Foodborne disease surveillance and outbreak investigations in Western Australia, first quarter 2015
OzFoodNet, Communicable Disease Control Directorate
Enhancing foodborne disease surveillance across AustraliaCommunicable Disease Control Directorate
Acknowledgments
Acknowledgement is given to the following people for their assistance with the activities
described in this report: Mr Damien Bradford, Ms Lyn O’Reilly, Ms Jenny Green, Mr Ray
Mogyorosy and the staff from the enteric, PCR and food laboratories at PathWest
Laboratory Medicine WA; staff from the Food Unit of the Department of Health, Western
Australia; Public Health Nurses from the metropolitan and regional Population Health
Units; and Local Government Environmental Health Officers.
Contributors/Editors
Nevada Pingault and Barry Combs
Communicable Disease Control DirectorateDepartment of Health, Western AustraliaPO Box 8172Perth Business CentreWestern Australia 6849
Email: [email protected]
Telephone: (08) 9388 4999
Facsimile: (08) 9388 4877
Web: OzFoodNet WA Health www.public.health.wa.gov.au/3/605/2/ozfoodnet_enteric_infections_reports.pmOzFoodNet Department of Healthwww.ozfoodnet.gov.au/
Disclaimer:
Every endeavour has been made to ensure that the information provided in this document
was accurate at the time of writing. However, infectious disease notification data are
continuously updated and subject to change.
This publication has been produced by the Department of Health, Western Australia.
1
Executive summary During the first quarter of 2015, the Western Australian (WA) OzFoodNet team conducted
surveillance of enteric diseases, undertook investigations into outbreaks and was involved
with ongoing enteric disease research projects.
The most common notifiable enteric infections in WA were campylobacteriosis (n=695),
salmonellosis (n=548), cryptosporidiosis (n=111) and rotavirus (n=77). Notifications of
Campylobacter, Salmonella and rotavirus were higher than the 5-year first quarter mean,
while Cryptosporidium notifications were lower.
Four foodborne or suspected foodborne outbreaks and a cluster of S. Kiambu infections
were investigated in the first quarter, while the investigation into the increase in S.
Typhimurium PFGE 0001 cases continued.
OzFoodNet also conducted surveillance of 37 non-foodborne outbreaks. Of these, the
most common mode of transmission was person-to-person (35 outbreaks), with a total of
690 people ill. Norovirus was the main agent responsible for infection (identified in 13
outbreaks), and half of the person-to-person outbreaks were in residential care facilities.
Figure 1 Notifications of the four most common enteric diseases by quarter from 2010 to 2015, WA
2
Table of Contents
Executive summary...........................................................................................................21 Introduction.................................................................................................................52 Incidence of notifiable enteric infections.................................................................6
2.1 Methods..................................................................................................................62.2 Campylobacteriosis.................................................................................................62.3 Salmonellosis..........................................................................................................72.4 Cryptosporidiosis.....................................................................................................82.5 Rotavirus infection...................................................................................................92.6 Other enteric diseases and foodborne illness.......................................................10
3 Foodborne and suspected foodborne disease outbreaks....................................113.1 Restaurant norovirus outbreak (outbreak code 01/15/JET)..................................113.2 Prison Salmonella Typhimurium PFGE 0003 outbreak (outbreak code 042-2015-001) 113.3 Function outbreak (outbreak code 03/15/COS).....................................................123.4 Convenience store lunch bar Salmonella Typhimurium PFGE 0013 outbreak (outbreak code 042-2015-002).......................................................................................12
4. Cluster investigations...............................................................................................124.1. S. Typhimurium PFGE 0001, phage type 9...........................................................134.2. Salmonella Kiambu...............................................................................................13
5. Non-foodborne disease outbreaks and outbreaks with an unknown mode of transmission.....................................................................................................................13
5.1. Person-to-person outbreaks..................................................................................145.2. Outbreaks with unknown mode of transmission....................................................145.3. Cryptosporidium suspected waterborne outbreak (outbreak code 081-2015-001)15
6. Site activities.............................................................................................................157. References.................................................................................................................16
List of Tables
Table 1 Number of campylobacteriosis notifications, 1st quarter 2015, WA, by region...................7Table 2 Number of salmonellosis notifications, 1st quarter 2015, WA, by region...........................7Table 3 Number of cryptosporidiosis notifications, 1st quarter 2015, WA, by region......................9Table 4 Number of rotavirus notifications, 1st quarter 2015, WA, by region..................................9Table 5 Outbreaks with non-foodborne transmission, 1st quarter 2015, WA................................14
List of Figures Figure 1 Notifications of the four most common enteric diseases by quarter from 2010 to 2015, WA..............................................................................................................................................................2
3
Notes:
1. All data in this report are provisional and subject to future revision.
2. To help place the data in this report in perspective, comparisons with other reporting periods are provided. As no formal statistical testing has been conducted, some caution should be taken with interpretation.
Copyright to this material is vested in the State of Western Australia unless otherwise indicated. Apart from any fair dealing for the purposes of private study, research, criticism or review, as permitted under the provisions of the Copyright Act 1968, no part may be reproduced or re-used for any purposes whatsoever without written permission of the State of Western Australia.
4
1 IntroductionIt has been estimated that there are 5.4 million cases of foodborne illness in Australia
each year at a cost of $1.2 billion per year1. This is likely to be an underestimate of the
total burden of gastrointestinal illness as not all enteric infections are caused by foodborne
transmission. Other important modes of transmission include person-to-person, animal-to-
person and waterborne transmission. Importantly, most of these infections are preventable
through interventions at the level of primary production, commercial food handling,
households and institution infection control.
This report describes enteric disease surveillance and investigations carried out during the
first quarter of 2015 by OzFoodNet WA, other WA Department of Health (WA Health)
agencies and local governments. Most of the data are derived from reports to WA Health
of 16 notifiable enteric diseases by doctors and laboratories. In addition, outbreaks caused
by non-notifiable enteric infections are also documented in this report, including norovirus,
which causes a large burden of illness in residential care facilities (RCF) and the general
community.
OzFoodNet WA is part of the Communicable Disease Control Directorate (CDCD) within
WA Health, and is also part of the National OzFoodNet network funded by the
Commonwealth Department of Health2. The mission of OzFoodNet is to enhance
surveillance of foodborne illness, including investigating and determining the cause of
outbreaks. OzFoodNet also conducts applied research into associated risk factors and
develops policies and guidelines related to enteric disease surveillance, investigation and
control. The OzFoodNet site, based in Perth, is responsible for enteric disease
surveillance and investigation in WA.
OzFoodNet WA regularly liaises with staff from Public Health Units (PHUs), the Food Unit
in the Environmental Health Directorate of WA Health; and the Food Hygiene, Diagnostic
and Molecular Epidemiology laboratories at PathWest Laboratory Medicine WA.
PHUs are responsible for public health activities, including communicable disease control,
within their respective administrative regions. The PHUs monitor RCF gastroenteritis
outbreaks and provide infection control advice. The PHUs also conduct follow-up of single
cases of important enteric diseases including typhoid, paratyphoid and hepatitis A.
5
The Food Unit liaises with Local Government (LG) Environmental Health Officers (EHO)
during the investigation of food businesses. The Food Hygiene, Diagnostic and Molecular
Epidemiology laboratories at PathWest Laboratory Medicine WA provide public health
laboratory services for the surveillance and investigation of enteric disease.
2 Incidence of notifiable enteric infections2.1 Methods
Enteric disease notifications were extracted from the Western Australian Notifiable
Infectious Diseases Database (WANIDD) by optimal date of onset (ODOO) for the time
period 1st January 2010 to 31st March 2015. The ODOO is a composite of the ‘true’ date of
onset provided by the notifying doctor or obtained during case follow-up, the date of
specimen collection for laboratory notified cases, and when neither of these dates is
available, the date of notification by the doctor or laboratory, or the date of receipt of
notification, whichever is earliest. Rates were calculated using estimated resident
population data for WA from Rates Calculator version 9.5.5 (WA Health, Government of
Western Australia), which is based on 2011 census data. Rates calculated for this report
have not been adjusted for age.
2.2 Campylobacteriosis
Campylobacteriosis was the most commonly notified enteric disease in WA during the first
quarter of 2015 (1Q15), with 696 notifications (Table 1) and a rate of 105 per 100 000
population per year. There was a 22% increase in Campylobacter notifications in the 1Q15
compared with the five year first quarterly mean (1QM). The increase appeared to be due
to sporadic disease, as there were no identified Campylobacter outbreaks during the
1Q15. At least some of the increase is likely to be due to the introduction by one large
private pathology laboratory of polymerase chain reaction (PCR) testing of faecal
specimens, which has greater sensitivity than culture techniques.
The place of acquisition of infection was reported for 59% (n=413) of cases, of which 79%
(325 cases) were locally acquired and 20% were acquired overseas (83 cases).
6
Table 1 Number of campylobacteriosis notifications, 1st quarter 2015, WA, by region
Number of Notifications
2015 1st QuarterMean of 1st Quarters
from 2010 to 20141st Quarter %
Change*Pilbara 22 10.4 111.5Kimberley 6 12.0 -50.0Midwest 16 12.8 25.0Goldfields 15 11.6 29.3Wheatbelt 22 16.0 37.5Greath Southern 13 16.6 -21.7Southwest 55 46.0 19.6South Metropolitan 260 197.8 31.4North Metropolitan 285 244.2 16.7Total 696 570.2 22.1© WA Department of Health 2015
Public Health Unit
*Percentage change in the number of notifications in the current quarter compared to the historical 5-year mean for the same quarter. Positive values indicate an increase when compared to the historical 5-year mean of the same quarter. Negative values indicate a decrease when compared to the historical 5-year mean of the same quarter.
2.3 Salmonellosis
Salmonellosis, was the second most commonly notified enteric disease in WA in the 1Q15,
with 548 notifications (Table 2) and a rate of 82 per 100 000 population per year. The
number of Salmonella notifications in the 1Q15 was 43% higher than the 1QM (n=384).
Table 2 Number of salmonellosis notifications, 1st quarter 2015, WA, by region
Number of Notifications
2015 1st QuarterMean of 1st Quarters
from 2010 to 20141st Quarter %
Change*Wheatbelt 16 10.4 53.8Goldfields 13 11.2 16.1Midwest 24 18.0 33.3Greath Southern 6 5.4 11.1Pilbara 22 17.2 27.9Kimberley 34 30.0 13.3Southwest 40 20.6 94.2South Metropolitan 179 126.6 41.4North Metropolitan 210 141.4 48.5Total 548 383.6 42.9© WA Department of Health 2015
Public Health Unit
*Percentage change in the number of notifications in the current quarter compared to the historical 5-year mean for the same quarter. Positive values indicate an increase when compared to the historical 5-year mean of the same quarter. Negative values indicate a decrease when compared to the historical 5-year mean of the same quarter.
7
Place of acquisition of infection was reported for 73% (n=398) of cases, of which 75%
(n=297) were locally acquired, 24% (n=95) were acquired overseas and 1% (n=6) were
acquired interstate.
The most commonly reported Salmonella serotype was S. Typhimurium (STM) (n=191),
and of those cases with information on place of acquisition (75%), 135 cases (94%) were
locally acquired. Pulsed-field gel electrophoresis (PFGE) is used in WA for the subtyping
of STM and the most common PFGE types were type 0001 (n=97) and type 0003 (n=21).
Cases with type 0001 were interviewed as part of an on-going cluster investigation (see
section 4); and cases with type 0003 were investigated as part of a prison outbreak (see
section 3).
S. Enteritidis was the second most common Salmonella serotype (n=57), and of those
cases with information on place of acquisition (96%), most (n=50, 91%) acquired their
infection overseas, primarily after travel to Indonesia (n=34, 68%), and almost exclusively
to Bali.
The next most commonly notified Salmonella serotypes were S. Saintpaul (n=31) and S.
Kiambu (n=21), which were both predominantly acquired in WA. Cluster investigations into
both of these serotypes are described in section 4.
2.4 Cryptosporidiosis
In the 1Q15, there were 111 Cryptosporidium notifications (Table 3) (17 per 100 000
population per year), which was a 12% decrease compared to the 1QM. However, large
increases in notifications were seen in the Kimberley and Pilbara regions. The increase in
the Pilbara was, in part, due to an outbreak epidemiologically associated with a local
swimming pool. No common source was identified for the increase in the Kimberley region.
The place of acquisition of infection was reported for 69% of cases (n=77) of which 90%
(n=69) were locally acquired and 10% (n=8) were overseas acquired.
8
Table 3 Number of cryptosporidiosis notifications, 1st quarter 2015, WA, by region
Number of Notifications
2015 1st QuarterMean of 1st Quarters
from 2010 to 20141st Quarter %
Change*Goldfields 1 5.0 -80.0Greath Southern 0 3.0 NAWheatbelt 2 4.0 -50.0Midwest 1 8.6 -88.4Pilbara 32 8.0 300.0Southwest 4 8.2 -51.2Kimberley 32 18.8 70.2North Metropolitan 17 36.6 -53.6South Metropolitan 22 34.2 -35.7Total 111 125.8 -11.8© WA Department of Health 2015
Public Health Unit
*Percentage change in the number of notifications in the current quarter compared to the historical 5-year mean for the same quarter. Positive values indicate an increase when compared to the historical 5-year mean of the same quarter. Negative values indicate a decrease when compared to the historical 5-year mean of the same quarter.
2.5 Rotavirus infectionIn the 1Q15 there were 77 notifications (Table 4) of rotavirus infection (12 per 100 000
population per year). There was a 32% increase in rotavirus notifications in the 1Q15
compared with the mean of the previous 3 years. This increase was predominantly seen in
the Perth metropolitan regions.
Table 4 Number of rotavirus notifications, 1st quarter 2015, WA, by region
Number of Notifications
2015 1st QuarterMean of 1st Quarters from 2012 to 2014**
1st Quarter % Change*
Goldfields 1 1.0 0.0Greath Southern 0 1.0 NAMidwest 0 1.0 NAWheatbelt 3 2.7 11.1Southwest 3 7.5 -60.0Kimberley 3 2.0 50.0Pilbara 1 2.0 -50.0South Metropolitan 29 21.7 33.6North Metropolitan 37 24.0 54.2Total 77 58.3 32.1© WA Department of Health 2015
Public Health Unit
*Percentage change in the number of notifications in the current quarter compared to the historical 3-year mean for the same quarter. Positive values indicate an increase when compared to the historical 3-year mean of the same quarter. Negative values indicate a decrease when compared to the historical 3-year mean of the same quarter.
**Rotavirus: comparison is only to 3 years (2012-2014) of data because changes in laboratory testing practices (increased use of more specific PCR over antigen testing) over the period 2009 to 2011 complicate comparison to 5-year data.
9
2.6 Other enteric diseases and foodborne illness During the 1Q15, other enteric disease notifications included:
Shigella infection: There were 44 Shigella notifications in 1Q15 that were culture
positive, which was 1.9 times the 1QM (n=24). Notifications comprised 34 S. sonnei
cases, which were predominantly locally acquired; eight S. flexneri cases (three
acquired overseas); one S. boydii case; and one isolate that was not speciated.
52% of notifications were in Aboriginal people; these were predominantly S. sonnei
infections in the Kimberley region.
Hepatitis A infection: Ten hepatitis A cases were notified in 1Q15, including seven
overseas and three locally acquired cases. The overseas acquired cases
contracted their infection in a variety of countries including Bangladesh, the
Philippines, Pakistan, United Kingdom, Vanuatu and Japan. One locally acquired
case appeared to be secondary to an overseas acquired case. One locally acquired
case was linked to the multi-jurisdictional outbreak associated with frozen berries.
The source of the third locally acquired case was unknown.
Yersinia infection: There were 12 Yersinia notifications in 1Q15 that were culture
positive (eight females, four males, aged 1-87 years). All cases were non-
Aboriginal. One case reported travel to India prior to onset.
Paratyphoid fever: Four cases (one female aged 8 years, three males aged 10-23
years) notified; three paratyphoid A cases and one paratyphoid B case. Cases
acquired their infections in Myanmar (n=2), Chile (n=1) and India (n=1).
Typhoid fever: Four cases (one male aged 29 years, three females aged 14-63
years) notified; three acquired their infections in India, and one in Myanmar.
Vibrio parahaemolyticus infection: Three locally acquired (all male, aged 28-89
years) and two overseas acquired (one male aged 42 years, one female aged 24
years) cases. The overseas-acquired cases reported travel to Vietnam and South
America, respectively.
Listeria monocytogenes infection: One elderly female, who died as a result of
her infection. The case was on oral corticosteroid therapy and had eaten a number
of high risk foods during her incubation period.
Hepatitis E infection: Two cases notified. One case (male, 52 years) acquired the
infection in India. The other case (male, 6 years) was identified post-liver transplant.
The source of the locally acquired case was unknown.
10
There were no notifications for botulism, shiga toxin E. coli or cholera in this quarter.
3 Foodborne and suspected foodborne disease outbreaks
There was one foodborne and three suspected foodborne disease outbreaks investigated
in this quarter.
3.1 Restaurant norovirus outbreak (outbreak code 01/15/JET)Two separate groups of people that ate lunch at a buffet restaurant on the 29/12/2014
reported gastroenteritis. At least nine people became ill following the meal, with a median
incubation period of 41 hours (range 35-47 hours) and median duration of 1.5 days (range
1-2 days). The single faecal specimen collected from an ill person was positive for
norovirus, and the incubation period, duration of illness and symptoms were consistent
with norovirus being the cause of the outbreak. An analytical study found a statistically
significant association between eating salads and becoming ill. The environmental
investigation found non-compliances related to the training of food handlers, and staff
members working while ill with gastroenteritis. One of these staff members was
responsible for preparation of salads on the day the two groups of patrons were exposed.
The epidemiological evidence indicated that the salads were the most likely vehicle of
transmission, and circumstantial evidence suggests possible contamination by an ill food
handler.
3.2 Prison Salmonella Typhimurium PFGE 0003 outbreak (outbreak code 042-2015-001)
A number of Salmonella outbreaks in WA prisons, along with sporadic cases of Salmonella
associated with prisons, were investigated in the 1Q15. In January, a regional prison
reported a gastroenteritis outbreak involving 32 prisoners and 10 staff, with eight STM
PFGE 0003-positive faecal samples collected from prisoners and a staff member. One
suspect meal was identified, as it was the only meal consumed at the prison by an ill
prison worker during their incubation period, which included a potato salad made with a
raw egg mayonnaise. The eggs were sourced from a prison farm. In February, the same
prison farm reported a gastroenteritis outbreak involving 13 prisoners, with two faecal
samples positive for STM PFGE 0003. Prisoners reported drinking raw egg milkshakes. In
March, a third outbreak occurred at a regional prison, involving six prisoners and one staff-
member, with two faecal samples positive for STM PFGE 0003. Prisoners again reported
11
drinking raw egg milkshakes. A further seven apparently sporadic cases of STM PFGE
0003 from six prisons were notified during the 1Q15. An inspection of the egg production
facilities at the implicated prison farm found a basic operation, with no candling or routine
cleaning of eggs. A chicken feed sample was positive for STM PFGE 0003 but eggs
sampled were negative for Salmonella. Further feed samples were negative for
Salmonella.
3.3 Function outbreak (outbreak code 03/15/COS)Following a midday function on the 27/3/15, several attendees became ill with
gastroenteritis. Of the 80 attendees, information was obtained from 11 people, seven of
whom were ill with diarrhoea and/or vomiting. The median incubation period was 30 hours
and median duration of vomiting and diarrhoea was 12 and 72 hours, respectively. One
person was positive for norovirus and illness characteristics of attendees were typical of
norovirus. Food served at the function included chicken sandwiches, tartlets, quiche,
sausage rolls, meatball skewers, scones and cake. One ill person did not attend the
function but ate function food later. Food was prepared by an unlicensed food business.
No staff reported illness. The source of the norovirus contamination was unknown.
3.4 Convenience store lunch bar Salmonella Typhimurium PFGE 0013 outbreak (outbreak code 042-2015-002)
A cluster of six cases of STM PFGE 0013 was identified in late March. Of the five cases
interviewed, four reported eating at the same convenience store lunch bar, with onset
dates between 12/3/15 and 21/3/15. Cases consumed a variety of pre-prepared
sandwiches and rolls. The environmental inspection did not identify any common
ingredients in the foods eaten. No staff members reported illness prior to the cluster of
cases and no deficiencies were identified at the premises.
4. Cluster investigationsThere was one ongoing and one new cluster investigation during the first quarter of 2015.
12
4.1. S. Typhimurium PFGE 0001, phage type 9 There were 97 cases of PFGE type 0001 infection notified, with specimen dates between
9/1/15 and 31/3/15. The cases included 59% males and 41% females, ranged in age from
<1 to 89 years (mean age 27 years), and most (76%) resided in the Perth metropolitan
area. Retail chicken meat sampled in September 2014 was also positive for PFGE type
0001. Of 58 cases with onsets from January to 24/2/15, 16 were interviewed using a
hypothesis-generating questionnaire. The leading hypothesis for the cause of illness was
consumption of free-range eggs or chicken meat. From the 25/2/15 to the 31/3/15, 39
cases were investigated as part of a case-control study of community acquired STM PFGE
0001 illness, with 27 cases enrolled. The investigation is ongoing.
4.2. Salmonella KiambuA cluster of S. Kiambu cases was identified, with 18 cases reported in the first quarter and
11 cases continuing into the second quarter. Onset dates were between 16/1/15 and
23/4/15, with 14 males and 15 females, ranging in age from <1 to 79 years (median age 8
years). Hypothesis-generating interviews were conducted with 14 cases. While no
common venues were identified, all cases reported eating eggs in the incubation period
and 71% (10/14 cases) reported eating raw or runny eggs during the incubation period.
Egg consumption in cases was increased compared to historical Salmonella cases (72%
egg consumption, 36% raw/runny egg consumption). No common brand of eggs was
identified. Retail egg sampling of both caged and free-range eggs was increased in
response to this cluster but no specimens were positive for S. Kiambu.
5. Non-foodborne disease outbreaks and outbreaks with an unknown mode of transmission
There were 37 outbreaks of enteric disease in this quarter that appeared to be non-
foodborne (see Table 5). Of these, 35 outbreaks were ascribed to person-to-person
transmission, one outbreak had an unknown mode of transmission and one outbreak was
suspected to be waterborne.
13
Table 5 Outbreaks with non-foodborne transmission, 1st quarter 2015, WA
Mode of transmission Setting Exposed Agent responsible
Number of outbreaks
Number of cases
Number hospitalised
1 Number died
Person to person Aged care Norovirus 13 371 3 2Aged care Unknown 7 100 1 0
Aged care total 20 471 4 2
Child care Unknown 11 161 7 0Hospital Norovirus 1 14 0 0Camp Unknown 1 23 0 0
Military Unknown 1 12 1 0Firefighters Unknown 1 9 0 0
Person to person Total
35 690 12 2
Unknown Aged care Unknown 1 8 0 0Suspected waterborne Pool Cryptosporidium 1 12 1 0
Grand total 37 710 13 2© WA Department of Health 2015
Outbreaks with non-foodborne transmission
1 Deaths temporally associated with gastroenteritis but contribution to death not specified
5.1. Person-to-person outbreaksIn the 35 non-foodborne outbreaks that were suspected to be due to person-to-person
transmission, 20 (57%) outbreaks occurred in RCFs, 11 (31%) were in child care centres,
and one each occurred in a hospital, camp, military site and in a group of firefighters. The
causative agent for 14 (40%) outbreaks was confirmed as norovirus. The remaining 21
(60%) outbreaks had unknown aetiology, as specimens were either not collected (n=14) or
were negative for common viral and bacterial pathogens (n=7).
A total of 690 people were affected in these 35 outbreaks, with 12 hospitalisations and two
associated deaths. The number of person-to-person outbreaks in the 1Q15 was 28%
higher than the 1QM (n=27.4).
5.2. Outbreaks with unknown mode of transmissionThere was one outbreak in a RCF in this quarter with an undetermined mode of
transmission, affecting eight people, with no reported hospitalisations or deaths. The most
common symptom reported in this outbreak was diarrhoea, while vomiting was reported
infrequently, which is not typical of norovirus outbreaks in RCF settings. Stool specimens
were collected and tested, but were negative for common bacterial and viral pathogens.
14
5.3. Cryptosporidium suspected waterborne outbreak (outbreak code 081-2015-001)
There were 12 cases of Cryptosporidium notified who lived in the same rural town, with
onsets from 2/2/2015 to the 4/3/2015, and comprising seven males and five females, with
a median age of 3 years (range <1-34 years). The median duration of diarrhoea was 7
days (range 1-28 days). All the cases had visited the same swimming pool during their
incubation period. The swimming pool management presumptively super-chlorinated the
pool to inactivate any Cryptosporidium.
6. Site activitiesDuring the first quarter of 2015, the following activities were conducted at the WA
OzFoodNet site:
Ongoing surveillance of foodborne disease in WA. Monitoring culture-independent nucleic acid amplification diagnostic testing in
private laboratories and impact on notification rates. Investigation of one foodborne and three suspected foodborne outbreaks. Investigation and monitoring of 35 non-foodborne gastroenteritis outbreaks and 1
outbreak of unknown mode of transmission. Investigation of one ongoing cluster and one new cluster of Salmonella infection. Responding to national OzFoodNet enteric disease surveillance requests. Attendance at the OzFoodNet face-to-face meeting in Darwin in March and
presentation of a talk on the WA prison outbreak. Interviewing Salmonella Enteritidis cases regarding travel status and attempting to
identify risk factors in locally acquired cases. Continuing to work with PathWest on the introduction in WA of MLVA typing of S.
Typhimurium isolates and PCR testing of bloody stools for STEC. Chairing the Series of National Guidelines (SoNG) working group for Listeria
infection. Membership of OzFoodNet working groups on:
o National STEC surveillanceo Outbreak registero Foodborne disease tool kito Egg-related outbreakso Culture-independent testing
Membership of national working groups on the: o Review of the SoNG for Hepatitis A o Rotavirus surveillance
15
Participating in monthly national OzFoodNet teleconferences.
7. References1 Hall G, Kirk MD, Becker N, Gregory JE, Unicomb L, Millard G, et al. Estimating
foodborne gastroenteritis, Australia. Emerg Infect Dis 2005;11(8):1257-1264.2 OzFoodNet Working Group. A health network to enhance the surveillance of
foodborne diseases in Australia. Department of Health and Ageing 2013. www.ozfoodnet.gov.au/internet/ozfoodnet/publishing.nsf/Content/Home-1 [14/03/2012].
16
This document can be made available in alternative formats on request for a person with a disability.
© Department of Health 2015
