“To confirm its presence, you have to kill the mouse and test its lymph nodes,” Couto explains, pointing out that “then you don’t have a subject anymore.”

Couto is so concerned about the threat that he launched a campaign to eradicate it from the University’s animal facilities. Along with relying only on “trusted” sources when importing new animals and replacing quarantine with derivation by embryo transfer, DLAM has instituted several operating practices to keep the pathogen at bay.

First, Couto recommends extensive washing of the embryos collected from infected mice.

“Parvovirus can come in with mice or the embryos, which is why it’s so important to wash them before they are implanted into their foster moms,” he says.

Parvovirus also spreads through contact, so decreasing human traffic is always a priority. In keeping with these limits, investigators are not permitted to enter the tier-one barrier facility. Within the vivarium DLAM enforces a closed-door policy to protect the breeding compartment as people move from room to room. With space at a premium, all mice in tier-one facilities are housed in racks of individually ventilated cages. Technicians are very careful to avoid overcrowding the cages as disease spreads so rapidly through dense animal populations.

Finally, Couto reports that anecdotal information out of New York’s Memorial Sloan Kettering Cancer Center (MSKCC) seems to indicate that irradiated food might make a difference in curtailing the pathogen. UCLA’s experience agrees with MSKCC’s observation.

“In those tier-one facilities that have remained free of parvovirus for more than three years, we use irradiated feed. That’s a very interesting relationship,” he concludes.

--NZS