Effect of different temperature conditions on survival time of Linguatula serrata nymphs

Objective: Linguatulosis is one of the food-borne parasitic zoonoses. Human infection mayoccurs following consumption of the raw or undercooked infected offal of slaughtered ruminants,especially mesenteric lymph nodes (MLNs), liver and lung. The main objective of this study was toevaluate the effect of different temperature conditions on survival time of Linguatula serrata nymphs.Material and Methods: Fifteen infected MLNs (5 in triplicate) were separately put in plastic bags andwere treated by +50°C, +60°C, +72°C and -18°C through water bath or freezer. Meanwhile, fifteeninfected MLNs (5 in triplicate) were stored in refrigerator (+4°C) as control group. The survival time ofthe nymphs was evaluated by observing their motility and wriggle under a stereomicroscope in differentperiods of time. Results: The infected MLNs were mainly edematous, hemorrhagic and dark comparingto the non-infected ones. The survival time of the nymphs stored at the high temperatures (+50°C,+60°C and +72°C) were short and all the isolated nymphs were found dead after maximum 1.5 hours.The other ones stored at freezing temperature (-18°C) were more resistant and died after 3 hours. But,the nymphs stored in +4°C (control group) had the longest survival time and were resistant until day20. Conclusion: It is concluded that cooking and freezing temperatures have a parasiticidal effect onLinguatula serrata nymphs and could be applied as a suitable method in processing of meat products.But refrigeration at +4°C is not a safe method and may increase the resistance of nymphs in meatproducts.