Streptobacillosis

Rat-bite fever is an acute disease from rat/rodent bites; the Streptobacillus moniliformis form presents as irregular fever, often with arthritis and rash.

Common Symptoms

Chills; ecchymosis; maculopapular rash; back pain

Causes and Pathogenesis

Streptobacillary rat-bite fever is caused by Streptobacillus moniliformis; Levaditi first described it in lab workers in 1925. Place and Sutton reported a 1926 outbreak from contaminated milk (Haverhill fever, epidemic erythema arthriticum); Parker and Hulson isolated the organism. It is a highly pleomorphic, aerobic, non-motile, non-spore-forming, non-encapsulated, heat-labile, Gram-negative bacillus; in suitable media it is short rods 2-4 µm in chains or long filaments 15-150 µm with moniliform swellings; aerobic/facultatively anaerobic, requiring blood/serum/ascites, growing slowly in 2-7 days, enhanced by 5-10% CO2 at 37°C; white fuzzy colonies 1-2 mm. It readily forms L-forms (lacking cell walls, thus penicillin-insensitive), which complicate treatment; blood cultures may remain positive for 10 days. It is weak environmentally, killed at 55°C/30 min, sensitive to disinfectants. Pathogenesis (from rare autopsies): visceral congestion, edema, mononuclear/plasma cell infiltration; ulcerative endocarditis, hepatic/splenic/renal infarcts, interstitial pneumonia, myocarditis, nephritis, adrenalitis, and arthritis.

Treatment

Drug therapy, supportive therapy

Preventive Measures

Rat control is the most important measure; prevent bites; lab workers should wear gloves; if bitten, besides local treatment, give prophylactic penicillin immediately.

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.