This presentation discussed a multi-species outbreak of Salmonella serotype Typhimurium infections linked to the application of uncomposted poultry litter as fertilizer on grazing pastures. Pulsed-field gel electrophoresis (PFGE) analysis showed that Salmonella isolates from a sick person, two sick cattle fetuses, and samples of poultry litter from one of the fertilized sites were indistinguishable. The investigation concluded that applying uncomposted poultry litter, which can harbor Salmonella, to pastures exposes animals and the environment to Salmonella and can lead to infections in cattle and people. Public health officials provided education to reduce the risks from uncomposted poultry litter.

1. Field Epidemiology Seminar
May 22,2014
Krisandra Allen, MPH
Senior Scientist
Division of Consolidated Laboratory Services
Poultry, Pastures, People, and the
Power of PFGE: A multi-species
outbreak of Salmonella
ser.Typhimurium

2. PRESENTATION OVERVIEW
 Salmonella Epidemiology and Background
 Pulsed-field Gel Electrophoresis (PFGE)
overview
 Outbreak investigation
 Conclusions

3. SALMONELLA BACKGROUND
 Most persons infected with Salmonella spp.
develop diarrhea, fever, and abdominal
cramps 12 to 72 hours after infection.
 Approximately 2000 serotypes cause human
disease.
 An estimated 1.2 million cases occur
annually in the United States; of these,
approximately 42,000 are laboratory-
confirmed cases reported to CDC.

4. SEROTYPES AND THEIR HOSTS
Singh, V. Salmonella Serovars and Their Host Specificity. Journal of
Veterinary Science & Animal Husbandry, 1, 1-4.

5. SALMONELLA AND POULTRY
 Serotypes involved in
multi-state outbreaks in
2013
 Salmonella ser. Infantis
 Salmonella ser. Lille
 Salmonella ser. Newport
 Salmonella ser. Mbandaka
 Salmonella ser.
Typhimurium

6. SALMONELLA IN VIRGINIA
http://www.vdh.virginia.gov/Epidemiology/Surveillance/SurveillanceData/AnnualReports/
Reports/2012FullText.pdf

7. Top Ten Salmonella Serotypes Reported to the CDC PulseNet System
by the Division of Consolidated Laboratory Services, Virginia, 2012
1 S. ser Enteritidis 239
2 S. ser Typhimurium 191
3 S. ser Newport 117
4 S. ser Javiana 87
5 S. ser Bareilly 58
6 S. ser I 4,[5],12:i:- 34
7 S. ser Saintpaul 28
8 S. ser Infantis 19
9 S. ser Braenderup 18
10 S. ser Heidelberg 18
Total Cases 2012 1144
SALMONELLA IN VIRGINIA

8. SALMONELLA IN VIRGINIA
Central Virginia Health
District

9. BACKGROUND OF PFGE
 Laboratory technique that further
characterizes organisms
 Sometimes referred to as “DNA
Fingerprinting”
 All clinical Salmonella spp. isolates are
required to be sent to DCLS; PFGE is done
on all isolates
 Standardized protocols allow comparison
across laboratories through the PulseNet
system

11. SCOPE OF PULSENET

12. INTERPRETATION OF PFGE DATA
 Organisms which yield indistinguishable
banding patterns by PFGE may indicate a
common source
 PFGE data must be used in conjunction with
epidemiologic data
 Some PFGE patterns are very commonly
seen while others are rare

13. OUTBREAK INVESTIGATION
 Health Department notified Thursday 8/1 of a
positive Salmonella spp. stool culture on a
hospitalized patient
 Patient was interviewed in the hospital on 8/2
 Interview revealed that the patient lived on a
cattle farm and two calf fetuses had recently
tested positive for Salmonella spp.

14. OUTBREAK INVESTIGATION
 Calf fetus Salmonella isolates were
forwarded from the Virginia Department of
Agriculture and Consumer Services
(VDACS) lab to DCLS
 Human Salmonella isolate was forwarded to
DCLS from hospital laboratory
 Interviews with the farm owner found that
they fertilized the pastures with 7-8 loads of
uncomposted poultry litter.

15. POULTRY LITTER AS A FERTILIZER
“Poultry manure is an excellent source of nutrients and can be
incorporated into most fertilizer programs.” North Carolina State
University Soilfacts Publication
http://www.soil.ncsu.edu/publications/Soilfacts/AG-439-05/AG-439-5.pdf

16. OUTBREAK INVESTIGATION
 Site visit to the
farm on 8/8
 Samples
collected from
three sites where
the litter had been
dumped
 Samples sent to
DCLS for culture

17. CULTURE RESULTS
 3 samples of chicken litter taken from each site
 Site 1 – no Salmonella spp. isolated from any
samples
 Site 2 – Salmonella spp. isolated from 3/3 samples
 Site 3 – no Salmonella spp. isolated from any
samples All isolates identified as Salmonella ser.
Typhimurium
 1 human isolate
 2 cattle fetus isolates
 3 poultry litter isolates

18. PFGE RESULTS
 All isolates were indistinguishable by PFGE
 PulseNet patterns JPXX01.0302/ JPXA26.0183
XbaI Analysis BlnI Analysis
Human
Cattle fetus A
Cattle fetus B
Poultry litter 2A
Poultry litter 2B
Poultry litter 2C

19. PFGE CLUSTER INVESTIGATION
Salmonella ser Typhimurium isolates July-
September 2013 JPXX01.0302/JPXA26.0183

20. INVESTIGATION SUMMARY
Cattle
necropsy7/24
Salmonella
isolates
received at
DCLS
8/8 PFGE
completed
8/16
Stool
sample
collected
7/30 Patient
interview8/2 PFGE
completed8/14
Site visit
to farm8/8 PFGE
completed8/29
Animal
Environment
al
Clinical
July August
Septembe
r

21. CONCLUSIONS
 Poultry can harbor Salmonella spp. and shed
the bacteria in their feces
 Applying uncomposted poultry litter to grazing
pastures can expose animals and the
environment to Salmonella spp.
 Salmonella spp. infections in cattle may cause
abortions and death; widespread infections may
manifest as an abortion storm
 This farmer reported 30 abortions, 13 dead cows
and 1 dead bull during the outbreak

22. The
complete
story
Environmental
• Farmer
• Epidemiologist
• Laboratorian
• Agriculture Extension
Agent
Clinical
• Physician
• Nurse
• Laboratorian
• Epidemiologist
• Infection Preventionist
Animal
• Veterinarian
• Epidemiologist
• Laboratorian
• Farmer
PUBLIC HEALTH IS A PARTNERSHIP

23. PUBLIC HEALTH IS PREVENTION
 District Epidemiologist and Veterinary
Epidemiologist spoke at a local Cattlemen’s
Association Meeting
 Presented information about the investigation
 Provided information about composting poultry
litter to reduce the risk of Salmonella spp.
transmission

24. ACKNOWLEDGEMENTS
 Haley Evans, District Epidemiologist
 Kerry Gateley, MD, MPH, CPE, Director, Central Virginia
Health District
 Lex Gibson, Southwest Regional Epidemiologist
 Chris McNeil, DVM, MPH - VDACS
 James Bower, DVM - VDACS
 DCLS Epidemiologic Support Group
 Karen Gruszynski, DVM MPH PhD
 Julia Murphy, DVM
 Jessica Watson, Foodborne Disease Epidemiologist
 Todd Scott, Campbell County Agriculture Extension Agent
 Marjorie Williamson, DCLS CDC/APHL EID Training
Fellow

25. QUESTIONS?

26. SAME PFGE PATTERN, DIFFERENT OUTBREAKS
http://www.aphl.org/conferences/proceedings/InFORM%20Conferences/InFORM%2020
13/010%20-%20Sandt.pdf

27. SAME PFGE PATTERN, DIFFERENT OUTBREAKS
http://www.foodsafetynews.com/2013/09/21-ill-in-salmonella-outbreak-linked-to-
chicken-jerky-for-pets/#.U3AUlvldXng