Each day, it tests "several hundred people" at those sites, Banner spokesperson Becky Armendariz told Phoenix New Times. Exact numbers vary and are "dependent on the daily supply of test kits," which are being supplied by state and county health departments, she said.
The hotline that people must call to secure an appointment at a drive-thru site is getting "thousands" of calls a day, indicating that many people — hundreds, maybe thousands, based on the estimates provided by Banner — who want to be tested still can't be.
Those thousands of calls are producing "longer than anticipated wait times," Armendariz said, although she said Banner was trying to screen and schedule patients "as quickly as we can" and for now, is offering same-day and next-day appointments.
The flood of requests to Banner underscores just how swamped Arizona's health care system is by requests for COVID-19 testing that remains difficult to procure.
Even with the new sites, Banner is strictly limiting who can get tested.
Sarah Cupples, a Gilbert resident and a former hospital nurse who now works for an insurance company, said she called Banner's hotline on Monday afternoon, the day Banner rolled out its drive-thru sites.
She had had symptoms of COVID-19 for three weeks, but she was told by Banner that she didn't meet criteria set by the Centers for Disease Control and Prevention for testing.
"While I was met with sincerity, and I felt like they were concerned, they just blankly said, 'We follow CDC guidelines, and unless you've come into contact with a COVID-19 patient, you don't qualify,'" Cupples told New Times by phone.
So, Cupples could not get an appointment at a Banner drive-thru site.
On Wednesday, she tried calling a local urgent care center where a former coworker recommended she get tested. They were out of test kits.
Supplies said her symptoms were manageable — "I'm listening to my own lung sounds at home, and I'm able to monitor my family," she told New Times — but she remained concerned because her husband is an emergency room charge nurse.
She feared that he could be an asymptomatic carrier of the virus and potentially spread it to patients.
Banner is following CDC guidelines for who can get testing, even though the CDC also says that health care providers sending tests to commercial laboratories, as Banner is, can use more expansive criteria in deciding who to test.
The state acknowledges that it has a testing shortfall.
"At this time, there are just not enough tests for everyone who wants one," Dr. Cara Christ, director of the state Department of Health Services, said in a joint press conference with Arizona Governor Doug Ducey on Wednesday.
The state is still expecting a surge of cases, she added. So far, the state has tested 6,600 people through state and commercial labs, she said, the first time the total number of tests in the state has been made public.
As of Wednesday, 401 Arizonans have tested positive for the virus and six people who contracted it have died.
The true number of cases is likely much higher because testing has been so limited.
The state public health laboratory has tested just 368 people to date, according to the Arizona Department of Health Services.