title: Nocturnal periodicity of Phlebotomus (Larroussius) orientalis (Diptera: Psychodidae) in an endemic focus of visceral leishmaniasis in Northern Ethiopia.
abstract: BACKGROUND
  Phlebotomus orientalis is the major vector of the intramacrophage protozoa, Leishmania donovani, the etiological agent of visceral leishmaniasis (VL) in northern Ethiopia and Sudan. The objective of this study was to determine the nocturnal periodicity of P. orientalis in the VL endemic focus of Tahtay Adiyabo district, northern Ethiopia.
  
  
  METHODS
  Sandflies were collected using CDC light traps by changing collecting bags at an hourly interval from dusk to dawn for six months (January-June 2013) from outdoors (i.e. peri-domestic and agricultural fields). Sandfly specimens collected in the study were identified to species level and counted.
  
  
  RESULTS
  In total, 21,716 nocturnally active sandfly specimens, which belong to two genera (i.e., Phlebotomus and Sergentomyia) were collected and identified. In the collection, P. orientalis, the dominant species in the genus Phlebotomus, constituted 33.79% while Sergentomyia spp. comprised 65.44%. Analysis of data showed that activity of P. orientalis females increased from 18:00 to 24:00 hours, with a peak after midnight (24:00-03:00 hrs). Likewise, activity of parous P. orientalis females was found to be unimodal, peaking at 24-01:00 hrs.
  
  
  CONCLUSIONS
  P. orientalis females had marked nocturnal activity, which peak after midnight. Similarly, the epidemiologically dangerous parous females generally were more active after midnight. Therefore, humans are at risk of L. donovani infections through the bite of P. orientalis possibly between midnight and dawn.
authors.affiliation: Department of Zoological Sciences, Addis Ababa University, Addis Ababa, Ethiopia. shambe2006@yahoo.com.|Department of Biology, College of Natural Science, Jigjiga University, Jigjiga, Ethiopia. shambe2006@yahoo.com.
authors.forename: Araya
authors.initials: A
authors.lastname: Gebresilassie
authors.affiliation: Department of Microbiology and Molecular Genetics, The Institute of Medical Research Israel-Canada The Kuvin Center for the Study of Infectious and Tropical Diseases, Faculty of Medicine, The Hebrew University, Hadassah Medical School, Jerusalem, Israel. oscark@ekmd.huji.ac.il.
authors.forename: Oscar David
authors.initials: OD
authors.lastname: Kirstein
authors.affiliation: Department of Biology, College of Natural Science, Jigjiga University, Jigjiga, Ethiopia. solyar2005@yahoo.com.
authors.forename: Solomon
authors.initials: S
authors.lastname: Yared
authors.affiliation: Department of Zoological Sciences, Addis Ababa University, Addis Ababa, Ethiopia. reyeesayas@gmail.com.
authors.forename: Essayas
authors.initials: E
authors.lastname: Aklilu
authors.affiliation: Department of Microbiology and Molecular Genetics, The Institute of Medical Research Israel-Canada The Kuvin Center for the Study of Infectious and Tropical Diseases, Faculty of Medicine, The Hebrew University, Hadassah Medical School, Jerusalem, Israel. adi.moncaz@mail.huji.ac.il.
authors.forename: Aviad
authors.initials: A
authors.lastname: Moncaz
authors.affiliation: Department of Zoological Sciences, Addis Ababa University, Addis Ababa, Ethiopia. habte_tm@yahoo.com.
authors.forename: Habte
authors.initials: H
authors.lastname: Tekie
authors.affiliation: Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia. meshesha_b@yahoo.com.
authors.forename: Meshesha
authors.initials: M
authors.lastname: Balkew
authors.affiliation: Department of Microbiology and Molecular Genetics, The Institute of Medical Research Israel-Canada The Kuvin Center for the Study of Infectious and Tropical Diseases, Faculty of Medicine, The Hebrew University, Hadassah Medical School, Jerusalem, Israel. alonw@ekmd.huji.ac.il.
authors.forename: Alon
authors.initials: A
authors.lastname: Warburg
authors.affiliation: Department of Microbiology, Immunology and Parasitology, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia. hailu_a2004@yahoo.com.
authors.forename: Asrat
authors.initials: A
authors.lastname: Hailu
authors.affiliation: Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia. teshomegm@gmail.com.
authors.forename: Teshome
authors.initials: T
authors.lastname: Gebre-Michael
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D019353:Endemic Diseases; D005002:Ethiopia / Q000453:epidemiology; D005247:Feeding Behavior / Q000502:physiology*; D006801:Humans; D007898:Leishmaniasis, Visceral; D008297:Male; D010691:Phlebotomus / Q000145:classification / Q000502:physiology*