Abstract
Monitoring for lymphocytic choriomeningitis (LCM) infections was maintained for 10 months on the first generations (123 litters) of a mouse colony of 16 pairs composed of 4 groups with each of the following combinations of LCM-free (SPF) and LCM congenitally infected (PTI) mice-SPF ♂ x SPF ♀, PTI ♂ x PTI ♀, SPF ♂ x PTI ♀, PTI ♂ x SPF ♀. The PTI mice were from a conventional colony recently found to be infected in some of its sections with LCM virus from an unknown source.
The studies confirmed that the epidemiological characteristics of this new virus strain were identical with those first noted by Traub in 1938.
Progeny of the PTI females had a persistent tolerant infection. The progeny of the PTI ♂ x SPF ♀ pairs, though born without infection, thereafter often acquired tolerant or non-tolerant infections through contact with the PTI male parent. Progeny of the SPF x SPF pairs remained LCM-free throughout the period despite the high infectivity of the excretions from the neighbouring PTI mice. This confirmed the feasibility of eradicating this latent infection from a mouse colony containing a proportion of LCM-free mice.