Status of Linguatula serrata infection in livestock: A systematic review with meta-analysis in Iran

OBJECTIVES: The present systematic review attempted to determine the prevalence of Linguatula serrata (L. serrata) infection among Iranian livestock. The L. serrata known as tongue worm belongs to the phylum pentastomida and lives in upper respiratory system and nasal airways of carnivores. Herbivores and other ruminants are intermediate hosts. METHODS: MEDLINE, Embase, Web of Science, Google Scholar, and the Cochrane Library were searched from Nov 1996 to 22 Apr 2019 by searching terms including “Linguatula serrata”, “linguatulosis”, “pentastomida”, “bovine”, “cattle”, “cow”, “buffalo”, “sheep”, “ovine”, “goat”, “camel”, “Iran”, and “prevalence” alone or in combination. The search was conducted in Persian databases of Magiran, Iran doc, Barakatkns (Iran medex) and Scientific Information Database (SID) with the same keywords. After reviewing the full texts of 133 published studies, 50 studies had the eligibility criteria to enter our review. RESULTS: By random effects model analysis, the pooled prevalence of linguatulosis was 25% (95%CI: 18.0–33.0, I(2) = 98.67 % , P < 0.001) in goats; 15.0% (95%CI: 10.0–20.0, I(2) = 97.95 % , P < 0.001) in sheep; 12.0% (95%CI: 7.0–18.0, I(2) = 98.05 % , P < 0.001) in cattle; 7% (95%CI: 2.0–16.0, I(2) = 97.52%) in buffalos and 11.0% (95%CI: 6.0–16.0%, I(2) = 96.26 % , P < 0.001) in camels. The overall prevalence in livestock was estimated to be 25%. The highest infection rate was recorded in West Azerbaijan Province (68%) and the lowest rate was in Khuzestan Province (0.23%) (P < 0.05). CONCLUSIONS: We concluded that the high prevalence of L. serrata infection in livestock (mainly ovine linguatulosis) show the endemic status of linguatulosis in several parts of Iran and will pose a risk for inhabitants. Control strategies to reduce the parasite burden among these animals are needed.