An undocumented immigrant family that has lived nearly three years in Philadelphia church sanctuary to avoid deportation has been stricken by the coronavirus.

Carmela Apolonio Hernandez, 39, and her eldest children — teenagers Fidel, Keyri, and Yoselin — suffered severe COVID-19 symptoms in late spring and early summer and continue to fight for their recovery inside the Germantown Mennonite Church.

Hernandez has memory loss and pain in her lungs. Fidel, 18, still has a cough, aches in his bones, and other cold symptoms. Yoselin, 14, has trouble breathing. Keyri, 15, suffers headaches, fever, bone aches, and fatigue.

“Thank God we survived, but we still have problems,” Keyri wrote in a letter asking government officials to help free the family. “I am afraid of becoming infectious again and passing the virus on to the community.”

The youngest child, Edwin, 11, did not become ill.

Isolation inside a church might seem a safe way to avoid the virus, which has killed more than 164,000 people in the United States. But not for this family. Supporters said they suspect the children may have been infected at school, which they had been able to attend while in sanctuary, before the Philadelphia School District closed in mid-March.

Hernandez’s only known time outside was on a day in 2018 when she went to seek answers from Sen. Bob Casey at his Center City office.

On Wednesday morning, the children held a vigil just outside the church, sharing letters they’ve written to members of Congress about living with COVID-19 in sanctuary, and about the urgency of their leaving to more easily get medical care.

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The letters will be delivered to Rep. Dwight Evans’ staff, which has agreed to share them with five other legislators with whom the family has been in contact.

“I was very afraid of losing my family because I was the only one who was spared by COVID-19,” Edwin wrote in a letter. “I was the one who had to give them tea and some tablets, because they could not go to the doctor, since doctors charge so much money. I am 11 years old, and I am very fearful.”

Most people with the coronavirus are no longer contagious 10 days after their symptoms resolve, according to Harvard Medical School. The same is true for people who test positive but never develop symptoms. But there are documented exceptions, and some experts still recommend 14 days of isolation.

No one else at the church was infected, according to Co-Pastor John Bergen.

As the pandemic hit, he said, church leaders sought to place the building in quarantine, knowing that outside visitors could potentially infect the Hernandez family. Still, while in-person services and programs have been halted, groceries, packages, and other supplies continue to be delivered to the church.

“Their access to medical care is pretty limited,” Bergen said. “If one of them would have had to have been hospitalized, it would have been a tremendous risk to get them safely to the hospital, given ICE’s willingness to bend those rules around hospitals being ‘sensitive places.’ ”

Immigration and Customs Enforcement guidelines dissuade agents from arresting immigrants at designated “sensitive locations,” such as churches, schools, and hospitals. But immigration advocates say rules around hospitals have been violated.

In Pennsylvania in March, ICE took a Honduran man into custody at a Scranton hospital, then placed him in detention at the Pike County Correctional Facility. Pennsylvania lawyer Juliette Gomez said her client’s arrest clearly broke the sensitive-locations policy. ICE said the arrest began at the federal courthouse, and what followed was a continuation of that process.

In 2017, federal border patrol agents in Texas stopped an ambulance at a checkpoint, then followed it to a hospital. Agents waited while an undocumented 10-year-old girl underwent surgery, then took her away to a juvenile detention center. Authorities released Rosa Maria Hernandez, who has cerebral palsy, after the American Civil Liberties Union filed a lawsuit.

On Wednesday, the Hernandez children, supported by church members and advocacy groups including the Free Migration Project and New Sanctuary Movement of Philadelphia, asked Pennsylvania’s congressional delegation to help them freely leave sanctuary and get outside health care.

“Carmela’s experience demonstrates the severe impact [the virus] has had on the immigrant community,” the activist groups said in a statement. “Fighting extremist anti-immigrant policies, lacking access to health care, and not being eligible for any COVID relief benefits has pushed this family fighting to stay together to the brink.” Given the uncertainty around the long-term health effects of COVID-19 and the possibility of re-infection, “winning Carmela’s freedom has become even more urgent.”

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At the height of their illness, the statement said, Hernandez worried that Fidel’s and Keyri’s fevers would require hospitalization. She feared that if she died, no one would be able to care for her children.

The Hernandezes have spent more time in sanctuary than any of the four families to seek refuge in Philadelphia churches in recent times, and their freedom has become the cause of immigration and church activists.

But the years of vigils, marches, rallies, political outreach, and public pleas have not moved the federal government to grant them permission to stay in the United States.

The family fled to this country from Mexico in August 2015, after being threatened by the same drug criminals who had killed Hernandez’s brother and two nephews. They were denied asylum, and took sanctuary only days before their Dec. 15, 2017, deportation date.

In late November 2017, Hernandez was knocking on the doors of churches, begging for protection. The family spent about a year inside the Church of the Advocate in North Philadelphia before moving to the Mennonite church.

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A second family, Oneita and Clive Thompson, originally from Jamaica, has spent nearly two years in sanctuary inside the First United Methodist Church of Germantown, fighting to avoid removal. Suyapa Reyes and her four children, of Honduras, were able to legally leave that church in March after 18 months inside.