Rat-bite fever (RBF) is an acute infectious disease that can be caused by two different bacteria. Streptobacillary RBF is caused by Streptobacillus moniliformis in North America while spirillary RBF or sodoku is caused by Spirillum minus in Asia. People usually get the disease from infected rodents or consumption of contaminated food or water. Rat bite fever is transmitted to people in around 10% of rat bites. Symptoms like fever, rash and myalgia usually occur 3-10 days after exposure to an infected rodent, but can be delayed as long as 3 weeks. RBF is confrimed by bacterial culture tests.
In Singapore, RBF is usually due to S. minus. The spirillary form causes relapsing fever, rash, and regional lymphadenitis. People who keep rats as pets, as well as laboratory technicians and pet shop employees working with rats, are at increased risk. Untreated RBF may cause complications like infection of the brain or soft tissue, infection of the heart valves, inflammation of the salivary glands and endocarditis. Rat-bite fever is treated with antibiotics (penicillin or tetracyclines for 7-14 days). Erythromycin might be administered to people who are allergic to penicillin.