A summary of the peer-reviewed literature relating to the “pros” of raw milk consumption was posted earlier this month. What about the “cons?” The overwhelming “con” of drinking raw milk according to the literature relates to food safety hazards. The following is an overview of the literature describing pathogens found in raw milk and outbreaks associated with consumption of raw milk and products made from raw milk.

Another possible “con” not well-documented in the literature is cost. First, commercial raw milk demands a premium price in the US with a gallon costing the consumer ~$12 compared with ~$7 for a gallon of organic pasteurized milk and ~$3-5 for a gallon of traditional pasteurized milk depending on the region and other factors. Second, the outbreaks, illnesses, and recalls resulting from raw milk consumption also incur costs for individuals and society:

• Medical expenses for acute care and long-term health problems
• Lost productivity and other indirect costs
• Costs to public health for investigation and control of outbreaks
• Losses to the dairy industry as a whole due to reduced consumer confidence following publicized outbreaks and recalls


I. Historical Perspective

Pasteurization has been revered as a triumph because of the significant reductions in morbidity and mortality following its implementation for dairy products in the 19th century. Today, some of the most devastating infections linked to raw milk consumption such as bovine tuberculosis and brucellosis have been virtually eliminated from livestock herds in developed countries through animal health programs. Before such programs, heat treatment was the key to preventing these infections, especially among infants and children. However, these “historical” diseases still plague developing countries, especially where raw milk is not boiled. These pathogens remain a threat to populations in endemic areas, especially children and the immunocompromised, as well as travelers that consume raw milk in these regions. And, unfortunately many examples exist of re-introduction into areas previously considered free of diseases such as brucellosis and bovine tuberculosis.

A sample of the literature:

1993. Greenstone, G. Brucellosis: a medical rarity that used to be common in Canada. Cmaj 148:1612-3.
1995. Brucellosis associated with unpasteurized milk products abroad. Wkly Epidemiol Rec 70:308-9.
2002. Shaalan, M. A., Z. A. Memish, S. A. Mahmoud, A. Alomari, M. Y. Khan, M. Almuneef, and S. Alalola. Brucellosis in children: clinical observations in 115 cases. Int J Infect Dis 6:182-6.
2004. Memish, Z. A., and H. H. Balkhy. Brucellosis and international travel. J Travel Med 11:49-55.
2005. K. L. Winthrop, J. Scott, D. Brown, M. T. Jay, R. Rios, S. Mase, D. Richardson, A. Edmonson, M. MacLean, and J. Flood. Investigation of human contacts: a Mycobacterium bovis outbreak among cattle at a California dairy. Int J Tuberc Lung Dis. 9:809-13.
2006. Gutierrez Garcia, J. M. Milk as a vector of transmission of bovine tuberculosis to humans in Spain: a historical perspective. Vet Herit 29:41-4
2006. Edwards, C., and A. S. Jawad. History of brucellosis. J R Soc Med 99:54.
45.
2006. Etter, E., P. Donado, F. Jori, A. Caron, F. Goutard, and F. Roger. Risk analysis and bovine tuberculosis, a re-emerging zoonoses. Ann N Y Acad Sci 1081:61-73.

II. The Health Hazards of Raw Milk

The remainder of this literature review focuses primarily on the more common emerging and uncontrolled foodborne pathogens in the dairy environment. Specifically, the “Big Four:” Campylobacter, E. coli O157:H7/EHEC, Listeria, Salmonella that are frequently implicated in outbreaks and tested for in regulatory programs.

Mechanisms of entry of pathogens into raw milk

Mechanisms of entry of pathogens into raw milk are well characterized in the literature.

The three major routes of contamination of raw milk include:
i. Mastitis or shedding from the udder
ii. Manure, dirt, other vectors in the dairy environment
iii. Human carriers

In a commentary on foodborne disease outbreaks about a decade ago, Keene states:

“There is no mystery about why raw milk is a common vehicle for salmonellosis and other enteric infections; after all, dairy milk is essentially a suspension of fecal and other microorganisms in a nutrient broth. Without pasteurization or other processing to kill pathogens, consumption of raw milk is a high-risk behavior.”

1999. Keene, W. E. Lessons from investigations of foodborne disease outbreaks. Jama 281:1845-7.

Selected references of pathogens found in bulk tank and raw milk

1987. Gaya, P., M. Medina, and M. Nunez. Enterobacteriaceae, coliforms, faecal coliforms and salmonellas in raw ewes’ milk. J Appl Bacteriol 62:321-6.
2006. Jayarao, B. M., S. C. Donaldson, B. A. Straley, A. A. Sawant, N. V. Hegde, and J. L. Brown. A survey of foodborne pathogens in bulk tank milk and raw milk consumption among farm families in pennsylvania. J Dairy Sci 89:2451-8.
2001. Jayarao, B. M., and D. R. Henning. Prevalence of foodborne pathogens in bulk tank milk. J Dairy Sci 84:2157-62.
2005. Karns, J. S., J. S. Van Kessel, B. J. McCluskey, and M. L. Perdue. Prevalence of Salmonella enterica in bulk tank milk from US dairies as determined by polymerase chain reaction. J Dairy Sci 88:3475-9.
1992. Rea, M. C., T. M. Cogan, and S. Tobin. Incidence of pathogenic bacteria in raw milk in Ireland. J Appl Bacteriol 73:331-6.
2004. Van Kessel, J. S., J. S. Karns, L. Gorski, B. J. McCluskey, and M. L. Perdue. Prevalence of Salmonellae, Listeria monocytogenes, and fecal coliforms in bulk tank milk on US dairies. J Dairy Sci 87:2822-30.

Examples of pathogens isolated from raw milk or linked to outbreaks/illnesses

Brucella
Campylobacter
Coxiella burnetii (Q fever)
Cryptosporidium
E. coli O157/EHEC
Listeria monocytogenes
Mycobacterium bovis (Bovine tuberculosis)
Rabies virus*
Salmonella enterica
Salmonella typhi (Typhoid fever)
Shigella
Staphylococcal enterotoxins
Steptococcus
Tick-borne encephalitis virus**
Toxoplasma
Yersinia enterocolitica

*Milkborne transmission of rabies virus has not been documented, but post-exposure prophylaxis (rabies shots) have been recommended for persons that drank raw milk from a rabid cow
**This disease is not endemic in the United States

Quantifying the number of raw milk consumers

Prior to considering the relative importance of raw milk associated outbreaks in the literature, it is worthwhile to consider the prevalence of raw milk consumption in the population. Headrick at al (1998) estimated raw milk comprised <1% of the total milk sold in states where raw milk was legal. In an earlier survey of 3,999 persons in California, 3.2% reported drinking raw milk (Headrick et al, 1997). Thus, the number of persons in the general population that consume raw milk appears to be very low, which makes the relatively large number of published outbreaks more striking.

1997. M. L. Headrick, B. Timbo, K. C. Klontz, and S. B. Werner. Profile of raw milk consumers in California. Public Health Rep. 112:418-22.

Review of outbreaks and raw milk

No recent (last 5 years) comprehensive review of raw milk outbreaks in the US or other countries could be found. A 1998 study by Headrick et al is among the most frequently cited reviews of the epidemiology of raw milk associated outbreaks. Below are other highlights from the paper.

1998. Headrick, M. L., S. Korangy, N. H. Bean, F. J. Angulo, S. F. Altekruse, M. E. Potter, and K. C. Klontz. The epidemiology of raw milk-associated foodborne disease outbreaks reported in the United States, 1973 through 1992. Am J Public Health 88:1219-21.
• The purpose of the study was to describe the epidemiology of outbreaks associated with raw milk reported to CDC from 1973-1992 and analyze the legal status of raw milk sales.
• 46 raw milk associated outbreaks were reported from 21 states during the study period; the median number of illnesses per outbreak was 19 (range 2 to 190); the total number of illnesses over the 20-year period was 1,733.
• 40/46 (87%) of outbreaks occurred in jurisdictions where the intrastate sale of raw milk was legal
• The majority of outbreaks were due to campylobacteriosis (57%) and salmonellosis (26%) followed by staphylococci food poisoning (2%) and E. coli O157:H7 (2%).
• The estimated volume of raw milk sold relative to pasteurized milk was less than 1%

Below are highlights of outbreaks published in the literature (peer-reviewed and public health reports such as MMWR). It should be noted that there are many potential variables that could impact whether or not an outbreak is published such as novelty, timeliness, and resources or motivation by the agency that conducted the investigation. Therefore, it is difficult to quantify the problem based on a literature review alone.

CAMPYLOBACTER

1979. Blaser, M. J., J. Cravens, B. W. Powers, F. M. Laforce, and W. L. Wang. 1979. Campylobacter enteritis associated with unpasteurized milk. Am J Med 67:715-8.

1980. Porter, I. A., and T. M. Reid. A milk-borne outbreak of Campylobacter infection. J Hyg (Lond) 84:415-9.

1981. Outbreak of Campylobacter enteritis associated with raw milk–Kansas. MMWR Morb Mortal Wkly Rep 30:218-20.

1981. Robinson, D. A., and D. M. Jones. 1981. Milk-borne campylobacter infection. Br Med J (Clin Res Ed) 282:1374-6.

1982. McNaughton, R. D., R. Leyland, and L. Mueller. Outbreak of Campylobacter enteritis due to consumption of raw milk. Can Med Assoc J 126:657-8.

1982. Taylor, D. N., B. W. Porter, C. A. Williams, H. G. Miller, C. A. Bopp, and P. A. Blake. Campylobacter enteritis: a large outbreak traced to commercial raw milk. West J Med 137:365-9.

1983. Potter, M. E., M. J. Blaser, R. K. Sikes, A. F. Kaufmann, and J. G. Wells. Human Campylobacter infection associated with certified raw milk. Am J Epidemiol 117:475-83.

1983. Wright, E. P., H. E. Tillett, J. T. Hague, F. G. Clegg, R. Darnell, J. A. Culshaw, and J. A. Sorrell. Milk-borne campylobacter enteritis in a rural area. J Hyg (Lond) 91:227-33.

1984. Campylobacter outbreak associated with certified raw milk products–California. MMWR Morb Mortal Wkly Rep 33:562.

1984. Hudson, P. J., R. L. Vogt, J. Brondum, and C. M. Patton. Isolation of Campylobacter jejuni from milk during an outbreak of campylobacteriosis. J Infect Dis 150:789.

1985. Hutchinson, D. N., F. J. Bolton, P. M. Hinchliffe, H. C. Dawkins, S. D. Horsley, E. G. Jessop, P. A. Robertshaw, and D. E. Counter. Evidence of udder excretion of Campylobacter jejuni as the cause of milk-borne campylobacter outbreak. J Hyg (Lond) 94:205-15.

1985. Campylobacter outbreak associated with raw milk provided on a dairy tour–California. MMWR Morb Mortal Wkly Rep 35:311-2.

1985. Korlath, J. A., M. T. Osterholm, L. A. Judy, J. C. Forfang, and R. A. Robinson. A point-source outbreak of campylobacteriosis associated with consumption of raw milk. J Infect Dis 152:592-6.

1985. Kornblatt, A. N., T. Barrett, G. K. Morris, and F. E. Tosh. Epidemiologic and laboratory investigation of an outbreak of Campylobacter enteritis associated with raw milk. Am J Epidemiol 122:884-9.

1986. Klein, B. S., J. M. Vergeront, M. J. Blaser, P. Edmonds, D. J. Brenner, D. Janssen, and J. P. Davis. Campylobacter infection associated with raw milk. An outbreak of gastroenteritis due to Campylobacter jejuni and thermotolerant Campylobacter fetus subsp fetus. Jama 255:361-4.

1986. Warner, D. P., J. H. Bryner, and G. W. Beran. Epidemiologic study of campylobacteriosis in Iowa cattle and the possible role of unpasteurized milk as a vehicle of infection. Am J Vet Res 47:254-8.

1987. Harris, N. V., T. J. Kimball, P. Bennett, Y. Johnson, D. Wakely, and C. M. Nolan. Campylobacter jejuni enteritis associated with raw goat’s milk. Am J Epidemiol 126:179-86.

1988. Humphrey, T. J., and R. J. Hart. Campylobacter and Salmonella contamination of unpasteurized cows’ milk on sale to the public. J Appl Bacteriol 65:463-7.

1994. Morgan, D., C. Gunneberg, D. Gunnell, T. D. Healing, S. Lamerton, N. Soltanpoor, D. A. Lewis, and D. G. White. An outbreak of Campylobacter infection associated with the consumption of unpasteurised milk at a large festival in England. Eur J Epidemiol 10:581-5.

1995. Orr, K. E., N. F. Lightfoot, P. R. Sisson, B. A. Harkis, J. L. Tweddle, P. Boyd, A. Carroll, C. J. Jackson, D. R. Wareing, and R. Freeman. Direct milk excretion of Campylobacter jejuni in a dairy cow causing cases of human enteritis. Epidemiol Infect 114:15-24.

1996. Evans, M. R., R. J. Roberts, C. D. Ribeiro, D. Gardner, and D. Kembrey. A milk-borne campylobacter outbreak following an educational farm visit. Epidemiol Infect 117:457-62.

2002. Outbreak of Campylobacter jejuni infections associated with drinking unpasteurized milk procured through a cow-leasing program–Wisconsin, 2001. MMWR Morb Mortal Wkly Rep 51:548-9.

2006. Schildt, M., S. Savolainen, and M. L. Hanninen. Long-lasting Campylobacter jejuni contamination of milk associated with gastrointestinal illness in a farming family. Epidemiol Infect 134:401-5.

E. COLI O157/EHEC

1996. Deschenes, G., C. Casenave, F. Grimont, J. C. Desenclos, S. Benoit, M. Collin, S. Baron, P. Mariani, P. A. Grimont, and H. Nivet. Cluster of cases of haemolytic uraemic syndrome due to unpasteurised cheese. Pediatr Nephrol 10:203-5.

1997. Bielaszewska, M., J. Janda, K. Blahova, H. Minarikova, E. Jikova, M. A. Karmali, J. Laubova, J. Sikulova, M. A. Preston, R. Khakhria, H. Karch, H. Klazarova, and O. Nyc. 1997. Human Escherichia coli O157:H7 infection associated with the consumption of unpasteurized goat’s milk. Epidemiol Infect 119:299-305.

1997. Keene, W. E., K. Hedberg, D. E. Herriott, D. D. Hancock, R. W. McKay, T. J. Barrett, and D. W. Fleming. A prolonged outbreak of Escherichia coli O157:H7 infections caused by commercially distributed raw milk. J Infect Dis 176:815-8.

2001. McIntyre, L., J. Fung, A. Paccagnella, J. Isaac-Renton, F. Rockwell, B. Emerson, and T. Preston. Escherichia coli O157 outbreak associated with the ingestion of unpasteurized goat’s milk in British Columbia, Can Commun Dis Rep 28:6-8.

2003. Allerberger, F., A. W. Friedrich, K. Grif, M. P. Dierich, H. J. Dornbusch, C. J. Mache, E. Nachbaur, M. Freilinger, P. Rieck, M. Wagner, A. Caprioli, H. Karch, and L. B. Zimmerhackl. 2003. Hemolytic-uremic syndrome associated with enterohemorrhagic Escherichia coli O26:H infection and consumption of unpasteurized cow’s milk. Int J Infect Dis 7:42-5.

2004. Liptakova, A., L. Siegfried, J. Rosocha, L. Podracka, E. Bogyiova, and D. Kotulova. A family outbreak of haemolytic uraemic syndrome and haemorrhagic colitis caused by verocytotoxigenic Escherichia coli O157 from unpasteurised cow’s milk in Slovakia. Clin Microbiol Infect 10:576-8.

2005. Honish, L., G. Predy, N. Hislop, L. Chui, K. Kowalewska-Grochowska, L. Trottier, C. Kreplin, and I. Zazulak. An outbreak of E. coli O157:H7 hemorrhagic colitis associated with unpasteurized gouda cheese. Can J Public Health 96:182-4.

2008. Schneider, J., J. Mohle-Boetani, D. Vugia, and M. Menon. 2008. Escherichia coli 0157:H7 infections in children associated with raw milk and raw colostrum from cows–California, 2006. MMWR Morb Mortal Wkly Rep 57:625-8.

LISTERIA

1985. Leads from the MMWR. Listeriosis outbreak associated with Mexican-style cheese–California. Jama 254:474.

1988. Linnan, M. J., L. Mascola, X. D. Lou, V. Goulet, S. May, C. Salminen, D. W. Hird, M. L. Yonekura, P. Hayes, R. Weaver, and et al. Epidemic listeriosis associated with Mexican-style cheese. N Engl J Med 319:823-8.

1995. Goulet, V., C. Jacquet, V. Vaillant, I. Rebiere, E. Mouret, C. Lorente, E. Maillot, F. Stainer, and J. Rocourt. Listeriosis from consumption of raw-milk cheese. Lancet 345:1581-2.

2001. From the Centers for Disease Control and Prevention. Outbreak of Listeriosis associated with homemade Mexican-style cheese–North Carolina, October 2000-January 2001. Jama 286:664-5.

.2004. Danielsson-Tham, M. L., E. Eriksson, S. Helmersson, M. Leffler, L. Ludtke, M. Steen, S. Sorgjerd, and W. Tham. Causes behind a human cheese-borne outbreak of gastrointestinal listeriosis. Foodborne Pathog Dis 1:153-9.

2005. MacDonald, P. D., R. E. Whitwam, J. D. Boggs, J. N. MacCormack, K. L. Anderson, J. W. Reardon, J. R. Saah, L. M. Graves, S. B. Hunter, and J. Sobel. Outbreak of listeriosis among Mexican immigrants as a result of consumption of illicitly produced Mexican-style cheese. Clin Infect Dis 40:677-82.

SALMONELLA

1964. Hutchinson, R. I. 1964. Milk-Borne Outbreak Of Salmonella Heidelberg. Br Med J 1:479-80.

1979. Small, R. G., and J. C. Sharp. A milk-borne outbreak due to Salmonella dublin. J Hyg (Lond) 82:95-100.

1979. Werner, S. B., G. L. Humphrey, and I. Kamei. Association between raw milk and human Salmonella dublin infection. Br Med J 2:238-41.

1981. Salmonella dublin associated with raw milk–Washington state. MMWR Morb Mortal Wkly Rep 30:373-4.

1981. Salmonellosis associated with raw milk–Montana. MMWR Morb Mortal Wkly Rep 30:211-2.

1981. Vogt, R. L., A. Hakey, and J. Allen. From the Vermont State Health Department. Salmonella enteritidis serotype derby and consumption of raw milk. J Infect Dis 144:608.

1983. Fierer, J. Invasive Salmonella dublin infections associated with drinking raw milk. West J Med 138:665-9.

1983. Schmida, T. O. Salmonella dublin infections from raw milk. West J Med 139:538.

1984. Leads from the MMWR. Salmonella dublin and raw milk consumption. Jama 251:2195, 2199.

1984. Tacket, C. O., L. B. Dominguez, H. J. Fisher, and M. L. Cohen. An outbreak of multiple-drug-resistant Salmonella enteritis from raw milk. Jama 253:2058-60.

1987. Schmid, G. P., R. E. Schaefer, B. D. Plikaytis, J. R. Schaefer, J. H. Bryner, L. A. Wintermeyer, and A. F. Kaufmann. A one-year study of endemic campylobacteriosis in a midwestern city: association with consumption of raw milk. J Infect Dis 156:218-22.

1988. Humphrey, T. J., and R. J. Hart. Campylobacter and Salmonella contamination of unpasteurized cows’ milk on sale to the public. J Appl Bacteriol 65:463-7.

1988. Richwald, G. A., S. Greenland, B. J. Johnson, J. M. Friedland, E. J. Goldstein, and D. T. Plichta. 1988. Assessment of the excess risk of Salmonella dublin infection associated with the use of certified raw milk. Public Health Rep 103:489-93.

1992. Maguire, H., J. Cowden, M. Jacob, B. Rowe, D. Roberts, J. Bruce, and E. Mitchell. An outbreak of Salmonella dublin infection in England and Wales associated with a soft unpasteurized cows’ milk cheese. Epidemiol Infect 109:389-96.

1996. Desenclos, J. C., P. Bouvet, E. Benz-Lemoine, F. Grimont, H. Desqueyroux,
Rebiere, and P. A. Grimont. 1996. Large outbreak of Salmonella enterica serotype paratyphi B infection caused by a goats’ milk cheese, France, 1993: a case finding and epidemiological study. Bmj 312:91-4.

1996. Campbell, D. M., J. M. Cowden, G. Morris, W. J. Reilly, and S. J. O’Brien. 1996. Cheese and Salmonella infection. All milk products should be heat treated. Bmj 312:1099.

1999. Cody, S. H., S. L. Abbott, A. A. Marfin, B. Schulz, P. Wagner, K. Robbins, J. C. Mohle-Boetani, and D. J. Vugia. 1999. Two outbreaks of multidrug-resistant Salmonella serotype typhimurium DT104 infections linked to raw-milk cheese in Northern California. Jama 281:1805-10.

1999. Villar, R. G., M. D. Macek, S. Simons, P. S. Hayes, M. J. Goldoft, J. H. Lewis, L. L. Rowan, D. Hursh, M. Patnode, and P. S. Mead. Investigation of multidrug-resistant Salmonella serotype typhimurium DT104 infections linked to raw-milk cheese in Washington State. Jama 281:1811-6.

2000. De Valk, H., E. Delarocque-Astagneau, G. Colomb, S. Ple, E. Godard, V. Vaillant, S. Haeghebaert, P. H. Bouvet, F. Grimont, P. Grimont, and J. C. Desenclos. 2000. A community–wide outbreak of Salmonella enterica serotype Typhimurium infection associated with eating a raw milk soft cheese in France. Epidemiol Infect 124:1-7.

2003. Multistate outbreak of Salmonella serotype typhimurium infections associated with drinking unpasteurized milk–Illinois, Indiana, Ohio, and Tennessee, 2002-2003. MMWR Morb Mortal Wkly Rep 52:613-5.

2003. Haeghebaert, S., P. Sulem, L. Deroudille, E. Vanneroy-Adenot, O. Bagnis, P. Bouvet, F. Grimont, A. Brisabois, F. Le Querrec, C. Hervy, E. Espie, H. de Valk, and V. Vaillant. 2003. Two outbreaks of Salmonella enteritidis phage type 8 linked to the consumption of Cantal cheese made with raw milk, France, 2001. Euro Surveill 8:151-6.

2004. Mazurek, J., E. Salehi, D. Propes, J. Holt, T. Bannerman, L. M. Nicholson, M. Bundesen, R. Duffy, and R. L. Moolenaar. 2004. A multistate outbreak of Salmonella enterica serotype typhimurium infection linked to raw milk consumption–Ohio, 2003. J Food Prot 67:2165-70.

2007. Salmonella typhimurium infection associated with raw milk and cheese consumption–Pennsylvania, 2007. MMWR Morb Mortal Wkly Rep 56:1161-4.

2008. Outbreak of multidrug-resistant Salmonella enterica serotype Newport infections associated with consumption of unpasteurized Mexican-style aged cheese–Illinois, March 2006-April 2007. MMWR Morb Mortal Wkly Rep 57:432-5.

OTHER PATHOGENS

1953. Bandy, W. H. Typhoid fever and raw milk. Del Med J 25:255-8.

1968. Brown, G. L., D. C. Colwell, and W. L. Hooper. 1968. An outbreak of Q fever in Staffordshire. J Hyg (Lond) 66:649-55.

1975 Riemann, H. P., M. E. Meyer, J. H. Theis, G. Kelso, and D. E. Behymer. Toxoplasmosis in an infant fed unpasteurized goat milk. J Pediatr 87:573-6.

1976. Jezyna, C., T. Weglinska, E. Nawrocka, W. Falecka, L. Wielizcko-Gebska, T. Rodkiewicz, Z. Piesiak, and T. Ciesielski. 1976. [Milk-borne outbreak of tick-borne encephalitis in Olsztyn Province]. Przegl Epidemiol 30:479-89.

1980. Ormsbee, R. Q fever and raw milk. J Am Vet Med Assoc 176:290.

1982. Multi-state outbreak of yersiniosis. MMWR Morb Mortal Wkly Rep 31:505-6.

1988. Edwards, A. T., M. Roulson, and M. J. Ironside. A milk-borne outbreak of serious infection due to Streptococcus zooepidemicus (Lancefield Group C). Epidemiol Infect 101:43-51.

1991. Wale, M. C., A. J. Liddicoat, and J. V. Pether. Yersinia enterocolitica biotype 2 serotype O9 septicaemia in a previously fit man, raw goats’ milk having been the apparent vehicle of infection: a cautionary tale. J Infect 23:69-72.

1992. Fishbein, D. B., and D. Raoult. A cluster of Coxiella burnetii infections associated with exposure to vaccinated goats and their unpasteurized dairy products. Am J Trop Med Hyg 47:35-40.

1994. Outbreak of tick-borne encephalitis, presumably milk-borne. Wkly Epidemiol Rec 69:140-1.

1999. From the Centers for Disease Control and Prevention. Mass treatment of humans who drank unpasteurized milk from rabid cows–Massachusetts, 1996-1998. Jama 281:1371-2.

2002. Harper, C. M., N. A. Cowell, B. C. Adams, A. J. Langley, and T. D. Wohlsen. Outbreak of Cryptosporidium linked to drinking unpasteurised milk. Commun Dis Intell 26:449-50.

2004. Zagrebneviene, G., V. Jasulaitiene, B. Morkunas, S. Tarbunas, and J. Ladygaite. 2005. Shigella sonnei outbreak due to consumption of unpasteurised milk curds in Vilnius, Lithuania, Euro Surveill 10:E051201 3.

2005. Ikeda, T., N. Tamate, K. Yamaguchi, and S. Makino. Mass outbreak of food poisoning disease caused by small amounts of staphylococcal enterotoxins A and H. Appl Environ Microbiol 71:2793-5.

2005. Jorgensen, H. J., T. Mathisen, A. Lovseth, K. Omoe, K. S. Qvale, and S. Loncarevic. An outbreak of staphylococcal food poisoning caused by enterotoxin H in mashed potato made with raw milk. FEMS Microbiol Lett 252:267-72.

2005. Kerbo, N., I. Donchenko, K. Kutsar, and V. Vasilenko. Tickborne encephalitis outbreak in Estonia linked to raw goat milk, May-June 2005. Euro Surveill 10:E050623 2.

2005. Kim, S. G., E. H. Kim, C. J. Lafferty, and E. Dubovi. Coxiella burnetii in bulk tank milk samples, United States. Emerg Infect Dis 11:619-21.

REVIEWS

1981. Hazards of untreated milk. Lancet 1:705.

1981. Currier, R. W. Raw milk and human gastrointestinal disease: problems resulting from legalized sale of "certified raw milk.". J Public Health Policy 2:226-34.

1982. Chin, J. Raw milk: a continuing vehicle for the transmission of infectious disease agents in the United States. J Infect Dis 146:440-1.

1985. Potter, M. E., A. F. Kaufmann, P. A. Blake, and R. A. Feldman. Unpasteurized milk. The hazards of a health fetish. Jama 252:2048-52.

1990. Donnelly, C. W. Concerns of microbial pathogens in association with dairy foods. J Dairy Sci 73:1656-61.

1998. Headrick, M. L., S. Korangy, N. H. Bean, F. J. Angulo, S. F. Altekruse, M. E. Potter, and K. C. Klontz. The epidemiology of raw milk-associated foodborne disease outbreaks reported in the United States, 1973 through 1992. Am J Public Health 88:1219-21.

1999. Keene, W. E. Lessons from investigations of foodborne disease outbreaks. Jama 281:1845-7.

2000. Steele, J. H. History, trends, and extent of pasteurization. J Am Vet Med Assoc 217:175-8.

2005. Oliver, S. P., B. M. Jayarao, and R. A. Almeida. Foodborne pathogens in milk and the dairy farm environment: food safety and public health implications. Foodborne Pathog Dis 2:115-29.

2006. Leedom, J. M. Milk of nonhuman origin and infectious diseases in humans. Clin Infect Dis 43:610-5.