Global Incidence of Cholera Is Declining

Cholera has historically been considered a global threat to public health, but a new report from the World Health Organization (WHO) suggests cases of the acute diarrheal disease are on the decline.

According to the new report, the global incidence of cholera cases decreased by 60% in 2018. In total, there were 499,447 cases of the disease with 2990 associated deaths documented in 2018, as per reports from 34 countries.

Outbreaks of cholera continue to affect several nations, but the annual case count reflects a downward trend in global transmission of the diarrheal disease. The report also indicates that some of the world’s major hotspots for cholera, which include Haiti, Somalia, and the Democratic Republic of the Congo, have made encouraging progress in preventing and controlling the disease.

“The global decrease in case numbers we are observing appears to be linked to large-scale vaccination campaigns and countries beginning to adopt the Global Roadmap to 2030 strategy in their national cholera action plans,” Dr Dominique Legros, who heads WHO’s cholera program, said in a statement. “We must continue to strengthen our efforts to engage all cholera-endemic countries in this global strategy to eliminate cholera."

In 2019, nearly 18 million doses of oral cholera vaccines were shipped to 11 countries. Currently, there are 3 WHO prequalified oral cholera vaccines—Dukoral, Shanchol, and Euvichol-Plus. All vaccines require 2 doses for full protection against cholera.

Dukoral, mainly used for travelers, is administered with a buffer solution that requires 150 ml of clean water. The vaccine can be administered to all individuals over the age of 2 years. Doses must be given at least 7 days apart, but no more than 6 weeks after initial vaccination. Children aged 2 to 5 years require a third dose.

Shanchol and Euvichol-Plus are “essentially the same vaccine” but are produced by 2 different manufacturers, according to XXXX. The vaccines do not require a buffer solution and can be given to individuals over the age of 1 year. There must be a minimum of 2 weeks between each dose. Two doses provide protection against cholera for 3 years; 1 dose only provides short-term protection.

Shanchol and Euvichol-Plus are the vaccines currently available for mass vaccination campaigns through the global oral cholera vaccine stockpile, which was created in 2013. Since its inception, nearly 60 million cholera vaccines have been shipped worldwide. Gavi, the Vaccine Alliance, has provided funding for purchase of the vaccine and financial support for the global vaccination drives.

In 2017, the Global Task Force on Cholera Control launched the Global Roadmap strategy for effective long-term cholera control and elimination. The roadmap aims to reduce cholera deaths by 90% and to eliminate transmission in up to 20 countries by 2030.

The strategy provides a framework for national action plans that emphasize early detection and rapid response to outbreaks; uses multiple sectors to strengthen surveillance, vaccination, sanitation, and hygiene to prevent cholera in hotspots and endemic countries; and employs an effective mechanism of coordination for technical support, resource mobilization, and partnership at the local and global levels.

Yemen has been battling the worst cholera outbreak in recorded history since September 2016. According to a WHO update issued on November 19, 2019, the cumulative number of suspected cholera cases between January 1, 2018, and November 3, 2019, is 1,145,292, with 1507 associated deaths.

Children under the age of 5 years represented 26% of the total suspected cases in 2019. Additionally, the outbreak has affected 311 of the 333 districts of Yemen.

Despite this devastating outbreak, the new report indicates significant progress has been made in the fight against cholera in Zambia, South Sudan, United Republic of Tanzania, Somalia, Bangladesh, and Nigeria.

The WHO has also played a role in supporting affected nations to work toward cholera control and improve surveillance, outbreak response, and preventive measures. In 2018, the agency worked alongside national health officials in Africa to respond to major outbreaks in the Democratic Republic of the Congo, Nigeria, Uganda, Yemen, Zambia, and Zimbabwe.

WHO representatives also worked with officials in Haiti, United Republic of Tanzania, and Zambia to transition from outbreak response to long-term cholera control and elimination.