Streptobacillus moniliformis is a species of bacteria.

Rat bite fever is caused by either Streptobacillus moniliformis or Spirillum minor.

It is a severe disease caused by Streptobacillus moniliformis, transmitted either by rat bite or ingestion of contaminated products (Haverhill fever).

Haverhill Fever (or epidemic arthritic erythema) is a form of "rat-bite fever" caused by the bacterium Streptobacillus moniliformis, an organism common in rats and mice.

There are a number of parasites that are common to rats, and these include Streptococcus pneumoniae, Corynebacterium kutsheri, Bacillus piliformis, Pasteurella pneumotropica, and Streptobacillus moniliformis, to name a few.