Infestation and pathological lesions of some lymph nodes induced by Linguatula serrata nymphs in sheep slaughtered in Shahrekord Area(Southwest Iran)

Objective: To determine the infection rates of mesenteric and mediastinal lymph nodes in relation to Linguatula serrata(L. serrata) nymphs. Methods: In the present study, mesenteric and mediastinal lymph nodes of 200 sheep with different sex and age that were slaughtered in a Shahrekord slaughterhouse were collected. The lymph nodes were examined macroscopically and for histopathological examination, tissue samples were taken from the gross lesions processed routinely by paraffin method and stained with hematoxylin and eosin. Results: Out of 200 examined sheep, the mesenteric lymph nodes in 18 sheep(9%) and the mediastinal lymph nodes of 9 sheep(4.5%) were infected by L. serrata nymphs. The infection rate increased with age, but no significant difference was observed between males and females or the two types of lymph nodes(P > 0.01). Different nonspecific gross and macroscopic lesions were seen in infected lymph nodes. L. serrata nymph sections were observed in some histopathological slides. Conclusions: It is concluded that the sheep may play an important role in linguatulosis of final hosts and human beings in this region.