Campylobacter jejuni enteritis associated with consumption of raw milk. (Features).

Introduction

Campylobacter jejuni is a curved, microaerophilic, Gram-negative rod with darting motility. It is a common cause of diarrheal illness in the United States. C. jejuni outbreaks have been related to consumption of contaminated water (Taylor, McDermott, Little, Wells, & Blaser, 1983; Vogt et al., 1982), poultry (Deming et al., 1987; Pearson et al., 2000), and unpasteurized milk (Kornblatt, Barrett, Morris, & Tosh, 1985; Taylor et al., 1982).

This article describes a Utah outbreak of diarrheal illness due to C. jejuni that occurred after consumption of raw milk at a high school athletic-team dinner. In Utah, raw milk cannot be sold in traditional retail settings. Sales to private individuals are not encouraged by the Utah Department of Agriculture, but are permitted under certain circumstances. The requirements for authorized sale include the following conditions: 1) Preparation, packaging, and sales all must occur at the site of production. 2) Containers must be labeled "raw milk." 3) The dairy must be licensed by the Utah Department of Agriculture.

Investigation and Analysis

People who had attended the dinner were interviewed by phone or in person. A case control study was conducted that included all people who had attended the meal; people who did not become ill served as controls. Stool cultures were obtained from individuals who had sought medical attention. A case was defined as diarrhea, either with or without abdominal pain, occurring within a week of the meal.

The results were analyzed with the Centers for Disease Control and Prevention's Epi Info 2000 software package. The Fisher exact test was used, and both point and exact 95 percent confidence values were determined for the odds ratio.

Results

Onset of illness was three to four days after the meal, and symptoms included diarrhea in all cases as well as abdominal pain, nausea, vomiting, body aches, chills, and headache. Illness lasted between one and seven days. All cases occurred in males; the mean age was 18.8 years (range: 11-50). Neither of the two females present drank raw milk or became ill. Twenty people attended the meal, and 13 of the 15 people who drank milk became ill; those figures give an attack rate of 86.7 percent. Two people drank milk but did not become ill. Six of the 13 who became ill required medical attention, but no one was hospitalized.

Meal items were waffles with fruit topping, pasteurized whipped cream, and raw milk. All persons in attendance ate the waffles, fruit topping, and whipped cream; however, not everyone drank milk. No poultry was served at the meal. People at the meal were aware that the milk being served was raw and had been brought as a gift to help support the athletic team.

C. jejuni was recovered from five of six stool specimens cultured. Milk from the meal was not available at the time the illness became apparent. Consumption of raw milk was associated with illness (p = .0072, Fisher exact test; odds ratio: 30; exact 95 percent confidence limits: 1.58-1531).

Discussion and Conclusion

Outbreaks of C. jejuni enteritis are largely preventable through effective public-health practices, including pasteurization of milk. Some outbreaks that now occur probably could be prevented if raw milk consumption, where it is allowed, were further discouraged. Utah currently has no regulation against consumption of raw milk by private individuals who produce it or by people to whom raw milk is given by the producer. The single dairy licensed in the state of Utah to sell raw milk for private consumption was not the dairy that supplied milk in this case.

In an outbreak such as the one reported here, medical professionals and public officials can work together to locate the source of the outbreak. Even if a specimen of milk is not available, rectal swab cultures from cattle at the suspected dairy can be completed and C. jejuni isolates can be analyzed and compared with those obtained from affected patients. Serotyping has traditionally been the method of choice for investigating outbreaks, but recently molecular techniques, which include pulsed-field gel electrophoresis and random amplified polymorphic DNA typing, have been used. A comparison of these techniques is beyond the scope of this paper, but their relative advantages and disadvantages have been thoughtfully reviewed in recent medical literature (Fitzgerald et al., 2001; Nielsen et al., 2000).

As follow-up to this outbreak, a local public-health official visited the dairy that had supplied the milk and discussed the risks and liabilities of supplying raw milk for social events. Further investigation, such as culture of rectal swabs, was at the discretion of local public-health officials and was not completed.

Acknowledgement: The editorial assistance of Karen A. Holmes is appreciated.

REFERENCE

Deming, M.S., Tauxe, R.V., Blake, PA., Dixon, S.E., Fowler, B.S., Jones, T.S., Lockamy, E.A., Patton, G.M., & Sikes, R.O. (1987). Campylobacter enteritis at a university: Transmission from eating chicken and from cats. American Journal of Epidemiology, 126, 526-534.

Fitzgerald, C., Helsel, L.O., Nicholson, M.A., Olsen, S.J., Swerdlow, D.A., Flahart, R., Sexton, J., & Fields, P.I. (2001). Evaluation of methods for subtyping Campylobacter jejuni during an outbreak involving a food handler. Journal of Clinical Microbiology, 39, 2386-2390.

Kornblatt, A.N., Barrett, T., Morris, G.K., & Tosh, FE. (1985). Epidemiologic and laboratory investigation of an outbreak of Campylobacter enteritis associated with raw milk. American Journal of Epidemiology, 122, 884-889.

Nielsen, E.M., Engberg, J., Fussing, V., Petersen, L., Brogen, C.H., & On, S.L.W (2000). Evaluation of phenotypic and genotypic methods for subtyping Campylobacter jejuni isolates from humans, poultry, and cattle, Journal of Clinical Microbiology, 38, 3800-3820.

Pearson, A.D., Greenwood, M.H., Donaldson, J., Healing, T.D., Jones, D.M., Shahamat, M., Feltham, R.K., & Colwell, R.R. (2000). Continuous source outbreak of campylobacteriosis traced to chicken. Journal of Food Protection, 63(3), 309-314.

Taylor, D.N., McDermott, K.T., Little, J.R., Wells, J.G., & Blaser, M.J. (1983). Campylobacter enteritis from untreated water in the Rocky Mountains. Annals of Internal Medicine, 99(1), 38-40.

Taylor, D.N., Porter, B.W., Williams, C.A., Miller, H.G., Bopp, C.A., & Blake, PA. (1982). Campylobacter enteritis: A large outbreak traced to commercial raw milk. Western Journal of Medicine, 137(5), 365-369.

Vogt, R.L., Sours, H.E., Barrett, T., Feldman, RA., Dickinson, R.J., & Witherell, L. (1982). Campylobacter enteritis associated with contaminated water. Annals of Internal Medicine, 96(3), 292-296.

Corresponding Author: Michael C. Peterson, M.D., F.A.C.P., Division of General Internal Medicine, University of Utah School of Medicine, 591 E. 500 N. Nephi, UT 84648. E-mail: [e-mail].