Claimed to be the first test of its kind available in the US, the new test service will allow physicians to assess patient's response to drug therapies used to treat infection with the (HBV).

The new quantitative test service will measure the quantity of viral antigen in blood to determine whether the immune system of an individual infected with HBV is responding to treatment.

The data from the test will help physicians to monitor response to antiviral medications, as well as enable them to modify or adjust treatment to minimize progression and reactivation of the infection.

At present, HBsAg qualitative test is widely used for the diagnosis of patients with HBV, while antiviral therapies or interferon alpha (PEG-IFN) are used to treat HBV.

The HBV virus will be transmitted by blood, semen, or other body fluid from a person infected with the virus, and may cause serious health issues such as cirrhosis or liver cancer.

Quest Diagnostics research and development vice president Dr Rick Pesano said: "An estimated 850,000 to 2.2 million persons in the U.S. are infected with chronic hepatitis B.

“While there are effective therapies that can functionally cure HBV infection, physicians in the U.S. have lacked tools that help predict individualized patient response to those treatments.

"With this new test capability, physicians can better develop tailored treatment plans and monitor HBV-infected patients to help prevent progression and better their chance for long-term immunity."