Liver fluke infection and bile duct cancer
Did you eat raw or undercooked fish while in Vietnam? Vietnam Veterans who did during service in Southeast Asia may have been exposed to tiny parasites called liver flukes. Rarely, these liver fluke infections can lead to a cancer of the bile ducts called cholangiocarcinoma. Liver flukes can live up to 30 years in a human’s bile ducts. Bile ducts are part of a network that carries the bile produced in the liver to be stored in the gall bladder and then emptied into the small intestine to help us absorb fats and some vitamins into our bodies.
There are many other risk factors for bile duct cancer besides liver fluke infection, including diabetes, obesity, and past hepatitis B or C infection, and the rate of occurrence increases dramatically with age.
Some Veterans may be aware of a study published in 2018 that reported that past liver fluke infections may be more common in Vietnam Veterans. The study was criticized for a number of methodological errors that contradicted the conclusions.
Fortunately, analyses of VA health care data have not identified increased rates of cholangiocarcinoma in Vietnam Veteran patients. VA’s Vietnam Era Health Retrospective Observational Study (VE-HEROeS), which compares the health of Vietnam Veterans, non-deployed Vietnam-era Veterans, and the U.S. public, is planning to conduct an analysis on cholangiocarcinoma to help characterize the occurrence of this disease in Vietnam Veterans compared to other populations. Additionally, researchers at the Department of Defense are planning to study liver flukes in Veterans returning from recent conflicts in Southeast Asia using more sophisticated laboratory techniques to measure possible exposure more accurately to these parasites.
Please see the website at https://www.publichealth.va.gov/exposures/infectious-diseases/cholangiocarcinoma.asp for more information.