The massive cholera outbreak in Yemen has now exceeded 275,000 suspected cases and 1,600 deaths, according to the World Health Organization (WHO). The United Nations declared it to be “the worst cholera outbreak in the world,” fueled by an ongoing war that has obliterated health, water, and sanitation systems, leaving 14.5 million people without clean water and sanitation. Additionally, famine and malnutrition have made Yemen’s youngest citizens particularly vulnerable to the disease, with more than half of the suspected cases occurring in children. Poor access to food, clean water, electricity and medical care have created ideal conditions for the rapid spread of cholera in the region.

Despite the anticipated challenges of delivering medical aid in the war-torn country, “trucks taking vast amounts of supplies to fight the epidemic have not encountered great difficulties in reaching areas in need,” according to Ahmed Zouiten, WHO’s senior adviser for Yemen. On June 30, “twenty ambulances, 100 cholera kits, hospital equipment, and 128,000 bags of intravenous fluids” arrived in Yemen, part of a 403-ton shipment sent by WHO, and more supplies are expected to arrive in the near future. Additionally, WHO, with funding assistance from the World Bank, is arranging treatment centers with the goal of establishing 5,000 total patient beds. WHO is also paying what are being described as “incentives” to healthcare workers to staff an emergency cholera network. Oral rehydration points—local facilities staffed by community health workers and nurses that have a clean, reliable water source and necessary supplies—can “provide rapid access to oral rehydration salts (ORS) solution” and provide public education regarding cholera prevention and treatment. These facilities have been particularly impactful, according to Zouiten, since they are located close to homes and are “able to get people who have just started to get diarrhea.”

In our previous post on this topic, we discussed the difficulties of deploying vaccination campaigns in conflict zones, examining the possibility of a cholera vaccination campaign being initiated in Yemen. Indeed, on June 21, WHO announced that the International Coordinating Group—which “coordinates the provision of emergency vaccine supplies and antibiotics”—approved the shipment of a million doses of the cholera vaccine to Yemen. However, the vaccine will still face a “major test in war-torn Yemen.” With more than 20 million people at risk for acquiring the disease, health experts will have to decide how best to deploy the vaccine. For optimal protection, the vaccine course is typically two doses administered two weeks apart, but due to supply concerns, the campaign will only use one dose per person in order to reach as many people as possible. While the two-dose regimen provides 80% protection against the disease, a recent study in South Sudan found “the unadjusted single-dose vaccine effectiveness to be 80.2%” during the first two months. The authors caution, however, that the dose may have acted as a booster to those previously exposed to cholera rather than conferring immunity in cholera-naïve individuals, noting that further research is needed to understand the extent to which one dose of the vaccine can protect those without previous exposure to cholera.

While a vaccination campaign may help slow the spread of cholera, it alone cannot stop the outbreak. The deployment of treatment centers and oral rehydration points will be paramount to decreasing mortality and interrupting transmission, and fresh water, functioning sanitation systems, and hygiene are the best long-term solution for controlling and preventing cholera outbreaks.


Photo courtesy CDC/Janice Haney Carr