ObjectiveTo investigate the distribution characteristics of hepatitis C virus (HCV) genotypes in patients with hepatitis C in Guizhou, China, and to provide a basis for the prevention and individualized treatment of HCV infection. MethodsA total of 1211 HCV RNA-positive patients with hepatitis C who were treated in Guiyang Public Health Clinical Center from September 2011 to October 2018 were enrolled. PCR direct sequencing was performed to obtain HCV sequences, which were then compared with the known HCV sequences in GenBank to obtain HCV genotypes and subgenotypes. The association of genotype distribution with sex, age, ethnic group, region, and route of infection was analyzed. The chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. ResultsA total of 4 genotypes and 11 subgenotypes were detected among the 1211 individuals with HCV infection, with the main genotypes of 1b (26.84%), 3b (27.17%), and 6a (24.28%). There was a significant difference in the distribution of HCV genotypes between the male and female individuals (χ2=15.428, P=0.009); 29.34% of the male individuals had genotype 3b, and 32.21% of the female individuals had genotype 1b. There was a significant difference in the distribution of HCV genotypes between different age groups (χ2=67.439, P＜0.001); genotype 1b was the main genotype in the individuals aged ≤18 years (66.67%) or ≥60 years (58.93%), genotypes 3b and 6 were the main genotypes in the individuals aged 19-39 years (28.93% and 29.29%, respectively), and genotypes 1b, 3b, and 6 were the main genotypes in the individuals aged 40-59 years (29.54%, 27.33%, and 24.28%, respectively). There was a significant difference in the distribution of HCV genotypes between the individuals with different routes of infection (χ2=153.916, P＜0001); the most common route of infection was intravenous drug addiction (57.97%), followed by sexual contact (8.42%) and invasive cosmetic surgery (8.42%); genotype 3b was the main genotype in the individuals with intravenous drug addiction (31.48%) or invasive cosmetic surgery (32.35%), and genotype 6 was the main genotype in the individuals with sexual contact (36.27%). There was no significant difference in the distribution of HCV genotypes between the individuals in different ethnic groups or from different regions of Guizhou (both P＞0.05). ConclusionThe distribution of HCV genotypes is diverse in Guizhou, and HCV strains with genotypes 3b, 1b, and 6a are the main epidemic strains. Several rare subgenotypes of HCV genotype 6 are observed. There is a significant difference in the distribution of HCV genotypes between the individuals with different ages, sexes, or routes of infection.

Objective To deveplope construct and validate a novel multiplex PCR system comprised of 30 Y-STR markers only with low and moderate mutation rates. Methods 30 Y-STRs characterized by low/moderate mutation rate and middle/high polymorphic was amplified simultaneously in a multiplex PCR system using the six color labeling fluorescence. PCR product was analyzed in a ABI 3500XL Genetic Analyzer. The accuracy, specifity, sensitivity and stability of the system and its validation on the mixtures were evaluated. Results The validation studies demonstrated that the system is a stable, accurate, and sensitive multiplex PCR system. The sensitivity was 0.0625ng DNA. Y-STR could be detection in a male/female DNA mixture ratio of 1:4. Conclusion The primary study demonstrates that this multiplex PCR system is effective and reliable for forensic routine DNA analysis. It will be very helpful for constructing Chinese forensic Y-STR database and population genetic research.