IV. Hepatitis E HE

IV. Hepatitis E (HE)

Before the 1970s, medical professionals widely believed that blood transfusions were one of the causes of hepatitis A and hepatitis B. In 1968, Goldfied et al. observed that among patients with post-transfusion hepatitis (PTH), approximately 10% did not have hepatitis A or hepatitis B; these patients were carefully labeled as non-A, non-B hepatitis (NANBH). In November 1987, WHO classified NANBH into two categories: ET-NANBH, transmitted via the intestinal tract, and PT-NANBH, transmitted via blood transfusion. In 1989, at the International Conference on Liver Diseases held in Tokyo, Japan, the group previously known as ET-NANBH—those transmitted via the intestinal tract—was renamed hepatitis E (HE), while those previously known as PT-NANBH—those transmitted via blood transfusion—were reclassified as hepatitis C (HC). Hepatitis E virus (HEV) belongs to the Caliciviridae family and is a member of the third subfamily of RNA viruses. HEV is unstable in the environment; acidic conditions, high salt concentrations, and cold temperatures can inhibit HEV activity, while alkaline environments offer better stability. This disease is transmitted via water, hands, flies, and the digestive tract, with both clinical and subclinical forms serving as major sources of infection. The incubation period is usually 2–6 weeks, with onset occurring between the ages of 20 and 40, more frequently in males than females. Clinical cases often present with obvious symptoms, whereas subclinical cases tend to be asymptomatic. The main symptoms include loss of appetite, aversion to fatty foods, abdominal distension, abdominal pain, nausea and vomiting, diarrhea, and joint pain; severe cases may develop jaundice, skin itching, rashes, and pain in the liver region, though fever is uncommon. The disease typically lasts for 1–2 months, though the duration may increase in cases with jaundice. Diagnosis of HEV relies primarily on detecting HEV in feces, with detection rates reaching up to 100% in the 1–14 days prior to symptom onset. This disease is also self-limiting; like hepatitis A, it can resolve spontaneously after 6 weeks of illness. Unlike hepatitis A, HE does not lead to chronicity; once cured, patients develop lifelong immunity. However, a small number of patients may develop severe cases, particularly pregnant women, who may experience miscarriage or stillbirth. The mortality rate for HE is approximately 10%. The disease has been prevalent in East Africa, South Asia, and North America. Regional outbreaks have occurred in Beijing, Jilin, Inner Mongolia, Hebei, Shanghai, Hubei, Xinjiang, and other regions across China. Among these, Xinjiang experienced a large-scale outbreak from 1986 to 1988, with a total of 119,280 patients. Treatment for HE is similar to that for hepatitis A—supportive care, liver protection, and symptomatic treatment. Traditional Chinese medicine has proven highly effective, and its diagnostic approach still focuses on clearing excess energy from the Shaoyang meridian, balancing liver wood to overcome earth, and addressing internal heat. The primary treatment choice remains the Xiao Chai Hu Tang formula with additions.