An outbreak of psittacosis in Minnesota turkey industry workers: implications for modes of transmission and control.

From June through November 1986, an outbreak of psittacosis occurred in turkey industry workers in central Minnesota. A total of 186 suspect cases were identified, and 122 cases (66%) were serologically confirmed. Cases occurred in three turkey processing plants, two rendering plants, one farm, and one "further processing" plant (where meat is removed from previously eviscerated carcasses and consumer products, such as roasts, are made). As in previous outbreaks, workers exposed to the viscera of infected birds were at greatest risk of becoming infected. However, our data showed that 31 (25%) of the confirmed cases occurred in workers at the further processing plant who had contact only with previously eviscerated carcasses. Although the specific source of infection and the mode of transmission in these workers are unclear, the use of gloves and masks by all processing workers during an outbreak might help to limit exposure. Control measures, which focused on identifying and treating ill turkey flocks, were initiated in early September; however, cases continued to occur in turkey industry workers through November. One of the flocks suspected of causing illness appeared healthy and, therefore, was not treated. Chlamydia psittaci infection in this flock was confirmed by culture after the flock had been processed. A rapid test for diagnosing C. psittaci infection in turkey flocks at the time of processing might be useful in preventing exposure of large numbers of workers.

An outbreak of a newly recognized chronic diarrhea syndrome associated with raw milk consumption.

A previously undescribed chronic diarrhea syndrome affected 122 residents of Brainerd, Minn, between December 1983 and July 1984. The illness lasted at least one year for 75% of case-patients and was characterized by acute onset, marked urgency, a lack of systemic symptoms, and a failure of response to antimicrobial agents. Clinical and laboratory data indicate that the diarrhea was caused by a secretory mechanism. Consumption of raw milk from a single dairy was associated with illness (odds ratio, 28.3; 95% confidence interval, 9.0 to 89.0). A median incubation period of 15 days was determined for seven case-patients. Possible secondary transmission was noted in one family. Extensive laboratory examination did not identify an etiologic agent. Outbreaks or sporadic cases of a similar illness have occurred in at least seven states; the outbreaks were less extensively investigated and findings were not published, but raw milk consumption was common in the affected persons. This illness appears to represent a previously unrecognized but important clinical entity and public health problem. The etiology and effective therapy for this illness must be determined by further studies of sporadic cases and outbreaks.

A point-source outbreak of campylobacteriosis associated with consumption of raw milk.

After a one-day field trip to a Minnesota farm, 22 (45%) of 49 third-grade students and three (14%) of 21 adult chaperones developed campylobacteriosis. Campylobacter jejuni was isolated from specimens of 13 children and one asymptomatic adult. Illness was associated with the consumption of raw milk during a picnic lunch (odds ratio = 41.0, P less than .0001) and participation in hand milking of cows (odds ratio = 37.5, less than .0001). Two additional findings implicated consumption of raw milk as the vehicle for transmission. First, the odds ratio for illness among those who drank raw milk and did not milk cows was 11.8 (P less than .01), whereas the odds ratio for illness among those who milked cows but did not drink raw milk was only 1.2 (P greater than .02). Second, there was a dose-response relation between the occurrence of illness and the quantity of raw milk consumed (P less than .0001). Neither the median incubation period nor duration of illness was related to the amount of milk consumed. All persons with a stool culture positive for C. jejuni excreted the organism for at least two weeks, but less than six weeks. No secondary cases of illness were documented.

Lyme disease in Minnesota: epidemiologic and serologic findings.

During the four years, 1980 to 1983, 83 Minnesota residents have been diagnosed with Lyme disease. Sixty-five of the patients were male. The median age of patients was 39 years with a range from one to 77 years. Seventy-five (90 percent) had onset in 1982 and 1983. Of these latter cases, 56 (75 percent) recalled a tick bite three to 27 days prior to the development of erythema chronicum migrans. Patients experienced possible exposure to Ixodes dammini in at least 24 (28 percent) of the 87 Minnesota counties; however, over 50 percent had reported exposure in one of eight east-central counties near or immediately west of the Wisconsin border. Serologic studies for antibody against the Ixodes dammini spirochete were completed on 30 patients with onset in 1982 and 1983. Of 28 patients with paired acute and convalescent serum samples, only two (7 percent) had fourfold rises in antibody titers. Lyme disease is an emerging public health problem in Minnesota. Additional studies are needed to define the risk of disease by geographic area within the state. Physicians statewide should be alert to the possibility of Lyme disease among their patients, since only 39 percent of patients with onset in 1982 and 1983 were exposed in their county of residence.

Norwalk gastroenteritis: a community outbreak associated with bakery product consumption.

From 23 to 26 August 1982, a gastrointestinal illness occurred among 129 of 248 (52%) persons interviewed who had attended four social events in the Minneapolis-St. Paul area. The median incubation period was 36 hours, and symptoms included diarrhea, nausea, headache, and vomiting. Findings of a food-specific questionnaire given to attendants of the four events confirmed that consumption of cake and frosting was significantly associated with development of the illness (odds ratio, 7.9 to 48.3; p = 0.006 to 0.00001). All cake items were purchased from a single bakery, where the employee who had prepared the frosting had had onset of diarrhea and vomiting on August 20. Given an approximate 60% attack rate among persons who ate frosted items, we estimate that 3000 outbreak-associated cases occurred. Serologic analysis confirmed that 17 of 25 ill persons had fourfold or greater rises in their antibody titer to Norwalk virus. Thus, foodborne transmission of Norwalk virus can result from contamination by a single foodhandler.

Surveillance of toxic shock syndrome in Minnesota: comments on national surveillance.

In January 1980, the Minnesota Department of Health began the surveillance of toxic shock syndrome with epidemiologically defined active and passive components. The intensity of surveillance has been constant since its inception. As of 30 June 1981, 197 confirmed cases of toxic shock syndrome, 15% of all cases nationwide, have been identified in Minnesota. During the 18 months of active surveillance, the total cases reported per calendar quarter ranged from 20 to 24 cases, and the number of tampon-associated cases ranged from 15 to 21. There was no difference in the quarterly distribution of total (p greater than 0.2) or tampon-associated (p greater than 0.2) cases of toxic shock syndrome during the six quarters. Fifty-five tampon-associated cases had onset of illness during the 9 months of surveillance in which Rely tampons (Proctor & Gamble) were on the market; 59 tampon-associated cases had onset of illness during the 9 months after Rely tampons were removed from the market.

Toxic shock syndrome: relation to catamenial products, personal health and hygiene, and sexual practices.

In 1980, the discovery of an association between vaginal tampon use and toxic shock syndrome affected the lifestyles of menstruating women and the catamenial products industry. It made both the general public and the medical community more aware of all aspects of menstruation. The relation between developing toxic shock syndrome and tampon use is unclear; tampon fluid capacity (absorbency) remains the best predictive measure of that risk. No unique aspect of tampon use other than absorbency seems to increase the risk of developing toxic shock syndrome, and numerous hygiene and medical history factors do not seem to play a role in the pathogenesis of the disease. Studies in Minnesota, Wisconsin, and Iowa indicate that 70% to 75% of women between the ages of 15 and 24, the group with the highest risk of developing menstrual toxic shock syndrome, continued to use tampons after news media attention in 1980 on the association of the syndrome with tampon use. This rate of use is higher than the rate found for the general population by recent tampon market research.

Tri-state toxic-state syndrome study. I. Epidemiologic findings.

Eighty women who had onset of toxic-shock syndrome (TSS) between October 1, 1979, and September 19, 1980, and 160 age- and sex-matched neighborhood controls participated in this study to evaluate risk factors associated with TSS in women. Of the 80 women, 76 had onset of illness during their menstrual periods. The odds ratio for developing menses-associated TSS with any use of tampons compared with no use of tampons was 18.01 (P less than 0.001). The odds ratios ranged from 5.29 to 27.5 for individual brand use compared with no use. When exclusive use of a particular tampon brand was compared with exclusive use of all other brands. Rely (Procter and Gamble, Cincinnati, Ohio) was the only brand with a significantly increased odds ratio (2.49; P = 0.005). By multiple logistic regression analysis, the risk of TSS was more closely associated with tampon fluid capacity (absorbency) than with the use of all tampon brands.

Tri-state toxic-shock syndrome study. II. Clinical and laboratory findings.

Clinical and laboratory findings were examined in 80 nonfatal cases of toxic-shock syndrome (TSS) which occurred in women from Minnesota, Wisconsin, and Iowa between October 1, 1979, and September 19, 1980. Among the clinical and laboratory factors reviewed, the presence of physician-diagnosed shock was the factor that most significantly correlated with other organ involvement. Vomiting, mucous membrane hyperemia, myalgias, and abnormal urinalysis were the factors noted to be manifest as frequently in the absence as in the presence of shock. Twenty-seven patients had recurrent episodes of TSS. The use of antistaphylococcal antibiotics during the initial TSS episode and the subsequent discontinuation of tampon use were independently statistically significantly associated with a decreased risk of recurrent illness. Only 44 of 54 patients had cervical/vaginal cultures positive for Staphylococcus aureus, a result indicating that a negative cervical/vaginal culture does not preclude the diagnosis of TSS.

Toxic-shock syndrome in Minnesota: results of an active-passive surveillance system.

In January 1980, the Minnesota Department of Health began a surveillance system for toxic-shock syndrome (TSS) with both epidemiologically defined active and passive components. As of June 30, 1981, 197 confirmed cases of TSS, 15% of all nationally reported cases, have been in Minnesota residents. The onset in 61 of the cases was before 1980; these cases were retrospectively recognized and reported. Of the 136 cases reported between January 1980 and June 1981, 114 (83.8%) cases were tampon-associated. During the 18 months of active surveillance, there was no difference (P greater than 0.2) in the quarterly distribution of total or tampon-associated TSS cases. The onset of illness in 55 tampon-associated cases was during the nine months of surveillance in which Rely tampons (Procter and Gamble, Cincinnati, Ohio) were on the market, whereas the onset in 59 tampon-associated cases was during the nine months following their removal from the market.