As Hurricane Matthew churned off the coast of Haiti last week, public health officials and aid groups issued warnings not just about the dangers from the storm itself but what could follow: a cholera outbreak.
In 2010, a devastating cholera outbreak infected hundreds of thousands in Haiti just months after a severe earthquake left more than 100,000 dead. Before that outbreak, cholera had not been reported in the country for nearly a century, according to medical literature and a 2011 United Nations report.
And in 2011, a United Nations report acknowledged that relief efforts by the U.N. likely brought cholera to Haiti from another part of the world.
Cholera is a bacterial infection that can lead to potentially serious symptoms of watery diarrhea, nausea, vomiting and muscle cramps, according to the U.S. Centers for Disease Control and Prevention. Often spread through contaminated water or food, the incubation period of the disease can be as short as two hours, meaning it can move quickly through a densely populated area. As the mucus membrane of the intestinal wall is affected, it can lead to diarrhea that can cause severe dehydration.
After a hiatus of a century, the disease reappeared in Haiti in October 2010 and spread quickly, causing an estimated 770,000 infections in the years since and approximately 9,200 related deaths, according to a 2016 published report in the American Medical Journal of Ethics.
The cause of the outbreak was initially unclear, but epidemiologists and other medical experts made an interesting discovery when they examined the strain of the Vibrio cholerae bacteria that causes cholera and found it was a match for a strain in Nepal and South Asia, according to a United Nations report and 2014 study published in mBio medical journal. The findings meant the disease hadn't been hiding in Haiti as an endemic disease but had likely arrived via infected humans in the aftermath of the earthquake, according to the 2011 United Nations report.
The 2011 U.N. report that researched the start of the outbreak acknowledged that members of the United Nation Stabilization Mission in Haiti arrived in the country after working in Nepal, where the disease is endemic. Furthermore, local hospital staff reported to the U.N. researchers that the first severe cases of cholera came from an area named Meye, which is located 150 meters downstream from the U.N. camp where the aid workers had been staying.
The report stopped short of putting blame specifically on that camp and instead cited multiple factors for the outbreak.
"The Independent Panel concludes that the Haiti cholera outbreak was caused by the confluence of circumstances as described above, and was not the fault of, or deliberate action of, a group or individual," the group said.
In 2013, a class-action lawsuit was filed against the U.N. and certain U.N. officials alleging they were responsible for the outbreak. A United States District Judge found that the U.N. had immunity from prosecution, according to court documents. That decision was again upheld on appeal this year.
This year, the United Nations finally acknowledged that their personnel likely played a part in the Haitian cholera outbreak.
"Over the past year, the U.N. has become convinced that it needs to do much more regarding its own involvement in the initial outbreak and the suffering of those affected by cholera," Farhan Haq, deputy spokesman for the Secretary-General, said in August.
On the day that the court upheld the U.N.'s immunity, a spokesman released statement from then-Secretary General Ban Ki-moon discussing the effects of the cholera epidemic on the day the court ruled against the plaintiffs on appeal.
"The Secretary-General deeply regrets the terrible suffering the people of Haiti have endured as a result of the cholera epidemic," Haq told reporters. "The United Nations has a moral responsibility to the victims of the cholera epidemic and for supporting Haiti in overcoming the epidemic and building sound water, sanitation and health systems."
A spokesman for the U.N. Secretary-General told ABC News a full presentation on the assistance and support to combat the Haitian cholera outbreak will be presented later this month.
As aid groups in Haiti work to help those injured or otherwise affected by Hurricane Matthew, they have also reported dozens of cholera infections after the storm. A spokeswoman for CARE, an aid group in Haiti, reported there have been an estimated 279 cholera infections in the Grand Anse region along with 10 related deaths.