Hepatitis C viral hepatitis (referred to as hepatitis C), is a viral hepatitis caused by hepatitis C virus (HCV) infection, hepatitis C virus infection is prone to chronicity, 85% of adults can develop chronic hepatitis C after acute infection. 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 infections. 2006 seroepidemiological survey in mainland China showed that the prevalence of anti-HCV in people aged 1-59 years was 0.43%, indicating that it is a low HCV prevalence area worldwide. From this, it is projected that the current number of HCV infected people in China is about 5.6 million. The most predominant HCV genotype in China is 1b (66%), followed by 2a (14%). I. Genotypic typing of hepatitis C 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. Second, the transmission route of hepatitis C The infectious source of hepatitis C is patients and carriers of hepatitis C virus, through blood transmission, medical transmission, sexual contact transmission, vertical transmission. Transmission by blood: HCV is mainly transmitted by blood, blood products or body fluids. In particular, intravenous drug use by sharing needles. Blood transmission can occur through the importation of blood or blood products contaminated with HCV, the use of needles and medical and cosmetic devices that are not strictly sterilized and contaminated with HCV. Shared razors and toothbrushes, tattoos and ear piercings are potential modes of transmission via blood. 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 a relatively greater risk of contracting hepatitis C. Vertical transmission: Pregnant women infected with hepatitis C virus have about a 5-10% chance of transmitting the virus to their newborn 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.