Nine out of 10 people infected with hepatitis worldwide are unaware of their infection status, according to official data.
More than one million people die every year from hepatitis viruses, which have become a global problem and pose a serious threat to health.
Every year on July 28, the world observes World Hepatitis Day to raise awareness of the risks posed by the five different types of deadly viruses, which include hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV).
Hepatitis B and C cause the majority of diseases and deaths among these five types of infections.
"Millions of people are living with undiagnosed and untreated hepatitis worldwide, even though we have better tools than ever to prevent, diagnose and treat it," said WHO Director-General Tedros Adhanom Ghebreyesus in a statement on Friday.
About 354 million people worldwide live with hepatitis B and hepatitis C, and millions more are at risk of chronic liver diseases, cancer, or death as a result of hepatitis viruses each year.
Hepatitis B and C, which cause the majority of the disease and deaths, claim the lives of 1.1 million people annually.
Hepatitis A is most common in low-income areas with poor hygiene, whereas a defective hepatitis D virus requires the helper function of a hepatitis B virus.
Hepatitis E, which can be found in both domestic and wild animals, can, however, causes death to pregnant women if they become infected.
A total of 6.1% of the population in Africa live with hepatitis B, while it is found in 6.2% of the Western Pacific population.
Some 2.3% of the population in the Eastern Mediterranean lives with hepatitis C, while it affects 1.5% of the European population.