A 23 year old male patient presented with abrupt onset of fever, headache and myalgia followed by petechial rash and ahritis 2 to 10 days after exposure to a rat bite. He is diagnosed with Rat-bite fever. What is the causative organism of this disease?

Streptobacillus moniliformis is a gram negative, non motile, non capsulated and highly pleomorphic sho bacillus. They causes rat - bite fever. In man, organism enter through the wound caused by bite of rat. When infection is acquired by ingestion of food, milk/ water contaminated with excreta of rat it is known as Haverhill fever or Erythema ahriticumepidemicum. This is characterised by fever, polyahritis and petechial rash. Good to know: Klebsiella granulomatis causes donovanosis. Eikenella corrodens causes oppounistic infections. Erysipelothrix rhusiopathiae causes erysipelas. Ref :Ananthanarayanan & Paniker's ed- 8th pg 39.