1. Q fever: Evidence of a massive yet undetected cross-border outbreak, with ongoing risk of extra mortality, in a Dutch-German border region.
- Author
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Hackert VH, Hoebe CJPA, Dukers-Muijrers N, Krafft T, Kauhl B, Henning K, Karges W, Sprague L, Neubauer H, and Al Dahouk S
- Subjects
- Animals, Antibodies, Bacterial blood, Blood Specimen Collection veterinary, Communicable Diseases, Imported mortality, Coxiella burnetii pathogenicity, Diagnostic Tests, Routine, Disease Outbreaks veterinary, Germany epidemiology, Humans, Immunoglobulin G blood, Immunoglobulin M blood, Linear Models, Mass Screening veterinary, Netherlands epidemiology, Q Fever mortality, Real-Time Polymerase Chain Reaction, Seroepidemiologic Studies, Sheep, Communicable Diseases, Imported transmission, Coxiella burnetii immunology, Disease Outbreaks statistics & numerical data, Q Fever transmission
- Abstract
Background: Following outbreaks in other parts of the Netherlands, the Dutch border region of South Limburg experienced a large-scale outbreak of human Q fever related to a single dairy goat farm in 2009, with surprisingly few cases reported from neighbouring German counties. Late chronic Q fever, with recent spikes of newly detected cases, is an ongoing public health concern in the Netherlands. We aimed to assess the scope and scale of any undetected cross-border transmission to neighbouring German counties, where individuals unknowingly exposed may carry extra risk of overlooked diagnosis., Methods: (A) Seroprevalence rates in the Dutch area were estimated fitting an exponential gradient to the geographical distribution of notified acute human Q fever cases, using seroprevalence in a sample of farm township inhabitants as baseline. (B) Seroprevalence rates in 122 neighbouring German postcode areas were estimated from a sample of blood donors living in these areas and attending the regional blood donation centre in January/February 2010 (n = 3,460). (C) Using multivariate linear regression, including goat and sheep densities, veterinary Q fever notifications and blood donor sampling densities as covariates, we assessed whether seroprevalence rates across the entire border region were associated with distance from the farm., Results: (A) Seroprevalence in the outbreak farm's township was 16.1%. Overall seroprevalence in the Dutch area was 3.6%. (B) Overall seroprevalence in the German area was 0.9%. Estimated mean seroprevalence rates (per 100,000 population) declined with increasing distance from the outbreak farm (0-19 km = 2,302, 20-39 km = 1,122, 40-59 km = 432 and ≥60 km = 0). Decline was linear in multivariate regression using log-transformed seroprevalence rates (0-19 km = 2.9 [95% confidence interval (CI) = 2.6 to 3.2], 20 to 39 km = 1.9 [95% CI = 1.0 to 2.8], 40-59 km = 0.6 [95% CI = -0.2 to 1.3] and ≥60 km = 0.0 [95% CI = -0.3 to 0.3])., Conclusions: Our findings were suggestive of widespread cross-border transmission, with thousands of undetected infections, arguing for intensified cross-border collaboration and surveillance and screening of individuals susceptible to chronic Q fever in the affected area., (© 2020 The Authors. Transboundary and Emerging Diseases published by Blackwell Verlag GmbH.)
- Published
- 2020
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