This site needs JavaScript to work properly. Please enable it to take advantage of the complete set of features!
Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

NIH NLM Logo
Log in
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
doi: 10.1038/srep09492.

Risk factors associated with Rift Valley fever epidemics in South Africa in 2008-11

Affiliations

Risk factors associated with Rift Valley fever epidemics in South Africa in 2008-11

Raphaëlle Métras et al. Sci Rep. .

Abstract

Rift Valley fever (RVF) is a zoonotic and vector-borne disease, mainly present in Africa, which represents a threat to human health, animal health and production. South Africa has experienced three major RVF epidemics (1950-51, 1973-75 and 2008-11). Due to data scarcity, no previous study has quantified risk factors associated with RVF epidemics in animals in South Africa. Using the 2008-11 epidemic datasets, a retrospective longitudinal study was conducted to identify and quantify spatial and temporal environmental factors associated with RVF incidence. Cox regressions with a Besag model to account for the spatial effects were fitted to the data. Coefficients were estimated by Bayesian inference using integrated nested Laplace approximation. An increase in vegetation density was the most important risk factor until 2010. In 2010, increased temperature was the major risk factor. In 2011, after the large 2010 epidemic wave, these associations were reversed, potentially confounded by immunity in animals, probably resulting from earlier infection and vaccination. Both vegetation density and temperature should be considered together in the development of risk management strategies. However, the crucial need for improved access to data on population at risk, animal movements and vaccine use is highlighted to improve model predictions.

PubMed Disclaimer

Figures

Figure 1
Figure 1. Rift Valley fever 2008–11 epidemics in South Africa.
(A) Epidemic curve (daily number of RVF affected farms). Risk maps of the fitted hazard ratio for the (B) 2008, (C) first 2009, (D) second 2009, (E) 2010 and (F) 2011 outbreaks. For each outbreak wave, dots represent the location of affected farms, and crosses the location of previously affected farms. These maps were created using the software ArcGIS version 10.1.

References

    1. Bird B. H., Ksiazek T. G., Nichol S. T. & MacLachlan N. J. Rift Valley fever virus. J Am Vet Med Assoc 234, 883–893 (2009). - PubMed
    1. Pienaar N. J. & Thompson P. N. Temporal and spatial history of Rift Valley fever in South Africa: 1950 to 2011. Onderstepoort J Vet Res 80, Art.384, 13 pages. 10.4102/ojvr.v80i1.384 (2013). - DOI - PubMed
    1. Metras R. et al. Exploratory space-time analyses of Rift Valley fever in South Africa in 2008–2011. PLoS Negl Trop Dis 6, e1808 (2012). - PMC - PubMed
    1. Anyamba A. et al. Climate teleconnections and recent patterns of human and animal disease outbreaks. PLoS Negl Trop Dis 6, e1465 (2012). - PMC - PubMed
    1. Anonymous. Rift Valley fever. Northern Cape province. 12p (2009) Available at http://sun025.sun.ac.za/portal/page/portal/Health_Sciences/Afrikaans/Sen... (Accessed 15 September 2010).

Publication types

Full text links
Nature Publishing Group full text link Nature Publishing Group Free PMC article
Cite

AltStyle によって変換されたページ (->オリジナル) /