infections
Rat Bite Fever
Diagnosis of Rat Bite Fever
For streptobacillary rat-bite fever, culture of a sample of blood or joint fluid For spirillary rat-bite fever, examination of a sample of blood or infected tissue Doctors can often diagnose the type of rat-bite fever by looking for key differences in symptoms. For example, doctors look to see whether people have joint pain, which occurs in streptobacillary rat-bite fever, or look to see whether people have swollen lymph nodes, which occur in spirillary rat-bite fever. To confirm the diagnosis of streptobacillary rat-bite fever, doctors take a sample of blood or joint fluid and send it to a laboratory where bacteria, if present, can be grown (cultured) and analyzed. Occasionally, the sample is stained using special stains and examined under a microscope. Blood tests are sometimes helpful. To confirm the diagnosis of spirillary rat-bite fever, doctors take a sample of blood or tissue around the bite or from an infected lymph node. Spirillary bacteria can be identified when a sample is examined under microscope. These bacteria cannot be cultured. 