Over a 4-wk period in 2017, we received notification from 7 different institutions that mice exported from our SPF barrier facilities had tested positive for mouse rotavirus (MRV). The exports originated from several different buildings across multiple campuses. Our institution excludes MRV in all of our barrier facilities and has historically been free of this virus. Extensive testing of our rooms from which the exported mice originated did not detect the presence of rotavirus. The single commonality among the 7 shipments was the use of shipping boxes acquired from one vendor. These shipping boxes arrived at our institution prepackaged with unsterilized feed and bedding, which we hypothesized was the source of the rotavirus. To test this hypothesis, we housed naïve sentinel mice in clean cages with feed and bedding transferred from 29 unopened, unused shipping boxes. Sentinel mice were exposed to this bedding and feed for 14 d and then evaluated through MRV serology and PCR assay. Of the 29 sentinels, 24 were seropositive for MRV, and 14 of the 29 were PCR positive. These results provided direct evidence that MRV detected by recipient institutions originated from the contaminated feed or bedding within the shipping boxes. To our knowledge, this report is the first description of contaminated materials in shipping boxes resulting in rotaviral infection of mice during export.

Fenbendazole is a broad-spectrum benzimidazole commonly used in laboratory animal medicine as an anthelmintic for elimination of pinworms. This drug is generally regarded as safe, with minimal side effects. Some data in rodent species indicate multiple physiologic effects of fenbendazole, including changes in immune parameters and behavior, but no studies to date have evaluated possible effects on reproduction in mice. The purpose of the current study was to determine the effects of several treatment regimens of fenbendazole on reproductive parameters in C57BL/6J mice. Uninfected mice were given fenbendazole-treated feed continuously or every other week until pups were born or weaned. This treatment also was combined with environmental decontamination. No significant differences in litter size, survival rate, or weaning weight were detected between groups. Under the conditions of this study, fenbendazole treatment does not affect reproduction in C57BL/6J mice.