Prevalence of Hepatitis Delta Virus Infection in Galicia: Results of the Universal Implementation of Double Reflex Testing.

Introduction: Chronic hepatitis caused by the hepatitis Delta virus is the most severe form of viral hepatitis and carries the greatest risk of complications. The real prevalence of this infection remains unknown.

Objectives: This study sought to determine the prevalence of both the antibodies and the active infection rates of hepatitis Delta in the Autonomous Region of Galicia, Spain.

Materials and methods: A prospective study was conducted including all patients carrying the hepatitis B surface antigen who attended any hospital within the Galician Health Service between 2023 and 2024. These patients underwent serum testing for antibodies against the hepatitis Delta virus (LIAISON® XL MUREX Anti-HDV Assay; Diasorin Saluggia, Italia); the viral load was then assessed in those that tested positive (Hepatitis Delta Real Time PCR Kit; Vircell, Granada, Spain). The samples with a positive viral load were subsequently genotyped.

Results: A total of 1,962 patients were included, 85 of whom had anti-HDV antibodies, and 20 of these (23.5%) had a detectable viral load. The prevalence obtained was 4.3% in carriers of the hepatitis B virus surface antigen, and 0.03 per 1,000 inhabitants. The most common genotype found in active infections was 1D.

Conclusions: The seroprevalence obtained in this study confirmed the low circulation of the hepatitis Delta virus in our region. However, a significant proportion of affected patients have an active infection, and early diagnosis is essential to prevent disease progression and the development of complications. As expected, most of our patients are infected with strains of genotype 1D, which is predominant worldwide, including Europe. However, we also found three strains of genotype 5 in patients from West Africa.