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QMRA for Ingestion of Bacterial Contamination of Paneer in Mumbai, India Hannah P Sassi, Aaron Bivins, Aurelie Pohl, Bradley Lampe, Mehran Ghasemlou, Hao Pang and Sandhya Shrivastava Overview • • • • • • • Background/Introduction Problem Statement Hazard ID Dose Response Exposure Assessment Risk Characterization Risk Management Introduction • Paneer is a South Asian variety of soft cheese in raw form or in preparation of several varieties of culinary dishes • Rich source of animal protein, fat, vitamins and minerals and high in digestibility • 5% of milk produced in India is converted to paneer (4,496 metric tons and growing) • Mechanized and controlled commercial manufacturing process (refrigerated shelf life 5-15days) • Preference is for fresh paneer: unorganized sector (small producers) • Concerns for consumer and product safety due to low quality milk, unhygienic conditions, inadequate refrigeration facility and poor storage conditions What is Paneer? Problem • Paneer cheese is known to be contaminated with Salmonella and E. coli O157:H7 at the point of retail • The health risks of this contamination is unquantified • We suspect that: The consumption of Paneer is responsible for a significant burden of foodborne disease with size of production facility as an important factor. The health risks associated with Paneer cheese increase as a function of time and temperature of storage between purchase and consumption. Increasing health risks correlate with consumer perceptions of quality over time. Hazard ID Escherichia coli (EPEC) • Morphology – Gram –ve bacilli • Pathology – 106 Infectious dose – Incubation time: 0.5-34hrs, mean 12.5hrs – Acute Gastroenteritis – ~17% attack rates (outbreaks in Southern Indian towns) Kang et al, 2001 Escherichia coli O157:H7 • Produces Shiga-like toxin • Pathology – 10-102 infectious dose – Incubation times: 3-8 days – Acute gastroenteritis – 5-10% of infections result in hemolytic uremic syndrome (HUS) – 8-14% (populations aged 11-30) (Belongia et al, 1991; Gupta & Gupta, 2009) NT Salmonella spp • Morphology – Gram –ve bacilli • Pathology – 103 infectious dose – Incubation times: 12-120 hrs – Salmonellosis – 75.73% (Ref. population: Indian soldiers) (Vemula et al 2012) Exposure Assessment Exposure assessment • Amongst three main routes of exposure only the ingestion route can be accounted for in this case • Exposure time: time of the purchase to 6 days • The mean consumption for Paneer is estimated as 10 g/person-day • We also addressed the growth of pathogen in paneer under different storage temperatures Exposure Framework Flow Chart EPEC, E. coli o157:H7 and Salmonella Bacteria concentration Storage temperature Daily ingestion (10 gr/day) Population of India Storage time Unorganized sectors-Retail Organized sectors-Retail Fresh Paneer Packaged Paneer Dose of pathogen received Dose Response E. coli O157:H7 Dose Response • Exponential model developed from a pig feeding trial, closest of available animal models to humans • 3 dose levels of the pathogen were evaluated • Fecal shedding of the pathogen was used as a proxy for infection E. coli Generic Dose Response • Beta-Poisson model developed from several human studies in milk, 15 doses evaluated • Measured mild to severe diarrhea in humans, measure of illness, underestimates infection • E. coli strains tested: Enteroinvasive E. coli (EIEC) and Enterotoxigenic E. coli (ETEC) • Excludes: non-pathogenic E. coli and Shiga Toxin-producing E. coli (STEC) strains Salmonella Dose Response • Beta-Poisson model developed from a 16 dose eggnog dose-response study of humans • Positive fecal cultures as a proxy for infection • Salmonella enterica subspecies enterica serotype Anatum, our data not serotyped • Salmonella Anatum is a commonly reported bovine Salmonella serotype associated with food products Risk Characterization Risk of Infection vs. Temp & Time Relative Risk (packaged v. loose) Statistical Significance of Relative Risk Uncertainty of Risk Estimates (E. coli) Sensitivity of Risk Estimates (E. coli) Risk management Implementation of microbiological criteria (MC) Current MC: E. coli Current MC MC1 MC2 n 2 5 10 m Absence in 4g Absence in 4g Absence in 4g c 0 0 0 Salmonella Current MC MC1 MC2 n 2 5 10 m Absence in 25g Absence in 25g Absence in 25g c 0 0 0 *n is the number of samples to be tested from the batch/ lot, m is microbiological limit, c is the maximum allowable number of samples exceed the limit. Modeled using ICMSF sampling tools Reduced shelf life Reduce shelf life from up to 6 days to up to 4 days Modeled by truncate the distribution at max 96 hrs. Risk management Comparison of predicted annual cases related to E. coli and paneer Name Mean Median %Risk reduction Baseline 694,736 52,282 N/A Current MC 5,517 144 99.2% MC1 1,460 106 99.8% MC2 980 86 99.9% Shelf Life 611,995 50,196 11.9% Comparison of Annual Cases related to Paneer and E. coli @4°C 1.0 0.5 Baseline Current MC 0.3 MC1 MC2 ShelfLife Annual cases in log scale 9 7 5 3 1 0.0 -1 Cumulative probability 0.8 Comparison of Annual Cases related to Paneer and E. coli @24°C Cumulative probability 1.0 0.8 0.5 Baseline Current MC 0.3 MC1 MC2 ShelfLife 9 10 Annual cases in log scale 8 7 6 5 4 3 2 0.0 Risk management Cost benefit analysis of alternative MCs comparing to current MC • Additional cost needed • Illness cost reduced MC1 4057 Illness cost reduced (USD) 5,415,634 MC2 4537 6,056,793 Reduced cases Percent rejection Rejection cost % (USD) Total cost (USD) 0.07 24,272,500 18,856,866 0.18 62,415,000 56,358,207 • Conclusion: alternative MCs not cost effective comparing to current MC Risk Communication Questions? References • • • • • • • • • • • • Chandan RC. (2007). Manufacturing of paneer. In: Gupta, S (ed.) Dairy India. Diary India Yearbook, New Delhi, p 411. DuPont HL, Formal SB, Hornick RB, Snyder MJ, Libonati JP, Sheahan DG, LaBrec EH, and Kalas JP. 1971. Pathogenesis of Escherichia coli diarrhea. The New England Journal of Medicine 285(1):1-9 Graham DY, Estes MK and Gentry LO. 1983. Double-blind comparison of bismuth subsalicylate and placebo in the prevention and treatment of enterotoxigenic Escherichia coli-induced diarrhea in volunteers. Gastroenterology 85(5):1017-1022. Gupta SN and N Gupta. 2009. Outbreak of gastroenteritis in Tibetan Transit School, Dharamshala, Himachal, Pradesh, India, 2006. Indian J Community Med 34(2): 97-101 Haas CN, Rose JB and Gerba CP. 1999. Quantitative Microbial Risk Assessment. John Wiley & Sons, Inc. Kang G, Ramakrishna BS, Daniel J, Mathan M and VI Mathan. 2001. Epidemiological and laboratory investigations of outbreaks of diarrhoea in rural South India: implications for control of disease. Epidemiol. Infection 127(1): 107-112 Khan SW and MA Pal. (2011). Paneer Production: A review. J Food Science Technol 48(6): 645-660 Kumar S, Rai DC, Niranjan K, and Bhat ZF. 2011. Paneer- An Indian soft cheese variant: a review. J Food Sci Technol. DOI 10.1007/s13197-011-0567-x (Published online). Rao KVSS, Zanjad PN, and Mathur BN (1992) Paneer technology—A review. Indian J Dairy Sci 45:281–291. Ryan KJ and Ray CG (Eds.). 2004. Sherris Medical Microbiology: An Introduction to Infectious Disease. (Fourth Edition. ed.). Published by McGraw-Hill (New York). Shrivastava, S. and Goyal, G. (2007). Preparation of paneer—A Review. Indian J Dairy Sci., 60(6): 377–388. Singh, S.P. and Singh, K.P. (2000). Quality of market Paneer in Agra City. J. Dairying Foods Home Sci. 19(1): 3438