San Francisco is leading the nation in getting to zero new HIV infections, but one group is not seeing the same improvements in care and treatment: homeless and marginally housed people. A new clinic called POP-UP aims to change this.

POP-UP stands for Positive Health Onsite Program for Unstably Housed People. It’s located at the University of California San Francisco’s Ward 86, which is part of Zuckerberg San Francisco General Hospital.

“We know that we’ve had the lowest number of new HIV infections ever reported in the city last year, which is remarkable,” Grant Colfax, MD, director of the San Francisco Department of Public Health, said in a UCSF article about the clinic. “And we also know that, going to the issue of health equity, we have a lot more to do in addressing inequities in the HIV epidemic, including among the people living with homelessness, where there is tremendous disparities in HIV infection.”

In San Francisco, 70 percent of people with HIV who are living in stable housing are virally suppressed, while only 33 percent of homeless people with HIV are undetectable, according to 2017 data cited in the UCSF article. What’s more, homeless people make up 14 percent of new HIV cases in the city, although they represent 1 percent of the population.

It’s no surprise that the more unstable a person’s housing situation is, the less likely he or she is to be undetectable.

“POP-UP was designed on the principle that patients who are unstably housed are failing to link to current models of care, so we have to change our model of care to conform to what the patient needs,” said Monica Gandhi, MD, MPH, the medical director of the Ward 86 HIV clinic.

To meet their needs, POP-UP offers primary care on demand from a group of health care professionals, including doctors and social workers, who will get to know clients’ cases and assist with a variety of issues.

For increased accessibility, the clinic is open Monday through Friday, and clients don’t need an appointment—they can simply pop in.

So far, the clinic has enrolled 23 patients and is seeking more funding to expand. You can read more about POP-UP on UCSF’s website here.

In related news, Ward 86 is the nation’s first AIDS clinic. It opened on January 1, 1983. Learn more about its history here.