Hepatitis B: new rapid diagnostic test to halt mother-to-child transmission

Scientists from the Institut Pasteur, in collaboration with Kumamoto University in Japan, have assessed a new rapid diagnostic test to identify pregnant women at elevated risk of transmitting hepatitis B to their babies. This diagnostic tool could help eliminate hepatitis B by preventing mother-to-child transmission during childbirth, especially in low- and middle-income countries. Hepatitis B is a liver inflammation caused by the hepatitis B virus (HBV). It is the second-leading infectious cause of death globally after tuberculosis. Prevention of mother-to-child transmission of HBV is crucial for global elimination of hepatitis B. The results were published on March 14, 2025 in The Lancet Gastroenterology & Hepatology.

Hepatitis B is a viral disease that affects the liver and can lead to severe complications, including cirrhosis and liver cancer. There are more than 254 million people living with hepatitis B, who can potentially transmit the virus, and more than 1.1 million deaths every year. In many resource-limited countries (particularly across sub-Saharan Africa and the Asia-Pacific region), chronic hepatitis B virus (HBV) infections affect 4 to 8% of the adult population. Infection is less common in Western Europe and North America, where chronic carriers account for less than 1 to 2% of the population. In France, an estimated 143,000 individuals live with HBV. The virus is transmitted through bodily fluids and secretions. Statistics show that the most common routes of transmission worldwide are mother-to-child transmission and transmission between children.

Effective vaccination has been available since 1981, but antiviral therapy does not yet definitively cure hepatitis B. Existing tests used to assess a person’s risk of transmitting hepatitis B, such as those measuring viral load, are often costly and require specialized laboratory equipment, limiting their accessibility in resource-limited regions.

Preventing mother-to-child transmission

Preventing mother-to-child transmission of hepatitis B is a crucial component of strategies to eliminate hepatitis B. As well as vaccinating newborn infants, the World Health Organization (WHO) recommends HBV screening for pregnant women. If this screening test is positive, a second test is required to measure the amount of virus present, as women with high viral loads are more likely to transmit the virus to their babies. Those at high risk can then receive preventive antiviral treatment to reduce the chance of transmission.

The first-line screening test, which detects the HBV surface antigen, is affordable and accessible in many low-income countries. But the second test, which uses PCR to measure viral load, is rarely available in these countries. This test, essential for assessing the risk of mother-to-child transmission, requires advanced laboratory equipment and costly reagents for viral quantification.

A rapid point-of-care test that can be used in decentralized settings to accurately identify women with high levels of the virus could provide a solution to this problem.

A reliable, rapid test to assess the risk of mother-to-child HBV transmission

The new rapid test assessed by Dr. Yusuke Shimakawa, a scientist in the Epidemiology of Emerging Diseases Unit at the Institut Pasteur, in collaboration with Prof. Yasuhito Tanaka from Kumamoto University and the company Fujirebio, offers an innovative solution that detects "HBV core-related antigen", considered as a reliable marker of active infection, and can be used even in regions with no laboratory access or electricity. It is inexpensive to produce, easy to use, does not require electricity, remains operable in temperatures up to 39°C and has a rapid turnaround time of just 45 minutes.

"Results show that this new test is highly effective at identifying women with a high viral load and offers significant advantages in speed and ease of use compared to traditional methods, such as PCR. This test can be used to reliably identify pregnant women who should benefit from preventive antiviral treatment at the point of care," explains Yusuke Shimakawa, the lead author of the study and a scientist in the Institut Pasteur's Epidemiology of Emerging Diseases Unit.

Global impact on hepatitis B management

The nature of the test means that it could be easily integrated into routine antenatal care in decentralized, resource-limited settings. This breakthrough could have a significant impact on hepatitis B management in low- and middle-income countries, where access to health care is often limited. The rapid test will enable early detection and intervention, thereby reducing the spread of the infection and development of related complications.

The research team is continuing its work to improve the test with a view to large-scale implementation. Additional research is under way to assess the efficacy of the test among pregnant women in different clinical and geographical settings.

This research was funded by the institutions cited above, as well as ANRS-MIE, the Japan Society for the Promotion of Science, Gilead Sciences and the Total Foundation.

See our viral hepatitis fact sheet