title: Irrigation in the arid regions of Tunisia impacts the abundance and apparent density of sand fly vectors of Leishmania infantum.
abstract: The distribution expansion of important human visceral leishmaniasis (HVL) and sporadic cutaneous leishmaniasis (SCL) vector species, Phlebotomus perfiliewi and P. perniciosus, throughout central Tunisia is a major public health concern. This study was designed to investigate if the expansion of irrigation influences the abundance of sand fly species potentially involved in the transmission of HVL and SCL located in arid bioclimatic regions. Geographic and remote sensing approaches were used to predict the density of visceral leishmaniasis vectors in Tunisia. Entomological investigations were performed in the governorate of Sidi Bouzid, located in the arid bioclimatic region of Tunisia. In 2012, sand flies were collected by CDC light traps located at nine irrigated and nine non-irrigated sites to determine species abundance. Eight species in two genera were collected. Among sand flies of the subgenus Larroussius, P. perfiliewi was the only species collected significantly more in irrigated areas. Trap data were then used to develop Poisson regression models to map the apparent density of important sand fly species as a function of different environmental covariates including climate and vegetation density. The density of P. perfiliewi is predicted to be moderately high in the arid regions. These results highlight that the abundance of P. perfiliewi is associated with the development of irrigated areas and suggests that the expansion of this species will continue to more arid areas of the country as irrigation sites continue to be developed in the region. The continued increase in irrigated areas in the Middle East and North Africa region deserves attention, as it is associated with the spread of L. infantum vector P. perfiliewi. Integrated vector management strategies targeting irrigation structures to reduce sand fly vector populations should be evaluated in light of these findings.
authors.affiliation: Laboratory of Vector Ecology, Pasteur Institute of Tunis, 13 Place Pasteur BP 74, 1002 Tunis, Tunisia.
authors.forename: Walid
authors.initials: W
authors.lastname: Barhoumi
authors.affiliation: Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, United States. Electronic address: w.qualls@med.miami.edu.
authors.forename: Whitney A
authors.initials: WA
authors.lastname: Qualls
authors.affiliation: Department of Geography and Regional Studies, University of Miami, Miami, FL, United States.
authors.forename: Reginald S
authors.initials: RS
authors.lastname: Archer
authors.affiliation: Department of Geography and Regional Studies, University of Miami, Miami, FL, United States.
authors.forename: Douglas O
authors.initials: DO
authors.lastname: Fuller
authors.affiliation: Laboratory of Vector Ecology, Pasteur Institute of Tunis, 13 Place Pasteur BP 74, 1002 Tunis, Tunisia.
authors.forename: Ifhem
authors.initials: I
authors.lastname: Chelbi
authors.affiliation: Laboratory of Vector Ecology, Pasteur Institute of Tunis, 13 Place Pasteur BP 74, 1002 Tunis, Tunisia.
authors.forename: Saifedine
authors.initials: S
authors.lastname: Cherni
authors.affiliation: Laboratory of Vector Ecology, Pasteur Institute of Tunis, 13 Place Pasteur BP 74, 1002 Tunis, Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Derbali
authors.affiliation: Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, United States.
authors.forename: Kristopher L
authors.initials: KL
authors.lastname: Arheart
authors.affiliation: Laboratory of Vector Ecology, Pasteur Institute of Tunis, 13 Place Pasteur BP 74, 1002 Tunis, Tunisia.
authors.forename: Elyes
authors.initials: E
authors.lastname: Zhioua
authors.affiliation: Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, United States.
authors.forename: John C
authors.initials: JC
authors.lastname: Beier
mesh_terms: D057914:Agricultural Irrigation; D000818:Animals; D003889:Desert Climate; D006801:Humans; D018314:Leishmania infantum / Q000302:isolation & purification; D016773:Leishmaniasis, Cutaneous / Q000453:epidemiology* / Q000635:transmission; D007898:Leishmaniasis, Visceral / Q000453:epidemiology* / Q000635:transmission; D010691:Phlebotomus / Q000469:parasitology; D011156:Population Density; D011157:Population Dynamics; D011576:Psychodidae / Q000469:parasitology; D014416:Tunisia / Q000453:epidemiology
keywords: Human visceral leishmaniasis; Integrated vector management; Phlebotomus perfiliewi; Remote sensing approaches