should be washed after contact and any scratches both cleaned and antiseptics applied. The effect of chemoprophylaxis following rodent bites or scratches on the disease is unknown. No vaccines are available for these diseases. Improved conditions to minimize rodent contact with humans are the best preventive measures. Animal handlers, laboratory workers, and sanitation and sewer workers must take special precautions against exposure. Wild rodents, dead or alive, should not be touched and pets must not be allowed to ingest rodents. Those living in the inner cities where overcrowding and poor sanitation cause rodent problems are at risk from the disease. Half of all cases reported are children under 12 living in these conditions. Treatment Treatment with antibiotics is the same for both types of infection. The condition responds to penicillin, and where allergies to it occur, erythromycin or tetracyclines are used. Prognosis When proper treatment is provided for patients with rat-bite fever, the prognosis is positive. Without treatment, the infection usually resolves on its own, although it may take up to a year to do so. A particular strain of rat-bite fever in the United States can progress and cause serious complications that can be potentially fatal. 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 rat's 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