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Updated: Aug 2, 2026
Dissecting Host-virus Interaction in Lytic Replication of a Model Herpesvirus
Published on: October 7, 2011
Pathogenicity of mouse hepatitis virus for mice depending upon host age and route of infection
Abstract:
Day-old to 4-week-old mice from a breeder colony which had been seromonitored to be free from mouse hepatitis virus infection, were tested for susceptibility to the virus by different routes of inoculation. After intraperitoneal, intravenous and intracerebral inoculation of 10(2) or more plaque-forming units of the virus, mice of all ages died of acute hepatitis. While day-old mice died also after subcutaneous, intranasal and peroral routes of inoculation, those 3 weeks or more of age resisted to infection by these routes. To intranasal inoculation mice 1 and 2 weeks of age were fully susceptible but some of the resisted to peroral inoculation. In the course of non-fatal infection in 4-week-old mice after intranasal inoculation, viremia and production of some hepatic lesions were recognized and infection became fatal in association with cortisone treatment. The results suggested that the intranasal route of infection may be of importance for spreading of infection in mouse breeding colonies in which inapparent infection is prevailing.
Insights
Young mice are highly susceptible to mouse hepatitis virus (MHV) infection via various routes. Older mice show resistance, but intranasal infection can still cause disease, especially with cortisone treatment.
Area of Science:
- Virology
- Animal Health
- Infectious Diseases
Background:
- Mouse hepatitis virus (MHV) is a significant pathogen in laboratory mouse colonies.
- Understanding MHV transmission routes is crucial for maintaining disease-free animal models.
Purpose of the Study:
- To determine the susceptibility of mice of different ages to MHV infection via various inoculation routes.
- To identify potential routes for MHV spread within breeding colonies.
Main Methods:
- Mice aged 1 day to 4 weeks were inoculated with MHV via intraperitoneal, intravenous, intracerebral, subcutaneous, intranasal, and peroral routes.
- Susceptibility was assessed by mortality rates and clinical signs.
- Viremia and hepatic lesions were monitored in surviving mice.
Main Results:
- Mice of all ages succumbed to acute hepatitis following parenteral inoculation (intraperitoneal, intravenous, intracerebral).
- Younger mice (day-old) were susceptible to subcutaneous, intranasal, and peroral routes, while older mice (≥3 weeks) resisted these routes.
- Mice aged 1-2 weeks were susceptible to intranasal inoculation, with some resistance to peroral routes.
- Intranasal infection in 4-week-old mice led to viremia and hepatic lesions, becoming fatal with cortisone treatment.
Conclusions:
- Age-dependent resistance to MHV exists, particularly for non-parenteral routes.
- The intranasal route is a significant factor in MHV transmission within mouse breeding colonies, especially with subclinical infections.
- Cortisone treatment can exacerbate MHV infection, increasing mortality even in older mice previously resistant to certain routes.
