In September 2024 WHO published the global cholera statistics for 2023, revealing an increase in cases and deaths. The current global risk from cholera is described as “very high”; WHO is responding “with urgency” to reduce deaths and contain outbreaks. The increased demand for cholera countermeasures, including the oral cholera vaccines (OCV), has applied pressure to disease control efforts. However, WHO emphasises the importance of “safe drinking water, sanitation, and hygiene” as “the only long-term and sustainable solutions”.
Cases increase
103 countries shared cholera data with WHO in 2023, revealing that the 7th cholera pandemic “continued to surge”. 535,321 cases were reported to WHO from 45 countries, territories, and areas. This is an increase from 472,697 in 2022. The geographical pattern of outbreaks continued to evolve, with a 32% reduction in the number of cases reported in countries in the Middle East and Asia and a 125% increase in cases in Africa.
Very large outbreaks (>10,000 suspected and confirmed cases per country) were reported by 9 countries on 3 continents in 2023: Afghanistan, Bangladesh, the Democratic Republic of the Congo (DRC), Ethiopia, Haiti, Malawi, Mozambique, Somalia, and Zimbabwe. This is 2 more than in 2022 and “more than double” the number of very large outbreaks reported annually between 2019 and 2021. It is possible that increased case numbers are attributable to efforts to enhance cholera surveillance and reporting.
“Conflict, climate change, limited investment in development, and population displacement due to emerging and re-emerging risks all contributed to the rise in the number of cholera outbreaks.”
OCV stockpile
The International Coordinating Group (ICG) manages the oral cholera vaccine (OCV) emergency stockpile; in response to limited OCV availability the ICG made the “unprecedented decision” to temporarily suspend the standard 2-dose regimen in outbreak response campaigns in October 2022. This has been replaced with a single-dose approach, which has continued throughout 2023 and into 2024. It enables available vaccines to protect more people and facilitates more responses to cholera outbreaks.
Although evidence on the duration of protection is “limited”, the strategy has “proven effective” in outbreak responses. Despite low availability, a record 35 million doses were shipped last year. The last doses of Shancol were distributed in 2023 after the product was discontinued in 2022. The new simplified OCV, Euvichol-S, prequalified in early 2024, is expected to enter the global market later this year. This will increase the global stockpile. While investment into vaccine production continues, the supply constraint is expected to continue into 2025.
WHO states that it is continuing to support countries with “strengthened public health surveillance, case management, and prevention measures”. Since 2022, US$18 million has been released from the WHO Contingency Fund for Emergencies. Although WHO has appealed for US$50 million to respond to cholera outbreaks in 2024, the need “remains unmet”.
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