The pilot program announced on Tuesday by the U.S. Centers for Disease Control and Prevention (CDC) will use information gleaned from the testing to develop a nationwide model for pharmacists and nurse practitioners to detect the virus.

"Our goal is to make HIV testing as routine as a blood pressure check," said Jonathan Mermin, M.D., director of CDC's Division of HIV/AIDS Prevention. "This initiative is one example of how we can make testing routine and help identify the hundreds of thousands of Americans who are unaware that they are infected."

CDC estimates that 1.1 million Americans have HIV, but nearly 20 percent of them don't know they are infected. One of the primary challenges in HIV diagnosis is that people can live with the infection for years without developing symptoms.

Late diagnosis, and development of the disease to full-blown AIDS, often means that many have already transmitted the disease to others and have missed a critical window for receiving life-extending medical care.

Walgreen's testing sites for the two-year CDC project include one Washington, D.C. location, along with another store in Chicago and a clinic in Lithonia, Georgia. In cases where a test shows a positive result, Walgreen will refer the patient to a local healthcare provider for further confirmation and care.

The CDC has partnerships with four other pharmacies, including one in Billings, Montana and another in Oakland, California, and aims to choose 17 more sites by the end of summer. It has budgeted $1.2 million for the project.

Early HIV detection may also become even simpler as the U.S. Food and Drug Administration weighs whether to approve the first over-the-counter test that can be taken at home. The agency is due to make its decision on the kit by OraSure Technologies Inc by July 7.

SEEKING ANSWERS AT THE CORNER DRUGSTORE

At the Walgreens store in Washington DC's Foggy Bottom neighborhood, the pilot has been operational since May. Manager Bethany Kuechenmeister said customers have already shown interest in the testing.

"We've seen about five to 10 people a day, and it's been an even split between men and women, though trending towards the younger," she said.

Three pharmacists at the store have been trained to administer the FDA approved rapid-HIV test which takes an oral swab from the gums or inside cheek. Results are available within 20 minutes. Health experts say the rapid tests are a powerful first step in HIV diagnosis, but must be followed by blood tests to confirm a patient's status.

Kuechenmeister said her team was prepared to help customers seek out care and support when they need it.

"We have some pamphlets and information we hand out and we're partnered with two clinics in the area and we can also connect with their primary care physician," she said. "We want to ensure that the patients don't leave here without information on what to do if they receive a reactive test."

She said that making the tests available in a neighborhood drugstore should attract more people who would otherwise avoid an HIV clinic.

"Because Walgreen's does a variety of testing there is no stigma basically associated with coming here. You could be getting a cholesterol test or an HIV test - it's the same clinic room for all of our testing and immunizations. It's very private."

Walgreen has been providing free HIV testing for a few days each year as part of a drive from local health departments and AIDS organizations. To mark National HIV Testing day this year, 47 Walgreen stores in 20 cities will offer testing from Wednesday through Friday.