UC Davis laboratory offers rapid, highly accurate test for multiple respiratory viruses

Known as the Respiratory Viral Panel (RVP) by RT-PCR, the test simultaneously detects 10 common respiratory viruses from patients with cold and flu-like symptoms, providing definitive results within 24 to 36 hours. In contrast, the tests used by most clinical laboratories detect fewer viruses and often take longer to generate results, potentially leading to delayed or inappropriate medical care.

The Respiratory Viral Panel by RT-PCR is particularly beneficial for severely ill patients when a fast and accurate diagnosis is needed to determine the optimal course of treatment. This was particularly true during the recent 2009 H1N1 influenza pandemic, when the RT-PCR test allowed rapid determination of whether a virus was the novel 2009 H1N1 strain or seasonal flu.

Physicians in the Sacramento area may request the RVP by RT-PCR test by ordering it through the UC Davis Health System Medical Diagnostic service.

“Rather than limiting this test to UC Davis patients, we would like to make the RVP by RT-PCR available to the entire Sacramento community, with the hope of improving diagnosis and care for as many patients as possible,” said Ralph Green, medical director of the health system’s Medical Diagnostics.

Before switching to the RT-PCR method, the UC Davis Clinical Laboratory used a combination of tests, which detected fewer viruses with lower overall sensitivity and accuracy. For example, the point-of-care tests used by many hospitals for rapid diagnosis of influenza miss as many as 30 to 50 percent of H1N1 influenza infections due to poor sensitivity for the pandemic virus.

“Viral cell culture, the traditional standard for respiratory viral detection, takes significantly longer to provide results than the RT-PCR test and still misses some viruses,” said Christopher Polage, medical director of the health system’s Clinical Microbiology Laboratory.

In contrast, the RT-PCR test produces results within a day and identifies both viruses and subtypes with high predictive accuracy. Equipped with a more rapid and reliable test, physicians will be able to recognize patients with viral infections more quickly and provide targeted treatment or prevent transmission to other patients. Of equal importance, the ability to more accurately rule out specific viruses will allow physicians to appropriately pursue other medical causes.

“We are now able to test for the viruses that may be circulating in each flu season,” Polage said. “For any given patient, the RT-PCR test will provide useful information as to whether to treat or quarantine them, or leave them alone.”

Interestingly, Polage said, the laboratory had been discussing switching to a new method for respiratory viruses last year. Then, with the onset of the H1N1 pandemic and the increased triage, isolation and treatment needs that came with it, the changeover took on a completely new significance.

UC Davis Medical Center is the leading referral center in the region for the most seriously injured or ill patients and the most medically complex cases, covering 33 counties, more than 65,000 square miles and 6 million residents. It operates inland Northern California’s only Level 1 trauma center, with comprehensive adult and pediatric emergency departments. The center has been instrumental in keeping Sacramento County’s preventable death rate at or below 1 percent, which is less than half the national average. Studies show patients with specific critical injuries have better survival rates and functional outcomes at Level 1 trauma centers and academical medical centers. For more information, visit the UC Davis Medical Center Web site.