Clonorchiasis caused by Clonorchis sinensis and opisthorchiasis caused by Opisthorchis viverrini are prevalent in the Far East, including Vietnam. The causal relationship between the 2 liver flukes and cholangiocarcinoma (CCA) has been well documented. Cholangiocarcinoma, a rare tumor of bile ducts, usually occurs in the sixth-seventh decade of life. In the United States, 8000 people are diagnosed with CCA each year. US Vietnam Veterans, 5 decades after the end of the war, are being diagnosed with CCA. Although CCA is linked to several conditions, no study has been done to our knowledge linking C. sinensis or O. viverrini as the culprits for CCA diagnosis in Vietnam Veterans.
A pilot prospective epidemiological study was performed at the Northport Veterans Affairs Medical Center. We screened Vietnam Veterans for exposure to eating raw or undercooked fish from the rivers in Vietnam during their service. Serological testing was performed by the multiantigen enzyme-linked immunosorbent assay in Seoul National University of Medicine, South Korea.
Of the 97 Veterans screened, 50 met the inclusion criteria with 1 Veteran being diagnosed with CCA. Of the 50 Veterans, 24% tested positive for serum IgG antibodies to C. sinensis. Those who tested positive had no detectable liver fluke parasites by fecal examination.
Our study is the first to show evidence of exposure to liver flukes in US soldiers during their service in the Vietnam War. Further research is needed to examine the possible link of liver fluke infection and risk for developing CCA in Vietnam Veterans.
Vietnam veterans are concerned about exposure to liver f lukes during their service in the war and its possible link to cholangiocarcinoma. Some of them are being diagnosed with this rare tumor. No study has been done, to the authors’ knowledge, screening for liver f luke infection and its potential link to developing cholangiocarcinoma in Vietnam veterans. The authors performed a pilot study and found evidence of liver fluke infection in Vietnam veterans who had eaten raw freshwater fish.
From the *Division of Infectious Diseases, Veterans Affairs Medical Center, Northport;
†Division of Infectious Diseases, Stony Brook University School of Medicine, Stony Brook;
‡Nursing Service, Veterans Affairs Medical Center, Northport, NY; and
§Department of Parasitology and Tropical Medicine, Seoul National University of Medicine, Seoul, South Korea.
Correspondence to: George Psevdos, MD, Chief of Infectious Diseases, Veterans Affairs Medical Center, 79 Middleville Rd, Northport, NY 11768. E-mail: George.Psevdos@va.gov.
This study was supported by Research Cooperation of Long Island.
The authors have no conflicts of interest to disclose.
The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the United States government.