A national outbreak of Salmonella enteritidis infections from ice cream. The Investigation Team.

BACKGROUND: In September 1994, the Minnesota Department of Health detected an increase in the number of reports of Salmonella enteritidis infections. After a case-control study implicated a nationally distributed brand of ice cream (Schwan's) in the outbreak, the product was recalled and further epidemiologic and microbiologic investigations were conducted. METHODS: We defined an outbreak-associated case of S. enteritidis infection as one in which S. enteritidis was cultured from a person who became ill in September or October 1994. We established national surveillance and surveyed customers of the implicated manufacturer. The steps involved in the manufacture of ice cream associated with cases of S. enteritidis infection were compared with those of products not known to be associated with infection matched for the date of manufacture. Cultures for bacteria were obtained from ice cream samples, the ice cream plant, and tanker trailers that had transported the ice cream base (premix) to the plant. RESULTS: We estimate that S. enteritidis gastroenteritis developed in 224,000 persons in the United States after they ate Schwan's ice cream. The attack rate for consumers was 6.6 percent. Ice cream associated with infection contained a higher percentage of premix that had been transported by tanker that had carried nonpasteurized eggs immediately before (P = 0.02). S. enteritidis was isolated from 8 of 226 ice cream products (3 percent), but not from environmental samples obtained from the ice cream plant (n = 157) or tanker trailers (n = 204). CONCLUSIONS: This nationwide outbreak of salmonellosis was most likely the result of contamination of pasteurized ice cream premix during transport in tanker trailers that had previously carried nonpasteurized liquid eggs containing S. enteritidis. To prevent further outbreaks, food products not destined for repasteurization should be transported in dedicated containers.

A look-back investigation of patients of an HIV-infected physician. Public health implications.

BACKGROUND: Transmission of the human immunodeficiency virus (HIV) to five patients receiving care from an HIV-infected dentist in Florida has recently been reported. Current data indicate that the risk of HIV transmission from health care workers to patients is low. Despite this low risk, programs to notify patients of past exposure to an HIV-infected health care worker are being conducted with increasing frequency. METHODS: We recently conducted an investigation of all the patients cared for by an HIV-infected family physician during a period when he had severe dermatitis caused by Mycobacterium marinum on his hands and forearms. After reviewing the patients' records, we notified 336 patients who had undergone one or more procedures (digital examination of a body cavity or vaginal delivery) placing them at potentially increased risk of HIV infection. The patients were offered tests for HIV infection and counseling. RESULTS: Of the 336 patients, 325 (97 percent) had negative tests for HIV antibody, 3 (1 percent) refused testing, 1 (less than 1 percent) died of a cause unrelated to HIV infection before notification, and the HIV-antibody status of 7 (2 percent) remained unknown. The direct and indirect public health costs of this investigation were approximately $130,000. CONCLUSIONS: The results of this investigation raise important questions about the risk of HIV transmission from health care workers to patients and the usefulness of HIV look-back programs, particularly in the light of recently published recommendations from the Centers for Disease Control. We propose that before a look-back investigation is undertaken, there should be a clearly identifiable risk of transmission of the infection, substantially higher than the risk requiring limitation of an HIV-infected health care worker's practice prospectively.

A statewide approach to adolescent tobacco-use prevention: the Minnesota-Wisconsin Adolescent Tobacco-Use Research Project.

Adolescent smoking rates remain high and the use of smokeless tobacco is increasing, especially among males. Despite this continuing public health problem and the recent development of more effective prevention programs, few adolescents now participate in such programs at school. Recent legislation in Minnesota established guidelines for tobacco-use prevention programming and provides financial incentives to school districts to use more effective methods. The Minnesota-Wisconsin Adolescent Tobacco-Use Research Project has implemented an evaluation design that will provide data on the efficacy of this statewide approach to the prevention of tobacco use among adolescents. This article describes the current state of tobacco-use prevention programming in Minnesota schools, current efforts to improve on that record, and the research design set up to evaluate these strategies.

Minnesota plan for nonsmoking and health: multidisciplinary approach to risk factor control.

In 1981, the Minnesota Department of Health began a long-term program to control risk factors for the major health problems of the State as determined by an expert committee. The methods chosen to initiate programs were social, economic, and epidemiologic background research and a multidisciplinary statewide planning process. Smoking was considered the most important problem. During 1983-84, department staff members analyzed the epidemiology and economics of smoking in Minnesota and reviewed the literature on methods of smoking control. They and a multidisciplinary technical committee prepared a coordinated plan to increase the prevalence of nonsmoking in Minnesota. The 39 recommendations address mass communication and marketing, educational programs in schools, public and private regulation, economic disincentives through taxation, and funding of programs and evaluation of results. The Minnesota Plan for Nonsmoking and Health was released in September 1984. During the first half year, the plan provided material for formation of a coalition of health organizations to promote nonsmoking. In June 1985, the Minnesota Legislature passed the Omnibus Nonsmoking and Disease Prevention Act, which provides $4 million over 2 years for promotion of nonsmoking through education, regulation, and public communications. These intervention activities will be funded by a portion of a 5-cent increase in cigarette excise tax. The foundations have been laid for what may be the most comprehensive statewide nonsmoking program in the United States.