Serovar typing and risk factors of Leptospira infection in dromedary camels (Camelus dromedarius) of Sistan and Baluchestan, Iran: An exploratory study, with a worldwide update of Leptospira infections in camels

<h2>Abstract</h2><h3>Objectives</h3> Leptospirosis is a significant zoonotic disease of camels that poses an economic burden on livestock industries worldwide. Hence, the present study investigated the serovars and risk factors of <i>Leptospira</i> infection in camels in the Sistan and Baluchestan province, Iran, and compared it with the incidence and prevalence of <i>Leptospira</i> infection in camels worldwide. <h3>Methods</h3> A total of 150 serum samples were collected from the camel population of Sistan and Baluchestan provinces, southeast of Iran, from the fall and winter of 2022 to the spring of 2023. The samples were then sent to the <i>Leptospira</i> Research Laboratory at the University of Tehran for the microscopic agglutination test. Results were compared against <i>Leptospira</i> infection seroprevalence and epidemiology from other worldwide studies on <i>Leptospira</i> infection in camels to ascertain the significance of these zoonoses in Iran. <h3>Results</h3> According to the results, 2 % of serum samples (3/150) were positive for <i>Leptospira</i> infections, and 4 % (6/150) were suspicious, with <1:100 titers. Moreover, of the three positive samples, two demonstrated reactivity to serovar Pomona, whereas the other positive sample demonstrated reactivity with serovar Icterohaemorrhagiae in the microscopic agglutination test. No significant difference in the prevalence of infection based on sex or age of camels was observed. The worldwide epidemiologic study of <i>Leptospira</i> infection in camels shows that the disease varies significantly in different regions regarding infection rates and pathogens. <h3>Conclusions</h3> The results of this study indicate that <i>Leptospira</i> infection continues to be a significant threat to livestock health management in Iran. To control <i>Leptospira</i> infection in camels, there is a need for systematic monitoring and more comprehensive research to identify environmental and management factors that affect its spread.