Rat Bite Fever (Haverhill fever)

Etiology:  Streptobacillus moniliformis is a Gram-negative pleomorphic rod.

Incidence:  The incidence of infection is rare in laboratory rats.

Transmission:  S. moniliformis is found in the saliva, ocular and nasal secretions.  It is spread through direct contact with or a bite from infected rats.

Clinical signs:  Rats carry S. moniliformis asymptomatically in the nasopharynx.

Diagnosis:  S. moniliformis can be diagnosed using culture, serology or PCR of a swab from the oral cavity.

Public Health Significance:  People infected with S. moniliformis develop irregular recurrent fever with lymphadenopathy, petechial hemorrhages, polyarthritis and endocarditis.