Emergence of alveolar echinococcosis in Canada: a warning for the USA

PURPOSE OF REVIEW: Locally acquired human alveolar echinococcosis has been rare in North America outside Alaska, yet recent Canadian observations indicate a meaningful increase and epidemiologic shift in North America. This review synthesizes data surrounding the recent spike in human alveolar echinococcosis cases in Canada. RECENT FINDINGS: Since 2013, an increasing number of alveolar echinococcosis cases have been identified in Canada with incidentally detected hepatic masses. Dog ownership and rural exposures feature prominently. Contributory factors include the new establishment of the European-like Echinococcus multilocularis (Em) haplotype in wildlife and domestic dogs (definitive hosts), high peri-urban coyote numbers and infection prevalence, and rising clinician awareness. Specific diagnosis relies primarily on histopathology, confirmed with serology and Nucleic Acid Amplification Test (NAAT). Heightened awareness amongst radiologists and pathologists plays a pivotal role in improving patient outcomes. Management includes multidisciplinary collaborations involving resection when feasible and long-term albendazole treatment. SUMMARY: Alveolar echinococcosis in Canada is an emerging infectious zoonotic disease and remains under-recognized. A high index of suspicion is required, particularly for patients thought to have liver cancer. Early recognition combined with Em-specific diagnostics leads to timely treatment that reduces morbidity and mortality. A One Health approach integrating human, veterinary, and wildlife health data is needed to improve understanding of this disease.