Epidemiological Status of Linguatula serrata Infection among Domestic Ruminants in Northwestern Iran: A Systematic Review and Meta-analysis

Background: Linguatulosis, caused by Linguatula serrata, is a neglected zoonotic parasitic infection of veterinary and public health importance. Domestic ruminants serve as intermediate hosts and contribute to parasite transmission to carnivores and humans. This systematic review and meta-analysis evaluated the prevalence of L. serrata infection among domestic ruminants in northwestern Iran, particularly West Azerbaijan Province.

Methods: This systematic review was conducted according to PRISMA guidelines. English and Persian databases, including PubMed, Scopus, Web of Science, Google Scholar, SID, Magiran, IranMedex, and ElmNet, were searched for studies published between 1996 and 2025. After duplicate removal, titles and abstracts were screened, followed by full-text assessment by two independent reviewers. Twenty-seven eligible cross-sectional and epidemiological studies were included. Data on host species, study area, diagnostic methods, and prevalence rates were extracted. Study quality and risk of bias were assessed. Meta-analysis was performed using a random-effects model with 95% confidence intervals. Heterogeneity was evaluated using the I² statistic, publication bias by funnel plot and Egger’s test, and subgroup analyses according to host species and geographical region.

Results: 27 studies involving more than 15,000 domestic ruminants were analyzed. The overall prevalence of linguatulosis in Iran was 24.8%, with the highest prevalence in goats (24.9%), followed by sheep (14.8%), cattle (12.4%), camels (11.3%), and buffaloes (6.8%). West Azerbaijan Province showed one of the highest prevalence rates (68.2%). Older goats (>2 years) had significantly higher infection rates than younger animals. Mesenteric and mediastinal lymph nodes were the principal predilection sites for nymphal stages. Molecular and parasitological diagnostic methods showed greater sensitivity than routine gross examination.

Conclusion: Linguatulosis remains an endemic zoonotic infection among domestic ruminants in northwestern Iran. Enhanced surveillance, slaughterhouse inspection, control of stray carnivores, and integrated preventive strategies are essential to reduce transmission and minimize the economic and public health impacts of L. serrata infection.