Skip to main content
×
Home
    • Aa
    • Aa

The trend towards habitat fragmentation is the key factor driving the spread of Crimean-Congo haemorrhagic fever

  • A. ESTRADA-PEÑA (a1), Z. VATANSEVER (a2), A. GARGILI (a3) and Ö. ERGÖNUL (a4)
Summary
SUMMARY

We aimed to characterize an environmental niche driving the distribution of Crimean-Congo haemorrhagic fever (CCHF) in Turkey, using a georeferenced collection of cases reported between 2003 and 2008 and a set of climate and vegetation features. We used mean monthly air temperatures and Normalized Derived Vegetation Index (NDVI) values, at a resolution of 0·1°, as well as climate features at and below the surface. We computed significant differences in monthly variables between positive and negative sites, within the range of distribution of the tick vector. Seasonal climate (growth season and summer length, accumulated temperatures in winter) and vegetation components (anomalies in NDVI data) were analysed. Fragmentation of habitat was obtained from NDVI monthly data at a resolution of 1 km. Neither single climate or vegetation variables, nor any individual seasonal component, accounted in both space and time for the delineation of areas of disease although accumulated temperatures in winter consistently showed lower values in areas where the disease was reported. Coherent and significant differences between disease-containing and disease-free sites were found when habitat fragmentation and connectivity were examined. High fragmentation and connectivity were unambiguously associated with sites where disease is reported and accounted for the spatial spread of cases in 2003–2008. CCHF cases were always associated with areas of highly fragmented and well-connected patches within the range of the tick vector, while there were no reports from areas with low fragmentation. There was a linear relationship between degree of fragmentation and case incidence. The implications of these findings are discussed with reference to the concept of disease spread through networks of connected spots with high densities of infected vectors and social factors driving different human activities in sites of high fragmentation.

Copyright
Corresponding author
*Author for correspondence: Dr A. Estrada-Peña, Department of Parasitology, Veterinary Faculty, Miguel Servet 177, 50013-Zaragoza, Spain. (Email: aestrada@unizar.es)
References
Hide All
1.ECDC Meeting Report. Consultation on Crimean-Congo haemorragic fever prevention and control. Stockholm, 2008, 25 pp.
2.Yilmaz GR, et al. The epidemiology of Crimean-Congo hemorrhagic fever in Turkey, 2002–2007. International Journal of Infectious Diseases 2009; 13: 380386.
3.Apanaskevich DA, Horak IG. The genus Hyalomma Koch, 1844: V. Re-evaluation of the taxonomic rank of taxa comprising the H. (Euhyalomma) marginatum Koch complex of species (Acari: Ixodidae) with redescription of all parasitic stages and notes on biology. International Journal of Acarology 2008; 34: 1342.
4.Estrada-Peña A, et al. An early warning system for Crimean-Congo haemorrhagic fever seasonality in Turkey based on remote sensing technology. Geospatial Health 2008; 2: 127135.
5.Hoogstraal H. The epidemiology of tick-borne Crimean-Congo hemorrhagic fever in Asia, Europe, and Africa. Journal of Medical Entomology 1979; 15: 307417.
6.Korsunova OS, Petrova-Pointovskaya SP. A virus isolated from Hyalomma marginatum marginatum Koch, ticks. Zoologisches Zheischrift 1949; 28: 186187. [Translation 793 (T793), Medical Zoology Department, US NAMRU, Cairo, Egypt.]
7.Ergönul Ö, et al. Changes in temperature and the Crimean Congo hemorrhagic fever outbreak in Turkey. Clinical Microbiology and Infection 2005; 11: 360.
8.Allan BF, Keesing F, Ostfeld R. Effect of forest fragmentation on Lyme disease risk. Conservation Biology 2003; 17: 267272.
9.Jackson LE, Hilborn ED, Thomas JC. Towards landscape design guidelines for reducing Lyme disease risk. International Journal of Epidemiology 2006; 35: 315322.
10.Purnak T, Selvi NA, Altundag K. Global warming may increase the incidence and geographic range of Crimean-Congo Hemorrhagic Fever. Medical Hypotheses 2006; 10: 924925.
11.Estrada-Peña A, et al. Modeling the spatial distribution of crimean-congo hemorrhagic fever outbreaks in Turkey. Vector Borne Zoonotic Disease 2007; 7: 667678.
12.Grimenes AA, Nissen Ø. Mathematical modelling of the annual temperature wave based on monthly mean temperatures, and comparisons between local climate trends at seven Norwegian stations. Theoretical and Applied Climatology 2004; 78: 229246.
13.Schimit PHT, Monteiro LHA. On the basic reproduction number and the topological properties of the contact network: An epidemiological study in mainly locally connected cellular automata. Ecological Modelling 2009; 220: 10341042.
14.Urban DL, Keitt TH. Landscape connectivity: a graph-theoretic approach. Ecology 2001; 82: 12051218.
15.Estrada-Peña A. The relationships between habitat topology, critical scales of connectivity and tick abundance Ixodes ricinus in a heterogeneous landscape in northern Spain. Ecography 2003; 26: 661671.
16.Estrada-Peña A, et al. A framework to map abundance of tick metapopulations. Ecological Modelling 2006; 193: 663674.
17.Estrada-Peña A. Effects of habitats suitability and landscape patterns on tick (Acarina) metapopulation processes. Landscape Ecology 2004; 20: 529541.
18.Wilson JRU, et al. Something in the way you move: dispersal pathways affect invasion success. Trends in Ecology and Evolution 2009; 24: 136144.
19.Karti SS, et al. Crimean-Congo Hemorrhagic fever in Turkey. Emerging Infectious Diseases 2004; 10: 13791384.
20.Randolph SE, Ergönül Ö. Crimean-Congo hemorrhagic fever: exceptional epidemic of viral hemorrhagic fever in Turkey. Future Virology 2008; 4: 303306.
21.Randolph SE. Evidence that climate change has caused ‘emergence’ of tick-borne diseases in Europe? International Journal of Medical Microbiology 2004; 293: 5–15.
22.Randolph SE, et al. Seasonal synchrony: the key to tick-borne encephalitis foci identified by satellite data. Parasitology 2000; 121: 1523.
23.Randolph SE, et al. Variable spikes in tick-borne encephalitis incidence in 2006 independent of variable tick abundance but related to weather. Parasites and Vectors 2008; 1: 4462.
24.Hoogstraal H. Birds as tick hosts and as reservoirs and disseminators of tickborne infectious agents. Wiadomyszc Parazytologia 1972; 18: 703706.
25.Kondratenko VF. Factors determining population density of Hyalomma plumbeum Panz. and the effect of the latter on the incidence of Crimean hemorrhagic fever [in Russian]. Meditsinskaya parazitologya i parazitarnye bolezni (Moscow) 1978; 47: 1520.
26.Estrada-Peña A. ESCMID Conference on viral hemorrahgic fevers. Istanbul, Turkey, June 2008.
27.Materna J, Daniel M, Danielova V. Altitudinal distribution limit of the tick Ixodes ricinus shifted considerably towards higher altitudes in central Europe: results of three years monitoring in the Krkonose Mts. (Czech Republic). Central Europe Journal of Public Health 2005; 13: 2428.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Epidemiology & Infection
  • ISSN: 0950-2688
  • EISSN: 1469-4409
  • URL: /core/journals/epidemiology-and-infection
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords:

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 5
Total number of PDF views: 36 *
Loading metrics...

Abstract views

Total abstract views: 168 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 21st October 2017. This data will be updated every 24 hours.