They waited patiently to get their blood drawn, a crowd of young and middle-aged Queens residents in Corona Square. Two city nurses stood under the plastic tent and pricked the index finger of each outstretched hand, and one by one, extracted a small sample of blood.
Franklin Munoz, a priest who works with Catholic Migration Office, an immigrants' rights organization, stood nearby and greeted the arrivals, many of them undocumented immigrants.
"When we do this type of work," he explained, "if they find out that they need further follow-up, they won't go!" He paused, "They're just too scared."
Though the extent is difficult to quantify, City health officials say that a large number of undocumented immigrants fear going to health centers and instead rely on an illegal network of doctors and traditional faith healers.
The free blood testing at Corona Square, sponsored by the Ecuadorian Consulate, was an effort to inform these unauthorized immigrants that their privacy was protected at City hospitals. The success of such events, though, is limited.
"New York City is probably the best possible place in the country to be undocumented, maybe in the world, because there are a lot of health care services that are available free of charge and that don't ask questions," said Dr. Peter Muennig, an associate professor at the Mailman School of Public Health at Columbia University.
"The flip side to this is that many undocumented groups are very fearful of seeking that kind of care for fear of being reported to the authorities," he said.
Undocumented immigrants, like other New Yorkers without insurance, can access three types of health services offered by the City. The Department of Health runs clinics that provide tuberculosis care, vaccinations, and treatment for sexually transmitted diseases. Community health centers, which are funded by a mix of federal funds, Medicaid, and out of pocket payments, offer primary care. Then there are hospital emergency rooms.
At all of these locations, federal privacy laws prohibit immigration officials from accessing health records of patients. But despite these protections, those without papers often stay away.
According to Muennig, at Columbia University, many immigrants without papers see the resources available to them as a "big complicated system that is very scary to access."
Health workers hear similar stories on the streets.
"The average person doesn't know that health services and the state are separate," said Helen Arteaga, the director of the Plaza Del Sol Family Health Center, a government-subsidized facility in Corona. "There is no big sign that says, 'All immigrants are welcome, immigration has no access to our records.'"
Arteaga, herself the daughter of an undocumented Mexican who for years avoided treatment in City hospitals, stressed that fear plays a major role in keeping immigrants away from clinics. "For a person to go to the emergency room, undocumented, it's really difficult. The fear that they have - the fact that they could be found and immigration called on them - is huge," she added.
Like other City health officials interviewed, Arteaga said that the undocumented often rely on an illegal network of unlicensed doctors and underground pharmacies to get treatment. In some cases, these illegal doctors were trained in their home country but do not have authorization to practice in the US, she said.
Thomas Healy, the pastor of Our Lady of Sorrows Church and a popular advocate of immigrants in Corona, said much of his congregation relies on "bogus" doctors.
"They go to these doctors because they are afraid to go to the hospital," he stressed. Healy said that these underground clinics, though they are cheaper than licensed services, operate without oversight and often lack the correct equipment to perform laboratory work. "They could be spreading germs," he warned.
Without an official prescription, purchasing prescription drugs at mainstream pharmacies is problematic. Interviews with undocumented Latino workers on Roosevelt Avenue, in Queens, revealed that some drug stores sell medicine without prescriptions.
Juan, 57, from Venezuela, said he recently bought prescription drugs for a stomach problem from a pharmacy on Roosevelt Avenue, without having consulted a doctor beforehand. He wished to withhold his last name because he is in the country without authorization.
"I went to the pharmacy and explained my stomach problems," he said. "I didn't have a prescription. I talked to the guy, and he helped me out, and it only cost $15," he continued. "Maybe he is a doctor, I don't know."
Arteaga, the director of Plaza del Sol, said this could prove dangerous. "They have no idea what they are prescribing - it's like getting a prescription from a vending machine."
Both documented and undocumented immigrants also rely on traditional faith-based healing centers called botanicas. Inside one such apothecary on Roosevelt Ave., El Indio, were rows of plaster statues of the Virgin Mary, shelved vials of colored elixir, and piles of herbs.
A small sachet of dried grass named oreja de burro, or donkey's ear, was recommended by the shopkeeper for general ailments. It sold for $2.
"You tell the guy at the botanica what your problem is, and he tells you what to take. We know about this since we were very young," said James, a 52-year-old Peruvian and resident of Corona who requested anonymity for fear of deportation.
"You don't need a prescription for that," he said.