Raw Milk Consumption among Patients with Non–Outbreak-related Enteric Infections, Minnesota, USA, 2001–2010 - Volume 20, Number 1—January 2014 - Emerging Infectious Disease journal - CDC

full-text ►
Raw Milk Consumption among Patients with Non–Outbreak-related Enteric Infections, Minnesota, USA, 2001–2010 - Volume 20, Number 1—January 2014 - Emerging Infectious Disease journal - CDC

Volume 20, Number 1—January 2014

CME ACTIVITY

Raw Milk Consumption among Patients with Non–Outbreak-related Enteric Infections, Minnesota, USA, 2001–2010

Article Contents

• Medscape CME Activity
• Methods
• Results
• Discussion
• Acknowledgments
• References
• Figure 1
• Figure 2
• Figure 3
• Table 1
• Table 2
• Suggested Citation

Trisha J. Robinson , Joni M. Scheftel, and Kirk E. Smith

Author affiliations: Minnesota Department of Health, St. Paul, Minnesota, USA

Suggested citation for this article

Abstract

Raw milk has frequently been identified as the source of foodborne illness outbreaks; however, the number of illnesses ascertained as part of documented outbreaks likely represents a small proportion of the actual number of illnesses associated with this food product. Analysis of routine surveillance data involving illnesses caused by enteric pathogens that were reportable in Minnesota during 2001–2010 revealed that 3.7% of patients with sporadic, domestically acquired enteric infections had reported raw milk consumption during their exposure period. Children were disproportionately affected, and 76% of those <5 years of age were served raw milk from their own or a relative’s farm. Severe illness was noted, including hemolytic uremic syndrome among 21% of Escherichia coli O157–infected patients reporting raw milk consumption, and 1 death was reported. Raw milk consumers, potential consumers, and policy makers who might consider relaxing regulations regarding raw milk sales should be educated regarding illnesses associated with raw milk consumption.

Raw milk is well-established as a vehicle for numerous infectious diseases (1–8) and has frequently been identified as the source of outbreaks of foodborne illness (9,10). From 1998 through 2011, a total of 148 outbreaks were documented in the United States associated with the consumption of raw milk products, resulting in 2,384 illnesses, 284 hospitalizations, and 2 deaths (11). A recent report concluded that the incidence of reported outbreaks associated with raw dairy products was ≈150 times greater, per unit of product consumed, than the incidence involving pasteurized dairy products (12).

Although pasteurization has been available for use in the United States for over a century, a small proportion of the population continues to consume raw milk. In a 2006–2007 population survey comprising 10 states in the Foodborne Diseases Active Surveillance Network, 3.0% of respondents reported consuming raw milk during the previous 7 days (13). Farm families have traditionally been the primary consumers of raw milk, but evidence in recent years suggests that the population of raw milk consumers may be changing (14). Raw milk advocates tout raw milk for its purported health benefits and better taste, and many persons view raw milk consumption as an opportunity to support local dairies (15,16). Some raw milk advocates fail to acknowledge the elevated health risk associated with raw milk consumption and minimize the significance of reported outbreaks. In doing so, these advocates convey a false sense of the safety of raw milk to those who are considering consuming this product, and this sense of safety discourages a balanced assessment of the potential risks and benefits involved.

Although outbreaks associated with raw milk occur frequently and receive much media attention, the number of reported cases determined to be outbreak-related likely represents a small proportion of the actual number of illnesses associated with this product. Two lines of evidence support this assumption. First, among reported illnesses caused by enteric pathogens that are laboratory-confirmed, non–outbreak-related (i.e., sporadic) cases far outnumber those associated with recognized outbreaks (17). Second, for each reported laboratory-confirmed illness caused by a bacterial or protozoal enteric pathogen, an estimated 26–100 additional illnesses likely occur, depending on the pathogen (18). Therefore, any estimates of the number of illnesses associated with raw milk consumption should include an evaluation of sporadic cases, including multipliers to account for underdiagnosis and underreporting. However, little information is available on the number of sporadic cases of illness associated with raw milk consumption.

Minnesota is among the 30 US states that permit raw milk to be sold in some capacity (19), allowing for raw milk to be occasionally secured or purchased for personal use at the farm or place where the milk is produced (20). To better estimate the true number of human enteric pathogen infections associated with consumption of raw milk, we characterized sporadic enteric illnesses that occurred among patients in Minnesota who reported raw milk consumption during 2001–2010. Our primary objective was to provide better data on the true number of sporadically occurring disease cases associated with raw milk consumption.

Acknowledgments

We thank the many staff members of the Foodborne, Vectorborne, and Zoonotic Diseases Unit at the Minnesota Department of Health who helped collect data used in this report.

This work was supported in part through cooperative agreements (5 U01 EH000698-03 and U50/CCU511190) with the Centers for Disease Control and Prevention as part of the Environmental Health Specialist’s Network and the Emerging Infections Program, Foodborne Diseases Active Surveillance Network.

References

1. Centers for Disease Control and Prevention. Human tuberculosis caused byMycobacterium bovis—New York City, 2001–2004. MMWR Morb Mortal Wkly Rep.2005;54:605–8.PubMed
2. Centers for Disease Control and Prevention. Outbreak of Campylobacter jejuni infections associated with drinking unpasteurized milk procured through a cow-leasing program—Wisconsin, 2001. MMWR Morb Mortal Wkly Rep. 2002;51:548–9.PubMed
3. Guh A, Phan Q, Nelson R, Purviance K, Milardo E, Kinney S, Outbreak of Escherichia coliO157 associated with raw milk, Connecticut, 2008. Clin Infect Dis. 2010;51:1411–7. DOIPubMed
4. Centers for Disease Control and Prevention. Multistate outbreak of Salmonella serotype Typhimurium infections associated with drinking unpasteurized milk—Illinois, Indiana, Ohio, and Tennessee, 2002–2003. MMWR Morb Mortal Wkly Rep. 2003;52:613–5.PubMed
5. Denny J, Bhat M, Eckman K. Outbreak of Escherichia coli O157:H7 associated with raw milk consumption in the Pacific Northwest. Foodborne Pathog Dis. 2008;5:321–8. DOIPubMed
6. Harper CM, Cowell NA, Adams BC, Langley AJ, Wohlsen TD. Outbreak of Cryptosporidiumlinked to drinking unpasteurised milk. Commun Dis Intell Q Rep. 2002;26:449–50.PubMed
7. Osterholm MT, MacDonald KL, White KE, Wells JG, Spika JS, Potter ME, An outbreak of a newly recognized chronic diarrhea syndrome associated with raw milk consumption.JAMA. 1986;256:484–90. DOIPubMed
8. Centers for Disease Control and Prevention. Multi-state outbreak of yersiniosis. MMWR Morb Mortal Wkly Rep. 1982;31:505–6.PubMed
9. Headrick ML, Korangy S, Bean NH, Angulo FJ, Altekruse SF, Potter ME, The epidemiology of raw milk–associated foodborne disease outbreaks reported in the United States, 1973 through 1992. Am J Public Health. 1998;88:1219–21. DOIPubMed
10. Lejeune JT, Rajala-Schultz PJ. Unpasteurized milk: a continued public health threat. Clin Infect Dis. 2009;48:93–100. DOIPubMed
11. Centers for Disease Control and Prevention. Food safety. Raw milk questions and answers. 2013 [cited 2013 Apr 22].http://www.cdc.gov/foodsafety/rawmilk/raw-milk-questions-and-answers.html
12. Langer AJ, Ayers T, Grass J, Lynch M, Angulo FJ, Mahon BE. Nonpasteurized dairy products, disease outbreaks, and state laws—United States, 1993–2006. Emerg Infect Dis. 2012;18:385–91. DOIPubMed
13. Centers for Disease Control and Prevention. Foodborne Diseases Active Surveillance Network (FoodNet) population survey atlas of exposures. 2006–2007 [cited 2012 May 1].http://www.cdc.gov/foodnet/surveys/FoodNetExposureAtlas0607_508.pdf 
14. Katafiasz AR, Bartlett P. Motivation for unpasteurized milk consumption in Michigan, 2011. Food Protection Trends. 2012;32:124–8.
15. Leedom JM. Milk of nonhuman origin and infectious diseases in humans. Clin Infect Dis.2006;43:610–5. DOIPubMed
16. Jay-Russell MT. Raw (unpasteurized) milk: are health-conscious consumers making an unhealthy choice? Clin Infect Dis. 2010;51:1418–9. DOIPubMed
17. Centers for Disease Control and Prevention. Vital signs: incidence and trends of infection with pathogens transmitted commonly through food–foodborne diseases active surveillance network, 10 US sites, 1996–2010. MMWR Morb Mortal Wkly Rep.2011;60:749–55.PubMed
18. Scallan E, Hoekstra RM, Angulo FJ, Tauxe RV, Widdowson MA, Roy SL, Foodborne illness acquired in the United States—major pathogens. Emerg Infect Dis. 2011;17:7–15.PubMed
19. National Association of State Departments of Agriculture. NASDA releases raw milk survey. 2011 [cited 2012 March 2].http://www.nasda.org/file.aspx?id=3916
20. Minnesota Statutes 2013, section 32.393, subdivision 1. Pasteurization. 2013 [cited 2013 May 1]https://www.revisor.mn.gov/statutes/?id=32.393
21. Minnesota Department of Health. Communicable disease rule, chapter 4605. 2012 May 29 [cited 2013 May 1].http://www.health.state.mn.us/divs/idepc/dtopics/reportable/rule/rule.html
22. Tserenpuntsag B, Chang HG, Smith PF, Morse DL. Hemolytic uremic syndrome risk andEscherichia coli O157:H7. Emerg Infect Dis. 2005;11:1955–7. DOIPubMed
23. Bradley J, Pickering LK, Jareb J. Advise families against giving children unpasteurized milk. AAP News. 2008 Dec 2. 2008;29:29.
24. Jayarao BM, Donaldson SC, Straley BA, Sawant AA, Hegde NV, Brown JL. A survey of foodborne pathogens in bulk tank milk and raw milk consumption among farm families in Pennsylvania. J Dairy Sci. 2006;89:2451–8. DOIPubMed
25. Hoe FG, Ruegg PL. Opinions and practices of Wisconsin dairy producers about biosecurity and animal well-being. J Dairy Sci. 2006;89:2297–308. DOIPubMed
26. Kassenborg HD, Hedberg CW, Hoekstra M, Evans MC, Chin AE, Marcus R, Farm visits and undercooked hamburgers as major risk factors for sporadic Escherichia coli O157:H7 infection: data from a case-control study in 5 FoodNet sites. Clin Infect Dis.2004;38(Suppl 3):S271–8. DOIPubMed
27. Wood RC, MacDonald KL, Osterholm MT. Campylobacter enteritis outbreaks associated with drinking raw milk during youth activities. A 10-year review of outbreaks in the United States. JAMA. 1992;268:3228–30. DOIPubMed
28. Friedman CR, Hoekstra RM, Samuel M, Marcus R, Bender J, Shiferaw B, Risk factors for sporadic Campylobacter infection in the United States: a case-control study in FoodNet sites. Clin Infect Dis. 2004;38(Suppl 3):S285–96. DOIPubMed
29. Hedberg CW, Smith KE, Besser JM, Boxrud DJ, Hennessy TW, Bender JB, Limitations of pulsed-field gel electrophoresis for the routine surveillance of Campylobacter infections. J Infect Dis. 2001;184:242–4. DOIPubMed
30. Santín M, Trout JM, Fayer R. A longitudinal study of cryptosporidiosis in dairy cattle from birth to 2 years of age. Vet Parasitol. 2008;155:15–23. DOIPubMed
31. Yoder JS, Beach MJ. Cryptosporidium surveillance and risk factors in the United States.Exp Parasitol. 2010;124:31–9. DOIPubMed
32. Thomson MA, Benson JW, Wright PA. Two year study of Cryptosporidium infection. Arch Dis Child. 1987;62:559–63. DOIPubMed
33. Fretz R, Svoboda P, Ryan UM, Thompson RC, Tanners M, Baumgartner A. Genotyping ofCryptosporidium spp. isolated from human stool samples in Switzerland. Epidemiol Infect.2003;131:663–7. DOIPubMed
34. Pangloli P, Dje Y, Ahmed O, Doane CA, Oliver SP, Draughon FA. Seasonal incidence and molecular characterization of Salmonella from dairy cows, calves, and farm environment.Foodborne Pathog Dis. 2008;5:87–96. DOIPubMed
35. Hussein HS, Bollinger LM. Prevalence of Shiga toxin–producing Escherichia coli in beef cattle. J Food Prot. 2005;68:2224–41.PubMed

Figures

• Figure 1. [[caption]]
• Figure 2. [[caption]]
• Figure 3. [[caption]]

Tables

• Table 1. Demographic characteristics of patients with domestically acquired, sporadic enteric infections, Minnesota, 2001–2010
• Table 2. Number of sporadic illnesses resulting from raw milk consumption, as estimated by using underdiagnosis multipliers, Minnesota, 2001–2010

Suggested citation for this article: Robinson TJ, Scheftel JM, Smith KE. Raw milk consumption among patients with non–outbreak-related enteric infections, Minnesota, USA, 2001–2010. Emerg Infect Dis [Internet]. 2014 Jan [date cited]. http://dx.doi.org/10.3201/eid2001.120920

DOI: 10.3201/eid2001.120920

Related Links

• More Medscape CME Articles