The Prevalence of Hepatitis B and C Virus in Patients With End-Stage Kidney Disease on Regular Hemodialysis in Duhok, Iraq: A Brief Report

Infection with hepatitis B and C virus (HBV and HCV) is a global health problem (1,2). Currently, around 350 and more than 150 million subjects are infected with HBV and HCV, respectively (1,2). Such infections are associated with long-term complications including liver cirrhosis, hepatic failure, and hepatocellular carcinoma (1,2). In addition, infections with HBV and HCV are considered as the most common blood-borne infections in subjects with end-stage kidney disease (ESKD) on regular hemodialysis (3). The prevalence of HBV has been studied in the general population and it ranges from less than 1% in Western countries to more than 10% in Southeast Asia (4). Additionally, the prevalence of HCV in the general population ranges from 10% in Egypt to less than 1% in developed countries (2). On the other hand, the prevalence of HBV infection in patients with ESKD on regular hemodialysis ranges from less than 1% in developed countries to as high as 20% in developing countries (5). Besides, the prevalence of HCV in such patients ranges from 5% in developing countries to up to 54% in developing countries (6). Previous studies have thoroughly evaluated the prevalence of HBV and HCV in the region (7-9). However, data about the prevalence of HBV and HCV in our region is sparse. Further, continuous monitoring of the prevalence of such viruses in patients with ESKD is important for the early discovery of the outbreaks and the elimination of the viruses.

hemodialysis were recruited based on their consent for participating in the study while those with acute renal failure were excluded from the study.
Enzyme-linked Immunosorbent Assay Hepatitis B surface antigen (HBsAg), hepatitis B core IgG (HBc IgG), and hepatitis C virus antibodies (HCV Ab) were tested using the commercial ELISA kit (DIA. PRO diagnostic Bioprobes ELISA kit, Italy) following the manufacturer's instruction.

DNA Extraction and Real-time Polymerase Chain Reaction
To extract HBV DNA, QIAamp commercial viral DNA extraction kit was utilized (Qiagen) following the manufacturer's instructions. Then, HBV viral load was tested by the artus HBV RG PCR-based RT-PCR (Qiagen), followed by performing the RT-PCR testing using the Rotor-Gene Q RT-PCR.
Quantification of HCV RNA To confirm HCV positivity, all HCV Ab positive samples were tested for HCV by Xpert HCV quantification assay (Cepheid, Sunnyvale, California, the USA). In this assay, the amplification ranges from 10 IU/mL to 10 8 IU/mL.

Hepatitis B Virus Positivity
In general, 143 patients within the age range of 9-72 years old were registered in the Duhok dialysis center between January 2019 and October 2019. In addition, 79/143 (52.44%) of the patients were females and all patients were recruited in the study and tested for HBsAg. Further, 5/143 (3.49%) patients (3 males and 2 females) were tested positive for HBsAg. Then, patients who were positive for HBsAg were tested for HBc IgG antibodies in order to confirm the chronicity of HBV infection. All tested patients were positive for HBc IgG. The viral load for those patients was undetected.

Hepatitis C virus Positivity
Among the recruited samples, 3 (2.1%) cases were tested positive for HCV Ab including 2 males and 1 female. Furthermore, all samples with positive HCV AB were tested to confirm HCV positivity and three patients were positive by RT-PCR.

Discussion
Infections with HBV and HCV are public health issues worldwide. The World Health Organization has set a plan for the elimination of the infection by 2030. To achieve this, it is important to eliminate the infection in patients who are at high risk such as those who are on hemodialysis (10). Recent studies have shown that the prevalence of HCV positivity in patients on regular hemodialysis is within the range of 1.4%-28.3% and 4.7%-41.9% in developed and developing countries, respectively (11). In two projects conducted in Saudi Arabia and Jordan investigating the prevalence of HBV in patients with ESKD on hemodialysis, the prevalence of HBV was found to be 4.6% and 5.9%, respectively (12,13). In the USA, the prevalence of HCV in patients with ESKD on regular hemodialysis ranged from 5% to 10% (14). In another study conducted in Turkey, the prevalence of HBV and HCV was 13% and 20%, respectively (15). Based on the results of a previous study in Iraq, HBV and HCV positivity in patients on hemodialysis were 3.2% and 4.3%, respectively (16). In this study, the prevalence of HBV and HCV in patients on hemodialysis was 3.49% and 2.1%, respectively. The low prevalence of HBV in this group encourages the elimination of the infection in such patients. Additionally, a good vaccination program may help to decrease the transmission of infection in this age group. On the other hand, the low prevalence of HCV positivity in this group of patients, along with the approval of direct-acting antiviral drugs with high success rates makes the elimination of the virus feasible (17,18). To conclude, the prevalence of HBV and HCV was low in patients with ESKD who were on hemodialysis. Accordingly, the elimination of viral infections is feasible by implementing a good infection control program, vaccination, and treatment of HCV.