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Q fever infection in dairy cattle herds: increased risk with high wind speed and low precipitation.

Nusinovici S, Frössling J, Widgren S, Beaudeau F, Lindberg A - Epidemiol. Infect. (2015)

Bottom Line: The implementation of effective control measures against Cb in ruminants requires knowledge about potential risk factors.The prevalence of test-positive herds was higher in the south of Sweden.Finally, the cumulated precipitation over 1 year was identified as a protective factor.

View Article: PubMed Central - PubMed

Affiliation: INRA,UMR1300 Biology,Epidemiology and Risk Analysis in Animal Health,CS 40706,F-44307 Nantes,France.

ABSTRACT
Ruminants are considered the main reservoir for transmission of Coxiella burnetii (Cb) to humans. The implementation of effective control measures against Cb in ruminants requires knowledge about potential risk factors. The objectives of this study were (i) to describe the spatial distribution of Q fever-infected dairy cattle herds in Sweden, (ii) to quantify the respective contributions of wind and animal movements on the risk of infection, while accounting for other sources of variation, and (iii) to investigate the possible protective effect of precipitation. A total of 1537 bulk milk samples were collected and tested for presence of Cb antibodies. The prevalence of test-positive herds was higher in the south of Sweden. For herds located in areas with high wind speed, open landscape, high animal densities and high temperature, the risk of being infected reached very high values. Because these factors are difficult to control, vaccination could be an appropriate control measure in these areas. Finally, the cumulated precipitation over 1 year was identified as a protective factor.

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Variogram quantifying the semivariance between pairs of observations (herd residuals from the logistic regression model) as the function of their Euclidean distance. The envelopes were based on 999 Monte Carlo permutations of the data, whereby positive and negative herds were randomly allocated to each farm location. In all, 1537 Swedish dairy herds tested in 2008–2009 were included in this study on risk factors for Coxiella burnetii infection.
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fig05: Variogram quantifying the semivariance between pairs of observations (herd residuals from the logistic regression model) as the function of their Euclidean distance. The envelopes were based on 999 Monte Carlo permutations of the data, whereby positive and negative herds were randomly allocated to each farm location. In all, 1537 Swedish dairy herds tested in 2008–2009 were included in this study on risk factors for Coxiella burnetii infection.

Mentions: Finally, as shown in Figure 5, the residuals of the model were distributed within the envelope. Thus, the choice of a classic logistic regression instead of a spatial model accounting for the spatial autocorrelation was appropriate.Fig. 5.


Q fever infection in dairy cattle herds: increased risk with high wind speed and low precipitation.

Nusinovici S, Frössling J, Widgren S, Beaudeau F, Lindberg A - Epidemiol. Infect. (2015)

Variogram quantifying the semivariance between pairs of observations (herd residuals from the logistic regression model) as the function of their Euclidean distance. The envelopes were based on 999 Monte Carlo permutations of the data, whereby positive and negative herds were randomly allocated to each farm location. In all, 1537 Swedish dairy herds tested in 2008–2009 were included in this study on risk factors for Coxiella burnetii infection.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594051&req=5

fig05: Variogram quantifying the semivariance between pairs of observations (herd residuals from the logistic regression model) as the function of their Euclidean distance. The envelopes were based on 999 Monte Carlo permutations of the data, whereby positive and negative herds were randomly allocated to each farm location. In all, 1537 Swedish dairy herds tested in 2008–2009 were included in this study on risk factors for Coxiella burnetii infection.
Mentions: Finally, as shown in Figure 5, the residuals of the model were distributed within the envelope. Thus, the choice of a classic logistic regression instead of a spatial model accounting for the spatial autocorrelation was appropriate.Fig. 5.

Bottom Line: The implementation of effective control measures against Cb in ruminants requires knowledge about potential risk factors.The prevalence of test-positive herds was higher in the south of Sweden.Finally, the cumulated precipitation over 1 year was identified as a protective factor.

View Article: PubMed Central - PubMed

Affiliation: INRA,UMR1300 Biology,Epidemiology and Risk Analysis in Animal Health,CS 40706,F-44307 Nantes,France.

ABSTRACT
Ruminants are considered the main reservoir for transmission of Coxiella burnetii (Cb) to humans. The implementation of effective control measures against Cb in ruminants requires knowledge about potential risk factors. The objectives of this study were (i) to describe the spatial distribution of Q fever-infected dairy cattle herds in Sweden, (ii) to quantify the respective contributions of wind and animal movements on the risk of infection, while accounting for other sources of variation, and (iii) to investigate the possible protective effect of precipitation. A total of 1537 bulk milk samples were collected and tested for presence of Cb antibodies. The prevalence of test-positive herds was higher in the south of Sweden. For herds located in areas with high wind speed, open landscape, high animal densities and high temperature, the risk of being infected reached very high values. Because these factors are difficult to control, vaccination could be an appropriate control measure in these areas. Finally, the cumulated precipitation over 1 year was identified as a protective factor.

Show MeSH
Related in: MedlinePlus