Volume 19, Number 6—June 2013
Research
Transmission Potential of Rift Valley Fever Virus over the Course of the 2010 Epidemic in South Africa
Figure 6
![Mean effective daily reproduction number (Re) during Rift Valley fever epidemic, South Africa, 2010. Re was estimated by using D0(s,t) values (dashed black line) and D0(s,t) smoothed surfaces obtained with bandwidth values of 1 (dark gray), 3 (medium gray), and 5 (light gray). D0(s,t) values were estimated by using the space–time K-function (19,20) and are a measure of the spatiotemporal proximity between cases. The horizontal dashed line represents the threshold value Re = 1.](/eid/images/12-1641-F6.jpg)
Figure 6. . Mean effective daily reproduction number (Re) during Rift Valley fever epidemic, South Africa, 2010. Re was estimated by using D0(s,t) values (dashed black line) and D0(s,t) smoothed surfaces obtained with bandwidth values of 1 (dark gray), 3 (medium gray), and 5 (light gray). D0(s,t) values were estimated by using the space–time K-function (19,20) and are a measure of the spatiotemporal proximity between cases. The horizontal dashed line represents the threshold value Re = 1.
References
- Pepin M, Bouloy M, Bird BH, Kemp A, Paweska J. Rift Valley fever virus (Bunyaviridae: Phlebovirus): an update on pathogenesis, molecular epidemiology, vectors, diagnostics and prevention. Vet Res. 2010;41:61 and. DOIPubMedGoogle Scholar
- Bird BH, Ksiazek TG, Nichol ST, Maclachlan NJ. Rift Valley fever virus. J Am Vet Med Assoc. 2009;234:883–93 and. DOIPubMedGoogle Scholar
- Linthicum KJ, Anyamba A, Tucker CJ, Kelley PW, Myers MF, Peters CJ. Climate and satellite indicators to forecast Rift Valley fever epidemics in Kenya. Science. 1999;285:397–400 and. DOIPubMedGoogle Scholar
- Anyamba A, Chretien JP, Small J, Tucker CJ, Formenty PB, Richardson JH, Prediction of a Rift Valley fever outbreak. Proc Natl Acad Sci U S A. 2009;106:955–9 and. DOIPubMedGoogle Scholar
- Logan TM, Linthicum KJ, Thande PC, Wagateh JN, Nelson GO, Roberts CR. Egg hatching of Aedes mosquitoes during successive floodings in a Rift Valley fever endemic area in Kenya. J Am Mosq Control Assoc. 1991;7:109–12 .PubMedGoogle Scholar
- Fontenille D, Traore-Lamizana M, Diallo M, Thonnon J, Digoutte JP, Zeller HG. New vectors of Rift Valley fever in West Africa. Emerg Infect Dis. 1998;4:289–93 and. DOIPubMedGoogle Scholar
- Alexander RA. Rift Valley fever in the Union. J S Afr Vet Med Assoc. 1951;22:105–9.
- Coetzer JA. The pathology of Rift Valley fever. I. Lesions occurring in natural cases in new-born lambs. Onderstepoort J Vet Res. 1977;44:205–11 .PubMedGoogle Scholar
- World Organisation for Animal Health. Rift Valley fever. Follow-up report no. 17. Report reference: Free State Bultfontein, OIE ref: 9982, report date: 2010 Nov 29, country: South Africa [cited 2011 Oct 17]. http://web.oie.int/wahis/reports/en_fup_0000009982_20101129_173322.pdf
- World Organisation for Animal Health. Rift Valley fever. Follow-up report no. 14, ref: 11073, report date: 2011 Sep 28, country: South Africa. 2011 [cited 2011 Oct 17]. http://web.oie.int/wahis/reports/en_fup_0000011073_20110929_143957.pdf
- World Organisation for Animal Health. Immediate notification report. Report reference: Free State Bultfontein, ref OIE: 8967, report date: 2010 Feb 19, country: South Africa. 2010 [cited 2012 May 18]. http://www.cnmsf.gob.do/Portals/0/docs/Textos%20Variados/Fiebre%20del%20Valle%20del%20Rift,%20Sud%C3%A1frica.pdf
- News 24. Rift Valley fever—South Africa (02): (Free State). ProMed; 2010 Mar 16 [cited 2011 Oct 17]. http://www.promedmail.org, archive no. 20100316.0845.
- AllAfrica.com. Rift Valley fever—South Africa (09): multi-province. ProMed; 2010 Apr 7 [cited 2011 Oct 17]. http://www.promedmail.org, archive no. 20100407.1119.
- World Organisation for Animal Health. Rift Valley fever, South Africa. Follow-up report no. 10, ref: 9305, report date: 2010 Apr 25, country: South Africa. 2010 [cited 2012 Oct 31] http://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?reportid=9305
- Vynnycky E, White RG. An introduction to infectious disease modelling. Oxford (UK): Oxford University Press; 2010.
- Lipsitch M, Cohen T, Cooper B, Robins JM, Ma S, James L, Transmission dynamics and control of severe acute respiratory syndrome. Science. 2003;300:1966–70 and. DOIPubMedGoogle Scholar
- Wallinga J, Teunis P. Different epidemic curves for severe acute respiratory syndrome reveal similar impacts of control measures. Am J Epidemiol. 2004;160:509–16 and. DOIPubMedGoogle Scholar
- Wallinga J, Lipsitch M. How generation intervals shape the relationship between growth rates and reproductive numbers. Proc Biol Sci. 2007;274:599–604 and. DOIPubMedGoogle Scholar
- Métras R, Porphyre T, Pfeiffer DU, Kemp A, Thompson PN, Collins LM, Exploratory space–time analyses of Rift Valley fever in South Africa in 2008–2011. PLoS Negl Trop Dis. 2012 2012;6:e1808. PubMedGoogle Scholar
- Diggle PJ, Chetwynd AG, Haggkvist R, Morris SE. Second-order analysis of space–time clustering. Stat Methods Med Res. 1995;4:124–36 and. DOIPubMedGoogle Scholar
- Onderstepoort Biological Products Limited. Annual Report. 2010 [cited 2012 Sept 30]. http://www.obpvaccines.co.za/Cms_Data/Contents/OBPDB/Media/downloads/OBP%20Annual%20Report.pdf
- von Teichman BF, Louw I, Engelbrecht A, Heath JA, Smit TK. Onderstepoort Rift Valley fever virus vaccines. In: Proceedings of the 9th annual congress of the Southern African Society for Veterinary Epidemiology and Preventive Medicine; Pretoria, South Africa; 2010 Aug 18–20; 25–31.
- R Development Core Team. R: a language and environment for statistical computing. Vienna (Austria): R Foundation for Statistical Computing; 2012.
- Furrer R, Nychka D, Sain S. fields: tools for spatial data. R package version 6.6.2. 2011. http://CRAN.R-project.org/package=fields
- McIntosh BM, Jupp PG. Epidemiological aspects of Rift Valley fever in South Africa with reference to vectors. Contr. Epidem. Biostatist. 1981;3:92–9.
- Jupp PG, Kemp A. Studies on an outbreak of Wesselsbron virus in the Free State Province, South Africa. J Am Mosq Control Assoc. 1998;14:40–5 .PubMedGoogle Scholar
- Brubaker JF, Turell MJ. Effect of environmental temperature on the susceptibility of Culex pipiens (Diptera: Culicidae) to Rift Valley fever virus. J Med Entomol. 1998;35:918–21 .PubMedGoogle Scholar
- Turell MJ, Rossi CA, Bailey CL. Effect of extrinsic incubation temperature on the ability of Aedes taeniorhynchus and Culex pipiens to transmit Rift Valley fever virus. Am J Trop Med Hyg. 1985;34:1211–8 .PubMedGoogle Scholar
- World Organisation for Animal Health. Follow-up report no. 3. Ref: 8937, report date: 08/02/2010 Feb 8, country: South Africa. 2010 [cited 2010 Aug 10]. http://web.oie.int/wahis/reports/en_fup_0000008937_20100208_164327.pdf
- World Organisation for Animal Health. Follow-up report no. 6. Ref: 8397, report date: 27/08/2009 Aug 27, country: South Africa. 2009 [cited 2010 Sept 10]. http://web.oie.int/wahis/reports/en_fup_0000008397_20090827_173721.pdf
Page created: May 20, 2013
Page updated: May 20, 2013
Page reviewed: May 20, 2013
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.