A study on the suitability of inactivated Trichinella spiralis larvae for proficiency samples

The consumption of raw or undercooked Trichinella infected meat, especially pork and horse meat, can have important implications for public health. Therefore each animal carcass from a Trichinella susceptible species intended for human consumption must be examined for Trichinella. Laboratories carrying out testing of official control samples must undergo a quality assurance program and should regularly participate in proficiency testing schemes. To date, Trichinella proficiency samples are prepared with live larvae, which, as a level 2 pathogen, require specific shipping and disinfection procedures. Therefore, the suitability of using inactivated Trichinella larvae as proficiency samples was tested. We found that Trichinella larvae treated with 2% formaldehyde for 24h had lost their infectivity and showed a comparable recovery rate to naïve larvae after artificial digestion, albeit with a prolonged sedimentation time.