Etiology:  Multiple Helicobacter species including H. aurati, H. mesocrecetorum and H. cholecystus have been isolated from the affected hamsters.  Helicobacter are Gram-negative motile bacteria.

Incidence:  The incidence of disease is low.

Transmission:  The disease is transmitted via direct contact, fecal-oral and fomite contamination.

Clinical signs:  Affected adult hamsters display no clinical signs or gross lesions or may have chronic wasting with no diarrhea.

Pathology:  There are several disease manifestations depending on the species of Helicobacter.

The typhlitis associated with colonization with several Helicobacter spp. resembles inflammatory bowel disease in A/J mice, and is characterized by moderate mucosal hyperplasia with lymphoplasmacytic infiltrates (see figure A,).

The hepatic disease is associated with H. cholecystus infection has histopathological similarities to lymphocytic cholangiohepatitis in horses and cats. Lesions include lymphoplasmacytic infiltrates with bile duct hyperplasia, pericholangial fibrosis and inflammation (see figure B,). Helicobacter infection can also cause causecentrilobular pancreatitis.

The antral gastritis from H. aurati infection is similar to that caused by H. pylori in man.  The gastritis is a lymphoplasmacytic proliferative gastritis that can lead to mucosal dysplasia.

Diagnosis:  Histologic lesions are characteristic for Helicobacter infections. PCR assays have been developed for each of the hamster helicobacters.