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?