Delta hepatitis is still a major global health problem affecting 15-20 million individuals worldwide. HDV coinfection or super infection means that the host liver cells have previously been infected with hepatitis B virus. HDV coinfection or super infection leads to the cirrhosis of the liver and finally hepatocellular carcinoma (HCC) or liver cancer
24-27. Recent studies have indicated that the prevalence of Delta hepatitis displays regional variations in Turkey Türkdoğan et al.
28 investigated the prevalence of chronic delta hepatitis in Eastern Anatolia (n=75) and they found that the rate of delta hepatitis among the cases of chronic hepatitis was 16.2% and 45.3% among the cases of cirrhosis.
Later on the data obtained from 6734 patients were analyzed in a meta-analysis conducted by Değertekin et al. 29 out of these 6734 patients, 5231 were diagnosed with chronic hepatitis and 1503 were diagnosed with cirrhosis and the data obtained from these patients were divided by region into three groups: the Southeast Turkey, Central Turkey and Western Turkey. The prevalence of hepatitis D in each region was calculated separately for either patients with chronic hepatitis or patients with cirrhosis. Based on the results, the rate of Delta hepatitis in the Southeast Turkey was found to be 46% in cirrhotic patients (LC) and 27.1% in patients with chronic hepatitis B (CHB). The rate of delta hepatitis in LC patients and CHB patients were found to be 20% and 12.1% in the Central Turkey Group respectively, and 20% in LC patients of the Western Turkey Group.
The prevalence of HDV infection in Turkey displays variations by region as well as by year The studies conducted by Değertekin et al. 23 indicated that the prevalence of HDV was higher in the East of the country in comparison to the Western regions and has been gradually declining over the years.
In addition, in a study conducted by Kose et al. 30 in the western regions revealed that the rate of HDV IgG positive patients was 2.5% in 3094 HBsAg positive patients (53% inactive hepatitis B carriers).
Furthermore, Dulger et al. 31 conducted a study to identify the socio-epidemiological risk factors associated with HBV infection. They showed that the majority of patients (n = 1480; 55.8%) were residents in the rural areas. They detected Anti-HDV-IgG in 18.4% of tested subjects who came from an urban area, 12.5% of subjects of the rural group had a positive result for anti-HDV-IgG. Delta hepatitis patients, 37.3% had liver cirrhosis, 7% in patients with hepatitis B monoinfection had liver cirrhosis.
Sanou et al. 32 monitored the seroprevalence of HBV-HDV co-infection in different population groups in the Western part of Burkina Faso, and described the genetic diversity of the detected virus strains.
In Turkey, HBV infection rates range from 2.5% to 20% in the general population, 20% to 40% in the cirrhotic patients 22,23,29-31, suggesting a high prevalence of HDV infection in HBsAg positive patients. Few studies only have assessed the epidemiological and clinical importance of HDV infection in Turkey, indicating different results in terms of HDV infection prevalences across regions. HDV infections are rather rare in Europe due to largely effective HBV vaccination programs and screening of blood products, hepatitis D remains of concern with highest rates in low-income HBV-endemic countries with insufficient HBV vaccination coverage 33. Due to deficiencies and low socio-economic conditions in vaccination programs for HBV in eastern parts of our country the prevelence of HBV and HDV infection is higher than the western region.
In our study, 1.8% of the patients with chronic hepatitis B and 20% of the cirrhotic patients were HDV seropositive. The seroprevalence for HDV in overall patients with hepatitis B was 3.4%. In our study, the prevalence of HDV was found to be lower than that of the Eastern regions since our hospital is located in the Western part of the country. These results are in line with the previous studies. Interestingly, higher rates of anti-HDV IgG seropositivity were observed in patients with cirrhosis 23.
As shown in the previous studies, our study indicated the rate of patients HDV positive patients was higher in hepatitis B patients with cirrhosis, in comparison to the hepatitis B patients without cirrhosis. The rate of HDV positive patients in the Group A was found to 11-fold higher in comparison to the Group B. Our results are important because of that they support the previous studies and include patients with follow-up in a single center. Our finding demonstrate that HDV infection is not rare in this country. HBV/HDV co-infection can cause more severe liver disease than HBV mono-infection, resulting in accelerated progression of cirrhosis. The higher prevalence of HDV in cirrhotic patients suggests that HDV is associated with poor prognosis. These results are in line with the results of the previous studies performed in our country and suggest that HDV is endemic in Turkey.
The higher prevalence of HDV in cirrhotic patients suggests that HDV is associated with poor prognosis. These results are in line with the results of the previous studies performed in Turkey 34 and suggest that HDV is endemic in Turkey.
In conclusion this study shows that 3.4% of the patients with hepatitis B patients were seropositive for HDV and its’ seroprevalence increases by 11-fold in cirrhotic patients which indicate that HDV increases the severity of liver disease and HDV is endemic in Turkey.