Rat-bite fever (RBF) is an 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. It is most commonly caused by rat bites and can also be transmitted throughout food or water that is contaminated with rat feces or urine. Symptoms of the streptobacillary form include recurrent fever, rash, and arthralgias. The spirillary form causes relapsing fever, rash, and regional lymphadenitis. This condition is diagnosed by detecting the bacteria in skin, blood, or lymph nodes.
The exact incidence in Mexico is unknown. S. moniliformis has been known to infect laboratory technicians and the poor. Children with rats as pets account for more than 50 percent of cases. Rat bite fever can be treated readily with antibiotics (penicillin or tetracyclines for 7-14 days), but untreated S. moniliformis infections are estimated to be fatal and may cause complications like infection of the brain or soft tissue, infection of the heart valves, inflammation of the parotid glands, the tendons and the heart lining.