Stories from the Frontline: Investigating causes of salmonellosis in Australia. Name of program

Transcription

1 Stories from the Frontline: Investigating causes of salmonellosis in Australia

2 Salmonellosis in Australia Disease rates among highest in developed world Responsible for majority of foodborne outbreaks in Australia Salmonella Typhimurium most common serovar 20-30% of all cases hospitalised > 18,000 human cases in 2016 >4,400 in NSW NSW Food Safety Strategy, % reduction in foodborne salmonellosis cases Biosecurity & Food Safety

3 Understanding the sources of Salmonella: Foodborne vs non-foodborne Rank Salmonella serovar NSW human cases, 2016 Common source(s) 1 Typhimurium 1576 Eggs, poultry 2 Enteritidis 245 Overseas acquired 3 Virchow 167 Poultry 4 Saintpaul 140 Sprouts* 5 Paratyphi B bv Java 127 Environmental 6 Wangata 104 Environmental 7 Eggs, poultry Infantis 100 ser 4,5,12:i:- 99 Hvittingfoss 95 Birkenhead 88 Anatum 43 Probably Foodborne Mostly Non-foodborne Pigs, cattle, poultry Rockmelons* Environmental Bagged salads* *denotes outbreak in 2016 Attribution studies essential for prioritising resources and food safety interventions The top 10 serovars in NSW account for >60% of all human Salmonella cases 20% of these cases are not foodborne Large number of other serovars account for remaining human cases

4 Outbreaks at retail/food service

5 Understanding the cause Salmonella outbreaks at retail & foodservice Three most common contributing factors for salmonellosis outbreaks at retail in NSW (up to 2014) Lack of skills and knowledge Failure to clean and sanitise Inadequate use of eggs/raw egg foods

6 Retail Case Study Salmonella outbreak linked to pork rolls April 2015 numerous complaints of illness liked to South Sydney bakery Investigation findings: Unclean premises and equipment No sanitising Use of raw eggs Uncovered foods in refrigerator Evidence of pest activity Proprietor s daughter had Food Safety Supervisor certificate Studying accounting, rarely at the food business

7 Pork roll outbreak test results and outcome Test results 10 different foods positive for Salmonella (raw egg butter, sliced meats, salad items) 14 different swabs positive (cleaning cloth, equipment, chilled display units, wash up sink, shelves, door handles) Prohibition order on service of pork rolls for 3 weeks Approximately 40 people ill Business received ~ $3000 fines, name and shame listing

8 Salmonella Strategy Measures to decrease S. Typhimurium in NSW Development of Guidelines for Safe Use of Raw Egg Foods Mandated training modules in Food Safety Supervisor units to address outbreak causes - raw egg use - cleaning & sanitising - skills & knowledge Diligence of local council EHOs in reducing raw egg use - Business adoption of raw egg guidelines Better compliance with cleaning & sanitising, skills & knowledge

9 Effect of interventions S. Typhimurium NSW and national Salmonella rates (per 100K population) S. Typhimurium v total Salmonella NSW Salmonella rate AUS Salmonella rate NSW STm rate AUS STm rate Up to 2014: S. Typhimurium rates in NSW had a similar pattern to national rate up to 2014 S. Typhimurium accounted for over 50% of all human Salmonella cases on NSW up to 2014 After 2014: S. Typhimurium rates diverging from Salmonella trend Now less than half of all Salmonella cases So far in 2017: S. Typhimurium ~ 20% lower than corresponding period in cases in 2016 Down from peak of 2456 total cases in 2014

10 Outbreaks at Primary Production

11 Understanding the cause Salmonella outbreaks linked to fresh produce Three separate, national outbreaks in Salmonella Saintpaul, mung bean sprouts - Salmonella Anatum, bagged salads - Salmonella Hvittingfoss, rockmelons Influenced by: - climate events - poor handling & processing - food safety culture, inadequate audit/oversight SA Health blames raw bean sprouts for surge in salmonella cases (Adelaide Advertiser) Lettuce recall: Salmonella outbreak traced to prepacked salad mixes from major supermarkets (ABC News) 'Red Dirt' rockmelons recalled as Salmonella outbreak affects 80 people (SMH)

12 Number of notifications Salmonella Hvittingfoss notifications, NSW Jan July 2016 Outbreak investigation initiated Month of specimen collection

13 Outbreak chronology key dates 15 July OzFoodNet multijurisdictional outbreak investigation declared 18 July Alert to Industry/Govt Food Incident Forum No specific food identified, but fresh produce considered likely 28 July National Food Incident Response Protocol triggered 28 July Alert to industry, Australian Melon Association that rockmelons are a possible cause based on epidemiology, traceback investigation 2 August Salmonella confirmed on rockmelons from Red Dirt by South Australia Health Department 2 August Media advice for public not to consume rockmelons already bought 3 August Red Dirt named publicly, trade level recall

14 Investigation outcomes Melons from one grower consistently implicated in supply chain High prevalence of Salmonella Hvittingfoss found on melons Whole genome sequencing from melons identical to human isolates Over 150 people affected Significant financial damage to implicated producer - Several ha rockmelons left to rot - Decline in sales of other fruit - ~$800,000 loss Decline in sales and price in rockmelons nationally Western Australia, Northern Territory, Queensland

15 Whole genome sequencing 110 S. Hvittingfoss cases 99 cases of outbreak strain 1 (OC1) 10 cases of outbreak strain 2 (OC2) 1 case with isolation of both strains on separate samples (OC1 & OC2)

16 Outbreak contributing factors Problems with washing, sanitising - Mixing of fungicide & sanitiser Lack of monitoring (physical, microbiological) - No initial monitoring of chlorine-based sanitiser - Use of 10ppm stick to measure a sanitiser level of 100ppm General hygiene of facility - Excess dirt, dust - Recirculated water unit not adequately cleaned

17 Food Safety Culture FSANZ Food Safety Hub

18 Food safety culture across other producers: Was S. Hvittingfoss a one-off event? Food safety of 4 other rockmelons suppliers - Lack of adequate sanitiser - No monitoring for concentration - No awareness of limitations - Dirt/dust buildup - Shed doors often left open, area prone to dust storms - General hygiene of equipment - Dirt build up - Lack of regular cleaning - Other peripheral issues - Hot water to handwash basins, toilets, - Cobwebs, bird nests/droppings

19 Stakeholder follow up Commercial/supplier audits not addressing key food safety risks - Desktop audits - Audits conducted out-of-season, or focused on another commodity Retailer/industry meeting to review and consider revised approach - HARPS/additional audit focus

20 What does the future hold?

21 Australia s first foodborne disease reduction strategy National disease reduction strategy Agreed to by Ministers in 2017 Draft high-level plan by November National focus for first time in Australia Consistent, cross border initiatives National attribution studies, research

22 Whole Genome Sequencing Greater resolution compared with other methods More disease clusters for investigation Antibiotic resistance surveillance Potential to replace several existing identification methods Serotyping, other molecular testing (MLVA, PFGE) US target for 2019 for full use of WGS

23 Acknowledgements NSW DPI Dr SP Singh, Agriculture Food Incident Response Team Food Safety Unit NSW Health Dr Katherine Todd Enteric Diseases Team