In their brief history, retail medical clinics have gone from being vilified as fast-food medicine to becoming an accepted -- or at least tolerated -- part of the medical establishment.

Now, retail clinics such as MinuteClinic are offering themselves for a new role: first line of defense in an outbreak of the new swine flu.

Since the first precursor to MinuteClinic opened in the Twin Cities in 2000, more than 1,200 retail clinics under different brands have sprung up in 30 states, with most of the growth in the last three years.

Operating in malls, grocery stores and pharmacies, the bare-bones clinics employ nurse practitioners who treat common conditions such as urinary tract infection and pink eye and administer flu vaccines without appointments. Collectively, they have the capacity to see 1.4 million patients a month, although they're currently seeing about half that.

The nurses enter patient information during each visit into a computer database, and national volumes are tallied daily.

That could make them an early warning signal for health authorities if they show a spurt in flu cases.

"As a first-line access point, we've seen surveillance data earlier than what the Centers for Disease Control and Prevention is seeing," said Tine Hansen-Turton, director of the Convenient Care Association, the industry group. "We are able to report very quickly to local health departments."

So far, there's been no uptick in flu-like cases, she said, but there has been a rise in the number of worried customers coming in with questions about swine flu.

In Minnesota, the Health Department already uses 29 "sentinel'' clinics around the state, which report cases of influenza-like illnesses. But those reports come in only weekly. By way of comparison, there are 69 retail clinics in the state, with MinuteClinic (23 outlets) and Target Clinic (22) leading the pack.

"It's certainly something that we could look at, partnering with them," said Kris Ehresmann, the department's director of infectious disease. "What the MinuteClinics would be able to give us is a high volume or a high number of individuals coming through their system."

Feasible?

The idea that a growing network of private retail clinics could someday be useful for disease surveillance surfaced a couple of years ago from the Convenient Care Association.

The association commissioned the consulting firm Deloitte to produce a feasibility report, which was presented to the Centers for Disease Control and Prevention in Atlanta. In addition to the real-time information of their electronic medical records, a clinic could fire off an alert to the local health department if, for example, it suddenly found 100 patients lined up outside its doors.

The idea went nowhere, said Ian Bonnet, an Atlanta-based consultant for Deloitte. But since then, the number of clinics nationwide has tripled.

If the government does end up ordering a vaccine for swine flu -- and that won't be ready until the fall, at the earliest -- the clinics could also be useful for delivering those shots. While the majority of Americans who get flu shots each year continue to get them from their regular clinics, a growing number are getting them from retail clinics.

Minneapolis-based MinuteClinic now has 459 clinics in 24 states located in CVS Pharmacy and Cub Foods stores, according to Merchant Medicine News. An additional 90 are closed and will reopen for the traditional flu season. Take Care has 341 clinics in Walgreens drugstores in 18 states and The Little Clinic has 96 clinics in nine states.

"You talk to MinuteClinic, Take Care and the Little Clinic and you hit 30-something states," said Tom Charland, a Twin Cities retail clinic consultant who publishes Merchant Medicine News.

Daily reports

At MinuteClinic, nurse practitioners can do a rapid influenza test with a nasal swab, which takes five minutes for a result. However, the tests can't confirm if it's the swine flu variety. For that, the samples need to be sent to the state health departments for viral cultures.

Still, MinuteClinic gets daily volume reports from around the country, giving headquarters "a sense of what's coming down the pike," said chief nursing officer Donna Haugland.

In the past, the clinics have dealt with localized outbreaks -- a particularly bad influenza season one year, a measles outbreak another. This time, there's one big difference.

"This is the first time we're having something like this on a national scale," Haugland said.

Staff writer Maura Lerner contributed to this report. Chen May Yee • 612-673-7434