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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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.</p> <p>Results</p> <p>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]).</p> <p>Conclusions</p> <p>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.</p

Evaluation of a Novel Broad-Spectrum PCR-Multiplex Genotyping Assay for Identification of Cutaneous Wart-Associated Human Papillomavirus Types

A large number of human papillomavirus (HPV) types, distributed over five papillomavirus genera, are detectable in the skin. HPV types belonging to the alpha, gamma, and mu genera have been detected in cutaneous warts. A state-of-the-art HPV genotyping assay for these cutaneous wart-associated HPV types does not exist although warts constitute a highly prevalent skin condition, especially in children (33%) and organ transplant recipients (45%). Cutaneous warts are again the focus of attention as their clinical relevance rises with the increasing number of chronically immunosuppressed patients. The objective of this study was to develop and evaluate a DNA-based genotyping system for all known cutaneous wart-related HPV types using PCR and Luminex xMAP technology. The broad-spectrum PCR amplified DNA of all known wart-associated HPV types from the genera alpha (HPVs 2, 3, 7, 10, 27, 28, 29, 40, 43, 57, 77, 91, and 94), gamma (HPVs 4, 65, 95, 48, 50, 60, and 88), mu (HPVs 1 and 63), and nu (HPV41). The probes were evaluated using plasmid HPV DNA and a panel of 45 previously characterized cutaneous wart biopsy specimens showing high specificity. HPV was also identified in 96% of 100 swabs from nongenital cutaneous warts. HPV types 1, 2, 27, and 57 were the most prevalent HPV types detected in 89% of the swabs. In conclusion, this Luminex-based genotyping system identifies all known cutaneous wart HPV types including phylogenetically related types, is highly HPV type specific, and is suitable for large-scale epidemiological studies.Minor Ailment

Dispersie van Q-koorts door de lucht : Een modelleerstudie met het OPS-model

The OPS ("Operational Priority Substances ") computer model simulates the dispersion of pollutants in the air. It also appears to be suitable for modelling the transmission of Q fever bacteria from farm animals to humans. This is the major finding of a study carried out by the RIVM within the context of RIVM's Strategic Research project (SOR). The study results demonstrate that the model was well able to describe the transmission of Q fever bacteria on two infected goat farms. Uncertainties remain, such as the amount of bacteria released during an outbreak. More data are needed before the model can be routinely used to simulate the transmission of zoonoses through the air (aerosol) on infected farms. Infected goat farms are considered to be the source of the Q fever epidemic in the Netherlands between 2007 and 2010. However, the factors which cause Q fever bacteria to be transmitted from farm animals to humans and how the contaminated particles disperse through the air still remain largely undetermined. A suitable model provides policy-makers with model results that can be used as the basis for policy advice on the placement and distribution of farms.Met het rekenprogramma OPS (Operationele Prioritaire Stoffen) kan de verspreiding van verontreinigende stoffen in de lucht worden nagebootst. Het OPS-model lijkt ook geschikt om de overdracht van Q-koorts-bacteriën van bedrijf naar de mens in kaart te brengen. Dit blijkt uit een studie van het RIVM, die vanuit het Strategisch Onderzoek RIVM (SOR) is uitgevoerd. Het model heeft laten zien de overdracht rond twee besmette geitenbedrijven goed te kunnen beschrijven. Er zijn nog wel veel onzekerheden, bijvoorbeeld over de mate waarin bacteriën vrijkomen bij een uitbraak. Meer data zijn nodig voordat het model routinematig kan worden ingezet voor de overdracht van ziekteverwekkers door de lucht vanuit besmette bedrijven. Besmette geitenbedrijven worden gezien als bron van de Q-koorts-epidemie in Nederland tussen 2007 en 2010. Voor een groot deel is nog onbekend welke factoren de transmissie van de Q-koorts-bacterie van dierbedrijven naar de mens veroorzaken en hoe de besmette stofdeeltjes zich door de lucht verspreiden. Met een geschikt model kunnen beleidsmakers advies geven over het plaatsings- en spreidingsbeleid van veehouderijen. Trefwoorden:RIV