Table 2. HDV screening recommendations.

EASL 25	• Patients with chronic HBV infection should be screened for coinfection with HDV • Long-term follow-up HDV RNA monitoring for all treated patients with HBV–HDV coinfection as long as HBsAg is present in serum
APASL 26	• Coinfection with HDV should be assessed in patients with chronic HBV infection • In patients with HBV-HDV coinfection, it is important to determine which virus is dominant, and the patient should be treated accordingly • Patients should be monitored for 6 months posttreatment and beyond
AASLD 20	• HBsAg-positive persons at high risk of HDV should be screened  ○ Persons from regions with high HDV endemicity   ▪ Africa (West Africa, horn of Africa)   ▪ Asia (Central and Northern Asia, Vietnam, Mongolia, Pakistan, Japan, Taiwan)   ▪ Pacific Islands (Kiribati, Nauru)   ▪ Middle East (all countries)   ▪ Eastern Europe (Eastern Mediterranean regions, Turkey)   ▪ South America (Amazon basin)   ▪ Other (Greenland)  ○ Persons who have injected drugs  ○ Men who have sex with men  ○ Individuals infected with HCV or HIV  ○ Persons with multiple sexual partners or history of sexually transmitted disease  ○ Individuals with elevated ALT or AST with low or undetectable HBV DNA • If there is any uncertainty regarding the need to test, an initial anti-HDV test is recommended • For those at risk for HDV acquisition, periodic retesting is recommended

Abbreviations: AASLD, American Association for the Study of Liver Diseases; ALT, alanine transaminase; APASL, Asian Pacific Association for the Study of the Liver; AST, aspartate transaminase; EASL, European Association for the Study of the Liver; HBsAg, HBV surface antigen; HBV, hepatitis B virus; HCV, hepatitis C virus; HDV, hepatitis delta virus.