A Greek refugee camp outside Athens in lockdown after 20 confirmed coronavirus cases have fueled fears that the overcrowded centers are ticking time bombs – and if they go off, it could have devastating humanitarian consequences.

Tens of thousands of migrants are living in dire conditions. At the notorious Moria migrant camp on the Greek island of Lesbos, 21,000 people are squeezed into a space intended for 3,000.

It was a health hazard long before the coronavirus pandemic. Now experts fear it will become a lethal breeding ground for the deadly disease.

"There is one waterpoint in Lesbos for 1,300 people. There is one latrine for 167 people. There is one shower for 200 people," said Apostolos Veizis, director of medical programs for Medecins Sans Frontieres, "It's the perfect place for the spread of the disease. It's the perfect place for a disaster."

With such overcrowded and dirty conditions, preventative measures such as social distancing and proper hygiene are all but impossible.

"Preventative measures sound to these people like a joke because how can you ask someone living in a tent to go back and isolate himself in his room?" said Marco Sandrone, field coordinator for Medecins Sans Frontieres in Lesbos. "How do you ask children or women to increase their level of hygiene if there's not enough toilets and showers and water points in the camp?"

It's a similar situation across the Aegean islands, where 42,000 refugees are crammed into camps intended to house only 6,000. As of now, there are no confirmed cases of COVID19 inside these island camps. But many fear that won't last long.

Calls to evacuate

Organizations such as Doctors Without Borders are calling for an action plan and the immediate evacuation of island camps.

At a meeting on Thursday, the EU commissioner for home affairs, Ylva Johansson, said an emergency action plan has been agreed upon. It includes relocating the most vulnerable from the camps to empty hotel rooms. The plan also calls for additional medical supplies and funding.

"What we need to do now is take immediate action to protect people," said Johannsson during a video conference on Thursday. "The new arrivals need to be separated from those already in the camps and we need to do much more testing."

But it could be days, if not weeks, before the aid makes it to where it's most needed. In the meantime, humanitarian groups have been filling the void. The UN Refugee Agency UNHCR has appealed for $255 million to help lessen the impact of COVID-19.

"Ultimately the virus doesn't discriminate and we can't afford to either. This means we need to work together to tackle the virus and, at the core of any response, we need to ensure there is empathy and equality," said Maeve Patterson, communications officer at the United Nations High Commissioner for Refugees.