New device aims to give patients the correct flu diagnosis

Flu season is about to begin. At this time of year, it’s common to get sick and go to your family doctor or, if you’re feeling really bad, to the emergency room. But a common but little-known problem is that you could leave not knowing if you’ve got the flu — which can be serious if not properly treated — or just a cold.

That’s because doctors say the most popular test given across the country to detect the flu virus, known as the Rapid Influenza Diagnostic Test, or RIDT, has a rate of false negatives up to 50%. That means up to 50% of the people who test negative for flu on an RIDT actually have the flu.

When Heritage Valley’s hospitals in Sewickley and Beaver relied on RIDT, “It was really a coin flip [if you had the flu] because of so many false negatives,” said Dr. Matthew Wheeler, Heritage Valley’s assistant director of emergency services.

But increasingly, hospitals, doctors’ offices and outpatient clinics are trying to avoid that problem by ending their use of RIDT. Instead, some are installing new, faster — but more expensive — technology, machines that replicate what laboratories have been doing for more than a decade as the gold standard for testing for flu and other viruses.

“We realized that this [technology] was superior to any rapid test we had used,” said Dr. Kelly Stefano, microbiology director at Allegheny Health Network.

Known as molecular testing, the new devices use the same sample from a patient as RIDT — typically a swab from deep inside your nose — to look at the RNA or DNA of the virus cell to tell exactly what it is, virtually eliminating false negatives.

Though large, centralized labs at UPMC, Allegheny Health Network and others have had these devices for several years, health networks and doctors are now getting them for outpatient sites.

Next month, AHN will install the devices in four of its largest outpatient clinics — in Bloomfield, Downtown, Monroeville and Pine — in a pilot program to see if they should then be installed in all 20 of their doctors’ offices and outpatient clinics in the region.

Dr. Jim Kimmel, a family medicine physician whose practice is part of Genesis Medical Associates, an independent practice, said his office decided to get a molecular testing device for flu four years ago after the test time came down dramatically.

“That traditional [molecular] test took 6 to 8 hours, which, for me in our office, I wouldn’t use, because by then, I’m already treating the patient,” Dr. Kimmel said.

The new device takes less than 10 minutes, he said.

Shifting to new technology

The movement to using molecular devices has been gaining in recent years, but it got a big boost in December 2018. That’s when the Infectious Diseases Society of America, with

the support of the federal Centers for Disease Control and Prevention, published an update of its clinical practice guidelines — the first such update in 11 years.

In that update, the authors recommended that rapid molecular tests be used for both hospitalized patients and outpatients to “improve detection of influenza virus infection.”

But not everyone is convinced the new technology is ready for the majority of flu patients’ testing.

“If you show up at the physician’s office with flu symptoms, we don’t recommend testing [with molecular tests] because you’re treating the symptoms anyway,” said Dr. Alan Wells, medical director of the UPMC clinical laboratories.

UPMC does have a molecular device in most of its regional hospitals’ labs. But Dr. Wells said using the molecular test is restricted to patients who are either admitted to the hospital or are in high-risk groups, such as the elderly or immunosuppressed patients.

Using a molecular test “is not going to change treatment” for most patients, he said.

UPMC has long appreciated the power of the molecular tests to help better identify the virus a person has — so much so that a dozen years ago, before any of the current molecular devices were available, UPMC developed its own in-house test.

It used that test until about seven years ago, Dr. Wells said, when some of the first commercial devices came out.

Two years ago, UPMC bought the more advanced devices that brought testing time down dramatically, putting those in most of its Pittsburgh-area hospitals.

AHN’s move to use molecular technology in outpatient settings came after it first stopped using RIDT at its seven regional hospitals and began testing patients immediately with the molecular test.

“In American culture, we’re so used to pushing through it. We go to work no matter what,” said Dr. Brian Lamb, an internal medicine physician at West Penn Medical Associates in Bloomfield, part of AHN. “I think people, when they hear, ‘Yes, you have the flu,’ they say, ‘Oh, I’m going to have to stay home now and not go over to my relative’s house and spread this.’

“It’s just the way people are. They need to hear it definitively.”