Geographic distribution of anti-Leptospira antibodies in humans in Côte d'Ivoire, West Africa.

Leptospirosis is a zoonotic bacterial disease with a worldwide importance, mostly frequent in tropical and subtropical countries. In Côte d'Ivoire, little is known about leptospirosis and human data are sparse. This disease is usually misdiagnosed with other febrile illnesses, and determining high-risk areas could allow better management of this disease, leading to policies. This study aims to map leptospirosis exposure areas by determining geographic distribution of anti-Leptospira antibodies in humans in Côte d'Ivoire. A total of 384 serum samples were randomly selected in the national surveillance system for communicable diseases in 2014. All the 82 health districts were include in the study. Serums were screened by ELISA at Institut Pasteur de Côte d'Ivoire and confirmed by MAT in the National Reference Centre for leptospirosis in Institut Pasteur in Paris. In these samples, ELISA screened 90 specimens showing anti-Leptospira antibodies and 36 specimens were confirmed by MAT (9.4%). Observed cases were mostly located in health districts of the western and the southern parts of the country. People with anti-Leptospira antibodies had a mean age of 34.5 years old and a sex ratio of 2. This pattern corresponds to active low-income farmers working into agricultural fields. This study reveals circulation of leptospirosis in human population in Côte d'Ivoire. The disease seems to be more frequent in the western and the southern parts of the country. Active low-income farmers working into agricultural fields without personal protective gear could be one of the most at-risk populations.