Although rare, AE occasionally occurs in humans and dogs, when it happens, they develop a severe condition frequently culminating in liver failure.
Humans are accidental hosts
No epidemiological study has been conducted to assess the true incidence of this infection in North America,
They can act either as definitive hosts contracting intestinal Em infections and spreading the helminthic eggs through their faeces, but also as aberrant intermediate hosts, ingesting eggs from the environment or autoinfecting themselves during an intestinal infection, and developing canine Alveolar Echinococcosis (AE).
Humans also become accidental hosts and may develop Alveolar Echinococcosis with lethal outcomes if untreated, as they ingest the infective eggs in contaminated food or transmitted by their pets.
AE results in the formation of vesiculated tumor-like lesions within the livers of intermediate hosts, primarily rodents. Normally, definitive hosts (wild and domestic canids) are not receptive to infection via eggs ingestion, instead they typically host adult tapeworms in the small intestine and release eggs that will be shed into the environment through faeces. Although rare, AE occasionally occurs in humans and dogs, when it happens, they develop a severe condition frequently culminating in liver failure. Nevertheless, AE should always be treated in a promptly manner as it is a disease that may lead to lethal outcomes.
Veterinarians often struggle to diagnose AE in dogs, due to a lack of understanding of this disease and due to its perceived rarity, it is often not included on their list of differential diagnoses. Diagnosis usually is considered only when clear liver involvement is detected by medical imaging and subsequent histological and molecular examination of liver biopsies reveal AE. Although, shedding of eggs in feces can be detected through floatation techniques in canids acting as definitive hosts, this is not a diagnostic test for AE. Often by the time a diagnosis of AE is made the disease is too advanced to treat and mortality is high.