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.

Impact of rotavirus vaccine introduction in Abidjan, Côte d'Ivoire.

Côte d'Ivoire introduced rotavirus vaccine in March 2017. Rotavirus surveillance is conducted at Centre Hospitalier Universitaire de Yopougon in Abidjan, the capital city. Children <5 years of age are enrolled in rotavirus surveillance if admitted to the hospital with acute gastroenteritis. We used sentinel surveillance data from 2014 through mid-2019 to compare trends in rotavirus pediatric gastroenteritis hospitalizations before and after rotavirus vaccine introduction. We used Poisson regression to analyze changes in rotavirus prevalence, adjusting for calendar month and accounting for total monthly admissions; January 2014 - December 2016 was considered "pre-vaccine," and January 2017 - June 2019 was considered "post-vaccine." Age distribution and severity were compared between periods using the Mann-Whitney U test. Rotavirus-positive admissions declined 51% (95% CI: 28%-67%), from 31.5% pre-vaccine to 14.9% afterward. The median age of rotavirus-positive children increased from 7 months (interquartile range [IQR]: 5-11) in the pre-vaccine period to 11 months (IQR: 7-18, p = .005) in the post-vaccine period. The median severity score decreased from 11 to 9 (p = .008) among all children, and from 12 pre- to 10.5 post-vaccine (p = .35) among rotavirus-positive children. Our findings suggest that rotavirus vaccine introduction contributed to reduced rotavirus hospitalization in Abidjan and possibly more broadly.