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. 2010 Mar 16:10:69.
doi: 10.1186/1471-2334-10-69.

The use of a geographic information system to identify a dairy goat farm as the most likely source of an urban Q-fever outbreak

Barbara Schimmer  1 , Ronald Ter Schegget, Marjolijn Wegdam, Lothar Züchner, Arnout de Bruin, Peter M Schneeberger, Thijs Veenstra, Piet Vellema, Wim van der Hoek
Affiliations

The use of a geographic information system to identify a dairy goat farm as the most likely source of an urban Q-fever outbreak

Barbara Schimmer et al. BMC Infect Dis. .

Abstract

Background: A Q-fever outbreak occurred in an urban area in the south of the Netherlands in May 2008. The distribution and timing of cases suggested a common source. We studied the spatial relationship between the residence locations of human cases and nearby small ruminant farms, of which one dairy goat farm had experienced abortions due to Q-fever since mid April 2008. A generic geographic information system (GIS) was used to develop a method for source detection in the still evolving major epidemic of Q-fever in the Netherlands.

Methods: All notified Q-fever cases in the area were interviewed. Postal codes of cases and of small ruminant farms (size >40 animals) located within 5 kilometres of the cluster area were geo-referenced as point locations in a GIS-model. For each farm, attack rates and relative risks were calculated for 5 concentric zones adding 1 kilometre at a time, using the 5-10 kilometres zone as reference. These data were linked to the results of veterinary investigations.

Results: Persons living within 2 kilometres of an affected dairy goat farm (>400 animals) had a much higher risk for Q-fever than those living more than 5 kilometres away (Relative risk 31.1 [95% CI 16.4-59.1]).

Conclusions: The study supported the hypothesis that a single dairy goat farm was the source of the human outbreak. GIS-based attack rate analysis is a promising tool for source detection in outbreaks of human Q-fever.

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Figures

Figure 1
Figure 1
Epidemic curve of Q-fever and wind direction. Number of Q-fever cases in the Municipal Health Service region Brabant Southeast by week of illness onset (n = 95, black bars); and number of days in the week with prevailing eastern or north-eastern wind (white bars). Information on date of illness onset is missing for one case.
Figure 2
Figure 2
Map of the study area. Locations of goat and sheep farms with >40 animals (farm A-G) and residential addresses of Q-fever cases in urban and rural areas, 14 April to 10 August 2008.
See this image and copyright information in PMC

References

    1. Karagiannis I, Schimmer B, van Lier A, Timen A, Schneeberger P, van Rotterdam B, de Bruin A, Wijkmans C, Rietveld A, van Duynhoven Y. Investigation of a Q fever outbreak in a rural area of The Netherlands. Epidemiol Infect. 2009;137:1283–1294. doi: 10.1017/S0950268808001908. - DOI - PubMed
    1. Schimmer B, Morroy G, Dijkstra F, Schneeberger PM, Weers-Pothoff G, Timen A, Wijkmans C, Hoek W van der. Large ongoing Q fever outbreak in the south of The Netherlands, 2008. Euro Surveill. 2008;13 pii: 18939. - PubMed
    1. Schimmer B, Dijkstra F, Vellema P, Schneeberger PM, Hackert V, ter Schegget R, Wijkmans C, van Duynhoven Y, Hoek W van der. Sustained intensive transmission of Q fever in the south of the Netherlands, 2009. Euro Surveill. 2009;14 pii: 19210. - PubMed
    1. Brom R Van den, Vellema P. Q fever outbreaks in small ruminants and people in the Netherlands. Small Ruminant Res. 2009;86:74–79. doi: 10.1016/j.smallrumres.2009.09.022. - DOI
    1. Tissot-Dupont H, Amadei MA, Nezri M, Raoult D. Wind in November, Q fever in December. Emerg Infect Dis. 2004;10:1264–1269. - PMC - PubMed