Assessing Environmental Data to Predict Shellfish Biotoxin Illness. Judy Ngo MFS Student Practicum, UBC. Lorraine McIntyre Industry Sponsor

Transcription

1 Assessing Environmental Data to Predict Shellfish Biotoxin Illness Judy Ngo MFS Student Practicum, UBC Lorraine McIntyre Industry Sponsor Dr. Kevin Allen Academic Supervisor, UBC

2 Objectives 1. Generate a history of marine biotoxin recalls in BC and Canada 2. Generate a history of PSP illness reports in BC 3. Map out MARTOX data* from to identify: o o o Geographic hotspots Seasonal patterns Temporal trends 4. Compare recall and monitoring data to illness reports *only PSP toxin levels

3 Objective 1: Marine Biotoxin Recalls Methods: Recall data collected from * Includes PSP and DSP reports Table 1. Marine biotoxin recall data sources Data Range Public Alerts Non Public Alerts * CFIA website CFIA website 2010 CFIA website Contacted CFIA CFIA website FOI material *November 19, 2013

4 Number of Recalls Results: 28 marine biotoxin recalls in Canada 79% (n=22) in BC All BC recalls took place between Marine Biotoxin Recalls by Location from 2006 to British Columbia East Coast * Year

5 April May June July August September October November December Number of Recalls 12 Number of Marine Biotoxin Recalls by Month Month

6 Objective 2: PSP Illness Reports Methods: Reports collected from 1793 to 2012 Sources: Disease Surveillance BC Health and Disease Surveillance Canada Diseases Weekly Report Canada Communicable Disease Report Anecdotal reports ( s, newspapers, file information) Reference document by Qualye iphis CNPHI Reports from BC Shellfish Related Illness Surveillance Form

7 Results: 39 incidents since incidents occurred in or after 1980 Of the 39 incidents, 194 cases and 6 deaths Summary of epidemiological illness data from PSP reports No. of Incidents Mean Median Range Age (years) Consumption (# pieces) Incubation period (hours) Duration of illness (hours)

8 Nausea Weakness Headache Numbness Tingling Loss of coordination Paralysis Difficulty breathing Diarrhea Vomiting Death Number of Cases incidents / 194 cases and 6 deaths Incidence of Symptoms (n=24) Symptoms

9 Number of Incidents : average 0.71 incidents per year : average 1.5 incidents per year 6 Number of Confirmed and Probable PSP Incidents between 1980 and Confirmed Probable Year

10 Number of Incidents Incidence of PSP Illness between 1980 and 2012: Commercially Purchased versus Self-harvested Self-harvested Commercially Purchased Year Self-harvested: 22 incidents Commercially purchased: 12 incidents Unknown: 5 incidents Incidence of illness due to commercially purchased product appears to be increasing Before 2007: 24% From 2007 to 2012: 67%

11 Objective 3: Mapping MARTOX Data Methods: 1. ArcGIS 10 Spatial analysis o Geographic Information Systems (GIS) organize, visualize, and analyze data in spatial format o Links geographically referenced MARTOX data to a location on a map Cartography o Displaying and communicating spatial information

12 2. Data sorting by Area by % positive (>80 ug/100g) Colour coding system (1 st attempt): Green < 5% Yellow 5%-10% Red > 10%

13 3. Meeting with key stakeholders Redefine colour coding system: - Green: X = 0% - Yellow: 0 < X < 5% - Orange: 5% X 10% - Red: X > 10% 4. Mapped data by: Geographic hotspots (all years) Seasonal patterns (seasons based on average sea temperatures) Temporal trends (per calendar year)

14 Results: Geographic Hotspots

15 Results: Seasonal Patterns PSP toxin prevalence: Warm season 8.1% Cold season 2.4%

16 Results: Temporal Trends

17 Results: Temporal Trends

18 Results: Temporal Trends

19 Results: Temporal Trends

20 Results: Temporal Trends

21 Results: Temporal Trends

22 Results: Temporal Trends

23 Results: Temporal Trends

24 Results: Temporal Trends

25 Results: Temporal Trends

26 Results: Temporal Trends

27 Objective 4: Comparing recall and monitoring data to illness reports Methods: Inclusion/exclusion criteria: Illnesses occurring between data collection period for recalls ( ) and monitoring ( ) were included Illnesses with adequate location data that included the harvest area were included Illnesses that met the aforementioned criteria, but could not be matched to MARTOX data due to lack of testing were excluded

28 Results: 4 illness reports met the criteria Recalls MARTOX Illness Reports Date of Recall (DD/MM/YYYY) Harvest Date (DD/MM/YYYY) Harvest Area Date of Test (DD/MM/YYYY) Harvest Area Toxin Level (µg/100g) # Date of Illness (DD/MM/YYYY) Harvest Date (DD/MM/YYYY) Harvest Area 11/09/ /09/ /09/ * < /09/2006 Tofino 09/06/ /06/ /06/ /06/ /07/ <44 < /06/ /06/ /10/ /10/ /10/ /10/ /10/ /10/ /10/ /10/ /10/ /10/ /10/ /10/ /07/ /07/ /07/ /07/ /07/ /07/ /07/ /07/ /07/ < /07/ *Harvest area corresponds to Tofino Harbour

29 In incident #1, spikes in toxin level were observed on the same day as the recall harvest date In incident #2 a spike was observed two days before the harvest date In incident #6, toxin levels spiked the week after the harvest date In incident #26, toxin levels did not correspond with illness (may be due to harvest area)

30 Conclusion MARTOX data might be useful to confirm illnesses once they occur As at least one illness (#6) occurred prior to elevated saxitoxin monitoring, the data appears to be a poor predictor for potential illness

31 Future Directions

32 Acknowledgements BC Centre for Disease Control Lorraine McIntyre (Industry Sponsor) Sarah Henderson Sunny Mak Marsha Taylor Canadian Food Inspection Agency Deirdre Kelly Andre Youssef Gerry Morello Katie Eloranta Hannah Bailey Department of Fisheries and Oceans Elysha Gordon University of British Columbia Dr. Kevin Allen (Academic Supervisor)