In recent weeks, large outbreaks of infectious diseases, such as cholera and diphtheria, have erupted in forcibly displaced populations in several countries. Displaced populations—or people who have fled their homes because of violence, persecution, natural disasters, or other emergencies—face significant risks from communicable diseases and other health challenges. Below, we review trends associated with ongoing outbreaks in two specific displaced populations: 1) diphtheria in Rohingya refugees in Bangladesh and 2) cholera in Somali refugees in Kenya.

Significant Health Risks

The Office of the United Nations High Commissioner for Refugees (UNHCR) reported that the global forced displacement population totaled 65.6 million people at the end of 2016. Of these, approximately 40 million are refugees, asylum-seekers, and internally displaced persons who have escaped conflict, persecution, human rights violations, or other generalized violence. The other approximately 25 million are displaced by natural disasters each year, such as earthquakes and weather-related disasters, according to the Internal Displacement Monitoring Centre.

Many of these individuals—such as those living in refugee camps—face significant health risks due to crowded living conditions, poor or no access to healthcare, and the absence of health and sanitation infrastructure. Among these health risks are malnutrition, disability, physical abuse, and psychological and emotional distress. However, infectious diseases are “the major causes of morbidity and mortality among refugees,” according to a 1995 UNHCR report on refugee health.

Measles, diarrheal diseases, acute respiratory infection, and malaria account for between 60% and 80% of all reported causes of death among refugees, according to the above report. Similarly, a retrospective mortality survey in the volatile Darfur region of Sudan reveals that between 2003 and 2008, “more than 80% of excess deaths were not a result of violence” and that “the main causes of mortality [during that period] were diseases such as diarrhea.” The paper suggests that “overcrowding and precarious situations in which the displaced people live increase the risk of death from communicable diseases.”

It’s important to note that many displaced populations have fled armed conflict or other humanitarian emergencies, which create conditions for the spread of disease. Outbreak Observatory previously reported on an outbreak of diphtheria and an outbreak of cholera—one of the largest ever recorded—in war-torn Yemen. Low vaccination coverage, poor access to fresh water and sanitation, limited healthcare services, and disruption of vaccine supply and distribution have enabled these diseases to spread amid Yemen’s general climate of conflict and instability.

Diphtheria in Bangladesh

On December 6, the WHO reported that diphtheria is “spreading fast” among displaced Rohingya refugees in Cox’s Bazar, Bangladesh. Between November 8 and December 25, 2017, a total of 2,204 cases of diphtheria were suspected in this population, including 26 deaths. This is even larger than the current diphtheria outbreak in Yemen, where 471 people are believed to be infected as of today. Most patients in Cox’s Bazar are between 5 and 14 years old. More than 646,000 Myanmar ethnic minorities, like the Rohingya, are estimated to have crossed over from Myanmar to Bangladesh to escape violence and persecution, leading to the formation of densely populated refugee settlements with limited access to water, sanitation, and health services.

Diphtheria, which is caused by a toxin produced by the Corynebacterium diphtheriae bacterium, is primarily transmitted directly to others via respiratory droplets. Symptoms include weakness, swollen glands, sore throat, and fever. It is fatal in up to half of all patients unless treated by diphtheria antitoxin and antibiotics, according to the CDC. The disease is a major cause of illness and death in children, but it is easily prevented by administration of a diphtheria vaccine.

The crowded living quarters of the temporary settlements at Cox’s Bazar—combined with a vulnerable refugee population with reportedly low vaccination coverage—make for ideal conditions for disease spread. There are also reports of shortages of diphtheria antitoxin in Bangladesh, for which there are limited quantities produced globally. In response, the WHO has released $1.5 million from its Contingency Fund for Emergencies to fight diphtheria in Bangladesh. In addition to providing 1,345 vials of diphtheria antitoxin and 300,000 doses of antibiotics, it is supporting mass vaccination efforts.

This week, the WHO and the United Nations Children’s Fund (UNICEF) helped to vaccinate school children as schools reopened in Cox’s Bazar following winter break, which will help to protect both the refugees and the host population. However, successfully vaccinating the Rohingya against diphtheria poses significant challenges for relief agencies. In addition to the large number of refugees and the transitory nature of the population, at least two doses of the diphtheria vaccine must be administered four weeks apart in order to provide adequate levels of immunity, leading to challenges associated with patient tracking and compliance.

Cholera in Kenya

A large cholera outbreak has swept across Kenya since early 2017, including refugee camps on the country’s eastern border. The WHO reported a total of 3,976 confirmed and probable cases, including 76 deaths, between January 1 and November 29. Approximately 23% of all the cases have been reported in the camps, including Dadaab and Kakuma. Dadaab is one of the world’s largest refugee camps, hosting nearly 250,000 refugees and asylum-seekers primarily from Somalia, who are fleeing violence and conflict along the Horn of Africa.

Cholera is an acute diarrheal disease caused by the bacterium Vibrio cholerae. The disease is spread primarily through contaminated drinking water, and it can lead to rapid onset of severe symptoms unless treated quickly with oral rehydration therapy. Although cholera is preventable, refugee camps are at higher risk of spreading the bacteria due to poor hygiene and sanitation conditions, lack of fresh drinking water, and limited access to medical services. A study analyzing cholera outbreaks in Kenya between 2008 and 2013 revealed that the risk of cholera “was associated with open defecation, use of unimproved water sources, poverty headcount ratio and the number of health facilities per 100,000 population,” although the researchers did not find a link with urbanization or population density.

The WHO is supporting the Kenyan government as it scales up its response, including surveillance, case management, quarantining affected individuals, and educating communities on good hygiene practices and other preventive measures, such as boiling water before drinking. Despite these efforts, the extent to which the Kenyan government is coming to the aid of affected refugee communities is unclear. In 2015, Médecins Sans Frontières accused the Kenyan government of failing to address the “dire hygiene and living conditions” that contributed to a cholera outbreak in Dadaab, and more recently—on December 21—Amnesty International accused the government of pressuring refugees to return to their native Somalia by withdrawing essential services from the camps.

Moving Forward

Ultimately, halting the spread of infectious disease outbreaks in Kenya, Bangladesh, and other nations will require addressing the underlying public health conditions facing these countries’ most vulnerable populations. There is a clear global trend of increasing numbers of forcibly displaced individuals in recent years due to frequent natural disasters and prolonged conflicts. For instance, the global population of forcibly displaced people has increased from 33.9 million in 1997 to 65.6 million in 2016, according to UNHCR. As a result, there is likely to be even more large outbreaks of deadly communicable diseases like cholera, diphtheria, and measles in the years to come, some of which can cause truly unfathomable illness and death among the most vulnerable of populations, as illustrated by the ongoing cholera epidemic in Yemen.


Outbreak Observatory aims to collect information on challenges and solutions associated with outbreak response and share it broadly in near-real time to allow others to learn from these experiences in order to improve global outbreak response capabilities.

Photo: Kakuma refugee camp, Kenya; courtesy of CDC