Hepatitis C virus is a non-early non-hepatitis B specific causative factor. Currently, post-transfusion hepatitis, chronic viral hepatitis, and chronic alcoholism have become the main causes of cirrhosis, advanced liver disease, and hepatocellular carcinoma Although HCV transmission is less acute than HBV and is recessive, the death statistics for hepatitis C are twice as high as those for hepatitis B patients. Prevention and early diagnosis and treatment of hepatitis C are of great importance in the perinatal period.
I. Virology
HCV is a single-stranded RNA virus. The structure of HCV consists of a nucleoprotein shell, membrane proteins and non-structural proteins. simmond proposed that there are 6 major genotypes and 11 subtypes of HCV (1a-c, 2a-c, 3a, 3b, 4a, 5a, 6a). the recognition of HCV subtypes is helpful to trace the root cause of HCV and determine the transmission route.
II. Epidemiology
In Guanguo, 20-40% of hepatitis cases are hepatitis C, and 90% of post-transfusion hepatitis is hepatitis C. HCV is transmitted mainly through contaminated blood products and venipuncture needles. HCBRNA can be detected in saliva, urine, semen, ascites, menstrual blood and breast milk, and is less commonly transmitted by Ren. HCVRNA cannot be detected from vaginal secretions. During sexual transmission, concomitant HIV infection promotes the transmission level of HCV, and home contact transmission of HCV is rare. Hepatitis C is more prevalent in Asian countries. Re-use of needles, needle-stick internships and related technical operations account for the majority of cases. There is little evidence of HCV transmission from daily social contact and sharing of household utensils.
Risk factors for HCV transmission are blood transfusion, venipuncture, HIV-positive patients, body piercing, piercing, organ transplant recipients, sexual partners with hermaphroditic men, cocaine abuse, prisoners, commercial workers, hepatitis B patients, HCV-exposed occupations, history of STDs, absence of biparental care, and hemodialysis patients.
III. Clinical manifestations
Acute HCV infection occurs after an incubation period of 30-60 days, but is asymptomatic in 75% of cases. If symptoms, mostly combined with hepatitis IV or B, there may be jaundice, fever, abdominal pain, fatigue and discomfort, hepatomegaly and elevated serum aminotransferase (AST), peak serum AST level is lower than that of hepatitis IV and B patients, but 75% of patients last about 12 months and fluctuate with time, liver failure and fulminant hepatitis are rarer. HCV transmission is more persistent and can lead to the development of chronic liver disease, most clinical symptoms The majority of clinical symptoms are not obvious.
HCV is more persistent, and some patients have symptoms such as weak will and blurred vision.
IV. Acute infection
After acute infection, serum HCV RNA can be detected within 5-7 days, and it takes 4 months to disappear in vivo. After chronic infection, HCV RNA persists in a small number of patients. After 8-12 weeks of infection, HCV antibodies are readily detectable and present in vivo for about 6 months, and antibodies can persist for several years, but cannot be used to distinguish acute infection from previous infection.
Because the enzyme-linked immunosorbent assay (ELISA) detects antibodies from antigens, the C100C3 antigen is in the NSC3 region of the genome and ESISA lacks sensitivity to offspring, but is significant for early diagnosis of HCV. Because ESISA is non-specific, diagnosis must rely on the complementary test recombinant immunosorbent assay (RIBA) antibodies. positive RIBA results are more closely associated with the presence of HCV RNA.
A positive HCV test by PCR is the best marker for viremia, and the patient can be monitored during treatment by applying PCR to monitor HCV RNA. False positive results can occur with contaminated specimens, specimens collected with heparin, and specimens stored at room temperature for too long.
Liver biopsy is rarely performed in patients with acute hepatitis, but it can guide the treatment of patients suspected of having chronic hepatitis C. The extent of the disease and its prognosis can be estimated by liver biopsy. Liver biopsy is not recommended during pregnancy because the amount of circulating blood in the liver is stingy during pregnancy and bleeding is easy after biopsy.
V. Treatment
Alpha-interferon has been successfully used to treat patients with chronic hepatitis C, but it is prone to relapse and is administered in colorful doses of 3 million/time, 3 times/week, subcutaneously for 6 months. The efficacy and prognosis are evaluated by testing HCV RNA after treatment. A longer duration of treatment has been suggested, with an initial treatment of 12 months being preferred.
Alpha-interferon enhances cell-mediated immune response and impedes viral protein synthesis. Side effects include flu-like symptoms such as fatigue, myalgia and chills; neurological symptoms such as irritability, depression and lack of energy; bone marrow suppression and autoantibody production.
Patients with progressive liver damage are not sensitive to alpha-interferon and liver transplantation should be considered. The application of alpha-interferon is not advocated during pregnancy, but when women have high levels of serum ALT during pregnancy, alpha-interferon therapy should be given after delivery.
VI. Impact of HCV on the perinatal period
Most patients with hepatitis C during pregnancy are asymptomatic, and less than 10% of patients have elevated ALT. The incidence of perinatal HCV infection in HIV-negative women with perinatal hepatitis C ranges from 0% to 33%, with an average of 5.2%; in HIV-positive patients, the incidence of vertical transmission of HCV ranges from 8.9% to 70.3%, with an average of 23.4%. Ohto et al. found that the risk rate of vertical transmission of HCV was related to the concentration of maternal virus, so the patient’s viremia needs to be actively managed. Mother-to-child HCV transmission is not associated with gestational age, time of rupture of membranes, mode of delivery, application of scalp electrodes to the infant, or chorioamnionitis.
Trace amounts of HCV RNA can be detected in the milk of HCVemic patients, and there is no data to prove that HCV can be transmitted through breastfeeding.
Reasons.
(1) trace amounts of HCV RNA in breast milk are not sufficient to infect the newborn.
(2) Trace amounts of HCV are inactivated by gastric acid.
(3) Oral mucosa effectively prevents HCV infection. Therefore, breastfeeding is not contraindicated in patients with hepatitis C.
The most appropriate time to screen newborns for hepatitis C is 6–12 months for the HCV RNA test and 18–24 months for the application of RIBA for hepatitis C antibodies. The current application of immunoglobulin prophylaxis for neonatal hepatitis C is not indicated as it does not reduce the chance of vertical transmission. there is a high mutation and variability of HCV and a vaccine for hepatitis C has not been completed. Most newborns retain viremia and convert to chronic hepatitis.
VII. Management of hepatitis C in the perinatal period
To reduce mortality and morbidity, patients with hepatitis C in the perinatal period should be managed systematically. Children of asymptomatic women with chronic hepatitis should be diagnosed with hepatitis C early so that A-interferon therapy can be given to prevent serious complications. Patients who test positive for hepatitis by ELISA are further confirmed by RIBA. Serum ALT levels can distinguish between past acute infection and chronic disease. If the ALT level is normal, the infection is within 6 months. patients with elevated ALT undergo liver biopsy or postpartum A–interferon therapy.
Co-infection with HIV, improper medication use, and alcohol consumption can aggravate the condition of hepatitis C patients. Seronegative hepatitis C patients should be vaccinated against hepatitis A and B. HCV-positive patients should not donate blood or organs. Enhancing sexual safety education can promote a healthy sex life. If there are HCV-positive patients in the family, razors, toothbrushes and nail clippers should be separated, and open wounds should be bandaged promptly. Isolation and separation of living utensils and meals are unnecessary.
Perform HCV RNA testing in pregnant women to let patients know that there are no measures to prevent HCV transmission. There is a 23% chance of transmission to the offspring if the patient has HCV RNA (+) and HIV (-). Ending the pregnancy by cesarean section reduces the chance of mother-to-child transmission, and breastfeeding is safe. If the mother is HCV-naemic, the newborn should be tested for HCV RNA until 1 week of age.