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Devising an indicator to detect mid-term abortions in dairy cattle: a first step towards syndromic surveillance of abortive diseases.

Bronner A, Morignat E, Hénaux V, Madouasse A, Gay E, Calavas D - PLoS ONE (2015)

Bottom Line: On average, the weekly MAIR among heifers increased by 3.8% (min-max: 0.02-57.9%) when the mean number of BT8 cases that occurred in the previous 8 to 13 weeks increased by one.The weekly MAIR among parous cows increased by 1.4% (0.01-8.5%) when the mean number of BT8 cases occurring in the previous 6 to 12 weeks increased by one.These results underline the potential of the MAIR to identify an increase in mid-term abortions and suggest that it is a good candidate for the implementation of a syndromic surveillance system for bovine abortions.

View Article: PubMed Central - PubMed

Affiliation: ANSES-Lyon, Unité Epidémiologie, 31 avenue Tony Garnier, 69364 Lyon Cedex 07, France.

ABSTRACT
Bovine abortion surveillance is essential for human and animal health because it plays an important role in the early warning of several diseases. Due to the limited sensitivity of traditional surveillance systems, there is a growing interest for the development of syndromic surveillance. Our objective was to assess whether, routinely collected, artificial insemination (AI) data could be used, as part of a syndromic surveillance system, to devise an indicator of mid-term abortions in dairy cattle herds in France. A mid-term abortion incidence rate (MAIR) was computed as the ratio of the number of mid-term abortions to the number of female-weeks at risk. A mid-term abortion was defined as a return-to-service (i.e., a new AI) taking place 90 to 180 days after the previous AI. Weekly variations in the MAIR in heifers and parous cows were modeled with a time-dependent Poisson model at the département level (French administrative division) during the period of 2004 to 2010. The usefulness of monitoring this indicator to detect a disease-related increase in mid-term abortions was evaluated using data from the 2007-2008 episode of bluetongue serotype 8 (BT8) in France. An increase in the MAIR was identified in heifers and parous cows in 47% (n = 24) and 71% (n = 39) of the departements. On average, the weekly MAIR among heifers increased by 3.8% (min-max: 0.02-57.9%) when the mean number of BT8 cases that occurred in the previous 8 to 13 weeks increased by one. The weekly MAIR among parous cows increased by 1.4% (0.01-8.5%) when the mean number of BT8 cases occurring in the previous 6 to 12 weeks increased by one. These results underline the potential of the MAIR to identify an increase in mid-term abortions and suggest that it is a good candidate for the implementation of a syndromic surveillance system for bovine abortions.

No MeSH data available.


Related in: MedlinePlus

Relative risk and confidence interval of the bluetongue covariate computed over common time intervals.Relative risks (RR) and confidence intervals of the bluetongue covariate are displayed for the départements in which the bluetongue covariate had a positive effect, for heifers (Fig. 5A, on the left, 31 départements), and for parous cows (Fig. 5B, on the right, 36 départements). Départements are sorted in the ascending order of their RR. In the other départements, the bluetongue covariate had a non-significant effect.
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pone.0119012.g005: Relative risk and confidence interval of the bluetongue covariate computed over common time intervals.Relative risks (RR) and confidence intervals of the bluetongue covariate are displayed for the départements in which the bluetongue covariate had a positive effect, for heifers (Fig. 5A, on the left, 31 départements), and for parous cows (Fig. 5B, on the right, 36 départements). Départements are sorted in the ascending order of their RR. In the other départements, the bluetongue covariate had a non-significant effect.

Mentions: Among heifers, time lags ℓ̅j and k̅j averaged among départements were of 13 and 8 weeks (Fig. 4). The number of BT8 cases averaged over a common time interval ranging between 8 and 13 weeks prior to week w (B̅tw−13,w−8) had a positive effect in 61% of départements (Table 1), with a relative risk (RR) ranging from 1.002 to 1.579 and a median and mean of 1.013 and 1.038, respectively (Fig. 5). Among parous cows, average time lags ℓ̅j and k̅j estimated among départements were of 12 and 6 weeks (Fig. 4). The number of BT8 cases averaged over a common time interval ranging between 6 and 12 weeks prior to week w (B̅tw−12,w−6) had a positive effect in 65% of départements (Table 1), with an RR ranging from 1.001 to 1.085 and a median and mean value of 1.008 and 1.014, respectively (Fig. 5).


Devising an indicator to detect mid-term abortions in dairy cattle: a first step towards syndromic surveillance of abortive diseases.

Bronner A, Morignat E, Hénaux V, Madouasse A, Gay E, Calavas D - PLoS ONE (2015)

Relative risk and confidence interval of the bluetongue covariate computed over common time intervals.Relative risks (RR) and confidence intervals of the bluetongue covariate are displayed for the départements in which the bluetongue covariate had a positive effect, for heifers (Fig. 5A, on the left, 31 départements), and for parous cows (Fig. 5B, on the right, 36 départements). Départements are sorted in the ascending order of their RR. In the other départements, the bluetongue covariate had a non-significant effect.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4352010&req=5

pone.0119012.g005: Relative risk and confidence interval of the bluetongue covariate computed over common time intervals.Relative risks (RR) and confidence intervals of the bluetongue covariate are displayed for the départements in which the bluetongue covariate had a positive effect, for heifers (Fig. 5A, on the left, 31 départements), and for parous cows (Fig. 5B, on the right, 36 départements). Départements are sorted in the ascending order of their RR. In the other départements, the bluetongue covariate had a non-significant effect.
Mentions: Among heifers, time lags ℓ̅j and k̅j averaged among départements were of 13 and 8 weeks (Fig. 4). The number of BT8 cases averaged over a common time interval ranging between 8 and 13 weeks prior to week w (B̅tw−13,w−8) had a positive effect in 61% of départements (Table 1), with a relative risk (RR) ranging from 1.002 to 1.579 and a median and mean of 1.013 and 1.038, respectively (Fig. 5). Among parous cows, average time lags ℓ̅j and k̅j estimated among départements were of 12 and 6 weeks (Fig. 4). The number of BT8 cases averaged over a common time interval ranging between 6 and 12 weeks prior to week w (B̅tw−12,w−6) had a positive effect in 65% of départements (Table 1), with an RR ranging from 1.001 to 1.085 and a median and mean value of 1.008 and 1.014, respectively (Fig. 5).

Bottom Line: On average, the weekly MAIR among heifers increased by 3.8% (min-max: 0.02-57.9%) when the mean number of BT8 cases that occurred in the previous 8 to 13 weeks increased by one.The weekly MAIR among parous cows increased by 1.4% (0.01-8.5%) when the mean number of BT8 cases occurring in the previous 6 to 12 weeks increased by one.These results underline the potential of the MAIR to identify an increase in mid-term abortions and suggest that it is a good candidate for the implementation of a syndromic surveillance system for bovine abortions.

View Article: PubMed Central - PubMed

Affiliation: ANSES-Lyon, Unité Epidémiologie, 31 avenue Tony Garnier, 69364 Lyon Cedex 07, France.

ABSTRACT
Bovine abortion surveillance is essential for human and animal health because it plays an important role in the early warning of several diseases. Due to the limited sensitivity of traditional surveillance systems, there is a growing interest for the development of syndromic surveillance. Our objective was to assess whether, routinely collected, artificial insemination (AI) data could be used, as part of a syndromic surveillance system, to devise an indicator of mid-term abortions in dairy cattle herds in France. A mid-term abortion incidence rate (MAIR) was computed as the ratio of the number of mid-term abortions to the number of female-weeks at risk. A mid-term abortion was defined as a return-to-service (i.e., a new AI) taking place 90 to 180 days after the previous AI. Weekly variations in the MAIR in heifers and parous cows were modeled with a time-dependent Poisson model at the département level (French administrative division) during the period of 2004 to 2010. The usefulness of monitoring this indicator to detect a disease-related increase in mid-term abortions was evaluated using data from the 2007-2008 episode of bluetongue serotype 8 (BT8) in France. An increase in the MAIR was identified in heifers and parous cows in 47% (n = 24) and 71% (n = 39) of the departements. On average, the weekly MAIR among heifers increased by 3.8% (min-max: 0.02-57.9%) when the mean number of BT8 cases that occurred in the previous 8 to 13 weeks increased by one. The weekly MAIR among parous cows increased by 1.4% (0.01-8.5%) when the mean number of BT8 cases occurring in the previous 6 to 12 weeks increased by one. These results underline the potential of the MAIR to identify an increase in mid-term abortions and suggest that it is a good candidate for the implementation of a syndromic surveillance system for bovine abortions.

No MeSH data available.


Related in: MedlinePlus