"Virus" - what is it, definition of the term
A viral particle is a submicroscopic infectious entity consisting of nucleic acid (DNA or RNA) encased in a protein shell, devoid of cellular structure and autonomous metabolism, and dependent on host cells for replication; it commandeers the host’s biosynthetic machinery to assemble new progeny, frequently causing disease, and includes strains that specifically infect rodent hosts such as rats and mice, spreading via bodily fluids, aerosols, or contaminated environments.
Detailed information
Viral agents that infect rodents represent a diverse group of pathogens with significant implications for laboratory research, public health, and wildlife ecology. These agents are primarily RNA viruses, although DNA variants also occur. Transmission routes include direct contact, aerosol exposure, contaminated bedding, and vector-borne spread via ectoparasites such as fleas and mites.
Key characteristics of rodent-associated viral pathogens:
- Host specificity: Many strains display a narrow host range, infecting only rats, only mice, or both species, while some can cross species barriers to infect humans or other mammals.
- Transmission dynamics: Horizontal spread is common; vertical transmission (from dam to offspring) occurs in certain agents, influencing colony health and breeding outcomes.
- Clinical manifestations: Infected rodents may exhibit respiratory distress, neurological signs, weight loss, or remain asymptomatic carriers, complicating detection.
Notable viral families and representative members:
- Arenaviridae – Includes agents such as lymphocytic choriomeningitis virus, which can cause encephalitis in humans after exposure to infected mouse excreta.
- Bunyaviridae – Hantaviruses, notably Seoul virus, are carried by rats and can lead to hemorrhagic fever with renal syndrome in humans.
- Paramyxoviridae – Sendai virus and mouse hepatitis virus are common laboratory contaminants, affecting respiratory and gastrointestinal systems.
- Retroviridae – Murine leukemia virus variants can induce neoplastic disease in mice, impacting experimental outcomes.
Diagnostic approaches rely on serology (ELISA, immunofluorescence), nucleic acid detection (RT‑PCR, quantitative PCR), and virus isolation in cell culture. Biosafety measures for handling infected colonies include containment cages, personal protective equipment, and routine health monitoring programs.
Control strategies emphasize eradication through depopulation, rederivation of breeding lines via embryo transfer, and strict quarantine of new animals. Vaccination options are limited; preventive hygiene and environmental decontamination remain primary defenses.
Understanding the biology, transmission, and pathology of these rodent viral agents is essential for maintaining the integrity of biomedical research, protecting personnel, and preventing zoonotic spillover.