Viral hepatitis C (hepatitis C for short) is a viral hepatitis caused by hepatitis C virus (HCV) infection, hepatitis C virus infection easily leads to chronicity, 85% of adults with acute infection can develop chronic hepatitis C. The global prevalence of hepatitis C is 3.0% on average, with 3-4 million new cases of HCV infection each year, and an estimated 130-170 million chronic HCV infected people. Therefore, it is estimated that there are about 5.6 million HCV infected people in China. The most predominant HCV genotype in China is 1b (66%), followed by 2a (14%). 1, hepatitis C genotype typing HCV is an RNA virus with a high degree of variability, and can be divided into different genotypes according to the differences in the gene sequence of HCV. Different genotypes can be divided into different subtypes. Currently, HCV is divided into 6 genotypes, which are indicated by Arabic numerals 1-6, and lowercase letters indicate subtypes. HCV genotypes and subtypes are distributed differently in different regions. Genotypes 1, 2, 3 and 6 are the main genotypes detected in China, with genotype 1 being the most widespread and subtype 1b being the most common, followed by subtype 2a. Genotype 3 is mainly distributed in Yunnan Province. 2, the transmission route of hepatitis C The source of hepatitis C infection is patients and carriers of hepatitis C virus, through blood transmission, medical transmission, sexual contact transmission, vertical transmission. (1) Transmission by blood: HCV is mainly transmitted by blood, blood products or body fluids. Especially the sharing of needles for intravenous drug injection. The importation of blood or blood products contaminated with hepatitis C virus, the use of needles contaminated with hepatitis C virus and not strictly sterilized, as well as medical and cosmetic devices can lead to transmission through blood. Shared razors and toothbrushes, tattoos and ear piercings are all potential modes of transmission via blood. (2) Sexual contact transmission: HCV can be excreted through semen and vaginal secretions, and unprotected sex with a person infected with hepatitis C virus can cause infection. People who have multiple sexual partners are at relatively greater risk of contracting hepatitis C. (3) Vertical transmission: Pregnant women infected with hepatitis C virus have a 5-10% chance of transmitting hepatitis C virus to their newborns during pregnancy and delivery. Co-infection with HIV in pregnant women can result in a 20% incidence of vertical transmission of HCV. To find out if a baby born to a pregnant woman with HCV is infected with HCV, the baby can be tested for quantification of hepatitis C virus after 6 months of life or for antibodies to hepatitis C after 15 months. Daily life and work contacts such as handshakes, hugs, courtesy kisses, sharing of utensils and glasses, sharing of work tools, office supplies, money, and other contacts without skin breaks or blood exposure do not transmit HCV. Coughing and sneezing do not transmit hepatitis C virus. Mosquito bites do not transmit hepatitis C virus.