- Category: HBV Testing & Diagnosis
- Published on Wednesday, 04 June 2014 00:00
- Written by HIVandHepatitis.com
The U.S. Preventive Services Task Force (USPSTF) last week issued a new recommendation for hepatitis B virus (HBV) screening of non-pregnant adolescents and adults without current symptoms of viral hepatitis. The task force called for screening of people at high risk for infection including people with HIV, gay and bisexual men, and people who inject drugs.
The latest recommendation, published in the May 27 online edition of the Annals of Internal Medicine and available online, updates the prior 2004 guidance. After reviewing evidence on the benefits and harms of antiviral therapy for hepatitis B, the benefits of education or behavior change counseling, and intermediate and clinical outcomes after antiviral therapy, the task force concluded that, "persons at high risk for infection should be screened for HBV infection." The revised recommendations are summarized in a new fact sheet, also available online.
It is estimated that 1 to 2 million people in the U.S. have chronic hepatitis B, many of whom are not aware they are infected. Often symptomatic during acute infection, over years or decades chronic HBV infection can lead to serious liver disease including cirrhosis and hepatocellular carcinoma (HCC). Screening would allow infected people to modify behavior that can transmit HBV, receive treatment if appropriate, and undergo regular monitoring for liver cancer.
The Centers for Disease Control and Prevention (CDC) recommends hepatitis B surface antigen (HBsAg) screening followed by a confirmatory test for positive results. Further testing for HBsAg and hepatitis B core antibodies help distinguish between people with acute or recent infection, those who have cleared the virus and developed natural immunity, those who are immune due to vaccination, and those with chronic or ongoing infection lasting more than 6 months.
In the U.S., individuals considered to be at high risk for HBV infection include people born in countries with a high prevalence of hepatitis B (and their unvaccinated children), HIV positive people, injection drug users, household contacts or sexual partners of people with HBV infection, and men who have sex with men. Estimates suggest that up to 95% of people with chronic hepatitis B in the U.S. were born in countries with HBV infection prevalence of 2% or greater; these include many countries in Asia, sub-Sahara Africa, the Pacific Islands, the Middle East, and Eastern Europe. These recommendations do not apply to pregnant women, who are generally screened for HBV so precautions can be taken to prevent mother-to-child transmission (see www.uspreventiveservicestaskforce.org/uspstf/uspshepbpg.htm).
The task force noted that the CDC also recommends HBV screening for people undergoing kidney dialysis or receiving cytotoxic or immunosuppressive therapy, such as cancer chemotherapy or post-transplant drugs to prevent organ rejection.
Some people who are not members of a defined risk group may still have combinations of factors that could put them at risk for HBV. "Clinicians should exercise their judgment in deciding whether these persons are at sufficiently high risk to warrant screening," the authors wrote. "For example, screening is probably appropriate in settings that treat a large proportion of persons at increased risk, such as clinics for sexually transmitted infections, HIV testing and treatment centers, health care settings that provide services for injection drug users or men who have sex with men, correctional facilities, and institutions that serve populations from countries with a high prevalence of infection, including community health centers."
People at ongoing risk for HBV infection should be screened periodically, but the task force did not find evidence to suggest a recommended testing interval and said providers should use their clinical judgment.
The task force gave the recommendation a "B" grade, indicating, "There is high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial." Under the Affordable Care Act, private insurers and Medicaid must cover preventive service with an "A" or "B" grade. The authors noted that they found norandomized, controlled trials that provide direct evidence of the health benefits (that is, reduced morbidity, mortality, and disease transmission) of HBV screening for asymptomatic, non-pregnant adolescents and adults.
An effective HBV vaccine is available, and it is part of the universal vaccine series for infants and recommended for adolescents and adults at risk who were not previously vaccinated. The USPSTF found "adequate evidence" that HBV vaccination is effective for decreasing HBV acquisition.
The task force also found "convincing evidence" that antiviral treatment -- using drugs such as entecavir (Baraclude), tenofovir (Viread), or pegylated interferon alfa -- is effective at improving intermediate outcomes including HBV DNA viral load reduction, histologic improvement, or hepatitis B "e" antigen (HBeAg) clearance, as well as "adequate evidence" that treatment improves longer-term health outcomes such as reduced risk for hepatocellular carcinoma.
"These 2014 recommendations are long overdue," wrote Ruma Rajbhandari and Raymond Chung in anaccompanying editorial, noting that the CDC and the American Association for the Study of Liver Diseases (AASLD) already recommend HBV screening for at-risk individuals."[M]any would argue that the USPSTF should have endorsed screening for HBV infection in high-risk populations a decade ago or at least soon thereafter. We may have thus missed an opportunity to screen many high-risk persons in the United States."
"The lack of randomized trials on the health benefits of screening for HBV infection in asymptomatic adolescents and adults contributed to the USPSTF's previous hesitancy to recommend screening," they added. "However, given the natural history of HBV infection, during which such clinical outcomes as cirrhosis and HCC develop 20 to 30 years after infection, a randomized, controlled trial of screening for HBV infection in asymptomatic adolescents and adults is unlikely to ever be done. In the absence of such trials, many modeling studies suggest that screening would have a large effect and be cost-effective."
ML LeFevre et al for U.S. Preventive Services Task Force. Screening for Hepatitis B Virus Infection in Nonpregnant Adolescents and Adults: U.S. Preventive Services Task Force Recommendation Statement. Annals of Internal Medicine. May 27, 2014 (Epub). Available online at www.uspreventiveservicestaskforce.org/uspstf/uspshepb.htm.
R Rajbhandari and RT Chung. Screening for Hepatitis B Virus Infection: A Public Health Imperative. Annals of Internal Medicine. May 27, 2014 (Epub).
Hepatitis Foundation International. Hepatitis Foundation International Supports U.S. Preventive Services Task Force for Hepatitis B Screening Recommendation. Press release. May 30, 2014.