In 1989, an outbreak among humans occurred in a US cancer research institute that studied the effects of various therapeutic and diagnostic agents in animal models. Such agents had been developed in the animal care facility, which periodically screened sentinel animals for extraneous infection. Due to an oversight, no sentinel animals were monitored from August 1988 to March 1989. When testing resumed, LCMV antibodies were found in the oldest sentinel hamsters. Several workers reported symptoms consistent with LCMV infection, leading to an investigation. Blood samples were obtained and tested for LCMV antibodies. Of the 82 workers that were tested, seven had definite serologic evidence of past LCMV infection, and two were hospitalized for an acute febrile illness. All seven reported direct contact with the animals at the institute.An additional hazard associated with LCMV in laboratories misleading experimental results. Interference with research may involve:

[Inhibition of] tumor induction due to polyoma virus, and mammary tumor virus in the mouse, and [interference] with transplantable leukaemia in the guinea pig and the mouse. Infection is associated with depression of cellular immunity in the mouse. Rejection of cutaneous grafts or transplantable tumors may be delayed. In addition, infection will increase the sensitivity of the mouse to ectromelia virus and to bacterial endotoxins.Reported outbreaks have decreased, perhaps due to improved biohazard management in laboratories. However, it is possible that sporadic cases have been overlooked because of the wide range of clinical presentations. Clare A. Dykewicz, et al.
Morbidity and mortality rates vary with the species of animal and its age at infection, as well as the strain of the virus and route of exposure. Neonatally and congenitally infected mice remain asymptomatic for many months, but the onset of glomerulonephritis reduces overall life expectancy. The morbidity rate in naturally infected post-neonatal mice is unknown; however, subclinical disease may be the most common form, as few natural outbreaks have been reported. In hamsters, approximately half of all congenitally infected animals clear the virus when they are approximately three months old and remain healthy; the remaining animals develop chronic disease. Hamsters infected as adults usually remain asymptomatic. Callitrichid hepatitis is reported to be highly fatal in naturally infected marmosets and tamarins in zoos. Since 1980, 12 outbreaks with 57 deaths have been reported in the U.S. In experimentally infected rhesusmacaques, three of four animals became fatally ill when inoculation was by the intravenous route. In contrast, inoculation by the intragastric route usually led to asymptomatic infections, with occasional disease and few deaths. In pets
Pet rodents are not known to be natural reservoirs for lymphocytic choriomeningitis virus. However, pets can become vectors if they are exposed to wild house mice in a breeding facility, pet store, or home. Such infections are rare. To date, (January 2017) documented infections in humans have occurred only after introduction to infected mice, guinea pigs, and hamsters, with the majority of cases transmitted by mice.