There are many viral, bacterial, fungal and parasitic diseases of animals that are mildly or severely infective to humans. A few of the most common zoonotic diseases found in the laboratory animal environment are reviewed here. Many laboratory animals are now purchased from commercial vendors who have extensive health prevention programs in place, therefore the risk of exposure has been reduced. The proper use of personal protective equipment (e.g. labcoats, gloves, masks, bonnets, shoe covers) and appropriate training in handling and restraint of laboratory animals can also decrease the risk of acquiring infections by research personnel.
Herpes B Virus
- A viral disease occurs in Macaca sp. (e.g. rhesus, bonnet, cynomolgus monkeys) that is much like Herpes simplex in humans (causing fever blisters). If untreated, Herpes B virus is usually fatal in humans. Treatment with acyclovir® or gancyclovir® has prevented the disease to date but people have to stay on the drug indefinitely. Very few clinical cases are reported.
- Hosts – macaca sp.
- Common route of infection – bite or scratch from an infected monkey (monkey shows no sign of illness). Also scratches from contaminated equipment.
- Vaccine available – None
- Important preventative measures – Wear protective clothing (e.g. masks, gloves, head covers, face shield, lab coats, shoe covers) when working with macaques. Be cautious working around these species to avoid bites, scratches or injury from equipment.
- A fungal disease.
- Hosts – A variety of species carry histoplasmosis. The agent is found in the dropping of chickens and other birds. Soil may be contaminated with infected droppings.
- Biologicals – none
- Important preventive measures – wear a face mask and protective gloves when working with these animals since infection is usually from inhaling organisms. Organisms are aerosolized from dried infected droppings.
Lymphocytic choriomeningitis (LCM)
- A viral disease that can be fatal. No specific treatment is available.
- Hosts – LCM is most common in wild mice and rats. The agent has been reported in research animal facilities.
- Most common route of infection – infected urine. The agent has also been transmitted through cell culture.
- Vaccine available – None.
- Important preventative measures – wear a face mask and protective gloves when working with these animals.
- A rickettsial disease caused by Coxiella burnetti.
- Host – can be found in sheep, goats, cattle, cats, dogs and domestic fowl. The agent is most commonly found in sheep, with pregnant sheep being the greatest hazard. Can be fatal in humans who have valvular heart disease. Animals normally are asymptomatic.
- Most common route of infection – the agent is shed in the urine, feces, milk, and in amniotic fluids. Inhalation of infectious aerosols is the most common route of infection.
- Diagnostic testing of animals – titer negative animals may be infected and shed organisms.
- Important preventative measures – wear protective clothing including mask and gloves when handling sheep or sheep by-products such as placenta, amniotic fluids or stillborn lambs. Personnel with valvular heart disease should limit exposure or have no contact with sheep.
- A viral disease that is usually fatal if not treated properly and promptly prior to the onset of symptoms.
- Hosts – dogs, cats and bats account for the largest percentage of human exposures. All warm-blooded animals are susceptible.
- Route of infection – bite wounds.
- Vaccine available – vaccines are available for the prevention of rabies for dogs, cats and humans. The DLAR orders only USDA Class A dogs and cats, which are vaccinated against rabies before arrival at the facility.
Salmonellosis and Shigellosis
- Bacterial diseases causing primarily gastrointestinal signs.
- Hosts – a variety of species, but poultry and non-human primates are the most common carriers.
- Most common route of infection – oral.
- Bacterin available – none.
- Important preventive measures – personnel should wear disposable gloves and/or wash hands frequently when working with these species.
- A mycobacterial disease.
- Hosts – reported in most mammals and a variety of birds, including pigeons and chickens. Aquatic species can transmit a cutaneous form of the disease.
- Most common route of infection – inhalation of infected air since the most common site of infection is the lung. TB can also infect the skin, bones, intestines and any other organ system, therefore all excretory products can be infectious in certain cases. Humans and animals are all susceptible to human and animal strains of the mycobacterium.
- Vaccine available – a bacterium called Bacillus Calmet Gruen (BCG) is available and is used in many countries.
- Important preventive measures – personnel should wear face masks and disposable gloves when working with these species.
- Note – There has been a resurgence of TB due in large part to drug users and AIDS victims. New treatment resistant TB strains have been reported.