Global & Disaster Medicine

Archive for the ‘Cholera’ Category

Protection against cholera from killed whole-cell oral cholera vaccines

CholeraVaccine-2017:  Document

“….In conclusion, kOCVs are effective in reducing the risk of cholera. Although vaccination alone will probably not lead to elimination of cholera, it can provide an important stopgap while improved water, sanitation, and health-care infrastructure are provided to vulnerable populations. More work is needed to understand how and when to best use existing vaccines and to design new and more effective ones. However, the past three decades of evidence points towards kOCV being a safe, effective, and important tool to fight cholera…”

The effects of ORT in this sequence of photos of a dehydrated Egyptian child

Beginning of ORT sequence. Image courtesy of Norbert Hirschhorn

Second step in ORT sequence. Image courtesy of Norbert Hirschhorn

Third step in ORT sequence. Image courtesy of Norbert Hirschhorn

Fourth step in ORT sequence. Image courtesy of Norbert Hirschhorn

Final step in ORT sequence

“……You can see the effects of ORT in this sequence of photos below of a dehydrated Egyptian child treated entirely with ORT. These pictures, taken by me, were made into large posters for use by NGOs in Goma.”


Norbert Hirschhorn, MD




Oral Rehydration Therapy: A Top Medical Advance of the 20th Century

History of Oral Rehydration Therapy (ORT)

A man being treated for cholera.

Credit: CDC
A man being treated for cholera.

Without treatment, the diarrhea caused by cholera infection can quickly lead to severe dehydration and death. The fluid loss is so rapid that half of those who will die of the disease succumb within 12 hours of developing symptoms. In the 1800s, many physicians believed that cholera destroyed the intestine and that medical intervention was futile. At the time, physicians had little knowledge of microbiology and human physiology, and since the disease was so aggressive, early efforts to rehydrate patients were not successful. There was some experimentation with intravenous (IV) methods to treat the most severely ill patients, but the chemical solutions that were administered tended to be non-sterile and dangerously unbalanced. Oral rehydration treatment was also confounded by immediate reflexive vomiting.

Finding the Right IV Formulation

Progress was slow, but after many years of fine-tuning IV formulations for cholera patients, this method began to reduce mortality. By 1965, improved understanding of physiology and the administration of sterile, well-balanced IV fluids prevented death in almost every case.

However, there were a number of practical limitations to IV administration in cholera-endemic areas such as Bangladesh and India. During seasonal epidemics, for example, hospitals had to admit hundreds of patients each day. The logistical challenges left many patients untreated at home or by the roadside on their way to treatment facilities. With each patient requiring up to 40 liters of sterile IV fluid, supplies quickly ran out.

Exploring Oral Fluid Administration

In the 1960s, a number of physicians began to explore oral fluid administration as a supplemental treatment for cholera patients once IV fluid rehydration had blunted the reflexive vomiting. Pioneering the field was retired Navy Captain Dr. Robert A. Phillips, the third director of the NIAID-funded Cholera Research Laboratory that later became the International Centre for Diarrhoeal Disease Research, Bangladesh (link is external) (ICDDR,B). Dr. Phillips, a pathophysiologist with many years’ experience in cholera research and treatment, had helped to refine IV rehydration methods, but like many physicians, was attracted to the theoretical simplicity and ease of oral rehydration—if it could be accomplished.

The main challenge with oral rehydration was that fluids were not absorbed, and any ingested liquids simply added to the volume of diarrhea. But Dr. Phillips had an idea. Guessing that the strength of the oral fluids was inadequate, he tried adding glucose to the fluids. He immediately noticed that patients drinking glucose-supplemented electrolytes passed less diarrhea, indicating that fluid was being absorbed. Dr. Phillips cautiously reported the phenomenon, and in so doing opened the door to one of the 20th century’s most important medical advances.

Soon afterward, research teams in what are now Dhaka, Bangladesh, and Kolkata, India, conducted careful clinical trials and established that oral rehydration fluids with balanced salts and glucose did indeed result in decreased diarrhea, rapid rehydration and surprisingly quick recovery.

The first clinical trials of what would become known as Oral Rehydration Therapy (ORT) took place in 1968. Patients who were given an oral solution containing glucose and electrolytes were found to need 79 percent less IV rehydration for full recovery than those who did not receive the oral solution. A follow-up study found that patients with mild and moderate cholera cases could be treated with ORT alone. Not only did most patients recover quickly, but the treatment was inexpensive and could be administered by family members in the home, and by other untrained individuals, increasing its effectiveness in emergency and low-resource situations.

Separate studies supported by NIAID showed that administration of the antibiotic tetracycline reduced the need for rehydration fluids by 60 percent. Pathophysiological studies revealed that in contrast to the understanding of earlier years, the cholera pathogen did not destroy the intestine, but used a toxin to alter the transport of solutes across the intestinal membrane. Oral rehydration with the correct fluids sped up recovery by compensating for the activity of the toxin.

ORT Saves Lives Today

ORT remains the current treatment of choice due to its safety, effectiveness, low cost, simple preparation, and easy administration. According to the World Health Organization, up to 80 percent of cholera patients can be successfully treated by ORT alone, the remaining severe cases requiring preliminary IV rehydration before transitioning to ORT. ORT is estimated to save over one million lives per year, and was described in the British Medical Journal’s “Medical Milestones” series as one of the most significant medical advances of the 20th century.

NIAID Research and Future Challenges

Emerging cholera pathogens present a challenge to the power of rehydration therapy and antimicrobials. For example, antimicrobial resistance can affect the ability of the cheap and widely available antibiotic tetracycline to reduce the duration and intensity of disease. In addition, novel cholera pathogens are emerging that possess a particularly active version of the cholera toxin. These strains result in a higher proportion of severe cases that must be immediately rescued with aggressive IV rehydration before receiving ORT. Finally, modern cholera strains are powerfully competitive in the environment, replacing endemic strains and occupying the natural waters upon which hundreds of millions of people depend.

Recent research has shown that these aggressive cholera strains have spread across Asia and Africa, and have recently appeared in Haiti. Cholera remains a fierce pathogen that ruthlessly exploits poverty, inequity, natural and man-made disaster, and poor access to health care. NIAID sponsors a robust research program to understand cholera evolution, develop new therapeutics and vaccines, and collaborate with international partners to continue the fight against this ancient and modern disease.


Carpenter CCJ, Sack RB, Mitra PP, Mondal A. Tetracycline therapy in cholera (link is external)Journal of the Indian Medical Association. 43:309-312 (1964).

Chatterjee HN. Reduction of cholera mortality by the control of bowel symptoms and other complications. (link is external) Postgraduate Medical Journal. 33(380):278-284 (1957).

Chin CS, Sorenson J, Harris JB, Robins WP, Charles RC, Jean-Charles RR, Bullard J, Webster DR, Kasarskis A, Peluso P, Paxinos EE, Yamaichi Y, Calderwood SB, Mekalanos JJ, Schadt E, Waldor MK. The origin of the Haitian cholera outbreak strain (link is external)New England Journal of Medicine. 364(1):33-42 (2011).

Fontaine O, Garner P, Bhan MK. Oral rehydration therapy: The simple solution for saving lives. (link is external) British Medical Journal. 334(supp1):s14 (2007).

Nalin DR, Cash RA, Islam R, Molla M, Phillips RA. Oral maintenance therapy for cholera in adults. (link is external) Lancet. 2(7564):370-373 (1968).

Nalin DR, Cash RA, Rahman M. Oral (or nasogastric) maintenance therapy for cholera patients in all age-groups. (link is external) Bulletin of the World Health Organization. 43(3):361-363 (1970).

Phillips RA. Water and electrolyte losses in cholera (link is external)Federation Proceedings. 23:705-712 (1964).

Savarino SJ. A legacy in 20th century medicine: Robert Allan Phillips and the taming of cholera (link is external)Clinical Infectious Diseases. 35(6):713-720 (2002).

Ruxin JN. Magic bullet: The history of oral rehydration therapy. (link is external) Medical History. 38(4):363-397 (1994).

World Health Organization. Fact Sheet No. 107: Cholera (link is external) (2010).

Yemen: Worst cholera outbreak in the world


• 332,658 suspected cholera cases and over 1,759 cholera deaths reported between 27 April and 13 July.

• Two million people more need assistance, bringing the number of people in need to 20.7 million from 18.8 million in January.

  • Children under 15 account for 40% of suspected cases and 1/4 of the deaths


WHO: To combat cholera in South Sudan


10 July 2017

Cholera contributes substantially to the disease burden in South Sudan, where outbreaks have been confirmed every year since 2014. Thus, cholera is endemic in South Sudan and requires an integrated and comprehensive approach that entails surveillance, patient care, optimal access to safe drinking water, sanitation, and hygiene (WASH); social mobilization and complementary use of oral cholera vaccines.

During the week ending 2 July 2017, a total of 304 new cholera cases and 0 deaths (Case Fatality Rate –CFR 0%) were reported across South Sudan. As of 2 July 2017, the cumulative total number of cases since the start of the current outbreak on 18 June 2016 is 17, 242 cases and 320 deaths (CFR 1.8%). The counties with active cholera transmission include Tonj East, Juba, Lankien, Pieri, Panyijar, Yirol East, Yirol West, Kapoeta East, Kapoeta South, and Kapoeta North. Suspect cholera cases are being investigated in Torit and Terekeka.

The integrated and comprehensive approach is core to the current cholera response in South Sudan. The cholera response strategy in South Sudan includes; case management, improving access to safe drinking water and sanitation; health promotion, risk communication, and community engagement; surveillance; patient care; and complementary use of oral cholera vaccines.

As a result, cholera transmission in Bor, Mingkaman, Duk, Ayod, Bentiu, Leer, Aburoc, Malakal Town, and several other areas has been controlled. The National cholera taskforce chaired by the Ministry of Health and co-chaired by WHO is leading the current response through its coordination, surveillance, case management, WASH, and social mobilization working groups.


Overall coordination of the cholera response at the national level is coordinated by the National cholera taskforce.

At the sub-national level, cholera taskforce committees are coordinating the cholera response in locations with active transmission including Yirol East and Yirol West, Bor, Duk, Tonj East, Kapoeta South, Kapoeta North, and Kapoeta East. Other non-affected states have also initiated cholera preparedness meetings in Aweil, Torit, Wau, Yambio, and Rumbek.

Health cluster support in coordination with the humanitarian partners responding to cholera outbreak and donors to fund cholera response in different locations.

Case Management

At least 50 cholera treatment facilities including cholera treatment centers and units; and oral rehydration points are currently operational in the areas with active cholera transmission. The cholera case management working group is coordinating patient care activities that are driven by the need to ensure timely access to rehydration at household level and at designated cholera treatment facilities. Ministry of Health-led and WHO supported rapid response teams have been deployed to support the cholera response in Kapoeta, Tonj, Jonglei, Eastern Lakes, and Northern Upper Nile states. The teams are evaluating transmission dynamics among the nomadic migratory communities in Kapoeta and devising appropriate epidemiological structures to break the chain and pattern of cholera transmission in this group. WHO, UNICEF, and health cluster partners have delivered cholera kits for patient care in areas with active transmission.

Water, Sanitation and Hygiene (WASH)

The WASH response is led by the WASH cluster and its partners and with interventions delivered as part of the integrated comprehensive approach in affected and at-risk areas. Point of use water treatment using PuR and water treatment tablets, hygiene promotion, distribution of other WASH NFIs, and repair of hand pumps are core to the current emergency WASH response in affected and high-risk areas. WHO is enhancing WASH capacities in cholera treatment facilities through training, deployment of public health officers, and water quality surveillance in affected and at-risk areas. Arrangements have been finalized for an intercountry planning meeting between South Sudan, Uganda, and Kenya to mitigate the risk of cross-border cholera spread.


With support from WHO, the Ministry of Health has rolled out electronic and mobile reporting of cholera alerts as well as cholera case based line listing in all affected locations. This has enhanced the transmission and accuracy, analysis, and dissemination of cholera situation reports to inform the response. Rapid response teams have been activated and supported with cholera investigation kits to facilitate timely verification and investigation of suspect cholera cases. Out of the 624 cholera samples tested by the National Public Health Laboratory, 247 (39.6%) have been confirmed by culture since 18 June 2016.

Social Mobilization

Partners have supported the Ministry of Health to intensify Social mobilization in the affected communities through community social mobilizers, and use of educational materials. WHO in collaboration with UNICEF and MOH has reactivated Cholera hotline (1144) Vivacell Telecom hotline to respond to calls, inquiries, alerts and as well as provide education on cholera prevention and control.

Oral cholera vaccination

As part of the ongoing cholera response, cholera vaccines have been deployed in Leer, Bor PoC, Malakal Town, Bentiu PoC, Mingkaman IDP settlement, Aburoc IDPs, Bentiu/Rubkona Town, Ayod (Pagil, Tar, Jiech, Karmun, Padek, and Kandak), and Juba (Don Bosco IDPs). Out of the 544 140 doses secured by WHO in 2017, a total of 384 971 doses have been deployed. There are no cholera cases reported from any of the sites where the oral cholera vaccines have been deployed in 2017.

An additional two million doses of oral cholera vaccines are required to mitigate the risk of cholera in high risk areas and to interrupt transmission in the areas with ongoing transmission. WHO is in the final stages of securing these additional doses to complement the ongoing cholera response.

WHO’s contribution to the cholera response

WHO provides overall technical guidance to MOH and health partners towards the cholera response. We also support to surveillance and cholera investigation as well as case management by deployment of Rapid Response Teams (RRTs), Clinicians, and support to WASH in Cholera Treatment Centers (CTCs) and monitoring standards of care.

WHO and partners conducting an assessment at Don Bosco Gumbo Oral Rehydration Point
WHO and partners conducting an assessment at Don Bosco Gumbo Oral Rehydration Point

Yemen: Since a severe outbreak began in late April, cholera has spread to 21 of the country’s 22 provinces, infecting at least 269,608 people and killing at least 1,614.

NY Times

  • “…..the fighting and airstrikes have killed more than 8,000 people and displaced at least three million…”
  • “…..27 million people lack access to clean water and 17 million do not have enough food….”
  • “…..the war has damaged 65 percent of Yemen’s medical facilities, denying more than 14 million people access to health care…..”
  • “….The United Nations says it needs $2.1 billion for its work in Yemen this year, but it has received only 29 percent of that amount despite repeated pleas for donations from aid groups……”


Yemeni healthcare system: Children dying of cholera in hospital hallways. Four sick people crammed into one bed. Patients connected to intravenous drips while sitting in their cars because the hospital is over capacity.


“…..The cholera outbreak has infected more than 200,000 people across Yemen, and it appears that 500,000 could eventually become sick. More than 1,300 people have already died…..”


Yemen: 37 079 suspected cholera cases and 196 associated deaths during the period 13 June to 19 June 2017.


Weekly update – cholera in Yemen, 22 June 2017

22 June 2017 – The Ministry of Public Health and Population of Yemen has recorded a total of 37 079 suspected cholera cases and 196 associated deaths during the period 13 June to 19 June 2017.

A cumulative total of 185 301 suspected cases of cholera and 1233 associated deaths have been recorded as of 21 June during this outbreak, which started in October 2016. The overall case-fatality rate is 0.7%; however, it is higher among people aged over 60.

WHO and health partners are actively supporting the Ministry through a cholera task force to improve cholera response efforts at the national and local levels. This includes the establishment of 18 diarrhoea treatment facilities and 28 oral dehydration centres, training of health workers to manage cases, water purification in communities, deployment of rapid response team to manage cholera cases investigations and respond to the outbreak, enhancement of Yemen’s disease early warning surveillance systems, and provision of emergency medical supplies to treatment facilities.

Cholera has affected around 268 districts in 20 governorates across the country. While cholera is endemic in Yemen, the country has experienced a surge in cholera cases since 27 April 2017.

WHO and the King Salman Centre for Humanitarian Aid and Relief recently agreed to provide around US$ 8.3 million through health partners to support 7.3 million people in 13 priority governorates with life-saving health services, medical supplies and cholera case management efforts.

The Ministry of Public Health and Population of Yemen has recorded an additional 13 912 cholera cases in Yemen between 3 and 6 June 2017.



Yemen is in the grip of a runaway cholera epidemic that is killing one person nearly every hour and if not contained will threaten the lives of thousands of people in the coming months


“The number of suspected cholera cases in war-torn Yemen has risen to more than 100,000 since an outbreak began on April 27…”


Yemen: 23 425 new suspected cases of cholera and 242 related deaths


Weekly update – cholera in Yemen, 20 May 2017

20 May 2017 – The Ministry of Public Health and Population of Yemen has released updated numbers of cholera cases in the country. Since the last update on 27 April, 23 425 new suspected cases of cholera and 242 related deaths (case-fatality rate 1.1%) have been reported, mainly from Amran, Hajjah and Sana’a governorates and Sana’a city.

A cumulative total of 49 495 suspected cases of cholera, including 362 associated deaths have been reported across the country since the outbreak started in October 2016. However, between 27 April and 18 May 2017, there has been a significant upsurge in the number of suspected cholera cases. The outbreak has spread to around 210 districts in 18 governorates across the country, and the case fatality rate has exceeded 1%.

WHO has intensified the cholera response activities to mitigate the outbreak, including the establishment of 4 cholera treatment and 16 oral dehydration centres, training of health workers to manage the cases, deployment of rapid response team to manage cholera cases investigations and respond to the outbreak, enhancement of Yemen’s disease early warning surveillance systems, and provision of emergency medical supplies to treatment facilities.

The ongoing response operations are severely hampered by limited active case-finding, population movement and displacement, poor accesses to health care services, food insecurity and malnutrition.


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