Not useful during “window period” of acute HBV infection, i.e., after disappearance of HbsAg and prior to appearance of anti-HBs. Testing for acute HBV infection should also include anti-HBc IgM antibody.
Positive results (S/CO>5.00) without need for confirmation testing should be interpreted in conjunction with test results of other HBV serologic markers (e.g., anti-HBs antibody, anti-HBc total antibody, anti-HBc IgM antibody).
Not suitable as a stand-alone prenatal screening test of HbsAg status in pregnant women.
Positive HbsAg test results should be reported by the health care provider to the State Department of Health, as required by law in some states.
Individuals, especially neonates and children, who recently received hepatitis B vaccination may have transient positive HbsAg test results because of the large dose of HbsAg used in the vaccine relative to the individual's body mass.
Performance characteristics have not been established for the following characteristics:
- Grossly icteric (total bilirubin level of >20 mg/dL)
- Grossly lipemic (trilein level of >3,000 mg/dL)
- Grossly hemolyzed (hemoglobin level >500 mg/dL)
- Containing particulate matter
- Cadaveric specimens