title: Interacting Effects of Newcastle Disease Transmission and Illegal Trade on a Wild Population of White-Winged Parakeets in Peru: A Modeling Approach.
abstract: Illegal wildlife-pet trade can threaten wildlife populations directly from overharvest, but also indirectly as a pathway for introduction of infectious diseases. This study evaluated consequences of a hypothetical introduction of Newcastle disease (ND) into a wild population of Peru's most trafficked psittacine, the white-winged parakeet (Brotogeris versicolurus), through release of infected confiscated individuals. We developed two mathematical models that describe ND transmission and the influence of illegal harvest in a homogeneous (model 1) and age-structured population of parakeets (model 2). Infection transmission dynamics and harvest were consistent for all individuals in model 1, which rendered it mathematically more tractable compared to the more complex, age-structured model 2 that separated the host population into juveniles and adults. We evaluated the interaction of ND transmission and harvest through changes in the basic reproduction number (R0) and short-term host population dynamics. Our findings demonstrated that ND introduction would likely provoke considerable disease-related mortality, up to 24% population decline in two years, but high harvest rates would dampen the magnitude of the outbreak. Model 2 produced moderate differences in disease dynamics compared to model 1 (R0 = 3.63 and 2.66, respectively), but highlighted the importance of adult disease dynamics in diminishing the epidemic potential. Therefore, we suggest that future studies should use a more realistic, age-structured model. Finally, for the presumptive risk that illegal trade of white-winged parakeets could introduce ND into wild populations, our results suggest that while high harvest rates may have a protective effect on the population by reducing virus transmission, the combined effects of high harvest and disease-induced mortality may threaten population survival. These results capture the complexity and consequences of the interaction between ND transmission and harvest in a wild parrot population and highlight the importance of preventing illegal trade.
authors.affiliation: Schubot Exotic Bird Health Center, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America.
authors.forename: Elizabeth F
authors.initials: EF
authors.lastname: Daut
authors.affiliation: Department of Mathematics, Texas A&M University, College Station, Texas, United States of America.|Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America.
authors.forename: Glenn
authors.initials: G
authors.lastname: Lahodny
authors.affiliation: Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America.
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Peterson
authors.affiliation: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America.
authors.forename: Renata
authors.initials: R
authors.lastname: Ivanek
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000821:virology*; D050936:Basic Reproduction Number; D001715:Bird Diseases / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D004196:Disease Outbreaks; D008962:Models, Theoretical; D009521:Newcastle Disease / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D010240:Parakeets / Q000821:virology*; D010568:Peru; D011157:Population Dynamics
references.citation: Avian Dis. 1979 Jan-Mar;23(1):70-9
references.pmid: 486009
references.citation: Conserv Biol. 2006 Oct;20(5):1349-57
references.pmid: 17002752
references.citation: J Wildl Dis. 1998 Jul;34(3):457-71
references.pmid: 9706555
references.citation: Proc Biol Sci. 2006 Aug 22;273(1597):2025-34
references.pmid: 16846909
references.citation: Ecol Lett. 2006 Apr;9(4):467-84
references.pmid: 16623732
references.citation: Biodivers Conserv. 2008;17(6):1493-1516
references.pmid: 32214694
references.citation: Avian Pathol. 2008 Feb;37(1):1-5
references.pmid: 18202943
references.citation: PLoS One. 2010 Jan 07;5(1):e8479
references.pmid: 20062531
references.citation: Ecohealth. 2010 Aug;7(1):24-32
references.pmid: 20524140
references.citation: Prev Vet Med. 2012 Jan 1;103(1):49-62
references.pmid: 21945812
references.citation: Appl Environ Microbiol. 2009 Sep;75(18):5893-909
references.pmid: 19648372
references.citation: Nature. 1979 Aug 9;280(5722):455-61
references.pmid: 460424
references.citation: J Zoo Wildl Med. 2005 Dec;36(4):598-605
references.pmid: 17312715
references.citation: Nihon Juigaku Zasshi. 1981 Aug;43(4):557-9
references.pmid: 7339142
references.citation: Avian Dis. 2005 Jun;49(2):195-8
references.pmid: 16094822
references.citation: Avian Dis. 1977 Oct-Dec;21(4):642-54
references.pmid: 606222
references.citation: Am J Vet Res. 1978 Jan;39(1):105-7
references.pmid: 629430
references.citation: Nat Rev Microbiol. 2004 Aug;2(8):675-81
references.pmid: 15263902
references.citation: Avian Dis. 1993 Jan-Mar;37(1):254-8
references.pmid: 8452504
references.citation: Avian Dis. 2009 Mar;53(1):39-49
references.pmid: 19432002
references.citation: Avian Dis. 1988 Oct-Dec;32(4):713-7
references.pmid: 3202769
references.citation: J Hyg (Lond). 1973 Jun;71(2):325-39
references.pmid: 4515881
references.citation: PLoS One. 2008;3(11):e3602
references.pmid: 18985148
references.citation: Acta Biotheor. 2002;50(3):189-204
references.pmid: 12211331
references.citation: J Zoo Wildl Med. 1997 Dec;28(4):368-77
references.pmid: 9523629
references.citation: J Theor Biol. 2014 Jan 7;340:50-9
references.pmid: 24035840
references.citation: Ecology. 2006 Sep;87(9):2356-65
references.pmid: 16995636
references.citation: Proc Biol Sci. 2004 Dec 22;271(1557):2569-77
references.pmid: 15615682
references.citation: J Am Vet Med Assoc. 1992 Dec 1;201(11):1709-14
references.pmid: 1293111
references.citation: Avian Dis. 1980 Apr-Jun;24(2):486-92
references.pmid: 7436966
references.citation: J Wildl Dis. 1995 Oct;31(4):523-8
references.pmid: 8592384
references.citation: Eur J Epidemiol. 2000;16(7):601-6
references.pmid: 11078115
references.citation: Science. 2010 Aug 6;329(5992):679-82
references.pmid: 20689016
references.citation: Avian Dis. 1973 Jul-Sep;17(3):486-503
references.pmid: 4748340
references.citation: Am J Vet Res. 1992 Sep;53(9):1512-8
references.pmid: 1416348
references.citation: Rev Sci Tech. 2009 Apr;28(1):93-111
references.pmid: 19618621
references.citation: Am J Primatol. 2010 Sep;72(10):877-86
references.pmid: 20806336
references.citation: Avian Dis. 1990 Oct-Dec;34(4):803-8
references.pmid: 2282010
references.citation: Trop Anim Health Prod. 2009 Oct;41(7):1325-33
references.pmid: 19253000
references.citation: J Clin Microbiol. 2012 Feb;50(2):378-87
references.pmid: 22135263
references.citation: Trends Ecol Evol. 2001 Jun 1;16(6):295-300
references.pmid: 11369107
references.citation: Vet Med Int. 2012;2012:708216
references.pmid: 22577610
references.citation: Science. 2000 Jan 21;287(5452):443-9
references.pmid: 10642539
references.citation: Conserv Biol. 2013 Dec;27(6):1421-8
references.pmid: 23869813
references.citation: Proc Biol Sci. 2004 Mar 7;271(1538):501-7
references.pmid: 15129960
references.citation: J Avian Med Surg. 2010 Sep;24(3):199-209
references.pmid: 21046940
references.citation: Avian Dis. 1986 Oct-Dec;30(4):813-5
references.pmid: 3814018
references.citation: Am J Vet Res. 1996 Aug;57(8):1162-7
references.pmid: 8836368
references.citation: J Wildl Dis. 2010 Jul;46(3):718-23
references.pmid: 20688677
references.citation: Anim Conserv. 2012 Feb 1;15(1):28-53
references.pmid: 22389582
references.citation: Math Biosci. 2002 Nov-Dec;180:29-48
references.pmid: 12387915
references.citation: Wien Tierarztl Monatsschr. 1972;59(11):353-6
references.pmid: 4679543
references.citation: Trends Microbiol. 2006 Mar;14(3):125-31
references.pmid: 16460942
references.citation: Vet Rec. 1986 Apr 12;118(15):424-7
references.pmid: 3705396
references.citation: J Am Vet Med Assoc. 1975 Oct 1;167(7):610-4
references.pmid: 1176357
references.citation: Philos Trans R Soc Lond B Biol Sci. 2015 Apr 19;370(1666):
references.pmid: 25750231
references.citation: Avian Pathol. 1994 Sep;23(3):405-23
references.pmid: 18671109
references.citation: Trends Ecol Evol. 2005 Sep;20(9):511-9
references.pmid: 16701428
references.citation: PLoS Biol. 2004 Dec;2(12):e383
references.pmid: 15510230
references.citation: Vet Microbiol. 2009 May 12;136(3-4):226-32
references.pmid: 19091492
references.citation: Nature. 2000 Feb 24;403(6772):853-8
references.pmid: 10706275
references.citation: Rev Sci Tech. 2002 Apr;21(1):159-78
references.pmid: 11974627
references.citation: Avian Pathol. 1998;27(6):541-6
references.pmid: 18484041
references.citation: Proc Natl Acad Sci U S A. 2000 May 9;97(10):5303-6
references.pmid: 10792031
references.citation: Avian Dis. 2006 Sep;50(3):336-41
references.pmid: 17039831