Both spirillary and streptobacillary rat-bite fever have a few individual symptoms, although most symptoms are shared. Streptobacillosis is most commonly found in the United States and spirillary rat-bite fever is generally diagnosed in Africa. Rat-bite symptoms are visually seen in most cases and include inflammation around the open sore. A rash can also spread around the area and appear red or purple. Other symptoms associated with streptobacillary rat-bite fever include chills, fever, vomiting, headaches, and muscle aches. Joints can also become painfully swollen and pain can be experienced in the back. Skin irritations such as ulcers or inflammation can develop on the hands and feet. Wounds heal slowly, so symptoms possibly come and go over the course of a few months. Symptoms associated with spirillary rat-bite fever include issues with the lymph nodes, which often swell or become inflamed as a reaction to the infection. The most common locations of lymph node swelling are in the neck, groin, and underarm. Symptoms generally appear within two to ten days of exposure to the infected animal. It begins with the fever and progresses to the rash on the hands and feet within two to four days. The rash appears all over the body with this form but rarely causes joint pain. Causes
Two types of Gram-negative, facultatively anaerobic bacteria can cause the infection. Spirillosis
Rat-bite fever transmitted by the Gram-negative coiled rod Spirillum minus (also known as Spirillum minor) is rarer, and is found most often in Asia. In Japan, the disease is called sodoku.
Before antibiotics were used, many cases resulted in death. If left untreated, streptobacillary rat-bite fever can result in infection in the lining of the heart, covering over the spinal cord and brain, or in the lungs. Any tissue or organ throughout the body may develop an abscess. Epidemiology
Rat-bite fever (RBF) is a zoonotic disease. It can be directly transmitted by rats, gerbils, and mice (the vectors) to humans by either a bite or scratch or it can be passed from rodent to rodent. The causative bacterial agent of RBF has also been observed in squirrels, ferrets, dogs, and pigs. The most common reservoir of the disease is rats because nearly all domestic and wild rats are colonized by the causative bacterial agent, Streptobacillus moniliformis. Most notably, the Black rat (Rattus rattus) and the Norwegian rat (Rattus norvegicus) are recognized as potential reservoirs due to their common use as laboratory animals or kept as pets. The bacteria Streptobacillus moniliformis is found in the rats upper respiratory tract. Most rats harbor the disease asymptomatically, and signs and symptoms rarely develop. It is estimated that 1 in 10 bites from a rat will result in developing RBF. A person is also at risk of acquiring the bacteria through touching contaminated surfaces with an open wound or mucous membrane or ingestion of contaminated water or food by rodent feces, though this is referred to as Haverhill Fever (epidemic arthritic erythema). RBF is not a contagious disease.