Reflex RNA testing should follow a positive HCV antibody test
Last Updated: 2013-07-09 18:15:20 -0400 (Reuters Health)
By Will Boggs, MD
NEW YORK (Reuters Health) - Between a third and half of patients with positive hepatitis C results do not undergo reflex HCV RNA testing to confirm their diagnosis, according to a report from the New York City Department of Health and Mental Hygiene.
"When screening for hepatitis C, order a reflex test rather than a simple antibody test," Katherine Bornschlegel, MPH, from the New York City Department of Health and Mental Hygiene (DOHMH), Long Island City, New York told Reuters Health by email. "If the antibody test is positive, the lab will immediately do the RNA test using the same specimen, and you will learn the patient's infection status without needing an additional visit or blood draw."
"Even if your patient is not currently a candidate for antiviral treatment, knowing the hepatitis C infection status can help you manage your patient's care (e.g., counsel to avoid alcohol, screen for HCC)," Bornschlegel said.
About 3.2 million people in the US (and an estimated 129,000 in New York City) have chronic HCV infection. National guidelines recommend that all patients with a positive HCV antibody test undergo HCV RNA testing to determine their infection status.
As part of their routine public health surveillance, Bornschlegel and colleagues assessed whether clinicians actually order HCV RNA tests for their antibody-positive patients.
As reported June 19 online in The American Journal of Medicine, they obtained information from clinicians for a sample of 245 patients newly reported with a positive HCV antibody test.
After the initial investigation (in which the DOHMH asked clinicians to order RNA tests for patients who had not had them), HCV RNA testing had not been ordered for 90 patients. Nine months after the DOHMH asked the clinician to order the HCV RNA test, 81 (33.1% of all patients) still did not have an HCV RNA test done.
About half of the 245 patients (119, 48.6%) had a positive RNA test. Of these, 22 had the HCV RNA test only after the DOHMH requested that the clinician order the test. Forty-five patients (18.4%) tested HCV RNA negative (12 of these after DOHMH requested that the clinician order the test).
Clinicians said 28 (34.6%) of the 81 patients who did not have HCV RNA testing completed had not returned for follow-up, 18 (22.2%) were seen in facilities that did not do HCV RNA testing or that referred the patient elsewhere for RNA testing, 12 (14.8%) were tested in jail, five (6.2%) had died, and two (2.5%) did not have insurance coverage.
Initial testing for these 81 patients had taken place in medical facilities (38 patients, 46.9%), drug or alcohol rehabilitation facilities (24, 29.6%), and jails (12, 14.8%).
"If we assume that 33% did not have RNA testing, then we estimate that 3332 of the 10,065 patients newly reported with a positive HCV test in New York City in 2010 were not tested for HCV RNA," the authors say. "Alternatively, if we used the percentage of patients who never had RNA testing plus those patients who got RNA testing only after our request (47%), then we estimate that 4721 patients would not have received RNA testing."
"We believe it is time for reflex HCV RNA testing for all positive antibody tests to become routine, just as reflex Western blot testing became routine for human immunodeficiency virus," the researchers say.
"Educating clinical staff as well as social workers and counselors in drug rehabilitation facilities and jails on the importance of HCV RNA testing will help ensure that more patients get RNA testing," they explain. "In response to our findings, in December 2010, the NYC DOHMH developed a bulletin for primary care providers about diagnosis and management of HCV."
"We are still assessing this," Bornschlegel said. "It will be difficult to ascribe any improvement to the bulletin, however, because there are other initiatives underway as well and many publications on improved antiviral treatments."
"Knowing which patients have HCV infection after a single visit would greatly streamline the process of ensuring that patients who screen HCV antibody positive get the additional testing necessary," the investigators say. "Patients with positive RNA can then be counseled about measures for protecting their liver and improving their health, and evaluated for antiviral treatment."
Am J Med 2013.