Rat-bite fever

Rat-bite fever is an acute, febrile human illness caused by bacteria transmitted by rodents, rats in most cases, which is passed from rodent to human via the rodent's urine or mucous secretions.

Causes

Two types of gram-negative facultatively anaerobic bacteria can cause the infection.

pirillosis

Rat-bite fever transmitted by the gram-negative spirochaete "Spirillum minus" is more rare, and is found most often in Asia. In Japan the disease is called Sodoku. Symptoms do not manifest for two to four weeks after exposure to the organism, and the wound through which it entered exhibits slow healing and marked inflammation. The fever lasts longer and is recurring, for months in some cases. Joint pain and gastrointestinal symptoms are less severe or are absent. Penicillin is the most common treatment.

treptobacillosis

The Streptobacillosis form of rat-bite fever is known by the alternative names Haverhill Fever and epidemic arthritic erythema. It is a severe disease caused by Streptobacillus moniliformis, transmitted either by rat bite or ingestion of contaminated products (Haverhill fever). After an incubation period of around 10 days, Haverhill fever begins with high prostrating fevers, rigors, headache and polyarthralgia. Soon an exanthem appears, either maculopapular or petechial and arthritis of large joints can be seen. The organism can be cultivated in blood or articular fluid. The disease can be fatal if untreated in 10% of cases due to malignant endocarditis, meningoencephalitis or septic shock. Treatment is with penicillin or tetracycline.

Treatment

Responds to penicillin antibiotics or where allergic to this erythromycin or tetracyclines for respectively streptobacillary or spirillary infections.

Prevention

Whilst obviously preventable by staying away from rodents, otherwise hands and face should be washed after contact and any scratches both cleaned and antiseptics applied.

External links

* [http://www.chclibrary.org/micromed/00063170.html Rat-bite fever description]
* [http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5351a2.htm Case report of fatal incidence in the USA]
* [http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=/healthatoz/Atoz/ency/rat-bite_fever.jsp Rat-bite fever (healthAtoZ.com)]