Published online Sep 14, 2016. doi: 10.3748/wjg.v22.i34.7824
Peer-review started: April 18, 2016
First decision: May 12, 2016
Revised: June 28, 2016
Accepted: August 8, 2016
Article in press: August 8, 2016
Published online: September 14, 2016
To review Hepatitis C virus (HCV) prevalence and genotypes distribution worldwide.
We conducted a systematic study which represents one of the most comprehensive effort to quantify global HCV epidemiology, using the best available published data between 2000 and 2015 from 138 countries (about 90% of the global population), grouped in 20 geographical areas (with the exclusion of Oceania), as defined by the Global Burden of Diseases project (GBD). Countries for which we were unable to obtain HCV genotype prevalence data were excluded from calculations of regional proportions, although their populations were included in the total population size of each region when generating regional genotype prevalence estimates.
Total global HCV prevalence is estimated at 2.5% (177.5 million of HCV infected adults), ranging from 2.9% in Africa and 1.3% in Americas, with a global viraemic rate of 67% (118.9 million of HCV RNA positive cases), varying from 64.4% in Asia to 74.8% in Australasia. HCV genotype 1 is the most prevalent worldwide (49.1%), followed by genotype 3 (17.9%), 4 (16.8%) and 2 (11.0%). Genotypes 5 and 6 are responsible for the remaining < 5%. While genotypes 1 and 3 are common worldwide, the largest proportion of genotypes 4 and 5 is in lower-income countries. Although HCV genotypes 1 and 3 infections are the most prevalent globally (67.0% if considered together), other genotypes are found more commonly in lower-income countries where still account for a significant proportion of HCV cases.
A more precise knowledge of HCV genotype distribution will be helpful to best inform national healthcare models to improve access to new treatments.
Core tip: Hepatitis C virus (HCV) infection is a global public health burden, causing an increasing level of liver-related morbidity and mortality due to the disease progression. Unfortunately, in many countries, there is a lack of robust epidemiological data, especially HCV genotypes distribution, upon which to base country-specific prevention, diagnosis and treatment strategies in order to reduce the disease burden represented by HCV. Stratification by viral genotypes at national and regional level, and a better understanding of viral diversity within target populations, might also critically inform the rational design and testing of future HCV vaccines.