LESVOS, Greece — On the Greek islands at the forefront of Europe’s unresolved migration crisis, social distancing and self-isolation are luxuries many can’t afford.

In Moria, Europe’s largest informal migrant camp, some 20,000 people live in an area designed to house no more than 3,000. Tents and makeshift shelters spill out past the official reception center’s fences and down the hill into the surrounding olive groves.

Here, it’s close to impossible to comply with the World Health Organization’s guidelines for slowing the spread of the coronavirus epidemic that’s claiming thousands of lives across Europe: Wash your hands frequently; maintain your distance from other people; self-isolate when you experience symptoms.

At the camp on the island of Lesvos, hundreds of people share the same water source, and most residents spend hours in queues on a daily basis for food and essential supplies. Sanitary conditions are notoriously poor.

"They don't have isolation facilities," said Siyana Mahroof-Shaffi, the founder of Kitrinos Healthcare, a charity that provides medical care inside Moria camp. “They don't have a home. All they can do is sit in a tent and hope for the best.”

Tasos Balis, who advises the mayor of Mytilene, the capital of Lesvos, said that “it’s only a matter of time” until the outbreak wreaks havoc on migrant camps on the islands.

Many migrants don't have their own tent and rely on the kindness of others for a place to sleep — something that could cause the virus to spread even faster. “One night in one friend’s tent, one night in another,” said 16-year-old Shams from Afghanistan. He regularly leaves the camp to escape the fights that break out at night. “We don’t have anything. We are alone.”

Tasos Balis, who advises the mayor of Mytilene, the capital of Lesvos, said that “it’s only a matter of time” until the outbreak wreaks havoc on migrant camps on the islands.

Aid workers and rights organizations rang the alarm bell after the first coronavirus case on Lesvos was confirmed on March 10.

They called on the Greek government to take urgent action and evacuate the migrants to stop mass infection — something that has not yet happened. There has yet to be a confirmed case of coronavirus inside the migrant camp.

“Containment is the only existing plan,” said Peter Casaer, Médecins Sans Frontières' representative on Lesvos. “[The virus] is at our doorstep and nothing is being done. It's like they're forgotten, abandoned, sacrificed for fortress Europe.”

In a statement on March 12, MSF warned that “with unhygienic, cramped living conditions, the threat of an outbreak among people is very real, yet there are no epidemic response plans in place.”

Ylva Johansson, the European commissioner for home affairs, said worries about the impact of the virus on asylum seekers keeps her awake at night. She said the situation for many in the Greek camps was "unacceptable already" before the current crisis. "The risk of having the virus in those camps is a really dangerous one," she told POLITICO's EU Confidential podcast.

Johansson said she is talking to Greek authorities, international refugee agencies and charities to try to improve conditions on the islands.

Members of the European Parliament on Monday took up the call for a “preventive evacuation” of the overcrowded camps, saying "the humanitarian crisis on the Greek islands risks becoming a public health issue for which an immediate European response has to be found."

“Many of those in the camps (42,000 people in total) are already in a precarious health situation, and despite the measures taken by the Greek authorities, the overcrowding and the dire living conditions make it difficult to contain COVID-19,” Juan Fernando López Aguilar, the chair of the European Parliament’s Civil Liberties Committee, wrote in a letter to Janez Lenarčič, the European commissioner for crisis management.

"Every human being has the capacity for empathy. But when fear rises, empathy goes" — Peter Casaer of Médecins Sans Frontières

There are only six intensive care beds available on the island, the letter said, and no chance of isolation or social distancing.

So far, Greece’s migration ministry has responded to the risk of an outbreak by passing measures to limit the movement of asylum seekers on the islands. The government is also accelerating the construction of a new permanent closed facility on the island of Samos and will expand the camps on Kos and Leros. The ministry did not respond to requests for comment.

Monitoring the spread of disease in sprawling, makeshift camps like Moria is infinitely more difficult than in a closed facility, where every movement is tracked, said Jason Straziuso, spokesperson for the International Committee of the Red Cross (ICRC), which has dealt with Ebola and cholera outbreaks in detention spaces

But many aid organizations also worry that limiting people's movements in government facilities could be detrimental to their human rights, robbing them of some of the personal freedom they have living in open camps like Moria.

There is also a fear that restrictions on movement could spark panic. The question is how to maintain calm while also preventing infection. "We don't have any magical solutions. In fact, we fear that it could be impossible to stop the spread,” said Straziuso.

In the absence of a comprehensive plan of action from the government, volunteers say they are doing their best to prepare for a situation that could tip into chaos quickly, in the hope that small measures that raise awareness and improve hygiene will have an impact.

Movement on the Ground, a Dutch NGO, has hung hand sanitizer dispensers from trees in Vathy camp on Samos. In Moria, they have established a new food line, so that people spend less time in queues, where they risk coming into contact with someone who has been infected.

Mahroof-Shaffi, of Kitrinos Healthcare, and a number of other aid organizations are waiting for approval from local authorities to erect two field hospitals beside the camp — one for isolation, and one to treat cases of COVID-19.

She is worried that migrants may be especially vulnerable to complications from contracting the coronavirus, as some 80 percent of her consultations are for respiratory tract infections caused by the fumes of fires migrants build to keep themselves warm, she said.

Another source of concern is the health of local doctors, officials and aid workers on the ground. A spike in violence and intimidation against aid workers by local vigilante groups in recent weeks — following protests against government plans to build permanent migrant facilities on the islands — has already driven some NGOs away.

For those living in the migrant camps, the situation puts them in even greater limbo. With Europe in crisis mode and borders being erected between countries wanting to contain to virus, their chances of receiving asylum — or their claims being processed soon — seem low.

"Every human being has the capacity for empathy,” said MSF’s Casaer. “But when fear rises, empathy goes.”