A 24-year old man presented himself to the emergency ward with complaints of 
fever, nausea, headache, muscle ache and chest pain. Two weeks before 
presentation he had been bitten by a pet rat. We determined that he had 
bacteraemia caused by a Streptobacillus moniliformis infection, which led to the 
development of an illness called rat bite fever. S. moniliformis is a 
pleomorphic gram-negative rod-shaped bacterium that is considered part of the 
normal nasopharyngeal flora in rats. It is the cause of two similar illnesses: 
rat bite fever and Haverhill fever. Clinicians should consider these infections 
in the work-up of unexplained fever or sepsis, certainly in the presence of 
known exposure to rats. Treatment consists of antibiotics.