World reported twice as many cholera cases in 2022 as in 2021: WHO | Data Premium

Cholera cases have more than doubled since 2021, with Africa and Asia reporting most cases. Climate change, conflict, and limited investments in care are blamed. A 2021 study found Vibrio bacteria could increase by 38,000 km by 2100. A 2023 study found Vibrio pathogens stick to microplastics. WHO shrank the recommended vaccination regime from two doses to one. Africa reported 29% fewer cases and 52% fewer deaths in 2022, but other countries reported more than double. Rapid diagnostic tests used by 56% of countries in 2022.

Cholera is a water-borne disease caused by two strains called O1 and O139 of the bacteria Vibrio cholerae . Of these, O1 is responsible for almost all outbreaks; outbreaks of O139 are rare and none have been recorded outside Asia. According to the World Health Organization (WHO)’s weekly epidemiological record, published on September 22, the world reported more than twice as many cholera cases in 2022 as it did in 2021 (Chart 1). Between these years, more than twice as many countries also reported at least 10,000 suspected as well as confirmed cases of cholera.

Chart 1 | The chart shows year-wise reported cholera cases between 1989 and 2022.

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Both these trends suggest a reversal of a short-term trend, of declining prevalence since 2019. The reversal also complicates a target the WHO specified in 2017, to reduce the number of cholera deaths worldwide by 90% by 2030. According to the United Nations health body, “Cholera transmission is closely linked to inadequate access to clean water and sanitation facilities.” Vibrio cholerae bacteria also favour warmer waters with lower salinity. All these conditions are created as a result of climate change — which increases the likelihood of floods, heatwaves, intense monsoonal rains and storms, and the duration of warm periods — and war.

The epidemiological record report blames the uptick on the decline of the COVID-19 pandemic, and its restrictions; “limited investments” in providing care to those most vulnerable to the disease; the effects of climate change; and increasing conflict.

A 2021 study published in the journal The Lancet Planetary Health concluded that the length of the coastline favourable to the development of Vibrio bacteria could increase by 38,000 km by 2100 over the 1850-2014 average, in the SSP5-8.5 emissions scenario.

A June 2023 study by researchers at the University of Florida found that “ Vibrio pathogens have a unique ability to ‘stick’ to microplastics, and that these microbes might be adapting to plastic”, including in the open ocean, according to a statement by the National Science Foundation.