Assessing the Prevalence and Histopathology of Linguatula serrata Infection of Camels and Cattle in Zabol County, Sistan and Baluchestan Province, Iran.

Abstract

Linguatula serrata (L. serrata) is a worldwide zoonotic parasite and one of the most widespread pathogens. This study aimed to determine the prevalence of L. serrata in cattle and camels of Zabol County, Sistan and Baluchestan Province, Iran. From March 2014 to February 2021, 300 cattle (48 female and 252 male) and 300 camels (31 female and 269 male) were examined at the Zabol slaughterhouse, encompassing different age groups. The cattle breeds were indigenous (native Sistani breeds) and non-indigenous (breeds introduced from external regions), while all the camels were native breeds. To identify L. serrata nymphs, three samples of mesenteric lymph nodes (MLNs) were meticulously collected in phosphate-buffered saline immediately after slaughtering. According to the results, 4.33% (13/300) of cattle were infected with L. serrata, with six females and seven males infected. There was a significant difference in the prevalence of infection between females (6/48, 12.5%) and males (7/252, 2.77%) of cattle (p=0.009). Moreover, cattle older than 3years had significantly more infections with L. serrata nymphs (16.07%, 9/56) than cattle of other ages (p<0.001). Compared to other seasons, autumn showed a high prevalence of parasites (8.1%, 6/74) (p=0.017). Regarding the camels, only 3.66% (11/300) were infected, and there was no significant difference in infection rates between male and female camels or between seasons (p>0.05). The infection rate was higher in camels older than 3years (n=9) than in camels younger than 3years (p<0.05). The MLNs of infected cattle were edematous, red, enlarged and characterized by an eosinophilic granulomatous reaction with mononuclear inflammatory cells. The present study had low rates of L. serrata infection because the farms were clean, and cattle and camels did not have contact with final hosts such as dogs and wild canids. This suggests that their management strategies, including secure and preventative measures, were effective.