The influence of filter top caging on the transmission of pinworm infections in mice.

The effectiveness of filter top cages in preventing infection of mice with pinworms, Aspiculuris tetraptera and Syphacia obvelata, was investigated by introducing mice from a pathogen-free colony into a colony in which both types of pinworms were enzootic. Half of the pathogen-free mice were maintained in filter top cages, while the remainder were held in similar cages without filters. All mice thus introduced were killed and examined after 3-8 week exposure periods. No pinworm were recovered from mice in 17 of 18 cages with filter tops while mice in 12 of 16 cages without filter tops were infected.