Hepatitis C infection epidemiology in Mongolia: protocol of a systematic review and meta-analysis

The burden of liver cancer in Mongolia from 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

Background

Liver cancer remains the leading cause of death and public health threat among the Mongolian population. So far, there has been no in-depth analysis to describe the burden of common attributable factors to liver cancer in Mongolia. Therefore, we aimed to explore the most prevalent causes of liver cancer and its trends from 1990 to 2019.

Methods

We extracted the primary liver cancer data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to examine the mortality and morbidity of liver cancer by its etiological types, which included alcohol, viral hepatitis B and C, and non-alcoholic steatohepatitis (NASH). The data was extracted by sex and 5-year age intervals from 1990 to 2019. Data included mortality, incidence, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) of liver cancer among the Mongolian population.

Results

Mongolia had the world's highest age-standardized DALYs for liver cancer (2558.1) in 2019. Alcohol-attributable DALYs (786.6) were 29 times higher than the global average (26.1), and liver cancer due to hepatitis C (752.6) and B (763.2) were 21.5 (35.0) and 10.9 (69.1) times higher, respectively. Over the past 30 years, there has been a steady increase in the incidence and number of deaths caused by liver cancer in Mongolia. In 2019, liver cancer incidence due to alcohol consumption was 3.1 times higher for males than females, and hepatitis B was 2.7 times higher for males than females. However, the incidence of hepatitis C and NASH were slightly higher for females. Deaths from liver cancer accounted for 9.51% (2365) of total deaths in Mongolia in 2019, with a continuously increasing trend in the fraction of death compared to 1990, which was 11 times higher than the global average (0.86%), particularly in females with a 319.6% (95% UI 234.9-435.7) increase observed during the study period. Liver cancer due to hepatitis B, C, and alcohol each shared about one-third of liver cancer deaths.

Conclusion

A comprehensive analysis of the burden of liver cancer in Mongolia reveals alcohol use as a primary cause of liver cancer mortality, particularly affecting men and significantly impacting the disease burden. Viral hepatitis continues to pose a major public health concern in the country. Although significant milestones have progressed, addressing the unique demographic and geographical challenges requires tailored approaches for specific target populations. The evidence generated from this analysis is crucial to support policy guidance, contribute to evidence-based decisions, guide public health prevention measures, and amplify population health promotion and disease prevention throughout Mongolia.

Prevalence and genotype distribution of hepatitis C virus in Mongolia: Systematic review and meta-analysis

OBJECTIVE

To characterize hepatitis C virus (HCV) infection epidemiology in Mongolia.

METHOD

Publications on HCV antibody (Ab) and RNA prevalence, and/or genotypes/subtypes were systematically reviewed and reported following PRISMA guidelines. Random-effects meta-analyses and age adjustments were conducted to estimate the prevalence of Mongolians exposed to HCV (pooled HCV-Ab prevalence) by time period, sex, and at-risk populations; and to estimate the prevalence of chronically-infected HCV individuals.

RESULTS

The national pooled HCV-Ab prevalence was 12.3% in 2000-2009 and 11.2% in 2013. Sex-specific pooled prevalence appeared higher among females than males (14.0% versus 6.8%). Age-specific pooled prevalence significantly increased from 3.7% among children (aged 0-10 years) to 34.1% among people aged ≥50 years (p < 0.001). Among the adult general population (low-risk population), the national age-adjusted prevalence was 8.1%. Age-adjusted chronic infection prevalence in adults was 6.0%. Among healthcare workers, pooled prevalence was 18.0%. Among patients with liver diseases, pooled prevalence was 53.7%. Among individuals engaging in risky sexual behaviors, pooled prevalence was 11.1%. The identified circulating genotypes/subtypes were 1b (58.0%), 2a (21.7%), and 1a (20.2%).

CONCLUSION

The national HCV prevalence in Mongolia appeared to be among the highest worldwide. Higher prevalence in the clinical setting indicated potential ongoing HCV iatrogenic and occupational transmission. Additionally, HCV transmission in community settings should be investigated.