June 23, 2010

Physicians Test for Hepatitis C Based on Risk Factors but Should Expand Screening for High-Prevalence Age Group

SUMMARY: Medical providers seeing patients in a high-risk urban setting tend to recommend hepatitis C virus (HCV) testing based on known risk factors such as drug or alcohol use and having symptoms of liver disease such as cirrhosis or elevated ALT, according to an analysis published in the May 20, 2010 advance online edition of the Journal of Viral Hepatitis. Overall prevalence was high, however, and the investigators suggested that broader HCV screening might be useful for people born between 1945 and 1964, even if they do not have other risk factors.

By Liz Highleyman

W.N. Southern from Albert Einstein College of Medicine and colleagues examined HCV testing practices to determine which patient characteristics are associated with getting tested and with testing HCV positive. They also sought to determine the prevalence of HCV infection in a high-risk urban population.

Approximately 3.2 million people in the U.S. have chronic hepatitis C, the study authors noted as background, but many are not aware of their infection.

The researchers analyzed all patients seen at the ambulatory care clinic at Montefiore Medical Center in the Bronx, New York City, between January 1 and February 29, 2008. In addition, they extracted demographic information, laboratory data, and ICD-9 diagnostic codes from electronic medical records of patients seen between March 1, 1997 and February 29, 2008. All participants were included in the baseline phase of the Hepatitis C Assessment and Testing Project (HepCAT), a serial cross-sectional study of HCV screening strategies.

Results 
  1. Among the 9579 participants analyzed, 3803 (39.7%) had been tested for HCV.
  2. Of these, 438 (11.5%) were HCV positive.
  3. The overall prevalence of HCV infection was estimated to be 7.7%, assuming that untested participants would test positive at the same rate as tested subjects, based on risk-factors.
  4. The following risk factors were associated with being tested for HCV, and with being HCV positive: 
          *Being in the high-prevalence birth cohort born during 1945-1964
            (roughly age 45 to 65);
          *History of drug or alcohol abuse; Being HIV positive;
          *Diagnosis of cirrhosis; Diagnosis of end-stage renal (kidney) disease; 
          *Elevated alanine transaminase (ALT).

"In a high-risk urban population, a significant proportion of patients were tested for HCV and the prevalence of HCV infection was high," the study authors concluded. The estimated 7.7% prevalence in this group of patients is several times higher than the 1.6% rate for the U.S. general population.

"We found strong evidence that physicians are using a risk-based screening strategy to identify patients with HCV infection, using known risk factors and other conditions associated with HCV to guide testing," they continued in their discussion. However, they added, broader screening may be indicated for people in the high-prevalence birth cohort, even those without behavioral or clinical risk factors.

Expanded testing might be useful given that a considerable proportion of people with HCV do not know how they became infected. Furthermore, sexual transmission of HCV is a growing concern among HIV positive gay men, but sexual behavior is not commonly regarded as a hepatitis C risk factor. At a recent hepatitis C forum attended by gay men in San Francisco, several participants said their providers had refused to test them for HCV because they did not have a history of injection drug use or other traditional risk factors.

Investigator affiliations: Albert Einstein College of Medicine, Montefiore Medical Center, New York, NY; School of Public Health, Boston University, Boston, MA; VA QUERI-HIV/Hepatitis Program, Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA; Division of Viral Hepatitis, Centers for Disease Control and Prevention, National Center for HIV/Viral Hepatitis/STD/TB Prevention, Atlanta, GA.

6/22/10

Reference

WN Southern, M-L Drainoni, BD Smith, and others. Hepatitis C testing practices and prevalence in a high-risk urban ambulatory care setting. Journal of Viral Hepatitis (Abstract). May 20, 2010 (Epub ahead of print).

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