Salmonella Dublin Herd Bulk Tank Seroprevalence of NY Dairy Farms

Transcription

1 NYS Department of Agriculture & Markets Salmonella Dublin Herd Bulk Tank Seroprevalence of NY Dairy Farms Belinda S Thompson Paul D Virkler Elizabeth A Lussier David Smith Bettina Wagner 1

2 Salmonella Dublin Zoonotic concerns Food safety Clinical Infectious Diseases, 2004, 38(Suppl 3):S149 56; Appl Environ Microbiol Apr;75(7): ; USAHA Salmonella Committee USDA reports Not endemic on some herds (Northeast?) Anecdotally more prevalent in regions west of the Mississippi River, limited data: USDA NAHMS Dairy 2002 Prevention versus treatment Opportunity for control animal welfare and economic concerns 2

3 Salmonella Dublin Host adapted serotype for cattle Carrier animals Group D (D1) Multi-drug resistant Sensitive to only 4/17 antibiotics (enrofloxacin, gentamicin, neomycin, and trimethoprim/sulfamethoxazole) Zoonotic British Medical Journal, 1979, 2, ; Public Health Rep., 1988 Sep-Oct;103(5):489-93; MMWR Morb Mortal Wkly Rep Apr 13;33(14):

4 Salmonella Dublin Salmonella Dublin isolated from samples from farms in NY and PA Calves, 7-16 weeks of age, presenting with pneumonia (2 adult cases) J Clin Microbiol Aug;37(8): Not found between 1996 and 2006 at AHDC/NYS/Cornell laboratory Has continued since September 2006 Multidrug resistant isolate Epidemiologic link between many farms and a wider variation in disease presentation 4

5 Clinical Presentation Acute respiratory disease in calves (5 days to 8 months) most common presentation High mortality High fever Septicemia Meningitis/encephalitis Diarrhea not reported in all cases Vet Clin NA: Food An Pr, 25:1, March 2009, Pages Vet Micro, 162:1, 22 February 2013, Pages 1 9 Picture courtesy of Dr. Julia Rodriguez-Ramos Fernandez 5

6 Adult Cattle Clinical Presentation Adult cattle Enteritis Abortion Can be seen at any stage but more common during last trimester based on literature Variation in presentation depending on infectious dose Vet Micro, 162:1, 22 February 2013, Pages 1 9 Great Britain: abortion was the predominant clinical sign reported in 27% of the adult cattle diagnosed with S. Dublin Carrique-Mas et al., 2010 AHDC has not seen adult cattle pneumonia 6

7 Salmonella Dublin carrier animals Sensitivity of fecal shedding for non-clinical carrier animal detection, estimated to be as low as 6-14% in one study Serology helpful in detecting carrier animals Nielsen et al., J Appl Microbiol. 2004;96(2):311-9; Prev Vet Med May 10;68(2-4):165-79; J Appl Microbiol. 2006;100(1):

8 Salmonella Dublin Serology Serology testing Prionics Salmonella Dublin ELISA Samples are serum from individual animal, individual milk sample, bulk tank milk sample Detection of antibodies specifically to Salmonella Dublin Possibility of cross reaction with other Salmonella such as S. Typhimurium Antibodies detected 5-7 weeks post infection. 8

9 Salmonella Dublin Serology Warnick et al. (2006) estimated if four bulk tank samples were collected over a 5-12 month period and analyzed with the S. Dublin ELISA then: Herd level sensitivity = 95% Herd level specificity = 96% (assuming a 15% herd prevalence) Single sample sensitivity 38% specificity 98.4% Veling et al., 2002Prev. Vet. Med. 53,

10 Salmonella Dublin Bulk Tank Prevalence Study NY herds only NYS Data for 2012: 5152 (avg.) licensed dairy farms in NYS 10

11 Salmonella Dublin Bulk Tank Prevalence Study Sample every herd one time Collect samples at processing labs Coded to blind study to herd and processor identity Herds assigned a unique number to allow correlation of multiple tank herds and duplicate samples Tested using Prionics Salmonella Dublin ELISA 11

12 Salmonella Dublin Bulk Tank Prevalence Study NY herds only NYS Data for 2012: 5152 (avg.) licensed dairy 5246 bulk tank samples representing 4896 herds 261 farms have more than 1 tank ~256 missed (4.97%) 12

13 Salmonella Dublin Bulk Tank Prevalence Study 5152 (avg.) licensed dairy farms in NYS 5246 bulk tank samples 4896 herds 44 positive herds 0.899% serologically positive Based on 38% sensitivity expect 116 infected herds or 2.4% (+/-0.1) 99% CL 13

14 Questions? NYS Dairy Bulk Tank Salmonella Dublin Antibody Prevalence Study supported by: United States Agriculture APHIS VS Prionics USA 14

15 Herd Sensitivity of different testing methods

16 Salmonella Dublin Serology Evaluation of the ELISA with regard to infection in the individual animal varies based on age and cut-off used: Sensitivity = 45-74% Specificity = % The strength of the ELISA is as a herd level test or in repeated sampling Nielsen, LR. Overview of the pathogenesis, epidemiology and diagnostic tools necessary for successful surveillance and eradication of Salmonella Dublin from the Danish cattle population.: Prize assignment Professor Dr.med.h.c. C.O. Jensens Mindefond. Large Animal Sciences, University of Copenhagen p 16

17 Salmonella Dublin 51,000 dairies in US To detect 5 % (+/- 2.96) prevalence with 95% confidence Need ~200 samples in each of 6 regions of ~8500 herds 100 samples per region would detect a prevalence of 25% +/-8.44 w/95% confidence 17