High-level seroprevalence against Leptospira interrogans serovars among wild foxes, jackals and stray dogs in the North Khorasan Province, Iran

Background: Leptospirosis is an important, neglected zoonotic disease that affects people and animals in humid (sub)tropical regions. Wild canines carry the pathogen and may contaminate natural resources which may then act as a source of human infection. Objectives: The study was designed to understand the seroprevalence of leptospirosis among domestic and wild canines in Bojnurd County, Northeast Iran. Methods: A total of 77 serum samples, comprising 29 sera from asymptomatic wild canines [foxes (n = 25) and jackals (n = 4)] and 48 sera from asymptomatic stray dogs, was investigated. Serovars were identified and antibody titres were measured by standard microscopic agglutination test (MAT) using serial serum dilutions. Results: Among all serum samples, 44.1% reacted positively to a Leptospira interrogans serovars. The average percentage of positive reactions was higher in stray dogs than in wild canines although this did not reach statistical significance (55.2% and 37.5%, p = 0.159). Positive reactions with L. i. Pomona, L. j. Australis and L. i. Tarasovi was detected only among jackals and foxes. Among the stray dogs, the highest number of positive sera were for L. i. Grippotyphosa (61.1%) and L. i. Canicola (50%). The highest titre detected was for L. i. canicola (1:1600) in two stray dogs and against L. i. Icterohaemorrhagiae and L. i. Pomona (1:800) in a single jackal. Conclusions: The study revealed that leptospirosis is endemic among various canine species in the North Khorasan Province of Iran. Detailed monitoring of canines is necessary for better understanding the epidemiology of infection in our and other Iranian regions.