Introduction: Hepatitis D virus, a defective virus that requires active hepatitis B virus replication, can only infect people with active HBV infection. The clinical picture of patients super-infected with HDV proceeds rapidly and progressively. Eventually, cirrhosis, liver failure and hepatocellular carcinoma may occur. In this study, it was aimed to investigate both HDV seroprevalence and coinfection/superinfection frequency in HDV infected patients in our region. Materials and Methods: A total of 740 patients (2015-2018) with HBsAg positivity were included in the study. The results of HDV Ab, HDV Ag, anti-HBe, HBe Ag, anti-HBc IgM and IgG, ALT and AST were examined in these patients. Results: 60% of the patients were males and 40% were females. HDV Ab positivity was detected in 10 (1.36%) of the 740 HBsAg positive patients. HDV Ag positivity was detected in four patients, whereas HDV Ag and Ab positivity was detected in only one patient. ALT and AST elevations were found in 3 of the patients (30%) with Delta antibody positivity. Anti-HBc IgG was positive in all patients with Delta ab positivity and there was no antiHBclgM positivity. Conclusion: In this study, HDV prevalence detected in our region was 1.36%, which is below the general average of Turkey. There is superinfection in the whole of what we identify as HDV Ab positive. In order to combat HDV infection, in addition to immunizing those who have not had Hepatitis B infection and the nonimmune community, transmission routes of HBV must be enlightened and the epidemiology of the disease must be well known. Screening of HBV-infected individuals for HDV will help identify infected persons and contribute to protection, control and treatment programs.

Background and Aim The serial serologic changes of hepatitis D virus (HDV) infection among chronic hepatitis B virus (HBV) infected patients who received oral nucleotide/nucleoside analogues are elusive. Methods Serum anti-HDV and HDV RNA among chronic hepatitis B (CHB) patients were tested at the time of initiating anti-HBV therapy and subsequently during the follow-up period. Results The seropositive rate of anti-HDV and HDV RNA among 2850 CHB patients, was 2.7% and 0.9%, respectively. Factors associated with anti-HDV seropositivity were platelet counts (odds ratio [OR]/95% confidence intervals [CI]: 0.995/0.992-0.999; P = 0.006), HBV DNA levels (OR/CI: 0.81/0.70-0.94; P = 0.005), and hepatitis B e-antigen (HBeAg) seropositivity (OR/CI: 0.22/0.05-0.95; P = 0.04). The only factor associated with HDV RNA positivity among anti-HDV seropositive patients was age (OR/CI: 0.95/0.90-1.00; P = 0.03). The spontaneous clearance rate of serum anti-HDV antibody was 3.0 per 100 person-years with a median follow-up period of 3.5 years (range 2-12 years), whereas the seroclearance rate of HDV RNA was 4.3 per 100 person-years among anti-HDV seropositive patients after a median follow-up period of 6.0 years (range 2-11 years). A baseline anti-HDV titer < 0.5 cut-off index was the only factor predictive of anti-HDV seroclearance (hazard ratio [HR]/CI: 30.11/3.73-242.85; P = 0.001). Conclusions HDV infection was not common among patients treated for HBV in Taiwan. Seroclearance of anti-HDV and HDV RNA did occur over time, albeit the chance is rare.