The Relative Frequency of Histomonas meleagridis Infection in Turkey Flocks in Some Provinces of Iran

Background: Histomoniasis is caused by the protozoan Histomonas meleagridis with an intermediate host of Heterakis gallinarum, which results in ulceration of the ceca walls, enlargement of the ceca by large casts, mesenteric inflammation, and liver necrosis. This disease is very important in Iran’s growing turkey breeding industry. Objectives: The present study aims to evaluate the relative frequency of H. meleagridis infection in different turkey flocks to draw a cross-sectional picture of H. meleagridis infection in Golestan, Mazandaran, Guilan, and Tehran provinces of Iran. Methods: This study is a cross-sectional survey of H. meleagridis infection during spring. Dropping samples were taken from backyard and commercial turkey flocks. After taking the fecal samples, they were investigated by Giemsa staining under a light microscope. A PCR test was performed to confirm the diagnosis of infection. Results: Out of 240 samples (from 19 flocks), 20 infected samples were detected by direct microscopic observation of H. meleagridis, and PCR confirmed 15 samples. Conclusion: The results of this study showed that the relative frequency of H. meleagridis infection was lower than in similar studies in other parts of the world. This finding may be due to Iran’s less widespread use of turkey production. Considering the growth of the turkey production industry in Iran over the last decade and its further production over the next few years, it is necessary to evaluate histomoniasis.