Prevalence, Risk Factors, and Molecular Epidemiology of Anaplasma phagocytophilum in Sheep Raising in Khuzestan Province, Iran

Background: Anaplasma sp. is a blood protozoon that causes economic damage to the livestock industry. Therefore, studying this disease’s epidemiology and distribution pattern in different regions is essential. Objectives: This study aimed to investigate the variety of infections of the Anaplasma sp. in the sheep population of Khuzestan Province in Iran. Methods: A total of 200 sheep blood samples were randomly collected and examined using specific nested polymerase chain reaction (nPCR) based on the 16S rRNA gene. Results: The prevalence of Anaplasma phagocytophilum was 17%, and infected sheep had no clinical signs. The effective risk factors in the spread of infection in Khuzestan Province include sheep aged 3-5 years, low sanitation, high-density farms, use of acaricides in the field, and hot season (P≤0.05). There was no significant association between the occurrence of A. phagocytophilum infection and variables of altitude, farm type, vectors, distance from other farms, and sex. Conclusion: Since the infection often has no clinical symptoms, identifying the risk factors and epidemiology is essential to develop control and prevention planning.