Tittle: Hepatitis Delta Virus superinfection: investigation of clinical progression in young individuals in the Brazilian Western Amazon

Background: There are approximately 15 million individuals co-infected with HBV and HDV spread across several countries in the world, however this number is underestimated. HDV superinfection is more frequently associated with liver failure, cirrhosis and even the development of hepatocellular carcinoma (HCC) when compared to HBV. Objective: This report presents cases of three young patients with possible superinfection who showed rapid development of liver disease in the severe form of HDV infection. Methods: Samples were collected at Ambulatório especializado em Hepatites Virais on July 31, 2023 and processed by Laboratório de Virologia Molecular da Fundação Oswaldo Cruz/Rondônia. The clinical and laboratory data of participants was collected through electronic medical records. To characterize HDV genotype, a Nested-PCR was used to obtain a 406 bp fragment of the HDV genome and subsequent genetic sequencing was performed. Results: Three individuals from a rural community in municipality of Lábrea/Amazonas showed a profile of rapid progression to chronic liver disease. Phylogenetic analysis showed that the sequences of all the cases were classified as HDV genotype 3. Conclusion: This case report demonstrates the impact of Delta Hepatitis as important public health problem for young-adult population and major challenge in the context of Brazilian Western Amazon region.