Glanders Re-emerging in Few Horses in East Azerbaijan, Iran

Background and Aim : Glanders is a zoonosis caused by Burkholderia mallei (B. mallei).Glanders has been re-emerging in recent years due to war in the Middle East, unauthorized transfer,the lack of formulated action plans, etc. The prevalence of glanders in Iran and the risk of B.mallei transmission and infection is high, therefore requires the quickly identify this disease inanimals, particularly in horses. This study investigated glanders re-emerging in horses in EastAzerbaijan Province, Iran.Methods : From ۲۲ September ۲۰۲۰ to ۲۰ March ۲۰۲۱, six-month periodic tests such as thecomplement fixation test (CFT) were implemented by the Veterinary Administration of EastAzerbaijan to detect glanders in horses. In the case of positive CFT results, the mallein test wasconducted. According to the test results, blood samples were taken to culture and prepare serumfor the ELISA test.Results : Deep swab samples were collected from nasal mucosa, lymph fluid, and blood. The CFTresults indicated ۱۲ horses susceptible to glanders, and three horses were diagnosed with glandersbased on the mallein confirmatory test results. B. mallei were not isolated in culturing the samples.Three cases were positive in the ELISA test which was consistent with the CFT and mallein testresults. However, the molecular test results were negative.Conclusion : It is challenging to isolate B. mallei in the early stage of disease, and the negativemolecular diagnostic test result may be misleading in glanders diagnosis. In susceptible cases witha positive CF test result, glanders can be diagnosed by skin mallein and ELISA tests.

Keywords:

Burkholderia mallei , Glanders , equine , Complement fixation test , Mallein test , ELISA