Case report public health screening for hepatitis b

The USPSTF recommends screening for hepatitis B virus (HBV) infection in adolescents and adults at increased risk for infection (Table 1). B recommendation.

• Persons born in countries and regions with a high prevalence of HBV infection (≥ 2%), such as Asia, Africa, the Pacific Islands, and parts of South America
• U.S.-born persons not vaccinated as infants whose parents were born in regions with a very high prevalence of HBV infection (≥ 8%)
• HIV-positive persons
• Persons with injection drug use
• Men who have sex with men
• Household contacts or sex partners of persons with HBV infection

See the Practice Considerations section for a description of adolescents and adults at increased risk for infection.

Importance

An estimated 862,000 persons in the United States are living with chronic infection with HBV. 1 Persons born in regions with a prevalence of HBV infection of 2% or greater, such as countries in Africa and Asia, the Pacific Islands, and parts of South America, often become infected at birth and account for up to 95% of newly reported chronic infections in the United States. Other high-prevalence populations include persons who inject drugs; men who have sex with men; persons with HIV infection; and sex partners, needle-sharing contacts, and household contacts of persons with chronic HBV infection. 2

According to the Centers for Disease Control and Prevention (CDC), an estimated 68% of people with chronic hepatitis B are unaware of their infection, 3 and many remain asymptomatic until onset of cirrhosis or end-stage liver disease. 4 , 5 This contributes to delays in medical evaluation and treatment and ongoing transmission to sex partners and persons who share objects contaminated with blood or other bodily fluids that contain HBV. 3 , 6 From 15% to 40% of persons with chronic infection develop cirrhosis, hepatocellular carcinoma, or liver failure, which lead to substantial morbidity and mortality. 4

USPSTF Assessment of Magnitude of Net Benefit

The USPSTF concludes with moderate certainty that screening for HBV infection in adolescents and adults at increased risk for infection has moderate net benefit.

See Table 2 for more information on the USPSTF recommendation rationale and assessment.

• Inadequate direct evidence on benefits of screening on health outcomes due to lack of studies.
• Convincing evidence that antiviral treatment of patients with chronic HBV infection is effective at improving intermediate outcomes, including HBeAg loss and virologic suppression.
• Adequate evidence from clinical trials and cohort studies that antiviral treatment of patients with chronic HBV infection improves health outcomes, such as reduced risk of mortality or hepatocellular carcinoma.
• Adequate evidence that improvements in intermediate outcomes of chronic HBV infection related to antiviral treatment (such as HBeAg clearance and virologic suppression) are associated with reduced risk of adverse health outcomes (such as cirrhosis and hepatocellular carcinoma).

• Inadequate direct evidence on the harms of screening for HBV infection due to lack of studies.
• Adequate evidence to bound the harms of screening as small to none based on the nature of the intervention and the low likelihood of serious harms. (When direct evidence is limited, absent, or restricted to select populations or clinical scenarios, the USPSTF may place conceptual upper or lower bounds on the magnitude of benefit or harms.)
• Adequate evidence that the magnitude of harms of treatment is small, based on several trials showing that risks of adverse events, nausea, and diarrhea are not significantly greater in persons receiving treatment than in persons receiving placebo or no treatment, and that some adverse events resolve after discontinuing therapy.

For more details on the methods the USPSTF uses to determine the net benefit, see the USPSTF Procedure Manual. 7

Practice Considerations

PATIENT POPULATION UNDER CONSIDERATION

This recommendation applies to asymptomatic, nonpregnant adolescents and adults at increased risk for HBV infection, including those who were vaccinated before being screened for HBV infection. The USPSTF has made a separate recommendation on screening in pregnant women. 8

ASSESSMENT OF RISK

The risk for HBV infection varies substantially by country of origin in non–U.S.-born persons living in the United States. Persons born in countries with a prevalence of hepatitis B surface antigen (HBsAg) of 2% or greater (Table 3, 2 , 9 Figure 10 at https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/hepatitis-b-virus-infection-screening#fig) account for the majority of cases of new chronic HBV infection in the United States; most persons in these countries acquired HBV infection from perinatal transmission. 2 Persons born in the United States with parents from regions with higher prevalence are also at increased risk of HBV infection during birth or early childhood, particularly if they do not receive appropriate passive and active immunoprophylaxis (and antiviral therapy for pregnant women with a high viral load) (Figure 10 at https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/hepatitis-b-virus-infection-screening#fig). 11 – 13 The CDC classifies HBV endemicity levels by prevalence of positive HBsAg (high [8%], moderate [2%–7%], or low [<2%]) (Figure 10 at https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/hepatitis-b-virus-infection-screening#fig). The estimated prevalence of HBV infection in the general U.S. population is 0.3% to 0.5%, 8 , 9 , 11 , 12 , 14 , 15 which makes it reasonable to screen adolescents and adults born in countries or regions with an HBsAg prevalence of 2% or greater (regardless of vaccination history in their country of origin) and adolescents and adults born in the United States who did not receive the HBV vaccine as infants and whose parents were born in regions with an HBsAg prevalence of 8% or greater (regardless of their biological mother's HBsAg status).

HBV screening should also be offered to other risk groups defined by clinical and behavioral characteristics in which prevalence of positive HBsAg is 2% or greater. Persons from such risk groups include persons who have injected drugs in the past or currently; men who have sex with men; persons with HIV; and sex partners, needle-sharing contacts, and household contacts of persons known to be HBsAg positive 2 , 3 , 9 , 12 – 14 , 16 , 17 (Table 4 2 , 9 , 11 , 12 , 15 – 19 ). Some persons with combinations of risk factors who are not members of risk factor groups listed previously may also be at increased risk for HBV infection. Clinicians should therefore consider the populations they serve when making screening decisions.