The Emerging Hepatitis E

Hepatitis E virus, courtesy wikimedia commons

Hepatitis E virus, courtesy wikimedia commons

Had a good morning report recently about a young healthy woman with nausea/vomiting, jaundice, LFTs in the 600s, and a tender RUQ after having returned from a vacation in China. Patient’s sister had similar symptoms but they had resolved.

Turns out it was probably Hepatitis E, as the patient had been vaccinated against A due to her prior world travels with both the initial and repeat vaccines. Hep A and Hep E are the classic acute hepatitis causers, with A being the much more common culprit. But with the increased vaccination for Hepatitis A, E is becoming a larger player — although you probably have to order it separately if your lab has an “Acute Hepatitis Panel” like ours does. (Also classically, the only other thing we’re taught about Hepatitis E is that it has a much higher morbidity and mortality in pregnant women.)

The story of its discovery is, in a word, foul. Similar to how Barry Marshall ingested H. pylori and a week later developed gastritis symptoms, Hepatitis E’s self-experimenter was a Russian virologist named Mikhail Balayan. Dr. Balayan, in the name of science (I hope), “ingested a fecal suspension from Asian patients and collected his feces during the incubation period.” Eww, eww, eww eww eww.

Several important differences: HepE has an overall higher mortality (1-4%) compared to HepA (0.1-2%), and like mentioned earlier, much higher (20%) in pregnancy. Scary. Also a bit longer incubation period than A (40 vs. 30 days), and actually has a dose-dependent severity curve: the more poop you eat, the sicker you get.

Hepatitis E in the US, courtesy pubmed article

Hepatitis E in the US, courtesy pubmed article

And if you’re working abroad, or have patients from abroad, Hep E is probably the most common cause of acute hepatitis in Asia, the Middle East, and Africa. It probably has reservoirs in several animal species — especially pigs — such that if you look at blood donors in swine-raising US states (see left), you’ll see more people have positive anti-HepE than anti-HepA.

The good news: a vaccine is being developed. The bad news: it may not go anywhere, as it probably couldn’t make any money since Hepatitis E affects mostly poor countries. (Time to donate to OneWorld Health.)

Thanks to the great review article, Hepatitis E: An emerging awareness of an old disease by Drs. Purcell and Emerson in the 2008 Journal of Hepatology for the information.

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  1. #1 by Sam Ko - September 7th, 2009 at 18:05

    Also, Hep E is particularly dangerous to vampires.

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