Field Epidemiology SeminarMay 22,2014Krisandra Allen, MPHSenior ScientistDivision of Consolidated Laboratory Services

Poultry, Pastures, People, and the Power of PFGE: A multi-species

outbreak of Salmonella ser.Typhimurium

PRESENTATION OVERVIEW Salmonella Epidemiology and

Background Pulsed-field Gel Electrophoresis (PFGE)

overview Outbreak investigation Conclusions

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.

SEROTYPES AND THEIR HOSTS

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

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

SALMONELLA IN VIRGINIA

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

Top Ten Salmonella Serotypes Reported to the CDC PulseNet System by the Division of Consolidated Laboratory Services, Virginia, 2012

1 S. ser Enteritidis 2392 S. ser Typhimurium 1913 S. ser Newport 1174 S. ser Javiana 875 S. ser Bareilly 586 S. ser I 4,[5],12:i:- 347 S. ser Saintpaul 288 S. ser Infantis 199 S. ser Braenderup 18

10 S. ser Heidelberg 18Total Cases 2012 1144

SALMONELLA IN VIRGINIA

SALMONELLA IN VIRGINIA

Central Virginia Health District

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

SCOPE OF PULSENET

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

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.

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.

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

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

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

PFGE RESULTS

All isolates were indistinguishable by PFGE PulseNet patterns JPXX01.0302/ JPXA26.0183

XbaI Analysis BlnI AnalysisHuman

Cattle fetus ACattle fetus B

Poultry litter 2A

Poultry litter 2B

Poultry litter 2C

PFGE CLUSTER INVESTIGATIONSalmonella ser Typhimurium isolates July-

September 2013 JPXX01.0302/JPXA26.0183

INVESTIGATION SUMMARY

Cattle necropsy7/24

Salmonella isolates

received at DCLS

8/8 PFGE completed8/16

Stool sample collected7/30 Patient

interview8/2 PFGE completed8/14

Site visit to farm8/8 PFGE

completed8/29

Animal

Environmental

Clinical

July AugustSeptemb

er

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

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

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

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

QUESTIONS?

SAME PFGE PATTERN, DIFFERENT OUTBREAKS

http://www.aphl.org/conferences/proceedings/InFORM%20Conferences/InFORM%202013/010%20-%20Sandt.pdf

SAME PFGE PATTERN, DIFFERENT OUTBREAKS

http://www.foodsafetynews.com/2013/09/21-ill-in-salmonella-outbreak-linked-to-chicken-jerky-for-pets/#.U3AUlvldXng