Seroepidemiology, Spatial Distribution, and Risk Factors of Francisella tularensis in Jordan.

Abstract

There is a paucity of data on Francisella tularensis in the Middle East and North Africa. This is the first countrywide study to determine the seroprevalence, spatial distribution, and risk factors for F. tularensis in Jordan. A total of 828 Jordanians were serologically tested for F. tularensis by ELISA. These individuals filled out a self-administered questionnaire to collect demographic and risk factor information. Bivariate and multivariate logistic regressions were performed to determine which variables are associated with seropositivity. The overall seroprevalence of F. tularensis was 7.7% (95% CI: 6.10-9.75). The bivariate analyses showed that age, region of residence, small ruminant ownership, and practicing horticulture were significantly associated with seropositivity, and these variables were controlled for in the multivariate analysis. The multivariate analysis showed an increased odds of seropositivity among individuals living in northern desert, middle, and northern highland areas, compared with individuals living in the drier southern area, as 7.27 (95% CI: 2.49-21.19), 3.79 (95% CI: 1.53-9.39), and 3.52 (95% CI: 1.45-388.55), respectively. Individuals owning a small ruminant had 1.86 (95% CI: 1.02-3.40) greater odds for seropositivity than individuals who do not own a small ruminant. Individuals practicing horticulture had 2.10 (95% CI: 1.20-3.66) greater odds for seropositivity than individuals who do not practice horticulture. This is the first study to address the seroprevalence of F. tularensis in Jordan and the Middle East. Further research is needed to identify clinical cases of tularemia in Jordan and to determine the circulating F. tularensis subspecies.