Causes and risk factors
Rat-bite fever can be caused by two bacteria – Streptobacillus moniliformis and Spirillum minus. Disease occurs after being bitten or scratched by the infected rodent, handling infected rodent, or consuming food or drink contaminated with the bacteria. People at increased risk of getting a rat bite infection are those who work in labs with rats, those with pets as rats, people living in rat infested areas, or people from low socioeconomic group.
Clinical presentation
The symptoms caused by the two bacteria are different. Symptoms due to infection with Streptobacillus moniliformis develop 3-10 days after the exposure to the bacteria. It includes fever with chills, vomiting, headache, muscle pain; swollen, red and painful joints. Both large and smaller joints are involved. It is called as migratory polyarthralgia. There is synovitis, nonsuppurative arthritis. There is maculopapular, petechial, or purpuric rash on hands and feet which is flat, red, with small bumps. Symptoms due to infection with Spirillum minus develop 7-21 days after the exposure to the bacteria. It includes fever and chills, headache, development of an ulcer at the bite wound, swelling of the lymph nodes, a skin rash characterised by reddish purple plaques or blood filled vesicles on hands and feet.
Investigation
Medical history by the patient and clinical examination by the doctor helps in diagnosis. Samples to identify bacteria can be taken from blood, sputum, or by lymph node aspirate. Blood antibody test, PCR is recommended.
Treatment
Treatment for rat bite due to any of the bacteria consists of antibiotic therapy for 7-10 days. Analgesic and antipyretic drugs may be required. Following measures can help in preventing rat-bite fever like avoiding contact with rodents, use of pasteurized milk, drinking water from safe source, wearing protective gloves while handling rodents, or cleaning their cages.
Other Modes of treatment
The other modes of treatment can also be effective in treating rat bite fever. Homoeopathy is a science which deals with individualization and considers a person in a holistic way. This science can be helpful in combating the symptoms. Similarly, the Ayurvedic system of medicine which uses herbal medicines and synthetic derivates is also found to be effective in treating rat bite fever.
Facts and figures
Risk of getting infected after a rat bite is 10%. Rat bite fever has 13% mortality rate if left untreated.
