title: Inter-epidemic and between-season persistence of rift valley fever: vertical transmission or cryptic cycling?
abstract: Rift Valley fever (RVF) is an emerging zoonotic mosquito-borne infectious disease that has been identified as a risk for spread to other continents and can cause mass livestock mortality. In equatorial Africa, outbreaks of RVF are associated with high rainfall, when vector populations are at their highest. It is, however, unclear how RVF virus persists during the inter-epidemic periods and between seasons. Understanding inter-epidemic persistence as well as the role of vectors and hosts is paramount to creating effective management programmes for RVF control. We created a mathematical model for the spread of RVF and used the model to explore different scenarios of persistence including vertical transmission and alternate wildlife hosts, with a case study on buffalo in Kruger National Park, South Africa. Our results suggest that RVF persistence is a delicate balance between numerous species of susceptible hosts, mosquito species, vertical transmission and environmental stochasticity. Further investigations should not focus on a single species, but should instead consider a myriad of susceptible host species when seeking to understand disease dynamics.
authors.affiliation: Department of Mathematics, Tulane University, New Orleans, LA, USA; Center for Computational Science, Tulane University, New Orleans, LA, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Manore
authors.forename: B R
authors.initials: BR
authors.lastname: Beechler
mesh_terms: D000818:Animals; D003198:Computer Simulation; D009033:Culicidae / Q000821:virology; D004196:Disease Outbreaks / Q000662:veterinary*; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary; D058751:Livestock / Q000821:virology*; D008954:Models, Biological; D012295:Rift Valley Fever / Q000453:epidemiology* / Q000635:transmission*; D012296:Rift Valley fever virus; D012621:Seasons; D013019:South Africa / Q000453:epidemiology; D013045:Species Specificity; D015047:Zoonoses / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology
keywords: African buffalo; Rift Valley fever; inter-epidemic persistence; mathematical model; mosquito-borne disease; seasonal variation; vertical transmission; wildlife
references.citation: Vet Microbiol. 2008 Feb 5;127(1-2):21-8
references.pmid: 17884306
references.citation: J Theor Biol. 2012 Aug 7;306:129-44
references.pmid: 22564391
references.citation: J Am Vet Med Assoc. 2008 Feb 15;232(4):514-29
references.pmid: 18279085
references.citation: J Am Mosq Control Assoc. 2008 Dec;24(4):502-7
references.pmid: 19181056
references.citation: Rev Sci Tech. 2004 Aug;23(2):535-55
references.pmid: 15702718
references.citation: Am J Trop Med Hyg. 2000 Jan;62(1):151-6
references.pmid: 10761742
references.citation: J Insect Sci. 2007;7:1-7
references.pmid: 20337552
references.citation: Med Vet Entomol. 1988 Jul;2(3):231-6
references.pmid: 2980179
references.citation: Curr Mol Med. 2005 Dec;5(8):827-34
references.pmid: 16375716
references.citation: Transbound Emerg Dis. 2015 Feb;62(1):24-32
references.pmid: 24330522
references.citation: Epidemiol Infect. 1998 Oct;121(2):441-9
references.pmid: 9825798
references.citation: Proc Natl Acad Sci U S A. 2009 Jan 20;106(3):955-9
references.pmid: 19144928
references.citation: Am J Trop Med Hyg. 1993 Jun;48(6):757-62
references.pmid: 8333569
references.citation: Epidemiol Infect. 2008 Sep;136(9):1261-9
references.pmid: 17988425
references.citation: Rev Sci Tech. 2008 Aug;27(2):413-26
references.pmid: 18819669
references.citation: J Wildl Dis. 2000 Apr;36(2):316-23
references.pmid: 10813614
references.citation: Am J Trop Med Hyg. 2011 Apr;84(4):641-6
references.pmid: 21460024
references.citation: J Biol Dyn. 2013;7:11-40
references.pmid: 23098257
references.citation: Ecol Lett. 2006 Jun;9(6):706-25
references.pmid: 16706915
references.citation: J Hyg (Lond). 1975 Oct;75(2):219-30
references.pmid: 1058243
references.citation: Onderstepoort J Vet Res. 2003 Mar;70(1):49-64
references.pmid: 12825681
references.citation: Euro Surveill. 2010 Mar 11;15(10):19506
references.pmid: 20403309
references.citation: Emerg Infect Dis. 2002 Feb;8(2):138-44
references.pmid: 11897064
references.citation: Int J Antimicrob Agents. 2003 Feb;21(2):153-7
references.pmid: 12615379
references.citation: Vet Res. 2010 Nov-Dec;41(6):61
references.pmid: 21188836
references.citation: Am J Vet Res. 2010 May;71(5):522-6
references.pmid: 20433377