What pathogen is often prevalent in conventional rodent colonies?

• A. Sendai virus
• B. Pinworms
• C. Minute virus of mice
• D. Mouse norovirus

Answer: (B)

Pinworms are among the most commonly encountered infections in conventional rodent colonies because their eggs are extremely hardy and easily spread through normal husbandry. Transmission is primarily fecal-oral, and the eggs can persist on cage surfaces, bedding, and equipment for weeks. In conventional housing, where barrier protections and stringent sanitation are not always as rigorous as in barrier or SPF facilities, infections can become widespread before health monitoring catches them. Many mice carry pinworms with few or no obvious signs, yet these parasites can influence experimental results by affecting gut function and immune responses. This combination of environmental persistence, easy transmission, and often subclinical infection makes pinworms a pathogen frequently prevalent in conventional colonies.