Case of Rat Bite Fever
Presentation : fever, chills , joint pains 3 days duration
Patient was bitten on the dorsum of the right hand by a seemingly dead squirrel 3 days prior to presentation . Patient was clearing his backyard in the company of family members when they chanced on a hole containing a rodent. They killed the rodent. Patient bent to pick the rodent but was to his surprise , bitten by the seemingly dead animal.
His acute illness was heralded by fever , rigors ,multiple joint pains and general malaise. 48hrs after the bite . He experienced bloody diarrhea (5 times prior to presentation), epistaxis, multiple joint , noticed multiple hemorrhagic blisters on his body M most of the blisters were on his upper and lower extremities and back. He reported to the polyclinic and was admitted for two days and refered to KATH
ill looking , pale , slightly jaundiced , febrile young man.
Temp 38deg, BP , pulse 120bpm , resp rate 20cpm
Respiratory , cardiovascular systems normal.
CNS grossly intact
Multiple painful haemorraghic blisters on upper and lower extremities, with few lesions on face , back and scrotum. Some of the lesions were ulcerated and were at various stages of healing. The scrotal lesions were still raw and needed attention. The ulcers on the plantar aspect of the feet made walking difficult for the patient.
Rat bite fever
blood for cultures and sensitivity, full blood count, electrolytes, lft , renal function test.
Admitted for bed rest
Intravenous fluids resuscitation
Transfusion of packed RBCs
Analgesics and antipyretics
Antibiotic therapy : caps doxycycline 100mg bd for three weeks
Care of ulcers were done with antibiotic cream and occlusive nonadhesive dressing
Literature review :
Rat bite fever is a severe acute febrile disease caused by the bacteria Streptobacillus moniliformis or Spirilum minus. The bacteria is found in the mucous secretions, urine and flesh of squirrels, rats, dogs , cats. The infection is transmitted through the bite , exposure to urine or consumption of meat of these animals infected by the bacteria. Domestic animals like cat and dogs become infected when they consume dead rodents
After an incubation of 2-10 days patient comes down with severe fever, chills, athralgia of multiple joints and headache. This is followed by multiple haemorragic bullae on the body. These later break down to produce painful ulcers.Symptoms will be different for every person and will be different depending on the type of rat bite fever that a person is infected with. The Streptobacillary organisms is associated with a relatively shorter incubation period of 2-10 days whilst the presentation associated with Spirillum sp infection may be delayed until 2 to 3 weeks . Spirillum sp is usually found in Africa whilst Streptobacillus is found in the USA. Infection associated with Spirillum sp causes painful lymphadenopathy
Bacteria can be cultered from the skin,joint fluid , blood or lymph nodes. Antibody tests may yield positive results. Other methods of diagnosis employs PCR. To diagnosis streptobacillary rat bite fever, blood or joint fluid is extracted and the organisms living in it are cultured. Diagnosis for spirillary rat bite fever is by direct visualization or culture of spirillum from blood smears or tissue from lesions or lymph nodes.
Valvular heart disease ,pericarditis, cerebral abscesses,
Dead rodents must not be handled and must be appropriately disposed off
Antiseptic solutions or soaps must be used to was off scratch marks sustained from suspect animals
Early presentation to hospital for treatment improves survival. Public health officers must be notified
The disease has 25% mortality but prognosis is good if antibiotics and supportive measures are instituted early
Dr Richard Ametih, Dr Steve Kpankpari (General surgery resident)