As the minority group least likely to have a primary-care doctor and with nearly half living beneath the poverty line, Latinos, especially recent immigrants, have challenged doctors for decades.
But this simple idea - using people from church or the barrio to encourage preventive care - has produced success noted in medical journals over the last five years.
The U.S. Department of Health and Human Services announced in May an initiative to encourage the use of promotoras for outreach and education about health services and insurance.
"Now that they have been recognized, we want to develop a national database of networks for training and certification," said Jose Velasco, a public health adviser at HHS's Office of Minority Health.
Philadelphia saw its first promotoras in action three years ago, when Matthew O'Brien, then a medical resident at the University of Pennsylvania, and Steve Larson, his mentor and an associate dean, decided to establish the Puentes de Salud clinic in South Philadelphia in 2006.
"We would talk to people at health fairs and after religious services. We heard about them over and over again," said O'Brien, who now teaches at Temple medical school.
The constant mention of women who visit homes and provide basic care, but were not nurses, prompted O'Brien to bury himself in the public health literature in what he calls his own "remedial M.P.H." He was surprised at how they were able to increase vaccinations and other preventive health measures in developing countries and border states.
The clinic opened with four promotoras and now has six.
Despite the praise, some academics ask if the promotoras - housekeepers, waitresses, nannies - are adequately trained and qualified to teach and guide their patient-peers. O'Brien said they are.
In a 2009 literature review in the American Journal of Preventive Medicine, he described finding his first promotora, Irma Zamora. A leader at another community-based organization, she was well-known among South Philadelphia Mexicans.
"That's really the skill set of a promotora. Some one who is a natural leader and has an extensive social network," O'Brien said.
He and colleagues selected and trained Zamora and several other women for Puentes' first promotora-led educational intervention on cervical cancer. One of the most important lessons, said O'Brien, was in boundaries and limitations - knowing when to bring in a medical professional.
Once the promotoras started leading classes, with doctors or nurses in the room, he also had them survey people in the community to see if it was making a difference.
In November 2010, O'Brien reported in the Journal of General Internal Medicine that Pap smear screenings had doubled - but, perhaps more important, general knowledge about the association between regular Pap smears and cervical cancer rose significantly.
The model is catching on.
"They can't diagnose, you know," said Chris Ann Smith, who trains promotoras at Esperanza Health Center in North Philadelphia, "but they can say, 'Hey, your blood pressure is really high and you should go to your doctor.' "
Barbara Schneider, a doctor with Community Health Collaborative, a nonprofit that works to reduce health disparities, specializes in diabetes outreach using three promotoras. She and O'Brien have launched a new diabetes campaign modeled after a California project to target the disease that disproportionately affects Latinos.
A week after their presentation at Annunciation Church, Puentes de Salud began the first class of its diabetes series. The classroom, colorful with tapestries and children's books, also serves as Puentes de Salud's cultural and educational laboratory for children.
It was the first class for promotora Isabel Garcia, who seemed a little nervous.
"You're going to be famous," teased Amarili Lopez, a certified nursing assistant who helped with the training. She pointed at a photographer.
Garcia frowned. "No. I do this because I am helping my people."
Contact staff writer Juliana Schatz at 215-854-4193, firstname.lastname@example.org, or @hooliana on Twitter.