WHO Global cholera overview

According to the WHO’s cholera assessment published on December 16, the risk of cholera at the global level is very high. Since 2021, cholera case numbers have increased globally. In 2021, 23 countries reported cholera outbreaks, and the average case fatality ratio (CFR) globally was 1.9 % (2.9% in Africa), the highest cholera CFR recorded in over a decade. In 2022, over 29 countries reported cholera cases (1).

Outbreaks in 13 countries are particularly concerning because many had not reported cholera outbreaks for many years, such as Haiti, Syria and Lebanon (1). For example, after over three years without a single cholera case in Haiti, the disease re-emerged in the country on October 2, 2022 (2). As of December 20, 2022, a total of 18,469 suspected cholera cases have been reported in Haiti since this new epidemic began (3). Furthermore, Haiti faces multiple concurrent threats including social unrest, violence by armed groups, and fuel shortages. Healthcare facilities are also experiencing shortages of supplies critical for the cholera response (including cholera kits, oral rehydration salts, cholera beds and antibiotics) (1). Syria has not reported cholera cases since 1979 (4,5); however, the country declared an outbreak in Aleppo on September 10, 2022 (6). As of December 10, a total of 61,671 suspected cholera cases have been reported in Syria (7). Lebanon has not been affected by a cholera outbreak since 1993; however, the outbreak in Syria has spread into Lebanon, with the first case reported on October 6, 2022 (8). As of December 9, a total of 5,105 suspected cholera cases have been reported in Lebanon (9).

Certain countries are also experiencing severe climate conditions that facilitate cholera spread and further hinder the response. In the Horn of Africa, 36 million people have been affected by drought in Kenya, Ethiopia and Somalia, which has triggered an increase in climate refugees and internally displaced persons and a high risk of cholera spread in the region. Furthermore, in Malawi, recent flooding in the south of the country has destroyed schools and healthcare facilities and displaced over 27,500 people. The ongoing cholera outbreak has spread to all districts, with a total of 12,556 cases and 363 deaths (CFR 3 %) as of December 12, 2022 (1).

In addition to limited access to potable water and proper sanitation facilities, several aggravating factors further facilitate cholera diffusion and hinder outbreak control:

Factors of cholera diffusion

Climate change and conflict, which both trigger population movement of vulnerable groups, contribute to outbreak spread (1).

• Many affected countries are experiencing natural disasters such as cyclones (Mozambique, Malawi), flooding (Pakistan, Nigeria) and drought (Horn of Africa).
• Humanitarian crises due to conflict, political instability are leaving an increasing number of people at risk for cholera. Nine of the affected countries are experiencing conflict or political violence in affected areas (Afghanistan, Cameroon, the Democratic Republic of Congo, Haiti, Iran, Nigeria, Somalia, Syria and Yemen). In Ethiopia and Cameroon, there is a high risk of cholera spreading into areas of ongoing conflict. 

Factors that hinder the cholera response

The compound crises in countries with an already limited capacity to respond to outbreaks poses significant challenges to the cholera response and risks further spreading the disease to neighboring countries (1). 

• Severe weather and conflict in affected areas not only facilitates cholera diffusion but also hinders the response.
• Sub-optimal and/or delayed surveillance data also hinders the response.
• Healthcare resources are stretched due to multiple large-scale outbreaks and other public health and humanitarian crises, which in many cases has caused the emigration of skilled medical personnel as well as destruction or inaccessibility of healthcare infrastructure. Furthermore, several countries with cholera outbreaks are also responding to multiple disease outbreaks including monkeypox, dengue, chikungunya, measles and COVID-19, thus straining the overall response capacity to cholera.
• With the current depleted stocks of cholera kits, suppliers are struggling to meet demand. Furthermore, the global OCV stockpile is currently insufficient to meet all requests for two doses of preventive vaccination. On October 20, 2022, the International Coordinating Group members have temporarily limited all reactive OCV campaigns to a single dose, although it is unclear how long immunity will last.

WHO recommendations

Access to safe drinking water and sanitation infrastructures should be improved, especially in affected and high-risk areas. It is critical to improve access to proper and timely case management as well as infection prevention and control in healthcare facilities. To prevent cholera transmission, preventive hygiene practices and food safety should be promoted in affected communities, ensuring effective risk communication and community engagement strategies to encourage behavioral change. When vaccination campaigns are planned, OCV should be used in conjunction with improvements in water and sanitation to control outbreaks and prevent cholera in high-risk areas. Cholera surveillance (especially at the community level) should be strengthened and maintained to detect suspected cases early. Finally, to prevent cross-border spread, cooperation and regular information sharing across all levels should be ensured (1).