Acute hepatitis E infection in a visitor to Louisiana.
Key Words: acute hepatitis, hepatitis E virus, travel medicine
Acute hepatitis E (HEV) infection is endemic in Asia, Africa, and Central America (1-5) and is becoming more frequent in Japan. (6) In the past few years, a number of cases have been reported in Americans returning from abroad as well as in visitors from endemic areas traveling to the United States. (7-12) We report a recent case of an African man visiting Louisiana and Mississippi. Although HEV antibody has been found in rats from Louisiana, (13) this is believed to be the first active human case reported in the state.
A 31-year-old man from Cameroon was visiting southern Mississippi for about 3 weeks before the sudden onset of nausea, vomiting, and abdominal and lower back pain. Upon physical examination, the patient was deeply jaundiced and had marked right upper quadrant and lower back tenderness. The metabolic panel and complete blood count were normal, but the total bilirubin was 20.4 mg/dL (<1.3 mg/dL), alanine aminotransferase was 2,899 U/L (<46 U/L), and aspartate aminotransferase was 2,815 U/L (<45 U/L). Except for his country of origin, he reported no risk factors for viral hepatitis. Hepatitis A (HAV) total antibody was positive, but the HAV IgM antibody was negative. Hepatitis B core total antibody was positive, whereas the core IgM antibody and surface antigen were negative. Hepatitis C antibody was negative. The ceruloplasmin was 35 mg/dL (16 to 35.6 mg/dL). There were undetectable serum levels of acetaminophen and ethanol, and the antinuclear antibody titer was less than 1:40. Abdominal ultrasound showed normal liver size and flow patterns within the hepatic veins, portal veins, and inferior vena cava. Liver biopsy revealed diffuse areas of inflammation with minimal iron deposits and without fibrosis. Supportive treatment was given, and the hospital course was uneventful, with a rapid improvement in both symptoms and liver enzymes. Given his country of origin, HEV was suspected and a serum sample was sent to the National Center for Infectious Diseases. HEV IgM antibody was positive, and on follow-up several weeks later the patient was asymptomatic with normal liver enzymes.
Hepatitis E is an icosahedral nonenveloped single-stranded RNA virus that is spread fecal-orally. Infections occur in endemic areas and sporadically in nonendemic areas. Epidemiology differs from HAV infection primarily by age group. Although both are spread fecal-orally, HAV typically occurs in children, whereas HEV patients tend to be older. This patient is typical in that there is evidence of past HAV infection, but HEV infection occurred in the adult. Epidemics have been associated with contaminated water supplies, (14) and sporadic cases may have animal intermediates. Although the reservoir is unknown and several animals have been linked to contact transmission, (15-18) person-to-person transmission is thought to be rare. (19) The incubation period has been reported to be as little as 2 weeks, with continued virus excretion in stool for up to 2 weeks after the onset of illness. The disease course is typically mild to moderate in severity and lasts only a few weeks. No evidence of chronic infection has been reported. (20,21) The overall case fatality rate is less than 3%, (22) with the main exception being pregnant women, in which mortality rates are as high as 20% during the third trimester. (23)
Although hepatitis E is endemic to many parts of the world and has been associated with large outbreaks, it has remained relatively uncommon in this country. Although the two most common genotypes are Asian/Burmese (genotype 1) and Mexican (genotype 2), at least one genotype (genotype 3) has been isolated that is unique to the United States, (24) suggesting that endemic infection in this country is possible.
With growing foreign travel and an ever-increasing number of cases reported nationally, the prevalence may begin to rise; therefore, hepatitis E infection should be considered more frequently in the differential diagnosis of acute hepatitis.
Prevention is the same for any enterically transmitted infection. This includes good hygiene, sanitary handling of food and water, and only eating cooked food. Immunoglobulin from endemic areas has not been shown to confer protection, (25) and supportive measures remain standard of care with therapy.
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James Edward Walker, Jr., MD, PHD, Todd Martin Brown, MD, Thomas Lanier Hagood, MD, and William Morgan Cassidy, MD
From the Department of Internal Medicine, Louisiana State University Health Sciences Center, Earl K. Long Memorial Hospital, 5825 Airline Highway, Baton Rouge, LA.
Reprint requests to Dr. William M. Cassidy, Earl K. Long Memorial Hospital, 5825 Airline Highway, Baton Rouge, LA 70805. Email: firstname.lastname@example.org
Accepted November 22, 2004.
RELATED ARTICLE: Key Points
* Hepatitis E virus infection is usually benign and self-limited.
* There is a higher fatality rate in pregnant women.
* Hepatitis E virus should be considered in the differential diagnosis of acute viral hepatitis with negative serology for hepatitis A, B, and C viruses.
* Person-to-person transmission is rare.