Cholera, primarily caused by the bacteria Vibrio cholerae strains O1 and O139, is a global public health challenge. According to the World Health Organization’s (WHO) weekly Epidemiological Record, the world witnessed more than double the cholera cases in 2022 than in 2021, presenting a serious hurdle to WHO’s ambitious goal set in 2017 of cutting down global cholera deaths by 90% by 2030.
Cholera is a water-borne disease that results in an acute diarrheal illness through an infection of the intestine. It often manifests with mild or no symptoms but can occasionally be severe. The significant symptoms include profuse watery diarrhea, vomiting, and leg cramps. Cholera spreads largely by drinking water or consuming food contaminated with the cholera bacterium, especially in areas with poor sewage and drinking water treatment. Oral Cholera Vaccines (OCV), including Dukoral, Shanchol, and Euvichol-Plus, are currently pre-qualified by WHO to prevent the disease.
Factors Responsible for Cholera Escalation
Several factors contribute to the surge in cholera cases. A primary cause is the relaxation of Covid-19 pandemic restrictions, allowing cholera to propagate. Other factors include inadequate investments in healthcare for vulnerable populations, effects of climate change, increasing conflicts, and insufficient access to sanitation and clean water. Vibrio cholerae bacteria tend to thrive in warmer waters with lower salinity, conditions exacerbated by climate change-induced weather events. Additionally, recent research indicates that Vibrio pathogens can adhere to microplastics, compromising cholera transmission dynamics.
Climate Change and Cholera
Climate change has a significant impact on cholera transmission. A study published in The Lancet Planetary Health in 2021 highlighted this relationship. It projected an increase of 38,000 km in coastline conducive to Vibrio bacteria development by 2100, compared to the average between 1850 and 2014.
Geographic Distribution and Cholera Trends
Most cholera cases originate from Africa and Asia, while Europe occasionally reports “imported cases.” In Africa, cholera cases in 2022 were more scattered compared to 2021, with no single country accounting for more than 25% of all cases and 30% of deaths. This data masks the fact that cholera cases and deaths doubled in countries other than Nigeria, which had a significant outbreak in 2021. A similar increase was noted in Asian countries such as Lebanon, Syria, and Afghanistan.
Global Initiatives against Cholera
In 2017, the global strategy on cholera control, Ending Cholera: A Global Roadmap to 2030, was launched, aiming to reduce cholera-related deaths by 90%. Additionally, WHO revitalized the Global Task Force for Cholera Control (GTFCC) to bolster its cholera eradication efforts. The GTFCC’s goal is to encourage the implementation of evidence-based strategies to control cholera.
Response Measures to Tackle Cholera
To combat the growing cholera burden, adaptations have been made in the oral cholera vaccine regimen. While waiting for larger-scale production, the management of the emergency stockpile has changed the vaccination regime from two doses to one. This tactical switch aims to boost cholera vaccinations’ efficiency and reach.
