Due to the diversity of clinical signs and the difficulties of establishing a confirmatory laboratory diagnosis, leptospirosis remains poorly investigated, particularly in the developing world. In Morocco, a descriptive study of the seroprevalence of Leptospira infection in animals has never been undertaken so far. In order to fill this gap, the current study was conducted on a subset of animals in north-western Morocco as a preliminary step to the understanding of clinical and epidemiological patterns of animal leptospirosis in the country.
The study was conducted on 289 serum samples collected between January and April 2012 from dogs, cattle, sheep, goats and donkeys in Rabat-Salé, Khémisset (low land) and Oulmès (high land). All serum samples were serologically tested by the standard MAT using two representatives of Leptospira biflexa (Patoc and Andaman) and 14 reference strains of the most widespread L. interrogans serovars. The threshold was established at 1:20. When a given serum reacted to more than one serovar and, despite cross-reactivity of various serovars, positives to more than one serovar were recorded as many times. The overall seroprevalence to Leptospira interrogans in cattle, sheep, goats, dogs and donkeys was respectively 15%, 18%, 20%, 21 and 20%. The following serovars were unevently distributed among different animal species: Ballum, Sejroe, Bratislava, Australis, Icterohaemorrhagiae, Poi, and Canicola. Of the 7 serovars revealed by this study, Icterohaemorrhagiae was the only serovar which have been previously reported in clinical leptospirosis in humans in Morocco. The majority of positive sera were collected from low the land area. Most sera that proved negative to all pathogen serovars reacted with L. biflexa Patoc and Andaman, which implies a possible presence of new, unclassified Leptospira serovars in Morocco. These will be further investigated and isolation of Leptospiras will be soon attempted in the author’s laboratory.