Prevalence and genotype distribution of hepatitis C virus among apparently healthy individuals in Mongolia: a population-based nationwide study

Background and Aims: Hepatitis C virus (HCV) is one of the major causes of liver cirrhosis and hepatocellular carcinoma (HCC) in Mongolia. However, there are no data concerning nationwide prevalence of HCV infection in Mongolia. We intended to investigate the population-based prevalence of HCV infection and genotype distribution among 1512 apparently healthy individuals in this country. Methods: Between April 2003 and December 2005, sera from 1512 residents of Ulaanbaatar and 12 provinces were collected by two-stage cluster random sampling, and anti-HCV was tested. Anti-HCV-positive samples were tested for HCV RNA by reverse transcription polymerase chain reaction, and HCV genotype was determined. Results: The mean age of the subjects was 46.2 +/- 17.8 years, and 812 (53.7%) were male. Overall, the prevalence of anti-HCV was 15.6% (236/1512) and HCV RNA was detected in 167 subjects (11.0%), with the most common genotype being 1b (165/167, 98.8%). When the HCV RNA-positive subjects were categorized by decade of age, the prevalence in each age group was as follows: 2.5% in subjects <= 10 years of age, 4.5% in teens, 10.1% in 20's, 12.5% in 30's, 24.2% in 40's, 29.0% in 50's and 32.6% in subjects >= 61 years of age. The seroprevalence of anti-HCV in a risk group, nurses, was not significantly different from the general population in each decade of age (P > 0.05). Conclusions: Approximately 11.0% of apparently healthy population had detectable HCV RNA in Mongolia, and the predominant genotype of HCV was 1b. Preventive and therapeutic strategies for chronic hepatitis C are urgently warranted in this HCV-endemic area.