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Biomedical subjects

L R Foster

Publications and source records attributed to L R Foster.

18 recordsLinked to original sources
PubMed1997

A large community outbreak of salmonellosis caused by intentional contamination of restaurant salad bars.

CONTEXT: This large outbreak of foodborne disease highlights the challenge of investigating outbreaks caused by intentional contamination and demonstrates the vulnerability of self-service foods to intentional contamination. OBJECTIVE: To investigate a large community outbreak of Salmonella Typhimurium infections. DESIGN: Epidemiologic investigation of patients with Salmonella gastroenteritis and possible exposures in The Dalles, Oregon. Cohort and case-control investigations were conducted among groups of restaurant patrons and employees to identify exposures associated with illness. SETTING: A community in Oregon. Outbreak period was September and October 1984. PATIENTS: A total of 751 persons with Salmonella gastroenteritis associated with eating or working at area restaurants. Most patients were identified through passive surveillance; active surveillance was conducted for selected groups. A case was defined either by clinical criteria or by a stool culture yielding S Typhimurium. RESULTS: The outbreak occurred in 2 waves, September 9 through 18 and September 19 through October 10. Most cases were associated with 10 restaurants, and epidemiologic studies of customers at 4 restaurants and of employees at all 10 restaurants implicated eating from salad bars as the major risk factor for infection. Eight (80%) of 10 affected restaurants compared with only 3 (11%) of the 28 other restaurants in The Dalles operated salad bars (relative risk, 7.5; 95% confidence interval, 2.4-22.7; P<.001). The implicated food items on the salad bars differed from one restaurant to another. The investigation did not identify any water supply, food item, supplier, or distributor common to all affected restaurants, nor were employees exposed to any single common source. In some instances, infected employees may have contributed to the spread of illness by inadvertently contaminating foods. However, no evidence was found linking ill employees to initiation of the outbreak. Errors in food rotation and inadequate refrigeration on ice-chilled salad bars may have facilitated growth of the S Typhimurium but could not have caused the outbreak. A subsequent criminal investigation revealed that members of a religious commune had deliberately contaminated the salad bars. An S Typhimurium strain found in a laboratory at the commune was indistinguishable from the outbreak strain. CONCLUSIONS: This outbreak of salmonellosis was caused by intentional contamination of restaurant salad bars by members of a religious commune.

Contact Tracing↗
PubMed1990

Partner notification: can it control epidemic syphilis?

STUDY OBJECTIVE: During 1987, the rate of syphilis among heterosexual adults in Oregon increased 159%, yet the number of cases of gonorrhea remained stable. Our study was done to evaluate why the same control measures contained gonorrhea but not syphilis in this population. DESIGN: Exploratory case-control study. SETTING: Public health clinics in Portland, and Salem, Oregon. PATIENTS: All 146 heterosexual adults with early syphilis and all 164 heterosexual adults with acute gonorrhea reported to the public health clinics during April to July 1988. INTERVENTION: A questionnaire was administered to all syphilis case-patients and control patients (those with gonorrhea) at the beginning of the routine, sexually transmitted disease (STD), investigative interview. MEASUREMENTS AND MAIN RESULTS: Syphilis case-patients had contact with an average of 5.0 sex partners for whom they could not supply locating information sufficient to initiate partner notification. In contrast, patients with gonorrhea had contact with an average of 0.4 sex partners for whom they could not supply locating information (P less than 0.005). The 28% (41 of 146) of syphilis case-patients who reported having exchanged sex for drugs or money accounted for 72% (527 of 729) of the unlocatable partners exposed to syphilis. In contrast, the 17% (28 of 164) of patients with gonorrhea who reported having exchanged sex for drugs or money accounted for 36% (25 of 69) of the unlocatable partners exposed to gonorrhea. CONCLUSIONS: Because patients infected with syphilis have relatively large numbers of anonymous sexual encounters, prevention strategies that supplement partner notification are urgently needed to control the syphilis epidemic among adults.

Adolescent↗
PubMed1990

Public health implications of the microbial pesticide Bacillus thuringiensis: an epidemiological study, Oregon, 1985-86.

Bacillus thuringiensis var. kurstaki (B.t.-k) is a microbial pesticide which has been widely used for over 30 years. Its safety for a human population living in sprayed areas has never been tested. Surveillance for human infections caused by B.t.-k among Lane County, Oregon residents was conducted during two seasons of aerial B.t.-k spraying for gypsy moth control. Bacillus isolates from cultures obtained for routine clinical purposes were tested for presence of Bacillus thuringiensis (B.t.). Detailed clinical information was obtained for all B.t.-positive patients. About 80,000 people lived in the first year's spray area, and 40,000 in the second year's area. A total of 55 B.t.-positive cultures were identified. The cultures had been taken from 18 different body sites or fluids. Fifty-two (95 percent) of the B.t. isolates were assessed to be probable contaminants and not the cause of clinical illness. For three patients, B.t. could neither be ruled in nor out as a pathogen. Each of these three B.t.-positive patients had preexisting medical problems. The level of risk for B.t.-k and other existing or future microbial pesticides in immunocompromised hosts deserves further study.

Abscess↗
PubMed1989

HIV testing in prisoners: is mandatory testing mandatory?

We studied 977 newly incarcerated Oregon inmates to compare voluntary versus mandatory human immunodeficiency virus antibody (HIVAb) testing in the prison setting. All inmates were offered HIVAb counseling and testing. Blood drawn for routine syphilis serology from those who declined this offer was also tested for HIVAb after personal identifiers had been removed. Only 1.2 percent (12) prisoners were HIV positive. However, 62.5 percent (611) inmates were at risk for HIV infection by being an intravenous drug user, a male homosexual, or hepatitis B core antibody (HBcAb) positive. The ratio of at-risk, as yet uninfected inmates to those already HIV infected was 53 to 1. Two-thirds of all inmates including those at-risk chose to receive counseling and testing. In areas where most at-risk inmates are not yet infected, it may be more appropriate for HIV prevention activities in prison to focus on voluntary programs that emphasize education and counseling rather than mandatory programs that emphasize testing.

Adolescent↗
PubMed1988

Trial of anonymous versus confidential human immunodeficiency virus testing.

Before December, 1986, all public human immunodeficiency virus (HIV) testing in Oregon was done confidentially (using names). In December, clients were offered the option of either anonymous or confidential services. As judged by questionnaire responses, the availability of anonymity increased overall demand for testing by 50%: 125% for homosexual/bisexual (gay) men, 56% for female prostitutes, 17% for intravenous drug users, and 32% for other clients. The number of gay clients who had tests increased from a mean of 42 per month during the 4 months before anonymity was available to 108 per month during the 4 months after, whereas, at public sites in Colorado or California and private sites in Oregon, the number of gay clients tested did not increase. Twice as many seropositive persons were identified during the 3 1/2 months after anonymity became available (n = 85) as in the 3 1/2 months before (n = 36). Thus, availability of anonymous HIV testing and counselling drew gay men who had not sought services under a confidential testing system.

California↗
PubMed1988

Prevalence of hepatitis B markers among pregnant Hispanic women in migrant/seasonal work in Oregon.

We screened 303 Hispanic pregnant women who were migrant or seasonal agricultural workers in Oregon for the presence of Hepatitis B serological markers. One carrier was identified (0.3 per cent, 95% confidence interval [CI] .02%, 2.1%). Evidence of previous HB infection was present in 5.3 per cent (16/303) of the women (95% CI 3.2%, 8.6%), rates similar to those for the general US population.

Adolescent↗
PubMed1987

Group A beta-hemolytic streptococcal skin infections in a US meat-packing plant.

In 1985, the second reported outbreak of group A beta-hemolytic streptococcal (GABHS) skin infections among US meat packers was recognized at an Oregon meat-packing plant. All 69 plant workers were interviewed and examined for the presence of pustular, draining, or inflamed lesions. During a three-month period, 44 episodes of skin infection occurred in 32 workers, all but four of whom worked in boning or killing areas. Acquiring infection was associated with job category (relative risk [RR], 5.7; 95% confidence intervals [CI], 2.9 to 11.3) and having at least two hand lacerations (RR adjusted for occupation, 6.2; 95% CI, 3.0 to 12.5). Group A beta-hemolytic Streptococcus (18), Staphylococcus aureus (12), or both (20) were isolated from 70 lesions cultured. Meat is suspected as a vehicle of transmission because cultures of two meat specimens contained the same GABHS strain as did 24 isolates from patients. Increasing reports of GABHS skin infections in meat packers suggest that this occupational risk may be more common than is realized.

Abattoirs↗
PubMed1987

An outbreak of watermelon-borne pesticide toxicity.

The largest reported United States outbreak of illness caused by a foodborne pesticide was due to aldicarb-contaminated watermelons. In Oregon, where the first episodes of toxicity were reported, 264 reports were received, and 61 definite cases were identified. Residues of aldicarb, a cholinesterase inhibitor, were found in 10 of 16 tested melons which had been eaten by persons meeting the case definition. The outbreak demonstrates the need for enhanced physician vigilance with respect to anticholinesterase intoxication. It also demonstrates the value of an established system for reporting of unusual illness to public health officials.

Aldicarb↗
PubMed1986

Methicillin-resistant Staphylococcus aureus: how reliable is laboratory reporting?

Microbiology laboratories in Oregon were surveyed in 1981 to determine how often methicillin-resistant Staphylococcus aureus (MRSA) was being reported to physicians in the state. Results of this survey were surprising in three respects. First, the mean percent of S. aureus isolates reported by laboratories as methicillin-resistant was 8.3%. Second, a significant inverse correlation was found between the percent of reported MRSA and laboratory size (p = 0.0001). Finally, laboratories which retested initially resistant isolates reported significantly less MRSA (mean 3.3%, median 1%) than those laboratories which accepted initial results (mean 20%, median 12%) (p = 0.0001). Independent testing by the Centers for Disease Control of isolates reported to be MRSA confirmed that some misidentification was occurring. Participating laboratories were notified of our initial findings and their potentially serious clinical ramifications. Laboratories were resurveyed in 1982, and a significant decrease in the reported MRSA to a mean percentage of 3.4% was observed (p = 0.002). It is unlikely that this situation is unique to Oregon, and similar misreporting of MRSA to physicians in other areas of the country may be compromising the safe and effective treatment of S. aureus infections.

Health Surveys↗
PubMed1986

Screening for coinfection with Cryptosporidium and Giardia in Oregon public health clinic patients.

During 1984, we screened 1,710 local public health clinic patients for Giardia and Cryptosporidium. Six patients (0.35 per cent) were positive for Cryptosporidium, and 214 (12.5 per cent) were positive for Giardia. One patient was positive for both parasites. In contrast to other reported studies, no evidence was found for an association between the two parasites (odds ratio = 1.39, 95 per cent CI 0.16, 11.8). The apparent prevalence of Cryptosporidium in our study population was lower than has been reported previously. More laboratory screening could contribute to a better understanding of the distribution of Cryptosporidium and its role in human diarrheal disease, especially in immunocompetent patients.

Adolescent↗
PubMed1986

Risk factors for traumatic infant death in Oregon, 1973 to 1982.

A retrospective study of risk factors for traumatic infant deaths in Oregon occurring from 1973 through 1982 was performed using vital records and medical examiner records. A total of 146 such deaths occurred during this period. Relative risks were calculated for various risk factors in the study group compared with all Oregon births. Factors found to be significantly associated with all traumatic deaths were low maternal age, out-of-hospital birth, unwed mother, late or no prenatal care, low birth weight, and low maternal education. Race, sex, and birth order were not associated with traumatic infant death. The traumatic deaths were grouped into homicides and accidents. The same risk factor associations, with the exception of out-of-hospital birth, were found for each group.

Accidents↗
PubMed1985

Isoniazid-resistant tuberculosis. A community outbreak and report of a rifampin prophylaxis failure.

The choice of effective preventive treatment for persons exposed to Mycobacterium tuberculosis resistant to isoniazid is uncertain. Although no data document the efficacy of any drug other than isoniazid for preventive treatment of tuberculosis, rifampin, with or without ethambutol, has been used for prophylaxis in contacts of cases with known isoniazid-resistant organisms. This report describes a community outbreak of isoniazid-resistant tuberculosis infection and a case of rifampin prophylaxis failure with acquired rifampin resistance. This raises concern about the efficacy of rifampin for the preventive treatment of contacts exposed to isoniazid-resistant tuberculosis.

Adult↗
PubMed1984

Toxic shock syndrome in Oregon. Risk of recurrence.

To define the risk of having a recurrence of toxic shock syndrome, we collected information on 53 cases (42 definite and 11 probable cases) that occurred in Oregon between Jan 1, 1980, and May 30, 1982. For the 777 person-months for which follow-up information was available, only one probable recurrent case of toxic shock syndrome occurred. The low frequency of recurrences may be associated with the high frequency (91%) with which beta-lactamase-resistant antibiotics were used in initial episodes of toxic shock syndrome and with the relatively low proportion (44%) of menstruating women who resumed the use of tampons after their first episode.

Adolescent↗
PubMed1983

Rubella screening and immunization of health care personnel: critical appraisal of a voluntary program.

At our health care center 1161 personnel and students were offered rubella antibody testing. Ninety-two percent were serologically screened or had been previously immunized or previously proven seropositive. Males were more likely to refuse serologic screening than females (p less than 0.01). Sixteen percent of the seroscreened individuals were found seronegative to rubella. Eighty-five percent of seronegative women less than or equal to 24 years old accepted immunization, as compared to 62% of older females and 55% of all males (p less than 0.01). The total cost of the program was over $11,000. Literature and data review failed to support an increased risk of rubella transmission and/or major consequences to pregnant patients in the health care setting as compared to the community. Voluntary rubella immunization is well received by seronegative young women. Programs for immunization of other health care personnel are unlikely to decrease the number of cases of congenital rubella, are costly, and are not well accepted. Education and immunization of all young susceptible women remain the best methods to substantially decrease the incidence of congenital rubella in a cost-effective manner in the near future.

Adult↗
PubMed1982

Toxic shock syndrome in Oregon: epidemiologic findings.

To ascertain the risk factors associated with toxic shock syndrome in Oregon a retrospective questionnaire was given to 18 patients (cases) and to two sets of age- and sex-matched controls. One set of controls consisted of friends (friend-controls) chosen by each patient. The second set of controls was selected from women attending a family planning clinic (clinic-controls). Patients were more likely to have used Rely (Procter & Gamble) tampons than friend-controls who were tampon users (p less than 0.05). There was no significant difference between cases and friend-controls with respect to birth control methods. There were no significant differences between cases and controls for history of sexually transmitted diseases or vaginal infection, frequently of intercourse, intercourse during menstruation, or frequency of tampon change.

Adolescent↗
PubMedDate not supplied

Hepatitis B and workers in institutions for the mentally retarded: risk of infection for staff in patient care.

In the fall of 1982, we conducted a serosurvey of 920 of 933 employees in a large residential institution for the mentally retarded in Salem, Oregon. This survey demonstrated an overall prevalence of 10% for antibody to hepatitis B core antigen (anti-HBc), a marker of present or previous hepatitis B virus infection. Antibody positivity was significantly associated with a history of ever having worked in a position involving direct patient care (adjusted odds ratio = 3.1, 95% confidence interval 2.6-4.2). The length of time employed at the institution was significantly associated with an increasing prevalence of anti-HBc positivity among those persons who had ever worked in direct patient care (chi 2 for linear trend = 19.3, P less than .00001, one tail), but not among those employees who had never worked in patient contact. This evidence supports the Immunization Practices Advisory Committee (ACIP) recommendation of hepatitis B virus screening and, where appropriate, vaccinations for those workers in institutions for the mentally retarded who work closely with patients.

Adolescent↗
PubMedDate not supplied

Survey of state health agencies' staff who practice the epidemiology of noninfectious diseases and conditions.

The primary causes of mortality in the United States are noninfectious diseases and conditions. Epidemiologic and intervention activities related to most of these diseases and conditions have increased in most State health agencies over the past decade. Because little was known of the practice of noninfectious disease epidemiology in State health agencies, a mail survey was undertaken in 1991. Persons working in State health agencies who responded to the survey had a graduate degree in epidemiology, biostatistics, or related fields and actively participated in the epidemiology of noninfectious diseases or conditions. Respondents were from 48 States, predominantly male (56 percent) and white (92 percent). On an average, respondents spent roughly half of their time actually doing epidemiology. The focus of noninfectious disease epidemiology has been categorized by risk factors (environment, occupation, nutrition, tobacco, and substance abuse), diseases (diabetes, cancer, and cardiovascular disease), and health conditions (injury, birth defects, and other reproductive conditions). The percentage of respondents who reported epidemiologic activity in any risk factor, disease, or condition varied from 55 percent for environmental epidemiology to 9 percent in nutritional epidemiology. Respondents from 41 States reported activity in environmental epidemiology, those from 18 States reported activity in substance-abuse epidemiology, and those from 13 States reported activity in nutritional epidemiology. Although the practice of noninfectious disease epidemiology appears to be considered important in the majority of States, the extent of practice varies markedly. Those risk factors, diseases, and conditions that are most frequently associated with morbidity and mortality are the least addressed epidemiologically in State health agencies. In addition,when events such as environmental disasters occur, appropriate surveillance systems frequently are not in place to monitor the most important health outcomes. As a result, public health planning and intervention programs may not be driven by solid epidemiologic data.

Cardiovascular Diseases↗