KATHMANDU VALLEY — Last spring, Nepal faced a high risk of a cholera outbreak following the earthquake that devastated the region. Yet, in the Kathmandu Valley, where many of the displaced sought refuge, only 82 infections were confirmed. Public health officials strategically utilized a small inventory of oral cholera vaccine (OCV) in conjunction with traditional hygiene methods to prevent an outbreak.
In April and May 2015, two earthquakes with magnitudes of 7.8 and 7.3 respectively struck Nepal killing over 8,500 people. The earthquakes displaced thousands, damaged infrastructure including water resources and destroyed many homes. As the nation began to recover cholera concerns mounted, especially in camps for displaced people.
Cholera, which is endemic in Nepal, is a waterborne disease which causes diarrhea and dehydration. Symptoms appear rapidly and can be severe, even fatal. When adequate sanitation and clean water sources have been compromised, cholera is a serious concern. In vulnerable populations, such as displaced Nepalese, infections may quickly scale up into an outbreak.
After Haiti’s devastating 2010 earthquake, the resulting cholera outbreak infected 750,000 people and killed 9,400 people. Nepal has a long and tenuous history of cholera outbreaks dating back to the 19th century. The nation’s condition after the earthquake gave public health professionals cause for concern.
The oral cholera vaccine (OCV) was not widely available during the Haiti epidemic. Shortly after, the World Health Organization (WHO) announced its approval of the vaccine, and the organization’s acceptance was pivotal. WHO began stockpiling OCV in 2013, yet the number of available doses is minuscule compared to those at risk.
These quantity limitations prompted a new approach. Officials chose to strategically administer the OCV to those most at risk. Often, the most at risk populations live near landfills or contaminated water sources. Refugee camps or displaced populations with temporary sanitation and water systems can foster the disease as well.
After the earthquake, Nepal acquired 18,000 doses of Shanchol, a brand of OCV. The full vaccine treatment calls for two doses per person and provides immunity for five years. Only 9,000 people could be vaccinated and an estimated 2.8 million had been displaced, perhaps even more at risk. With public health infrastructure already stretched thin, a proactive approach became imperative.
Public health officials remained vigilant while monitoring camps, water quality and any suspected cholera infections. Ensuring those who did receive the vaccine took both doses was a high priority as well. The director of the Nepal Epidemiology and Disease Control Division, Babu Ram Marasina, reported a follow-up rate close to 99 percent, ensuring the vaccine’s full potential could be realized.
Traditional cholera prevention efforts were also utilized by focusing on hygiene and disease education, otherwise known as WASH (water and sanitation hygiene). However, Marasina told the media it did not have the same impact as the vaccine: “We tried for the WASH intervention, we could not do it. It was very difficult.”
While cholera infections did occur in Nepal, it never reached the scale of an outbreak. In the future, OCVs in conjunction with clean water and sewage control will be looked to for preventing cholera outbreaks following natural disasters.
Public health officials shouldn’t underestimate the likelihood of a cholera outbreak. It can spread far and fast, killing large numbers of people. Utilizing OCVs helped Nepal avert a cholera outbreak as they continue rebuilding a shaken nation.