These are a few of the specific rodent-borne illnesses that might be contracted through work with lab rodents.  As indicated, prompt medical treatment is necessary if one of these diseases is suspected.  Be sure to advise your health care practitioner of your work with lab rodents. 

RAT BITE FEVER (RBF).…refers to two similar systemic diseases caused by different anaerobic bacteria: Streptobacillary RBF is caused by Streptobacillus moniliformis (gram neg. rod) and Spirillary RBF caused by Spirillium minus (gram negative spiral).   These organisms can be found in the nasal and oro-pharyngeal secretions of healthy laboratory rats (10% to 100%) and in the wild rodent population 50% to 100%).   Mice, squirrels, weasels, gerbils dogs and cats may also transmit the disease by bites or scratches.  Most cases result from bites or scratches by wild or lab rats, but can also be introduced by direct contact with secretions or blood of an infected rodent, as well as ingestion of food or water contaminated by feces.  Symptoms in Streptobacillary RBF:  Usually characterized by prompt healing of wound with minimal local irritation and minimal lymphadenitis.  Onset (usually 2-10 days) of relapsing fever, joint pain and swelling, followed by rash on extremities, soles, and palms.  Headache, nausea, vomiting may also be present.  Recovery is usually spontaneous within 2 weeks, but further complications may occur, and 13% of untreated cases are fatal.  Symptoms in Spirallary RBF:  usually characterized by an ulceration of the bite wound with regional adenopathy and joint pain.  Prevention is through reduction of animal bite risk, and immediate first aid treatment for all animal bites (wounds should be scrubbed vigorously with 1% povidone-iodine scrub for 10 minutes).  Promptly seek medical attention regarding need for prophylactic antibiotics and tetanus/diphtheria booster (Td).   

LYMPHOCYTIC CHORIOMENINGITIS VIRUS (LCMV)is important as a natural infection of laboratory animals.  The natural reservoir is the domestic mouse (M. musculus); infected females transmit infection to the offspring, which become asymptomatic persistent viral shedders.  Infection also occurs in mouse and hamster colonies and in transplantable tumor lines.  LCMV is widely distributed among wild mice throughout most of the world and presents a zoonotic hazard.  Human cases have occurred in houses where infected mice were caught.  Athymic, severe-combined-immunodeficiency  and other immunodeficient mice can pose a special risk of harboring chronic infections, and can present a hazard to laboratory personnel.

The virus is transmitted to humans by parenteral inoculation, contamination of mucous membranes or broken skin with infectious tissues or fluids (blood, cerebrospinal fluid, saliva, nasal secretions, urine, feces, semen, and milk) and from infectious aerosols.  Bedding material and other fomites contaminated by LCMV are potential sources of infection, as are infected ectoparasites.  The virus can be transmitted to the fetus in  pregnancy:  Human-to-human transmission has not been documented.

SYMPTOMS:  The incubation period is 1-3 weeks. Typical LCMV infection in adults is biphasic, with an influenza-like illness characterized by fever, headaches, malaise, myalgias, and anorexia nausea, vomiting, pharyngitis, cough, and adenopathy followed by a pause and a second phase of CNS disease.  However, CNS symptoms may appear without any prodrome or may never develop.  In severe cases of the disease, patients might develop a maculopapular rash, lymphadenopathy, and, rarely, orchitis, arthritis, and epicarditis. Meningitis and meningoencephalitis are the most frequent neurologic manifestations of the disease, although myelitis, Guillain-Barr -syndrome, and sensorineural deafness have been reported .  Very few patients progress to aseptic meningitis, which is characterized by a very high lymphocyte count in the cerebrospinal fluid.  CNS involvement has resulted in several deaths. Intrauterine LCMV infection has resulted in fetal or neonatal death, as well as hydrocephalus and chorioretinitis in infants.  Prevention of this disease in the laboratory is achieved through the periodic serological surveillance of new animals that have inadequate disease profiles and of resident animal colonies at risk, and through screening for the presence of  LCMV in all tumors and cell lines intended for animal passage.  Laboratory work with feral mice should be performed utilizing appropriate zoonotic precautions and guidelines.   Appropriate engineering controls, work practices and procedures, personal protective devices, and training are all essential in preventing spread of disease to humans and into colonies of immunosuppressed animals.