HEV incubates for 15 to 60 days with a mean incubation period of 40 days. The severity of signs and symptoms ranges from subclinical, asymptomatic infection to fulminant liver disease. Similar to other forms of viral hepatitis, the majority of patients present with jaundice, anorexia, hepatomegaly, malaise, and dark urine. Approximately 50% of cases involve abdominal pain, nausea, vomiting, and fever (Knipe et al. 3056-7). Arthralgia, diarrhea, pruritus, and urticarial rash are less common. In the majority of cases, the disease is self-limiting and does not result in chronic infection or heptocellular carcinoma.
Diagnosis:
Hepatitis E infection cannot be distinguished from other cases of viral hepatitis based on symptomalogy alone. Definite diagnosis utilizes serologic tests, which are not widely distributed. HEV should be suspected in outbreaks of water-borne hepatitis in developing nations, particularly if the clinical presentation is more severe among pregnant women. Physicians in developed nations should include hepatitis E in the differential diagnosis of individuals who have recently traveled to endemic regions.
Infection occurs in all age groups, but 15 to 40 year olds have the highest rate of clinically apparent disease. HEV accounts for 50% of viral hepatitis among reproductive-age adults in the third world (Chibber 2). Although overall mortality varies from 1-3%, the case-fatality rate increases to 15-20% in pregnant women. Complications include acute maternal hepatitis, fetal wastage, and intrauterine infection, causing perinatal morbidity and mortality.
Methods of diagnosis:
- Enzyme immunoassay (EIA)
- Western blot
- Immunofluorescent antibody blocking assay
- RT-PCR