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.
Timeliness of diagnosis is important not only in expediting treatment of infected persons, but also in preventing further LCMV transmission to other workers and animals.Clinical diagnosis of LCM can be made by the history of prodrome symptoms and by considering the period of time before the onset of meningitis symptoms, typically 15–21 days for LCM.Pathological diagnosis of congenital infection is performed using either an immunofluorescent antibody (IFA) test or an enzyme immunoassay to detect specific antibody in blood or cerebrospinal fluid. A PCR assay has been recently developed which may be used in the future for prenatal diagnosis; however, the virus is not always present in the blood or CSF when the affected child is born." Diagnoses is subject to methodological shortcomings in regard to specificity and sensitivity of assays used. For this reason, LCMV may be more common than is realized.Another detection assay is the reverse transcription polymerase chain reaction (RT-PCR) tests which may detect nucleic acids in the blood and cerebrospinal fluid. (CSF) Virus isolation is not used for diagnosis in most cases but it can be isolated from the blood or nasopharyngeal fluid early in the course of the disease, or from CSF in patients with meningitis. LCMV can be grown in a variety of cell lines including BHK21, L and Vero cells, and it may be identified with immuno-fluorescence. A diagnosis can also be made by the intracerebral inoculation of blood or CSF into mice. Prevention
LCMV is susceptible to most detergents and disinfectants including 1% sodium hypochlorite, 70%
ethanol, 2% glutaraldehyde and formaldehyde.