Epidemiology and genetic analysis of Oestrus ovis from slaughtered sheep in Sulaymaniyah province, Iraq.

Introduction: Oestrosis is a type of nasal myiasis that is caused by larvae of flies from the Oestrus genus and is a disease of economic significance in small ruminants. The research aimed to investigate the prevalence of oestrosis and detect differences in the COX1 gene among haplotypes found in Sulaymaniyah, in the Kurdistan region of Iraq.

Material and methods: The research was conducted in a Sulaymaniyah abattoir from September 2023 to August 2024. The heads of 328 sheep were carefully incised and inspected to record the larvae of Oestrus ovis. A conventional polymerase chain reaction and sequencing of the COX1 gene were used for diagnosis and genetic analysis of O. ovis.

Results: The rate of oestrosis was 22.25% and the disease was significantly (P-value < 0.05) higher in imported breeds (26.50%) than the local breed (15.65%), in adults (26.88%) than in young animals (16.19%), in females (27.05%) than in males (17.08%), and in the summer (34.09%) than in other seasons of the year. Comparison of the sequences of the conservative COX1 gene of the parasite led to identification of five different haplotypes in the research area. Two of the haplotypes were previously recorded internationally, while three new haplotypes associated with five novel mutations were recorded for the first time in the study region.

Conclusion: A phylogenetic analysis revealed a strong relationship among O. ovis populations from various countries. The current research offered valuable molecular data for O. ovis species, essential for evaluating phylogenetic relationships and identifying these parasites at a molecular level.