APHEO Annual Conference, May 15-17, 2011 Cyclospora Outbreak Investigation in Lambton County: Utilization of EpiData Software Crystal Palleschi, Epidemiologist County of Lambton, Community Health Services Department Image source: http://www.dpd.cdc.gov/dpdx/html/imagelibrary/A-F/Cyclosporiasis/body_Cyclosporiasis_il1.htm 1
Overview • Background • Methods – EpiData Entry & Analysis • Results Results • Conclusions 2
Background • Cyclospora cayetanensis is a protozoan parasite that infects the upper small bowel • Cyclospora is not endemic in Canada • Previous outbreaks in N.A. have been associated with ingestion of imported fresh produce ingestion of imported fresh produce • Cyclospora is transmitted through food or water contaminated by human feces • Oocysts require days to weeks outside the host to sporulate and become infectious • Incidence in Lambton County is low (0-1 cases/year) 3
Background • On May 28, 2010 we were notified of six individuals who were experiencing gastroenteric symptoms • All had attended “The Big Sister’s Chef’s Challenge” on May 12, 2010 • Event involved sampling 10 dishes prepared by 10 Event involved sampling 10 dishes prepared by 10 different caterers/restaurateurs • Up to 400 attendees, including staff and volunteers • On June 2, 2010 all six were confirmed positive for Cyclospora infection 4
Methods • Surveillance • Environmental Investigation • Epidemiological Investigation – Developed an outbreak questionnaire – Developed an outbreak questionnaire – Case Definition – Data input into EpiData Entry – Analysis run using EpiData Analysis – Analysis re-run by OAHPP using STATA, included multivariate analysis 5
Data Entry • Only essential fields were input from questionnaires • Single person dedicated to data entry to data entry • Most fields coded 0/1 for quick entry • Paper questionnaires forwarded to epidemiologist for reference 6
Data Analysis Simple Code: freq ill /c /r • tables ill sex /c • tables ill agegrp /c • Epicurve ill onset /ti="As of June 17, 2010, 10:00am" /ytext="Number Ill" /yinc=4 • missingvalue f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 /9 missingvalue f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 /9 • • tables ill f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 /ct /ar /ex • missingvalue f11 f12 f13 f14 f15 f16 f17 f18 f19 f20 /9 • tables ill f11 f12 f13 f14 f15 f16 f17 f18 f19 f20 /ct /ar /ex • missingvalue f21 f22 f23 f24 f25 f26 f27 f28 /9 • tables ill f21 f22 f23 f24 f25 f26 f27 f28 /ct /ar /ex • select ill=1 • freq hospital admit /c /r • select • freq test /c /r • 7
Data Analysis • 3-4 page report generated and shared with staff, MOHLTC, OAHPP, CFIA, etc. 8
Timeline Over 770 phone calls received Interviews conducted (n=292) June 18 th: June 2 nd : June 4 th : June 14 th : OAHPP May 12 th Outbreak Analysis Analysis Analysis Event Declared (n=233) (n=281) (n=286) May 28 th : June 3 rd : June 8 th : June 17 th : June 21 st : Notified Analysis Analysis Analysis Outbreak of 6-8 ill (n=128) (n=272) (n=292) Closed persons Food Samples Submitted (n=13) 9
Results • 292 interviews conducted – 210 ill, 82 well – 43 lab confirmed, 167 probable – 285 attended event, 7 leftovers • Hospitalizations – 23 reported a hospital visit – 7 admitted to hospital • No fatalities reported 10
Results 11
Results Exposed Not Exposed Unadjusted Food Item Ill Total AR (%) Ill Total AR (%) RR p-value Coffee and Jerk Chicken 164 235 69.8 36 47 76.6 0.91 0.348 Mexican Empanuadas 191 264 72.3 15 24 62.5 1.16 0.306 Fireball Chicken Sticks 177 248 71.4 26 35 74.3 0.96 0.720 Stuffed Mushroom Caps Stuffed Mushroom Caps 180 180 250 250 72.0 72.0 27 27 39 39 69.2 69.2 1.04 1.04 0.721 0.721 Chicken Summer Roll 191 266 71.8 11 18 61.1 1.17 0.333 Red Wine Risotto Arancinis 183 254 72.0 17 25 68.0 1.06 0.668 Yia Yia Lamb 165 225 73.3 39 61 63.9 1.15 0.150 Roasted Garlic Chevre 175 243 72.0 23 35 65.7 1.10 0.441 Cool Pesto Crunch 207 278 74.5 0 11 0.0 ∞* 0.000 Thai Chicken and Shrimp 154 209 73.7 49 75 65.3 1.13 0.169 12
Results • Epidemiological evidence suggested one dish: Cool Pesto Crunch • Further evidence from 7 ill individuals eating leftovers of this dish • 13 food samples submitted to CFIA; all negative, indeterminate or unfit for testing • Cool Pesto Crunch contained fresh basil from Costa Rica; grab samples tested negative 13
Conclusions • Difficult to obtain lab confirmation of food source due to long incubation period • Unknown why outbreak was limited to this event • Successful collaboration at the local, provincial and • Successful collaboration at the local, provincial and national levels • Demonstrates the impact of international trade and risks of importing produce • Emphasizes the importance of special events policies 14
Conclusions - EpiData • Quick and efficient entry and analysis • Designate staff for data entry • Enter only essential information required for analysis • Minimal training required • Minimal training required • APHEO educational sessions & materials valuable • Demonstrates that a small health unit can respond to a large outbreak 15
Acknowledgements • Ministry of Health and Long Term Care • Ontario Agency for Health Protection and Promotion • Public Health Agency of Canada • Canadian Food Inspection Agency • Canadian Food Inspection Agency • Toronto Public Health Lab • London Public Health Lab • Community Health Services Department • Local restaurants/caterers 16
Thank you! Questions? Questions? 17
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