poultry associated salmonella outbreak investigation case study bc zoonoses symposium november 10,...
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Poultry associated Salmonella outbreak investigation
Case StudyBC Zoonoses Symposium
November 10, 2015
Marsha Taylor, Jennifer Jeyes, Gwen Barker, Clayton Botkin, Brian Radke
So it beginsApril 30• Alberta (AB) informs BC Ministry of Agriculture (MAg) of 5 AB cases of Salmonella Enteritidis (SE) with live poultry contact, 1 case had contact with live poultry in AB & BC.
May 4• IH CD Unit notices an increase in Salmonella cases • MAg contacts BCCDC re: information from AB• BCCDC calls AB for further details on cluster investigation and shares information with IH
– cluster of Salmonella cases in Alberta – cases were associated with live poultry– 1 had a possible link to a community in IH
May 5-8• IH flags recent and new cases of Salmonella with live poultry contact for review
• IH notifies BCCDC of 4 cases of Salmonella with a history of close live poultry contact (in their house, snuggling/kissing).
– Store A was identified by one case as a purchase location of live chicks.
– None of the four cases were associated with the community initially reported by BCCDC/AB
• Unclear if these are related to the AB cluster.
• IH identifies:– 2 new cases of Salmonella associated with live chick exposure.– 2 new chick purchase locations (Stores B & C). – Miller Hatchery and Rochester Hatchery in AB are being named by
multiple Salmonella cases as the source for purchasing their live chicks.
• 6 cases under investigation in IH
• BCCDC receives name of hatchery (Miller/Rochester) and feed store that has received chicks (Store A) from AB, shares with IH.– Confirms link between AB and BC cases to common hatchery in AB
May 11-12
What questions do you have?What are you concerned about?
What would you want to investigate?
Hatchery flowSupp
ly Flock
•Broilers•Layers•Dual Purpose•Turkeys
Hatchery
• Received Eggs• Ships chicks/poults
Catalogue
• External Marketing
Client
• Via delivery agent
May 13-14• BC, AB, SK agree to national outbreak coordination by PHAC including public health and agriculture of each jurisdiction
Who is at risk? How will we communicate the risk? • 156 BC towns received chicks• Hatchery will distribute letter to clients regarding Salmonella risk of live chicks.
Concern from cases re: risk of Salmonella and managing risk at feed stores• IH receiving numerous questions from cases about flock management and safe
handling of live birds. • IH contacts 2 stores to understand purchaser notification of risk, ongoing chick
sale & infection control practices• Collaboration with MAg (contact information, communication package,
sampling)
May 19-21• BC prepares letter for hatchery dissemination to customers• IH reports chick sharing/online groups and occupational exposure
– Indicates hatchery letter won’t reach all affected individuals
• FHA and VIHA both report cases associated with live chicks contact from the hatchery of interest
• 13 cases in BC, 47 cases nationally
• AB, CFIA, PHAC have received media requests, will likely mention BC in
their interviews
May 22-25Ongoing communication challenges:• Incomplete list of all retail locations that received
chicks• Inaccurate information sent to BC clients directly
from hatchery• AB requests BC not share name of hatchery in any
public communication
Media
Naming the Hatchery?• Even with PHAC, BCCDC and IH press releases,
there is ongoing pressure from the media & the public to release the hatchery’s name
Should the hatchery be publically identified? Why or why not?
How we named the hatcheryBC public health and MAg agree to provide the hatchery names to individuals that call enquiring about the risk associated with their chicks
–Ensure people could identify risk accurately
Naming the hatchery, the rest of the story
• PHAC coordinates call with FPT organizations to discuss media and naming of the hatchery. Request is made that hatchery re-consider disclosing their name publically.
• Hatchery posts outbreak information to its websites (somewhat) self-identifying its involvement
May 27-29 May 27• The hatchery’s BC customers number are estimated
in the 100sMay 28 • 1st test kits mailed
500 sponges orderedMay 29• 96 kits mailed
900 sponges ordered
June 1-3 June 1 • 1st kit received by MAg for testingJune 2• Some kits are improperly packaged • Hatchery letters have been sent
to 1,100 BC customersJune 3• No more test kits available
Disposition of SE positive flocks
The Ministry of Agriculture needs to provide a recommended approach to owners of SE positive broiler flocks and layer flocks.
What are your recommendations & why?
June 3-4 • MAg begins work on SE carcass disposal
options• MoE Hazardous
Waste Regulations: each producer requires written authorization from Director for disposal of carcasses
June 11• 16 cases in BC, 47 cases nationally • MoE finalizes SE disposal options (on-site
composting or burial, off-site landfill) & requirements
• Kits: 371 mailed, 49 received• Testing results: 10 of 21 kits (48%) SE pos., 11 (52%)
neg. for Salmonella• Commercial producers might have received infected
chicks
Worse than AI• More producers, new clients• Less informed• Less resourced
June 16• 19 cases in BC, 53 cases nationally• Kits: 472 mailed, 133 received, 51% (39) of 76 SE pos.• Canada Post refuses to deliver SE kits; previous day smelly,
wet kits delivered, & deliverer told kits pose a zoonotic risk
June 17-19• Kits picked up from Canada Post depot with
deliveries to resume next day
• Confirmed 1 BC commercial broiler received chicks
July 18• 19 cases in BC, 61 cases nationally
• PHAC declares outbreak over
• Receiving about 5 kits/day for testing at AHC
Oct 7• Kits: 664 mailed, 491 received as of Sept 23
(74% return rate), • 42% pos. for SE, 54% neg., 4% pos. for
Salmonella• Cost to AHC
– Free kits: $10/kit x 664 = $6,640– Free testing $126/kit x 480 = $60,480
Outbreak summary• 61 lab-confirmed cases nationally (AB-35, BC-19, SK-5, MB-1, NT-1)
– All reported exposure to live poultry prior to illness• Onset dates reported between April 5 and June 17, 2015• 9 hospitalizations, 0 deaths
<April
5
April 5 - 1
1
April 12 - 1
8
April 19 - 2
5
April 26 - M
ay 2
May 3 - 9
May 10 - 1
6
May 17 - 2
3
May 24 - 3
0
May 31 - J
une 6
June 7 - 1
3
June 14 - 2
0
June 21 - 2
7
> June 2
80
5
10
15
SuspectProbableConfirmed
Illness Onset Date by Week
Num
ber o
f Cas
es
Integrating animal and human case information
Animal health • flock results• submitter list = exposed
population• some submitters volunteered
human health information
Public health • Identifiers
and exposure information on cases
• How do we integrate this analysis to help inform the investigation?– % positive among humans exposed to chicks– Impact of management on outcome of testing– Actions taken at case level
• Phage typing, MLVA, PFGE
→ WGS– One predominate outbreak clade
including:• clinical cases from AB, BC, SK, MB,
NT• hatchery isolates & all flock
isolates from AB and BC (except for 3)
• Clinical cases not identified as associated with outbreak?