Integrated management of a Psocid infestation in a SPF animal facility: Response strategy and preservation of health status

On September 20, 2024, an infestation of psocids (Psocoptera sp.) was detected by animal care staff in several bags of feed stored within a Specific Pathogen Free (SPF) animal facility and an adjacent laboratory. Although psocids are not pathogenic to rodents, their presence in an SPF environment poses a critical risk of cross-contamination, particularly in animal housing areas.
An immediate, coordinated response was initiated. The entomology department at the University of Liège confirmed the identification of the specimens through microscopic examination and on-site photographic documentation. An emergency meeting involving entomology experts, feed manufacturers, and animal facility personnel was held to develop a strategy aligned with the stringent SPF requirements.
The action plan comprised multiple complementary measures: immediate destruction of
contaminated feed batches by the manufacturer; targeted insecticide treatment of peripheral zones (storage rooms, corridors) using deltamethrin-based products (Deltasect®) by a professional pest control company; and thorough cleaning and decontamination of premises and equipment, including removal of non-essential materials.
New feed batches received between September 23 and October 24 were frozen for 48 hours before use to prevent reinfestation. Two suspect animal rooms were quarantined and monitored using entomological sticky traps, which were regularly replaced. A biweekly enhanced cleaning protocol was established, combining chemical disinfection (Umonium®), application of 7° vinegar (potentially repellent), and diatomaceous earth (a natural insecticide). All cages and housing materials were replaced completely every week for eight weeks. By week six, no psocids were detected. The protocol was maintained for three months as a precaution. The use of ventilated cages on racks effectively minimized the risk of insect spread to animals.
This rapid, multidisciplinary approach preserved the SPF status, highlighting the importance of proactive bio-contamination management in highly controlled environments.