Aus Dem Institut Für Parasitologie Und Tropenveterinärmedizin
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Aus dem Institut für Parasitologie und Tropenveterinärmedizin des Fachbereiches Veterinärmedizin der Freien Universität Berlin und dem International Livestock Research Institute Flies as vectors for Salmonella spp. and their control in pork butcheries in Kampala, Uganda – A contribution to improve public health Inaugural-Dissertation zur Erlangung des Grades eines Doktors der Veterinärmedizin an der Freien Universität Berlin vorgelegt von Martin Heilmann Tierarzt aus Zwenkau Berlin (2016) Journal-Nr.: 3902 Institute for Parasitology and Tropical Veterinary Medicine of the Department of Veterinary Medicine of the Freie Universität Berlin, Germany and the International Livestock Research Institute Flies as vectors for Salmonella spp. and their control in pork butcheries in Kampala, Uganda – A contribution to improve public health Thesis submitted for the fulfilment of a doctoral degree in veterinary medicine at Freie Universität Berlin, Germany Submitted by Martin Heilmann Veterinarian from Zwenkau Berlin (2016) Journal-Nr.: 3902 Gedruckt mit Genehmigung des Fachbereichs Veterinärmedizin der Freien Universität Berlin Dekan: Univ.-Prof. Dr. Jürgen Zentek Erster Gutachter: Prof. Dr. Peter-Henning Clausen Zweiter Gutachter: Univ.-Prof. Dr. Thomas Alter Dritter Gutachter: Prof. Dr. Martin Groschup Deskriptoren (nach CAB-Thesaurus): Pork, Diptera, abattoirs, Salmonella Gallinarum, Salmonella Enteritidis, meat production,epidemiology, prevalence, food safety, public health, Uganda Tag der Promotion: 14 September 2016 Contents Figures ...................................................................................................................................... III Tables ........................................................................................................................................ V Abbreviations ........................................................................................................................... VI 1 Introduction .................................................................................................................... - 1 - 2 Literature review ............................................................................................................ - 3 - 2.1 Changing pork consumption patterns in Uganda ................................................... - 3 - 2.2 Foodborne diarrheal diseases .................................................................................. - 6 - 2.3 Flies and their role as vectors ................................................................................. - 9 - 2.3.1 Systematics ...................................................................................................... - 9 - 2.3.2 Morphology ................................................................................................... - 10 - 2.3.3 Development ................................................................................................. - 11 - 2.3.4 Epidemiology ................................................................................................ - 12 - 2.3.5 Diseases ......................................................................................................... - 12 - 2.3.6 Vector control ................................................................................................ - 16 - 2.4 Choice experiment ................................................................................................ - 21 - 2.4.1 Best-worst method ......................................................................................... - 21 - 3 Materials and Methods ................................................................................................. - 22 - 3.1 Study design ......................................................................................................... - 22 - 3.2 Study area ............................................................................................................. - 23 - 3.3 Interviews with butchers and customers ............................................................... - 24 - 3.3.1 Choice experiment ......................................................................................... - 25 - 3.4 Insecticide-treated fence material intervention ..................................................... - 28 - 3.4.1 Monitoring of fly numbers ............................................................................ - 31 - 3.4.2 Net efficacy and environmental persistence .................................................. - 32 - 3.5 Microbiological sampling ..................................................................................... - 33 - I 4 Results .......................................................................................................................... - 34 - 4.1 Interviews ............................................................................................................. - 34 - 4.1.1 Socio-economics ........................................................................................... - 34 - 4.1.2 Knowledge, attitudes and practices ............................................................... - 36 - 4.1.3 Choice experiment ......................................................................................... - 40 - 4.2 Entomological monitoring .................................................................................... - 43 - 4.2.1 Insecticide persistence ................................................................................... - 46 - 4.3 Microbiological sampling ..................................................................................... - 48 - 5 Discussion .................................................................................................................... - 49 - 5.1 Interviews ............................................................................................................. - 49 - 5.2 Choice experiment ................................................................................................ - 50 - 5.3 Sampling ............................................................................................................... - 51 - 5.4 Intervention ........................................................................................................... - 53 - 5.5 Feedback ............................................................................................................... - 55 - 6 Summary ...................................................................................................................... - 57 - 7 Zusammenfassung ........................................................................................................ - 59 - 8 References .................................................................................................................... - 62 - Annex 1: Questionnaire for butchers .................................................................................. - 72 - Annex 2: Questionnaire for customers ................................................................................ - 83 - Publications ......................................................................................................................... - 93 - Acknowledgements ............................................................................................................. - 94 - Declaration of authorship .................................................................................................... - 95 - II Figures Figure 1 Distribution of pigs kept for meat production worldwide in percent according to regions (GLEAM, 2010) ....................................................................................................... - 3 - Figure 2 Increase of pig numbers from 2005 to 2010 in percent according to regions (GLEAM, 2010) .................................................................................................................... - 4 - Figure 3 Pork joint in Uganda with the pork hanging in the window © Martin Heilmann, ILRI / Freie Universität Berlin .............................................................................................. - 5 - Figure 4 Pork joint in Uganda from the inside © Martin Heilmann, ILRI / Freie Universität Berlin .................................................................................................................. - 6 - Figure 5 M. domestica on pork meat using its proboscis with the labellum for identifying and liquefying food © Martin Heilmann, ILRI / Freie Universität Berlin .......................... - 10 - Figure 6 Distal end of housefly’s proboscis with labellum and pseudotracheae. Scanning electron micrograph © Prof. Dr. H. Mehlhorn .................................................................... - 14 - Figure 7 Section of study area with pork butcheries from baseline (dark) and the one of them who took part in the intervention (light) © 2014 Google Maps Engine Lite ............. - 23 - Figure 8 Example for a choice card used in the questionnaire for butchers ....................... - 26 - Figure 9 Pork joint from intervention where net is installed as door frame on the right © Martin Heilmann, ILRI / Freie Universität Berlin .......................................................... - 29 - Figure 10 Pork joint from intervention with a net frame at the bottom of a glazed butchery © Martin Heilmann, ILRI / Freie Universität Berlin .......................................................... - 29 - Figure 11 Pork joint from intervention with a net stapled to the wall (sticky