Leishmania Seroprevalence in Jordanian Horses: Zarqa Governorate Hotspot and Strong Association with Stall Housing and Twice-Yearly Deworming

The emergence of equine leishmaniasis is of particular concern as horses, being the second most numerous reservoir host after dogs, are involved in the transmission cycle to humans. Although horses are increasingly recognized as secondary hosts of Leishmaniasis no large-scale data exist for Jordan. A cross-sectional serosurvey was conducted on 326 horses of different breed (Arabians, mixed local, Thoroughbred and Quarter) from seven governorates using a commercial indirect ELISA. After excluding animals with incomplete metadata, 274 horses were retained for risk-factor analysis. Overall apparent seroprevalence was 11.3% (31/274). Seropositivity was highly focal: 55.0% in Zarqa Governorate versus 0–11.1% elsewhere (P < 0.001). Independent risk factors in multivariable analysis were Zarqa residence (aOR 39.8), stall-only housing (aOR 6.12), deworming exactly twice per year (aOR 8.74), and male sex (aOR 3.11). No seropositive horses were found among competitive animals or those with pasture access. Jordan harbors a previously unrecognized equine Leishmania focus in Zarqa Governorate driven by intensive stall confinement. Simple changes in housing and deworming practices could substantially reduce exposure. = Further studies are needed on equine leishmaniasis in Jordan using more advanced molecular studies. This study represents a first large-scale serological assessment of equine leishmaniasis in Jordan and constitutes a contribution to determine its geographic distribution and estimate its zoonotic potential in Jordan.