Epidemiological survey of tularemia in Ilam Province, west of Iran

Abstract

Background Francisella tularensis is the causative agent of tularemia in humans and a large number of animal species. Considering recent evidence of the circulation of this bacterium in different parts of Iran, especially in the western provinces, the aim of current study was to determine the tularemia seroprevalence in the human population living in Ilam Province. Methods In 2015, 360 serum samples were collected from five groups of people: ranchers ( n = 112), farmers ( n = 79), butchers and slaughterhouse workers ( n = 61), Nature Conservation Officers ( n = 34), and referents of medical diagnostic laboratories ( n = 74). These samples were tested for the presence of anti- F. tularensis IgG antibodies using the ELISA method. Results According to the ELISA manufacturer cutoffs, we found that 10 (2.78%) and 9 (2.5%) sera, respectively, were positive or borderline for F. tularensis IgG antibodies. The highest tularemia seroprevalence was observed among farmers (7.59%). Conclusions Our results strongly support the circulation of tularemia in Ilam Province. Because no human tularemia case has been reported so far in this province, we recommend specific education programs to increase knowledge of local health care professionals about this important zoonotic disease.

Francisella tularensis, Tularemia and Serological Diagnosis

“…No specific risk factor was found. In Iran, the first human case of tularemia was reported in 1980 (Esmaeili et al, 2014a;Esmaeili et al, 2014b;Esmaeili et al, 2019). Altogether, the above seroepidemiological studies strongly suggest that tularemia is still endemic in Iran.…”

“…Overall, most studies have reported low seroprevalences (0.19 to 4%) in the general populations studied (Koskela and Herva, 1982b;Gutieŕrez et al, 2003;Porsch-Ozcürümez et al, 2004;Schmitt et al, 2005;Jenzora et al, 2008;Splettstoesser et al, 2009;Tobudic et al, 2014;Rossow et al, 2015;Zaḱutnáet al, 2015;De Keukeleire et al, 2017;Njeru et al, 2017;Akhvlediani et al, 2018). Higher seroprevalences (5.02 to 18%) have been reported in tularemia highly endemic areas, in rural populations, in hunters, and in specific occupational groups (including farmers, butchers, slaughterhouse workers, ranchers, and park workers) (Feldman, 2003;Splettstoesser et al, 2009;Clark et al, 2012;Esmaeili et al, 2014a;Esmaeili et al, 2014b;Büyük et al, 2016;Gazi et al, 2016;Akhvlediani et al, 2018;Esmaeili et al, 2019;Harrist et al, 2019).…”

“…Several seroepidemiological studies have been recently conducted in Iran (Esmaeili et al, 2014a;Esmaeili et al, 2014b;Esmaeili et al, 2019) using the Serion ® ELISA test. A first study conducted in 2011-2012 in the Kurdistan province (Sanandaj, Marivan, and Sarvabad counties) was focused on hunters, butchers, and slaughterhouse workers (Esmaeili et al, 2014b).…”

“…A positive ELISA was found in 12 (6.5%) individuals, including 6 (5%) butchers and 6 (9.4%) slaughterhouse workers. In 2015, a survey was conducted in the Ilam province (Esmaeili et al, 2019) in 112 ranchers, 79 farmers, 61 butchers and slaughterhouse workers, 34 Nature Conservation officers, 74 diagnostic laboratory referents. The participants were mostly men (76.3%), living in urban (158) or rural (159) areas, or nomadic (39).…”

“…These studies have evaluated the tularemia seroprevalence in specific areas, either in the general population or in specific groups of individuals. ELISA tests were performed in most recent studies because they allow easy testing of a large number of serum samples (Jenzora et al, 2008;Splettstoesser et al, 2009;Zaḱutnáet al, 2015;Büyük et al, 2016;Njeru et al, 2017;Esmaeili et al, 2019). Overall, most studies have reported low seroprevalences (0.19 to 4%) in the general populations studied (Koskela and Herva, 1982b;Gutieŕrez et al, 2003;Porsch-Ozcürümez et al, 2004;Schmitt et al, 2005;Jenzora et al, 2008;Splettstoesser et al, 2009;Tobudic et al, 2014;Rossow et al, 2015;Zaḱutnáet al, 2015;De Keukeleire et al, 2017;Njeru et al, 2017;Akhvlediani et al, 2018).…”