German scientists recently introduced the world’s first test for hepatitis delta virus (HDV), a blood-borne superinfection that affects nearly 10 million people around the globe and kills up to 20 percent of those infected, The Scientist reports.

The new liver disease test was developed by biotech firm Analytik Jena AG, based in Jena, Germany, and tests for the RNA of both hep D and hepatitis B virus (HBV) simultaneously from serum and blood plasma samples.

According to experts, hep D is one of the severest and deadliest forms of viral hepatitis in the world. The virus only exists in people who are either already infected with chronic hep B, or in those who acquire a hepatitis two-in-one superinfection.

Hep D has no vaccine or highly effective treatment and can lead to a rapid progression of liver cirrhosis, as well as an increased chance of developing liver cancer in those who have it.

HDV infections are found most frequently in the Mediterranean basin, the Middle East, South and Central Asia, West Africa and South America’s Amazon region. The virus is uncommon in the United States.

Researchers say the new hep D test will be rolled out immediately for routine tests among those already living with hep B.