Dr. Jorge Garrido - Cost Effective Influenza Sampling Strategies for Pigs
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- 1. Cost Effective Influenza Sampling Strategies for Pigs Jorge
Garrido Mantilla, Julio Alvarez, Marie Culhane, Montserrat
Torremorell
- 2. Introduction Materials and methods Results Conclusions This
image cannot currently be displayed. OVERVIEW
- 3. Manage the disease is not easy Surveillance is fundamental
to the control, elimination and prevention of influenza
Surveillance should be cost effective USDA Surveillance program
reduced funding There is a need for cost effective surveillance
since just detecting the virus is not enough: Need to conduct
sequencing and isolate virus APHIS USDA. Influenza Virus
Surveillance in Swine. Program Overview for Veterinarians
- 4. Influenza surveillance Surveillance is a balance of cost,
easiness to obtain sample, sensitivity, others. Sample size
Easiness Sensitivity Sequence Isolation Cost Individual sampling
Nasal swabs Group sampling Oral fluids
- 5. What is the best and most cost effective sampling strategy
to detect and to isolate influenza in pig farms?
- 6. Objectives To determine the most sensitive sampling method
to detect and isolate influenza virus in pigs To assess which
sampling strategy is most cost effective. Hypothesis Group and
environmental sampling strategies have similar sensitivity to
individual sampling in pig farms for detecting influenza and
isolating viruses.
- 7. METHODS 6 breeding herds and 6 wean to finish facilities (+)
Sample size calculation per farm - Individual samples: 30 samples
tested in pools of 3a - Assuming 20% prevalence, 80% test
sensitivity, 100% of specificity - Pen / litter samples: 8 10
samples - Assuming 40% prevalence, 80% test sensitivity, 100%
specificity. - Environmental samples:8 10 samples - 40%b
prevalence, 80% test sensitivity, 100% specificity. Tests: - FluA
Matrix rRT-PCR and cell culture in Madin-Darby Canine Kidney (MDCK)
cell line Statistical analysis and cost - Kappa, McNemar, z-test,
GLMM a. Lee C, et al. The impact of pooling nasal swab samples on
diagnostic sensitivity of IAV RRT-PCR. b. Neira V, et al.
Characterization of Viral Load, Viability and Persistence of
Influenza A Virus in Air and on Surfaces of Swine Production
Facilities
- 8. POS = ct < 35 SUS = ct 35.1 39.9 NEG = ct > 40 POS =
ct < 35
- 9. PCR results by sample type and farm 1 POS 8/10 (80) 7/10
(70) 10/10 (100) 3/3 (100) 9/10 (90) 10/10 (100) 10/10 (100) 10/10
2 POS 7/10 (70) 6/10 (60) 9/10 (90) 1/1 (100) 7/10 (70) 9/10 (90)
10/10 (100) 10/10 3 NEG 0/10 (0) 0/10 (0) 0/10 (0) 0/3 (0) 0/10 (0)
0/10 (0) 0/10 (0) 0/10 4 POS 2/10 (20) 3/10 (30) 4/10 (40) 1/2 (50)
3/10 (30) 5/10 (50) 5/10 10/10 5 POS 5/10 (50) 5/10 (50) 8/10 (80)
1/1 (100) 5/10 (50) 7/10 (70) 10/10 10/10 6 NEG 0/10 (0) 0/10 (0)
0/10 (0) 0/10 (0) 0/10 (0) 0/10 (0) 0/10 0/10 Total - 55.0% 53.0%
78.0% 86.0% 60.0% 78.0% 88.0% 100.0% 1 NEG 0/10 0/10 - 0/10 0/10 -
0/10 0/10 2 POS 6/10 6/10 - 4/10 3/10 - 0/10 1/10 3 POS 2/10 2/10 -
10/10 5/10 - 9/10 10/10 4 POS 4/10 4/10 - 5/10 5/10 - 7/10 6/8 5
POS 2/10 3/10 - 7/8 10/10 - 9/10 10/10 6 POS 1/10 1/10 - 4/10 2/10
- 4/10 4/10 Total - 30.0% 32.0% - 62.5% 50.0% - 58.0% 65.9% WEAN TO
FINISH BREEDING HERDS
- 10. Kappa showed moderate to substantial agreement among all
sampling strategies Sampling technique kappa coefficient Kappa CI
Nasal swabs Vs. Nasal wipes 0.760 (0.554, 0.965) Nasal swabs Vs.
Oropharyngeal swabs 0.597 (0.375, 0.819) Udder wipes Vs. Oral
fluids 0.775 (0.389, 1.161) Oral fluids Vs. Surfaces wipes 0.790
(0.423, 1.157) Surfaces wipes Vs. Udder wipes 0.552 (0.356, 0.749)
Airborne particle deposition Vs. Air 0.794 (0.575, 1.014) Nasal
swabs Vs. Nasal wipes 0.636 (0.452, 0.820) Oral fluids Vs. Surfaces
wipes 0.440 (0.257, 0.623) Airborne particle deposition Vs. Air
0.492 (0.304, 0.679) BREEDING HERDS WEAN TO FINISH
- 11. Generalized linear mixed model Two random effects (farm and
litter/pen) Nasal swab as the baseline 1 2 5 10 20 50 100 15.97***
6.63** 22.11*** 5.59* 1.99
- 12. Conclusions In this study, group and environmental sampling
strategies have similar sensitivity to individual sampling For
individual sampling strategies, oropharyngeal swabs were the best
Group and environmental sampling strategies based on PCR testing
were more cost effective given that they detected more positives.
Airborne influenza was readily detected in the air of farrowing
rooms
- 13. Acknowledgements Dr. Montserrat Torremorell Dr. Marie
Culhane Dr. Julio Alvarez Swine group students My Yang
Jayaveeramuthu Nirmala
- 14. Thanks garri098@umn.edu