How common are human Eurytrema pancreaticum infections and where have they been reported?
Executive summary
Human infection with the pancreatic fluke Eurytrema pancreaticum is exceptionally uncommon and primarily reported as incidental, with only sporadic case reports and autopsy findings rather than evidence of ongoing, widespread human transmission [1] [2] [3]. By contrast, Eurytrema spp. are common parasites of ruminants across parts of Asia and South America, and human cases appear to be accidental, usually linked to ingestion of infected insects in regions where that occurs [1] [4] [5].
1. What “common” means here: livestock vs humans
Eurytrema pancreaticum is a well-documented and sometimes highly prevalent parasite of cattle, sheep and goats in many countries, with animal prevalences reported as high as regional endemic hotspots (China, Brazil and parts of Southeast and East Asia) and up to very high rates in local herds in those areas [4] [6] [7]. Those veterinary patterns do not translate into common human infection: the literature and reviews emphasize that human eurytremiasis is an accidental, low‑probability event compared with the parasite’s veterinary burden [1] [8].
2. What the case literature shows about human infections
The best‑documented human reports are individual incidental findings: a classic autopsy report described about 15 adult E. pancreaticum flukes in the pancreatic ducts of a 70‑year‑old woman in Fukuoka Prefecture, Japan (reported in American Journal of Tropical Medicine and Hygiene and indexed on PubMed) [3] [2]. Broad review papers and case compilations reference a handful of similar occasional human detections historically, but do not present evidence of sustained human transmission chains or sizeable case series [9] [1].
3. Where human cases have been reported or suspected
Most recorded human observations come from Asia, consistent with the parasite’s range in ruminants: Japan and China appear in the case literature, and reviews that map Eurytrema spp. discuss distributions across China, Indonesia, Malaysia, South Korea, Thailand and neighbouring regions for animal infections—human detections have been reported sporadically within that geographic envelope [4] [10] [11]. In Brazil and parts of South America the parasite is endemic in livestock and authors note incidental human reports or the potential for under‑detected cases, but clear, confirmed human case counts are minimal and not systematically recorded [12] [6] [7].
4. How people become infected and why human cases are rare
The life cycle requires two intermediate hosts—land snails and terrestrial arthropods such as grasshoppers—so human infection is presumed to occur mainly by ingesting infected insects (entomophagy) carrying metacercariae, an exposure route uncommon in most populations; reviews explicitly call human infections “accidental” and emphasize low zoonotic potential where insect consumption does not occur [13] [5] [1]. Experts cited in recent fact‑checks characterize human infection as a “rare event” and note an absence of reported cases in regions where eating grasshoppers or crickets is uncommon [14].
5. Limits, detection gaps and misinformation risks
Surveillance for human Eurytrema is scant and routine stool tests can miss infections, so reviewers acknowledge the theoretical possibility of under‑detection in endemic rural areas [12]. Nevertheless, the available literature does not support claims of widespread human infection; recent social‑media misinformation linking Eurytrema to common human diseases (for example diabetes) has been debunked and experts warn such narratives conflate rare incidental zoonoses with common non‑infectious conditions [14]. There is no reliable, population‑level incidence estimate in the sources consulted; therefore statements about exact frequency beyond “rare/accidental” cannot be made from the provided reporting [1] [12].