This piece was originally published in NBC News.

By Dan De Luce

WASHINGTON — The coronavirus outbreak threatens to inflict "carnage" on refugees around the world who often live in cramped conditions, lack access to clean water and are in countries with failing or stretched medical systems, humanitarian aid groups say.

From Syria to Bangladesh to Uganda, the risk posed to people who have fled war and persecution is potentially dire, and only urgent international action can avert a catastrophe, aid organizations told NBC News.

As of Tuesday, only 10 cases had been reported among refugees and displaced persons, and all of those were patients in Germany, according to the U.N. refugee agency. But in the absence of extensive testing at refugee camps in the Middle East, Africa or Asia, it's unclear whether the fast-moving virus has already reached them, medical experts and humanitarian workers said.

"We don't know, and that's largely because we haven't done any testing," said Muhammad Zaman, a professor of bioengineering at Boston University. "We need to know how acute the problem is before we come up with an intervention."

Given the fast-moving nature of the epidemic, if COVID-19 hasn't already spread to refugees, it's only a matter of time, Zaman added.

Beyond the potentially tragic consequences for refugees, failing to counter the spread of the virus among large refugee communities near the border of Europe or elsewhere could undercut any success in containing the outbreak and enable it to spread further, aid officials said.

Experience with the Ebola virus and other outbreaks has shown that governments need to include refugees and displaced persons in their plans to counter epidemics and to ensure that the refugees have the same access to medical treatment, said Andrej Mahecic, a spokesman for the U.N. High Commissioner for Refugees, or UNHCR.

"If we keep them safe, it's keeping all of us safe," he told NBC News.

The UNHCR has issued an initial appeal to governments for $33 million to help provide hygiene kits, protective gear, water sanitation and training for health workers to protect refugees from the coronavirus.

The two main tactics recommended to halt the spread of the virus — hand-washing and social distancing — are sometimes impossible for refugees to follow at crowded camps.

Jan Egeland, secretary general of the Norwegian Refugee Council, warned that the epidemic could cause devastating consequences at crowded refugee camps and in countries with damaged health care systems.

"Millions of conflict-affected people are living in cramped refugee and displacement sites with desperately poor hygiene and sanitation facilities," Egeland said in a statement.

"There will also be carnage when the virus reaches parts of Syria, Yemen and Venezuela where hospitals have been demolished and health systems have collapsed. "

Refugee advocates are especially concerned about nearly 1 million Syrians who have fled an offensive by Russia and the Syrian regime of Bashar al-Assad in recent weeks. Many of them are sleeping in bombed-out structures, in tents or out in the open.