WHO update on cholera in 2018

November 29, 2019 – Weekly Epidemiological Record

An excerpt – While the true global disease burden is not entirely captured by annual reporting of cholera epidemiological indicators by Member States to WHO, the overall number of cholera cases was 60% lower in 2018 than in 2017.

The decrease in the global cholera burden is attributable to a large reduction in the number of cases in Yemen and significant decreases in other countries, such as the Democratic Republic of Congo (DRC), Somalia and South Sudan.

Overall, in 2018, 34 countries reported 499 447 cholera cases and 2990 cholera deaths to WHO, with a case-fatality rate (CFR) of 0.6% (Figure 1, Map 1 and Table 1).

Africa – Overall, in 2018, 34 countries reported 499 447 cholera cases and 2990 cholera deaths to WHO, with a case-fatality rate (CFR) of 0.6% (Figure 1, Map 1 and Table 1). After exclusion of cases reported in Yemen (where reporting is imprecise), the total numbers of cases and deaths reported globally in 2018 were 128 121 and 2485, respectively, a 34% decrease in the number of cases and a 27% decrease in that of deaths from 2017. The case load represents the fewest cases reported worldwide since 2004, when there were 101 383 cases (with 2345 deaths).

The epidemiology of cholera on the African continent showed the typical regional tendency. In West Africa, cholera transmission was high in Nigeria (with 45 000 cases in 2018 and only 12 000 in 2017), with subsequent spill-over into Cameroon and Chad. Other countries in the West African region saw no cholera cases, and only 2 cases were reported in Liberia.

Middle East and Asia – As in 2017, Yemen reported by far the most cholera cases in a single country in 2018, with 371 326 cases and 505 deaths (Figure 2). This nevertheless represented a great improvement over the previous year, with a 64% decrease in the number of cases and a 78% decrease in the number of deaths. While the way in which cholera cases were reported changed during the year, the decreases in numbers of cases and deaths represented greater mobilization by the Government and partners in improving water, sanitation and hygiene and in providing adequate medical care of cases.

The Americas – In Haiti, a strategy for an integrated rapid response to outbreaks resulted in 2018 in the fewest cases since the start of the cholera epidemic in 2010 (Figure 2). The Dominican Republic continues to report relatively few cases, and the number is decreasing over time, in parallel with the numbers in Haiti.

A Bibliography of WASH and Cholera Studies

A Bibliography of WASH and Cholera Studies, September 17, 2019

In response to an information request, we have compiled a bibliography of 29 studies and reports published in 2018 and 2019 that discuss WASH-related aspects of cholera epidemiology and prevention/control. Please add additional studies to this google document or contact us to add additional resources such as videos, webinars, etc.

Overviews

Global Cholera Epidemiology: Opportunities to Reduce the Burden of Cholera by 2030. J Infect Dis. November 2018.  The roadmap consists of targeted multi-sectoral interventions, supported by a coordination mechanism, along 3 axes: (1) early detection and quick response to contain outbreaks; (2) a multisectoral approach to prevent cholera recurrence in hotspots; (3) an effective partnership mechanism of coordination for technical support, countries capacity building, research and M&E, advocacy and resource mobilization.

Broad approaches to cholera control in Asia: Water, sanitation and handwashing. Vaccine, August 2019.  Increased research to develop and policy flexibility to implement a new generation of solutions that are designed specifically to address the physical, financial and political constraints of low-income communities offers the best prospect for reducing the burden of cholera across Asia.

Cholera Treatment Centers/Healthcare Facilities

Formative research for the design of a scalable water, sanitation, and hygiene mobile health program: CHoBI7 mobile health program. BMC Public Health, 2019. This study presents a theory- and evidence-based approach that can be implemented for the development of future water, sanitation, and hygiene mHealth programs in low-resource settings.

Technical Note: Water, Sanitation and Hygiene and Infection Prevention and Control in Cholera Treatment Structures. Global Task Force on Cholera Control, January 2019. Cholera treatment facilities provide inpatient care for cholera patients during outbreaks. Proper case management and isolation of cholera patients is essential to prevent deaths and help control the spread of the disease.

Assessment of Recommendation for the Containment and Disinfection of Human Excreta in Cholera Treatment Centers. Water, January 2019. These findings suggest that the use of 30% hydrated lime suspensions or 2% chlorine solutions may offer a simple public health protection measure for the containment, safe handling, and disinfection of human excreta during humanitarian emergencies.

USAID OFDA – Social Science in Epidemics: Cholera lessons learned

Social Science in Epidemics: Cholera lessons learned. Social Science in Humanitarian Action, December 2018.

This report is the first installment of the ‘Social Science in Epidemics’ series, commissioned by the USAID Office of U.S. Foreign Direct Assistance (OFDA). In this series, past outbreaks are reviewed in order to identify social science ‘entry points’ for emergency interventions and preparedness activities.

The aim is to determine tangible ways to address the social, political and economic dynamics of epidemics and to ensure that interventions build on the social and cultural resources of the communities they aim to support.

This report focuses on the lessons learned primarily from countries affected by cholera outbreaks in the past four decades, in what is called the 7th Cholera pandemic.

The most important case studies considered are the epidemics in Peru (1991), Haiti (2010), South Sudan (2016), India (endemic outbreaks), Mozambique (2014 and 2017) and Zimbabwe (2008 and ongoing outbreak), yet other countries’ experiences are incorporated.

Lessons are also integrated from literature around cultural responses to Oral Rehydration Therapy in the context of acute diarrheal disease.

2018 studies, reports and news updates on cholera prevention and control

The latest biweekly update contains journal articles, reports, etc. that have been published so far in 2018. Please let us know if you have additional studies and resources that should be added to this list:

OPEN ACCESS JOURNAL ARTICLES

Setting priorities for humanitarian water, sanitation and hygiene research: a meeting report. Conflict and Health, June 15, 2018.
In June 2017, the Research for Health in Humanitarian Crises (R2HC) programme of Elrha, convened a meeting of representatives from international response agencies, research institutions and donor organisations active in the field of humanitarian WASH to identify research priorities, discuss challenges conducting research and to establish next steps. Topics including cholera transmission, menstrual hygiene management, and acute undernutrition were identified as research priorities.

Cholera epidemic in Yemen, 2016–18: an analysis of surveillance data. The Lancet Global Health, June 2018.
Our analysis suggests that the small first cholera epidemic wave seeded cholera across Yemen during the dry season. When the rains returned in April, 2017, they triggered widespread cholera transmission that led to the large second wave. These results suggest that cholera could resurge during the ongoing 2018 rainy season if transmission remains active.

Editorial: No end to cholera without basic water, sanitation and hygiene. WHO Bulletin, May 2018.
A shared vision and unanimous agreement among Member States, partners and donors to prioritize broader social and environmental determinants of health, including water, sanitation and hygiene, is needed to end cholera.

Satellites Predict a Cholera Outbreak Weeks in Advance

Satellites Predict a Cholera Outbreak Weeks in Advance. Scientific American, January 3, 2018.

A test in Yemen showed satellite data could foresee an outbreak four weeks before it exploded 

Vibrio cholerae. Credit: Getty Images

Orbiting satellites can warn us of bad weather and help us navigate to that new taco joint. Scientists are also using data satellites to solve a worldwide problem: predicting cholera outbreaks.

Cholera infects millions of people each year, leading to thousands of deaths. Often communities do not realize an epidemic is underway until infected individuals swarm hospitals. Advanced warning for impending epidemics could help health workers prepare for the onslaught—stockpiling rehydration supplies, medicines and vaccines—which can save lives and quell the disease’s spread.

Back in May 2017 a team of scientists used satellite information to assess whether an outbreak would occur in Yemen, and they ended up predicting an outburst that spread across the country in June.

Read the complete article.

In Haiti, a Building Fights Cholera

In Haiti, a Building Fights Cholera. New York Times, September 12, 2017.

Next month marks the seventh anniversary of the cholera outbreak that ravaged Haiti. The disease, which can cause death within hours if left untreated, came less than a year after Haiti was rocked by an enormous earthquake that left hundreds of thousands dead and millions injured, displaced and destitute.

Haiti is prone to earthquakes and tropical storms — the island was spared the worst of Hurricane Irma last week — but the cholera outbreak was an anomaly; the disease had never before struck Haiti. It was brought in, it is widely believed, by United Nations peacekeepers from Nepal.

A child with cholera symptoms being examined in the Cholera Treatment Center in Port-au-Prince, Haiti. Credit Dieu Nalio Chery/Associated Press

One of the world’s most infectious waterborne diseases, cholera spreads quickly and has proved extremely difficult to contain in Haiti. Over 10,000 have died and nearly a million have been stricken to date.

But one organization has managed to nearly eradicate it in a large slum in Port-au-Prince that lacks clean water and sanitation.

One of the game changers that would surprise most people, including global health experts, was actually a building.

It wasn’t just any building, but a very intelligently and beautifully designed one: the Cholera Treatment Center, operated by Les Centres Gheskio, an acronym that stands for the Haitian Group for the Study of Kaposi’s Sarcoma and Opportunistic Infections.

Read the complete article.

‘It’s a Slow Death’: The World’s Worst Humanitarian Crisis

‘It’s a Slow Death’: The World’s Worst Humanitarian Crisis. New York Times, August 23, 2017.

SANA, Yemen – After two and a half years of war, little is functioning in Yemen.

Repeated bombings have crippled bridges, hospitals and factories. Many doctors and civil servants have gone unpaid for more than a year. 

Malnutrition and poor sanitation have made the Middle Eastern country vulnerable to diseases that most of the world has confined to the history books.

In just three months, cholera has killed nearly 2,000 people and infected more than a half million, one of the world’s largest outbreaks in the past 50 years.

Read the complete article.

The life and death struggle against cholera in Yemen – WHO

The life and death struggle against cholera in Yemen. WHO, July 2017.

Cholera continues to spread in Yemen, causing more than 390 000 suspected cases of the disease and more than 1800 deaths since 27 April.

WHO and its partners are responding to the cholera outbreak in Yemen, working closely with UNICEF, local health authorities and others to treat the sick and stop the spread of the disease. 

Each of these cholera cases is a person with a family, a story, hopes and dreams. In the centres, where patients are treated, local health workers work long hours, often without pay, to fight off death and help their patients make a full recovery.

Read the complete article.

Cholera Hitches A Ride On The Backs Of Soft-Shell Turtles

Cholera Hitches A Ride On The Backs Of Soft-Shell Turtles. NPR, June 26, 2017.

You can catch cholera from drinking contaminated water.

You can catch it from raw or undercooked shellfish.

And you can catch it from soft-shell turtles.

Cholera bacteria can colonize the outer surfaces of the Chinese soft-shell turtle, a species that’s found in parts of Asia. Frank Greenaway/Getty Images

That’s the finding of a study published this month by scientists at the Chinese Center for Disease Control and Prevention. And it’s a particular concern in China and many other countries in East Asia, where turtle meat is often used in stews and soups.

The researchers found that the bacterium that causes cholera, Vibrio cholerae, can colonize many of the outer surfaces of a soft-shell turtle, including its shell, legs, neck and calipash — a gelatinous material just underneath the shell and highly prized as a delicacy. The bacteria can also live in turtles’ intestines. The study was published in the scientific journal, Applied and Environmental Microbiology.

Although China has relatively few cholera cases compared to other countries, several small outbreaks of cholera are linked to soft-shell turtles every year, often at rural banquets — a troubling sign, considering that turtle consumption in the country has grown to somewhere between 220 million and 330 million pounds per year.

“We found that soft-shell turtles really can carry Vibrio cholerae and cause cholera outbreaks,” said Meiying Yan, one of the study’s authors. “The surface of the turtle was the most important source of Vibrio cholerae O139.” O139 is a strain of cholera circulating in Asia that was discovered in 1992.

Read the complete article.

 

How El Niño forecasts can help prevent cholera deaths in Africa

How El Niño forecasts can help prevent cholera deaths in Africa. The Conversation, May 14, 2017.

Pit latrine in Dar es Salaam, Tanzania. Access to clean water and sanitation are key to preventing cholera epidemics. D. Schafer, SuSanA/Flickr, CC

Since it first emerged from the Ganges River delta 200 years ago, cholera has killed tens of millions of people around the world. It causes acute diarrhea that can kill quickly without proper treatment. Before the 1970s it was not unusual for healthy adults to die of dehydration within days of infection, despite drinking large amounts of water.

By some estimates, over a billion people worldwide live in areas where there is risk of cholera, and hundreds of thousands die every year. But when people have access to clean water, appropriate treatment or vaccine, the risk of cholera is greatly reduced. With well-trained medical staff and supplies, appropriate and timely treatment of cholera patients can ensure that almost no one dies.

In a recent study, our group sought to understand how weather changes caused by El Niño impact cholera risk in Africa, where most cholera deaths occur. El Niño events can now be forecast as much as a year in advance, so knowing this relationship may help forecast where cholera outbreaks are most likely to occur.

Read the complete article.