera-cases-could-hit-1-million-by-year-end-red-cross-idUSKCN1C41WA |title=Yemen cholera cases could hit 1 million by year-end: Red Cross &#124; Reuters |format= |work= |accessdate=}}</ref>
 
[[Image:Cholera achievements.jpg|center|500px|thumb|Source: http://www.who.int/en/]]
|}


==Epidemiology and Demographics==
==Epidemiology and Demographics==
===Incidence===
*In 2015, 172,454 cases and 1,304 deaths of cholera were reported to WHO worldwide. Outbreaks continued to affect several countries.
*Overall, 41% of cases were reported from Africa, 37% from Asia, and 21% from the Americas.<ref name="WHO-epi2">World Health Organization. Global Health Observatory (GHO) data. http://www.who.int/gho/epidemic_diseases/cholera/en/ Accessed on October 5th, 2016</ref>
*Worldwide, cholera affects an estimated 1.4 to 4.3 million people and causes 28,000 to 142,000 deaths a year as of 2012.<ref name="Cholera-fact">World Health Organization. Cholera. (2016) http://www.who.int/mediacentre/factsheets/fs107/en/ Accessed on October 5th,2016</ref><ref name="WHO_ref">Ali M, Lopez AL, You YA, et al. The global burden of cholera. Bulletin World Health Organization 2012; 90: 209–18A.</ref>
===Origin and Spread===
===Origin and Spread===
Cholera was originally [[endemic (epidemiology)|endemic]] to the Indian subcontinent, with the Ganges River likely serving as a contamination reservoir. It spread by trade routes (land and sea) to Russia, then to Western Europe, and from Europe to North America. It is now no longer considered an issue in Europe and North America, due to filtering and [[chlorination]] of the water supply.
Cholera was originally [[endemic (epidemiology)|endemic]] to the Indian subcontinent, with the Ganges River likely serving as a contamination reservoir. It spread by trade routes (both land- and sea-based) to Russia, then to Western Europe, and from Europe to North America. Cholera is no longer considered an issue in Europe and North America, due to filtering and [[chlorination]] of the water supply.
 
===Gender===
Cholera occurs equally in males and females.
===Age===
*In non-endemic areas, cholera occurs equally in all age groups.
*In [[endemic]] regions, children older than the age of 2 years are most commonly infected which cholera. Illness is uncommon before children reach 2 years of age, likely due to [[passive immunity]].


* 1816-1826 - '''First Cholera pandemic''': Previously restricted, the pandemic began in Bengal, then spread across India by 1820. It extended as far as China and the Caspian Sea before receding.
===Geographic Distribution===
* 1829-1851 - '''Second Cholera pandemic''' reached Europe, London and Paris in 1832. In London, it claimed 6,536 victims (see: http://www.mernick.co.uk/thhol/1832chol.html); in Paris, 20,000 succumbed (out of a population of 650,000) with about 100,000 deaths in all of France [http://www.amicale-genealogie.org/Histoires_temps-passe/Epidemies/chol01.htm]. It reached Russia (Cholera Riots), Quebec, Canada, Ontario, Canada] and New York in the same year and the Pacific coast of North America by 1834.
====Cholera in the United States====
* 1849 - Second major outbreak in Paris. In London, it was the worst outbreak in the city's history, claiming 14,137 lives, ten times as many as the 1832 outbreak. In 1849 cholera claimed 5,308 lives in the port city of Liverpool, England, and 1,834 in Hull, England.<ref>IBMS Institute of Biological Science [http://www.ibms.org/index.cfm?method=science.history_zone&subpage=history_choleraAn ]</ref> An outbreak in North America took the life of former U.S. President James K. Polk. Cholera spread throughout the Mississippi river system killing over 4,500 in St. Louis [http://www.stlgs.org/DBpublicationsNewsCholera.htm] and over 3,000 in New Orleans [http://www.rootsweb.com/~txpanola/epidemics.html] as well as thousands in New York.<ref>The Cholera Years: The United States in 1832, 1849, and 1866 by Charles E. Rosenberg</ref> In 1849 cholera was spread along the California and Oregon trail as hundreds died on their way to the California Gold Rush, Utah and Oregon.<ref>Trails of Hope: California, Oregon and Mormon Trails [http://overlandtrails.lib.byu.edu/ctrail.htm]</ref>
In the United States, the occurrence of [[cholera]] is very low (0-5 cases per year) and is usually due to ingestion of contaminated food or infection during international travel. There has been a modest increase in imported cases since 1991 related to travel and ongoing [[epidemics]].<ref name="CDC">Centers for Disease Control and prevention. Sources of Infection & Risk Factors. http://www.cdc.gov/cholera/infection-sources.html Accessed on October 5th, 2016</ref>
* 1852-1860 - '''Third Cholera pandemic''' mainly affected Russia, with over a million deaths. In 1853-4, London's epidemic claimed 10,738 lives.
* 1854 - Outbreak of cholera in Chicago took the lives of 5.5 per cent of the population (about 3,500 people).[http://www.chipublib.org/004chicago/timeline/riverflow.html]. Soho outbreak in London stopped by removing the handle of the Broad Street pump by a committee instigated to action by John Snow .<ref> On the Mode of Communication of Cholera (1855) by John Snow, M.D. (1813-1858) [http://eee.uci.edu/clients/bjbecker/PlaguesandPeople/week8a.html </ref>
* 1863-1875 - '''Fourth Cholera pandemic''' spread mostly in Europe and Africa.
* 1866 - Outbreak in North America. <!-- taken from above paragraph. Not sure if this is separate from the 4th pandemic --> In London, a localized epidemic in the East End claimed 5,596 lives just as London was completing its major sewage and water treatment systems--the East End was not quite complete. William Farr, using the work of John Snow et al. as to contaminated drinking water being the likely source of the disease, was able to relatively quickly identify the East London Water Company as the source of the contaminated water. Quick action prevented further deaths.<ref> "The Ghost Map" by Steven Johnson, pg. 209 </ref> Also a minor outbreak at Ystalyfera in South Wales. Caused by the local water works using contaminated canal water, it was mainly it's workers and their families who suffered. Only 119 died.
* 1881-1896 - '''Fifth Cholera pandemic '''; The 1892 outbreak in Hamburg, Germany was the only major European outbreak; about 8,600 people died in Hamburg, causing a major political upheaval in Germany, as control over the City was removed from a City Council which had not updated Hamburg's water supplies. This was the last serious European cholera outbreak.
* 1899-1923 - '''Sixth Cholera pandemic''' had little effect in Europe because of advances in public health, but Russia was badly affected again.
* 1961-1970s - '''Seventh Cholera pandemic''' began in Indonesia, called [[El Tor]] after the strain, and reached Bangladesh in 1963, India in 1964, and the USSR in 1966. From North Africa it spread into Italy by 1973. In the late 1970s there were small outbreaks in Japan and in the South Pacific. There were also many reports of a cholera outbreak near Baku in 1972, but information about it was suppressed in the USSR.
* January 1991 to September 1994 - Outbreak in South America, apparently initiated when a ship discharged ballast water. Beginning in Peru there were 1.04 million identified cases and almost 10,000 deaths. The causative agent was an O1, El Tor strain, with small differences from the seventh pandemic strain. In 1992 a new strain appeared in Asia, a non-O1, nonagglutinable vibrio (NAG) named O139 Bengal. It was first identified in Tamil Nadu, India and for a while displaced El Tor in southern Asia before decreasing in prevalence from 1995 to around 10% of all cases. It is considered to be an intermediate between El Tor and the classic strain and occurs in a new serogroup. There is evidence of the emergence of wide-spectrum resistance to drugs such as [[trimethoprim]], [[sulfamethoxazole]] and [[streptomycin]].
* 2007 - The U.N. reported recently of a Cholera outbreak in Iraq.<ref>{{cite news |first= |last= |authorlink= |author= |coauthors= |title=U.N. reports cholera outbreak in northern Iraq |url=http://www.cnn.com/2007/WORLD/meast/08/29/iraq.cholera/index.html |format=HTML |work= |publisher=CNN |id= |pages= |page= |date= |accessdate=2007-08-30 |language=English |quote= }}</ref>


===False report of Cholera===
====Cholera in the Developing World====
A persistent myth states that [[Chicago 1885 cholera epidemic myth|90,000 people died in Chicago]] of cholera and [[typhoid fever]] in 1885. This story has no factual basis. In 1885 there was a torrential rainstorm that flushed the Chicago river and its attendant pollutants into Lake Michigan far enough that the city's water supply was contaminated. Fortunately, cholera was not present in the city and this is not known to have caused any deaths. It did, however, cause the city to become more serious about their sewage treatment.
The highest incidencce of cholera in the developing world occurs in the following regions:<ref name="WHO-Archive-Cholera">World Health Organization. Cholera Emergencies preparedness, response. http://www.who.int/csr/don/archive/disease/cholera/en/</ref><ref name="WHO-Archive-Cholera2">World Health Organization. Cholera Global Health Observatory
Map Gallery http://gamapserver.who.int/mapLibrary/app/searchResults.aspx</ref>
*'''Africa:''' Zambia, Mozambique, Liberia, Democratic Republic of Congo, Niger
*'''Asia:''' Indonesia, Bangladesh, India
*'''The Americas:''' Dominican Republic, Haiti
*'''The Middle East:''' Yemen
 
[[Image:Screen Shot 2016-10-06 at 9.58.35 PM.png|500px|thumb|left|Source: http://www.who.int/en/]]
[[Image:Screen Shot 2016-10-07 at 1.36.22 PM.png|500px|thumb|left|Source: http://www.who.int/en/]]
 
<br style="clear:both" />
 
===Case Fatality Rates===
*In 2015, the [[case fatality rate|case fatality rates (CFRs)]] for [[cholera]] ranged from 0.0% to 11.7%; globally, the overall CFR was 0.8%.<ref name="WHO-GHO">World Heath Organization. Global Health Observatory (GHO) 2016. dathttp://www.who.int/gho/epidemic_diseases/cholera/case_fatality_rate_text/en</ref>
*CFRs >1% were reported by 15 countries.  
**Of these 15 countries, CFR >5% were reported in Myanmar and Niger.
**In Yemen, the case-fatality rate is reported to be between 4% to 5%.
*The average [[case fatality rate]] for Europe and the Americas is estimated to be around 1%.
*At the Treatment Center of the International Center for Diarrheal Disease Research in Bangladesh, less than 1% of patients with [[severe dehydration]] die.
*In Africa, a marked decline in case fatality rates has reported since 1970.
*in South America, low case fatality rates have been achieved.


== References ==
== References ==
{{Reflist|2}}
{{Reflist|2}}


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Latest revision as of 20:55, 29 July 2020

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editors-In-Chief: Sara Mehrsefat, M.D. [2], Tarek Nafee, M.D. [3], Priyamvada Singh, MBBS [4]Ahmed Younes M.B.B.CH [5]

Overview

In 2015, 172,454 cases and 1,304 deaths of cholera were reported to WHO worldwide. Outbreaks continued to affect several countries. Overall, 41% of cases were reported from Africa, 37% from Asia, and 21% from the Americas.[1] In the early 1980s, mortality rates are believed to exceeded 3 million deaths a year. It is difficult to calculate exact numbers of cases, as many go unreported due to concerns that an outbreak may have a negative impact on the tourism of a country.[2] Cholera remains both epidemic and endemic in many areas of the world. Although much is known about the mechanisms behind the spread of cholera, this has not led to a full understanding of what makes cholera outbreaks happen some places but not others. Lack of adequate treatment of human feces and/or drinking water greatly facilitates the spread of cholera. Bodies of water can serve as a reservoir of the disease. Seafood shipped over long distances can also spread the disease. Cases of cholera were not observed in the Americas for most of the 20th century, thought the disease reappeared towards the end of that century and seems likely to persist.[3]

2017 Yemen outbreak

Date Cases (confirmed and suspected) Deaths More details
June 11th, 2017 101,820 791 (0.7%)
  • Since the outbreak started in April 27, 2017, a total of 101,820 cases were suspected from which 791 died.[4]
  • Most of the fatalities are children below 15 years (46% of cases) and elderly over 60 years (33% of cases).
  • The disease is spreading in 19 out of 23 governorates in the country that is war torn.[5]
  • The health system in the country is nearly destroyed which makes the mission to control the disease even harder. After 2 years of conflict, less than half of the healthcare centers are working. Medical supplies are entering Yemen in a rate that is third of what it used to be before the conflict. Moreover, infrastructure is terribly damaged preventing 14.5 million people from having access to clean water and sanitation.
  • Efforts by WHO and UNICEF are made to control the outbreak especially in the “hotspots” or the most affected areas.
  • 66.7 million US dollars are invested in the fight against the outbreak. Till the moment, 3.5 million people have been reached through disinfecting water tanks, chlorination of water and distributing hygiene kits.[4]
June 25th, 2017 200,000 1300 (0.65%)
  • Number of suspected cases has doubled so has the number of dead, making it the worst cholera outbreak in the recent history.[6]
  • Numbers are expected to rise in the next few weeks.
  • WHO and UNICEF are scaling up their efforts to contain the outbreak.
  • Rapid response teams are going from house to house educating people about the effective measures for primary and secondary prevention.
  • Local health workers (estimated 30,000 of them) have not been paid for 10 months due to the ongoing conflict and economic crisis, making the efforts to contain the infection more difficult.[6]
July 2nd, 2017 246,000 1500 (0.6%)
  • WHO is paying incentives to the local health workers who have not been paid for 10 months.
  • WHO is setting up treatment centers in 10 governorates with the capacity of 50 each. Centers will be working around the clock in the efforts to fight the epidemic.
July 10th, 2017 297,438 1706 (0.57%)
  • After 10 weeks of the outbreak, the international committee of the red cross has declared that the recent outbreak is a disaster added to the economic collapse and the near famine in Yemen.
  • The daily growth of the cases has decreased to 2%. However, new outbreak hotspots are discovered.
  • The west region is the area most affected by the outbreak and that is due to the continuous war there.
  • The spread of the disease is thought to be limited due to acquistion of “herd immunity” by the population from surviving patients.
  • The mortality rate is controlled due to the early catching of the disease and the abundant network of rehydration points.
July 16th, 2017 326,082 1,743 (0.53%)
  • The outbreak has spread to 91% of the yemeni governorates.
  • The plans to deploy cholera vaccines were suspended.
  • According to WHO spokesperson, priority now comes to the measures to stop the progress of the outbreak such as ensuring clean water supply and treating patients.
  • Up till now, about 2300 diarrhea treatment centers and 700 oral rehydration facilities were set up in the efforts to stop the spread of the outbreak.
  • The limited numbers of vaccine doses can not cover the whole country and can cause more disputes between different regions of the country. This was another reason to suspend the plans to deploy the vaccines.
  • Up till now, 42% of the infected population are children below 15 years and 32% of the deaths are 60 years or above.
July 22nd, 2017 462, 545 1817 (0.39%)
  • Cholera cases is now over 360,000 cases in three months only. The epidemic is declared the worst (in terms of the cases per one year) since the start of the modern recording system (highest number was in Haiti in 2011 and it recorded 340, 311 cases/year).[7][8]
  • Oxfam estimates that the number of cases might rise above 600,000 cases making it the worst epidemic since 1949.
  • Unicef states that most of the children do not have access to clean water or the proper medical care and that 17 million Yemenis do not know from where they are getting their next meal.
Distribution of cholera cases per 1000 people on July 17 - Source: http://www.who.int/en/
July 29th, 2017 408,583 1,885 (0.46%)
  • The rate of daily infected cases is now dropping and so is the case fatality rate.
  • The outbreak is thought to have peaked 3 weeks ago.
  • Despite the slowing of the spread, the number of daily cases remains high (5,000 to 6,000 cases per day) and the outbreak remains one of the worst in the recent history.
  • The WHO is preparing for a massive campaign of vaccination in 2018 using 500,000 doses of oral cholera vaccine. WHO is targeting not only Yemen, but also Somalia, Kenya, Congo, Nigeria, Tanzania and South Sudan where cholera remains a concern.
August 5th, 2017 453,175 1,930 (0.42%)
  • Estimates that one million children are acutely malnourished with one fifth of them has severe malnutrition.[9]
  • Malnourished children are three times more at risk to contract the infection because of the reduced immunity.
  • Children below 15 years account for 44% of the new cases and 32% of the deaths.[10]
Source: http://www.who.int/en/
August 12th, 2017 473,701 1,953 (0.41%)
  • The outbreak is now affecting 96% (22/23) governorates and 89% (297/333) districts.[11]
  • Seventy Percent of Yemen’s 28 million population live in these affected areas.[12]
  • The overall number of suspected cases have been declining in the past five weeks, however, it has reached a plateau stage in the top 4 governorates affected.
An epidemic curve showing the weekly number of cases during the first wave (in 2016) and the second wave (in 2017) of the outbreak - Source: http://www.who.int/en/
The figures show the distribution of cases by age and sex. The right most figure shows the percentage of the different outcomes of suspected cases -Source: http://www.who.int/en/
The map on the left shows the total number of cases in the different governorates while the map on the right shows the attack rate per 10,000 people in the same governorates - Source: http://www.who.int/en/
September 5th, 2017 607,065[11] 2,047 (0.34%)
  • The number of cases hit the 600,000 mark. This is the double of the WHO estimates for the worst case scenario in April.
  • The number of cases has been falling in August but some districts report sharp increase in the number of suspected cases for the past two weeks.[13]
  • WHO investigates if the new rise of cases is due to cholera or due to another diarrheal illness.
  • With the continuation of civil war, nearly 16 million Yemenis are deprived of clean water and proper sanitation.
September 29th, 2017 754,373[11] 2,119 (0.28%)
  • The outbreak is declared as the worst recorded cholera outbreak after the number of suspected cases exceeded the Haiti outbreak of 2010.[14]
  • There number of cases are expected to reach one million by November this year.[15]
Source: http://www.who.int/en/

Epidemiology and Demographics

Incidence

  • In 2015, 172,454 cases and 1,304 deaths of cholera were reported to WHO worldwide. Outbreaks continued to affect several countries.
  • Overall, 41% of cases were reported from Africa, 37% from Asia, and 21% from the Americas.[1]
  • Worldwide, cholera affects an estimated 1.4 to 4.3 million people and causes 28,000 to 142,000 deaths a year as of 2012.[16][17]

Origin and Spread

Cholera was originally endemic to the Indian subcontinent, with the Ganges River likely serving as a contamination reservoir. It spread by trade routes (both land- and sea-based) to Russia, then to Western Europe, and from Europe to North America. Cholera is no longer considered an issue in Europe and North America, due to filtering and chlorination of the water supply.

Gender

Cholera occurs equally in males and females.

Age

  • In non-endemic areas, cholera occurs equally in all age groups.
  • In endemic regions, children older than the age of 2 years are most commonly infected which cholera. Illness is uncommon before children reach 2 years of age, likely due to passive immunity.

Geographic Distribution

Cholera in the United States

In the United States, the occurrence of cholera is very low (0-5 cases per year) and is usually due to ingestion of contaminated food or infection during international travel. There has been a modest increase in imported cases since 1991 related to travel and ongoing epidemics.[18]

Cholera in the Developing World

The highest incidencce of cholera in the developing world occurs in the following regions:[19][20]

  • Africa: Zambia, Mozambique, Liberia, Democratic Republic of Congo, Niger
  • Asia: Indonesia, Bangladesh, India
  • The Americas: Dominican Republic, Haiti
  • The Middle East: Yemen
Source: http://www.who.int/en/
Source: http://www.who.int/en/


Case Fatality Rates

  • In 2015, the case fatality rates (CFRs) for cholera ranged from 0.0% to 11.7%; globally, the overall CFR was 0.8%.[21]
  • CFRs >1% were reported by 15 countries.
    • Of these 15 countries, CFR >5% were reported in Myanmar and Niger.
    • In Yemen, the case-fatality rate is reported to be between 4% to 5%.
  • The average case fatality rate for Europe and the Americas is estimated to be around 1%.
  • At the Treatment Center of the International Center for Diarrheal Disease Research in Bangladesh, less than 1% of patients with severe dehydration die.
  • In Africa, a marked decline in case fatality rates has reported since 1970.
  • in South America, low case fatality rates have been achieved.

References

  1. ↑ 1.0 1.1 World Health Organization. Global Health Observatory (GHO) data. http://www.who.int/gho/epidemic_diseases/cholera/en/ Accessed on October 5th, 2016
  2. ↑ Sack DA, Sack RB, Chaignat CL (2006). "Getting serious about cholera". N. Engl. J. Med. 355 (7): 649–51. doi:10.1056/NEJMp068144. PMID 16914700. Unknown parameter |month= ignored (help)
  3. ↑ Blake, PA (1993). "Epidemiology of cholera in the Americas". Gastroenterology clinics of North America. 22 (3): 639–60. PMID 7691740.
  4. ↑ 4.0 4.1 "WHO | Number of suspected cholera cases reaches 100 000 in Yemen".
  5. ↑ "Yemen cholera cases pass the 100,000 mark: WHO | Reuters".
  6. ↑ 6.0 6.1 "WHO | Statement from UNICEF Executive Director Anthony Lake and WHO Director-General Margaret Chan on the cholera outbreak in Yemen as suspected cases exceed 200,000".
  7. ↑ "Yemen's cholera epidemic is worst on record: Oxfam | Yemen News | Al Jazeera".
  8. ↑ "WHO | Yemen crisis".
  9. ↑ "Yemen cholera toll rises to 1,992: WHO | Business Standard News".
  10. ↑ "WHO | Statement by UNICEF Executive Director, Anthony Lake, WFP Executive Director, David Beasley and WHO Director-General, Dr Tedros Adhanom Ghebreyesus, following their joint visit to Yemen".
  11. ↑ 11.0 11.1 11.2 "WHO EMRO | Situation reports | Yemen-infocus | Yemen, WHO EMRO | Situation reports | Yemen-infocus | Yemen".
  12. ↑ "Yemen's civil war turns country into cholera breeding ground - ABC News".
  13. ↑ "Yemen's cholera epidemic hits 600,000, confounding expectations | Reuters".
  14. ↑ "Yemen cholera outbreak set to be worst on record | The Independent".
  15. ↑ "Yemen cholera cases could hit 1 million by year-end: Red Cross | Reuters".
  16. ↑ World Health Organization. Cholera. (2016) http://www.who.int/mediacentre/factsheets/fs107/en/ Accessed on October 5th,2016
  17. ↑ Ali M, Lopez AL, You YA, et al. The global burden of cholera. Bulletin World Health Organization 2012; 90: 209–18A.
  18. ↑ Centers for Disease Control and prevention. Sources of Infection & Risk Factors. http://www.cdc.gov/cholera/infection-sources.html Accessed on October 5th, 2016
  19. ↑ World Health Organization. Cholera Emergencies preparedness, response. http://www.who.int/csr/don/archive/disease/cholera/en/
  20. ↑ World Health Organization. Cholera Global Health Observatory Map Gallery http://gamapserver.who.int/mapLibrary/app/searchResults.aspx
  21. ↑ World Heath Organization. Global Health Observatory (GHO) 2016. dathttp://www.who.int/gho/epidemic_diseases/cholera/case_fatality_rate_text/en

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