Biomedical subjects

S M Ostroff

Publications and source records attributed to S M Ostroff.

At least 37 records · Page 2Linked to original sources

PubMed1994

Sources of sporadic Yersinia enterocolitica infections in Norway: a prospective case-control study.

Yersinia enterocolitica is a recognized cause of gastroenteritis in northern Europe. During October 1988-January 1990, a prospective case-control study was performed to address risk factors associated with sporadic Y. enterocolitica infections in southeastern Norway. Sixty-seven case-patients (mean age 23.4 years, range 8 months-88 years) and 132 age-, sex- and geographically-matched controls were enrolled in the study. Multivariate analysis of the data showed that persons with Y. enterocolitica infection reported having eaten significantly more pork items (3.79 v. 2.30 meals, P = 0.02) and sausage (2.84 v. 2.20 meals, P = 0.03) in the 2 weeks before illness onset than their matched controls; only one patient had eaten raw pork. Patients were also more likely than controls to report a preference for eating meat prepared raw or rare (47 v. 27%, P = 0.01), and to report drinking untreated water (39 v. 25%, P = 0.01) in the 2 weeks before illness onset. Each of these factors was independently associated with disease, suggesting a link between yersiniosis and consumption of undercooked pork and sausage products and untreated water. Efforts should be directed towards developing techniques to reduce Y. enterocolitica contamination of pork and educating consumers about (1) proper handling and preparation of pork items and (2) the hazards of drinking untreated water.

Adolescent↗

PubMed1994

Predicting Mycobacterium avium complex bacteremia in patients infected with human immunodeficiency virus: a prospectively validated model.

In cases of advanced infection with human immunodeficiency virus, mycobacterial blood cultures are frequently used to diagnose disseminated infection with the Mycobacterium avium complex (MAC). However, no prospectively validated guidelines exist for the use of such cultures. In this study, a two-part model for predicting MAC bacteremia was developed and then validated prospectively. First, a CD4+ cell count of < or = 50/microL was used to predict bacteremia. Then, among patients with < or = 50 CD4+ cells/microL, the documentation of fever on more than 30 days during the preceding 3 months, a hematocrit of < 30%, or a serum albumin concentration of < 3.0 g/dL was used to predict bacteremia. This model had a sensitivity of 89% and positive and negative predictive values of 30% and 98%, respectively, for the identification of patients with bacteremia. Had the model been applied to patients in this study, the number of blood cultures performed would have decreased by 61%, but 11% of the positive cultures would have been missed. In short, this model can predict MAC bacteremia and can potentially guide the use of mycobacterial blood cultures.

AIDS-Related Opportunistic Infections↗

PubMed1994

Mycobacterium avium complex in the respiratory or gastrointestinal tract and the risk of M. avium complex bacteremia in patients with human immunodeficiency virus infection.

Mycobacterium avium complex (MAC) is frequently isolated from the respiratory or gastrointestinal tract of patients with advanced human immunodeficiency virus (HIV) infection. Whether they are at increased risk of MAC bacteremia and whether culture of respiratory tract or stool specimens is useful for predicting bacteremia are unclear. HIV-infected patients with < or = 50 CD4+ cells/microL were prospectively studied. The risk of MAC bacteremia was approximately 60% within 1 year for patients with MAC in either the respiratory or gastrointestinal tract and was greater than for those without MAC in these sites (relative hazards for respiratory and gastrointestinal tract, 2.3 and 6.0; 95% confidence intervals, 1.1-4.6 and 2.5-14.6, respectively). Both respiratory tract specimen and stool culture had poor sensitivities (22% and 20%, respectively) but good positive predictive values (approximately 60%) for bacteremia. Symptomatic HIV-infected patients with MAC in the respiratory or gastrointestinal tract are at a substantial risk for developing MAC bacteremia; culture of these sites has limited usefulness as a screening test.

Adult↗

PubMed1994

The impact of Mycobacterium avium complex bacteremia and its treatment on survival of AIDS patients--a prospective study.

It is currently recommended that patients with AIDS and Mycobacterium avium complex (MAC) bacteremia receive antimycobacterial treatment. However, no study has prospectively evaluated the impact of this infection and its treatment on survival. This study prospectively followed a cohort of 367 AIDS patients with < or = 50 CD4+ cells/microL and found that MAC bacteremia was independently associated with an increased risk of death (relative hazard [RH] = 1.8, 95% confidence interval [CI] = 1.3-2.4, P < .001). Patients with MAC bacteremia who were treated had a longer median survival than those who were not (263 vs. 139 days, P < .001); treatment was independently associated with a lower risk of death (RH = 0.45, 95% CI = 0.23-0.89, P < .001). However, 23% of patients with bacteremia died within 28 days of that diagnosis; few were treated. MAC bacteremia contributes to the death of patients with AIDS, and treatment increases survival. However, many patients will not survive long enough to receive treatment. These results underscore the importance of early diagnosis and chemoprophylaxis for MAC bacteremia.

AIDS-Related Opportunistic Infections↗

PubMed1993

Epidemiological investigation of risk factors for campylobacter colonization in Norwegian broiler flocks.

An epidemiological investigation was conducted to identify risk factors related to hygiene and husbandry practices which determine the introduction of Campylobacter spp. into broiler chicken flocks. All 176 broiler farms in an area in southeastern Norway participated in the study. Each farm was represented by one flock selected at random during a one-year period. The flocks were examined for campylobacter colonization at slaughter, and the flock managers were subsequently interviewed about hygiene and husbandry practices. Campylobacter spp. were recovered from 32 (18%) of the flocks. The proportion of colonized flocks varied geographically and seasonally with a peak in the autumn. The following variables were found to be independently associated with an increased risk of campylobacter colonization using logistic regression analysis: (i) feeding the broilers undisinfected water (odds ratio (OR) = 3.42, P = 0.045), (ii) tending other poultry prior to entering the broiler house (OR = 6.43, P = 0.007), (iii) tending pigs before entering the house (OR = 4.86, P = 0.037), (iv) geographic region (Hedmark versus Ostfold county) (OR = 2.91, P = 0.023, (v) season (autumn versus other seasons) (OR = 3.43; P = 0.008). Presence of rats on the farm was associated with an increased risk, but this factor did not reach statistical significance (OR = 3.96, P = 0.083). Preventive measures should include disinfection of drinking water and strict hygienic routines when the farm workers enter the rearing room. The results indicate that disinfection of drinking water is the preventive measure most likely to have the greatest impact on the prevalence of campylobacter among broiler chicken flocks in the study area (population attributable fraction = 0.53).

Animal Husbandry↗

PubMed1993

A nosocomial pseudo-outbreak of Mycobacterium xenopi due to a contaminated potable water supply: lessons in prevention.

OBJECTIVES: To determine risk factors for Mycobacterium xenopi isolation in patients following a pseudo-outbreak of infection with the organism. DESIGN: Retrospective cohort analysis of mycobacteriology laboratory specimen records and frequency-matched case-control study of hospital patients. SETTING: General community hospital. PATIENTS: For the case-control study, 13 case patients and 39 randomly selected controls with mycobacterial cultures negative for M xenopi, frequency matched by specimen source, whose specimens were submitted from June 1990 through June 1991. RESULTS: Between June 1990 and June 1991, M xenopi was isolated from 13 clinical specimens processed at a midwestern hospital, including sputum (n = 6), bronchial washings (2), urine (4), and stool (1). None of the patients with M xenopi-positive specimens had apparent mycobacterial disease, although five received antituberculosis drug therapy for a range of one to six months. Specimens collected in a nonsterile manner were more likely to grow the organism than those collected aseptically (3.1% versus 0, relative risk = infinity, P = 0.003). M xenopi isolation was attributed to exposure of clinical specimens to tap water, including rinsing of bronchoscopes with tap water after disinfection, irrigation with tap water during colonoscopy, gargling with tap water before sputum collection, and collecting urine in recently rinsed bedpans. M xenopi was isolated from tap water in 20 of 24 patient rooms tested, the endoscopy suite, and the central hot water mixing tank, but not from water in the microbiology laboratory. The pseudo-outbreak occurred following a decrease in the hot water temperature from 130 degrees F to 120 degrees F in 1989. CONCLUSIONS: Maintenance of a higher water temperature and improved specimen collection protocols and instrument disinfection procedures probably would have prevented this pseudo-outbreak.

Adult↗

PubMed1993

State regulation of hospital water temperature.

OBJECTIVE: The purpose of this study was to determine current regulations and policies in the United States concerning maximal water temperatures in acute care hospitals. DESIGN: A standardized questionnaire administered by telephone to health department officials from 50 states and the District of Columbia. SETTING: State Health Departments in the 50 states and the District of Columbia. RESULTS: All states responded to the survey. Respondents from 39 states (77%) reported regulating maximum allowable hospital water temperature at a mean of 116 degrees F (median, 120 degrees F; mode 110 degrees F; range, 110 degrees F to 129 degrees F). Twelve states (23%) have no regulations for maximum water temperature. Of the 39 states regulating maximum water temperature, 30 (77%) routinely monitor hospital compliance. Nine states (23%) conduct inspections only in response to a complaint or incident. CONCLUSIONS: There is great variation among the states with respect to the existence, enforcement, and specific regulations controlling hospital water temperature. Risk-benefit and cost-effectiveness analyses would help to assess the risk of scald injuries at water temperatures that will inhibit microbial contamination.

Burns↗

PubMed1993

Common somatic O and heat-labile serotypes among Campylobacter strains from sporadic infections in the United States.

Somatic O (formerly heat-stable) and heat-labile (HL) serotyping methods are commonly used to type Campylobacter jejuni and Campylobacter coli isolates. Although both systems are effective, the labor and time required for each have limited their application. These systems can be simplified by reducing the number of antisera used. To find an appropriate panel of antisera, we determined the distribution of common serotypes in the United States among a representative sample of 298 Campylobacter isolates. The strains, obtained between July 1989 and June 1990 from persons with sporadic cases of diarrhea, were collected from 19 randomly chosen counties in all geographic (census) regions of the United States. All strains were serotyped by the O and HL systems. By phenotypic methods, 288 C. jejuni, 9 hippurate-negative C. jejuni/C. coli, and 1 Campylobacter lari were identified. Of 57 O antisera, 24 typed 252 (84.6%) strains. Of the 55 HL antisera, 23 serotyped 253 (84.9%) strains. All strains were typeable in the unabsorbed O antisera. In the absorbed HL antisera, four strains were nontypeable and 14 were rough and untypeable. In each geographic region, 9 or more O and HL serotypes were found. Serotypes O:1, O:4, and O:13,16,43,50 and HL 1 were identified in all regions. The combination of both schemes gave greater discrimination than either system alone, but the maintenance of both requires a large resource investment. A serotyping scheme incorporating the 24 most prevalent O and 23 most prevalent HL serotypes could be useful for outbreak support and for surveillance. In the near future, we anticipate using a molecular subtyping method in combination with limited serotyping to distinguish Campylobacter strains.

Campylobacter↗

PubMed1992

Lymphocytic choriomeningitis outbreak associated with nude mice in a research institute.

OBJECTIVE: After an employee at a cancer research institute was diagnosed with lymphocytic choriomeningitis, an investigation was performed to determine the extent of lymphocytic choriomeningitis virus (LCMV) infections among the institute's employees and to identify risk factors for infection. DESIGN: Retrospective cohort study. SETTING: A US cancer research institute. PARTICIPANTS: Eighty-two of 90 institute employees. MAIN OUTCOME MEASURES: Serum LCMV antibodies. RESULTS: Seven workers (9%) with definite LCMV infection (LCMV IgG antibody titer greater than or equal to 16) and one worker (1%) with probable infection (IgG titer = 8) were identified (10% overall seroprevalence). All infected employees handled animals or animal tissues and were more likely than other animal handlers to have worked with nude mice (Mus musculus) (P less than .02). Among the 31 employees who worked with nude mice at the institute, infected workers were more likely to clean the cages of nude mice (P much less than .001), change their bedding (P less than .01), and change their water (P less than .001). The institute had been injecting nude mice with LCMV-infected tumor cell lines and had recently increased the nude mouse population and the duration of experiments. These changes would have increased the LCMV burden at the facility and were temporally associated with the cluster of LCMV infections in employees. CONCLUSIONS: This LCMV outbreak, the first reported since 1974, is the first associated with nude mice. It illustrates the ongoing hazard LCMV poses in research laboratories. Since the symptoms of LCMV infection can be nonspecific, clinicians should consider this diagnosis in ill patients who report laboratory rodent exposure.

Adult↗

PubMed1992

Clinical features of sporadic Yersinia enterocolitica infections in Norway.

During October 1988 through January 1990, a study of sporadic Yersinia enterocolitica infections was done in the Oslo region to assess the clinical impact and risk factors for this disease. Sixty-seven case-patients (mean age, 23.4 years) and 132 population-based age- and sex-matched controls were enrolled. Among patients who were well when interviewed, illness lasted a mean of 20 days, but 10% of the others remained symptomatic a year later. Bloody diarrhea occurred only in persons less than 18 years old (P = .002); joint pain was more common in adults (P = .001). Prolonged carriage was found in 47% of patients after resolution of symptoms. Patients were less likely to shed the organism after antimicrobial treatment (relative risk, 0.3; P = .003). Case-patients were more likely than controls to have antecedent enteric illness (odds ratio, 8.2; P less than .001). Y. enterocolitica infection in Norway is notable for its severity and chronicity. Postsymptomatic shedding, which occurs commonly, may be reduced by antimicrobial treatment.

Adolescent↗

PubMed1992

Risk factors for sporadic Campylobacter infections: results of a case-control study in southeastern Norway.

In 1989 and 1990, a case-control study designed to identify risk factors for sporadic infections with thermotolerant Campylobacter bacteria was conducted in three counties in southeastern Norway. The investigation was confined to infections which were acquired in Norway. A total of 52 bacteriologically confirmed cases and 103 controls matched by age, sex, and geographic region were interviewed. The following risk factors were found to be independently associated with illness in conditional logistic regression analysis: consumption of sausages at a barbecue (odds ratio [OR] = 7.64; P = 0.005), daily contact with a dog (OR = 4.26; P = 0.024), and eating of poultry which was brought into the house raw (frozen or refrigerated) (OR = 3.20; P = 0.024). The risk associated with consumption of sausages at a barbecue could not be attributed to cross-contamination from poultry products. By univariate analysis, consumption of poultry which was brought raw and frozen was associated with illness (OR = 2.42; P = 0.042), even though freezing substantially reduces the number of viable campylobacters. When poultry consumption was examined by country of origin, eating of poultry produced in Denmark or Sweden was strongly associated with illness (OR = 13.66; P = 0.014), whereas consumption of poultry produced in Norway was not (OR = 1.33; P = 0.41).

Adolescent↗

PubMed1992

Clinical features of sporadic Campylobacter infections in Norway.

To assess risk factors and clinical impact of campylobacteriosis in Norway, a case-control study of sporadic cases of infection with thermotolerant Campylobacter spp. was conducted. This report describes: (1) the frequency and duration of signs and symptoms, antimicrobial treatment, hospitalization, and faecal carriage among the study patients; (2) diarrhoeal illness and campylobacter carriage among their household members; and (3) antimicrobial susceptibility pattern among bacterial isolates. A total of 135 patients with bacteriologically confirmed campylobacter infection were enrolled in the study. Of these, 58 (43%) were domestically acquired while 77 (57%) were acquired abroad. If the study enrollees are representative of the cases reported to the national surveillance system, the reported infections led to an estimated annual average of at least 8590 days of illness, 78 admissions to hospital, 329 days of hospital stay, 2236 days lost at work or at school, 1000 physician consultations, and 96 antimicrobial prescriptions among the 4.2 million Norwegians. Convalescent carriage of campylobacter was detected in 16% of the patients who submitted follow-up stool specimens; the organism was carried for a mean of 37.6 days (median 31, range 15-69) after the onset of illness. Antimicrobial treatment appeared to have reduced the likelihood of carriage once symptoms had resolved. Diarrhoeal illness was more commonly reported in members of case households than control households (OR = 5.44, p < 0.0001). Cases were more likely than controls to report antecedent recurrent diarrhoea (OR = 6.00, p = 0.034). Two cases of neonatal infection, probably acquired from the mother at the time of delivery, were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Pain↗

PubMed1991

An outbreak of shigellosis at an outdoor music festival.

In August 1988, an estimated 3,175 women who attended a 5-day outdoor music festival in Michigan became ill with gastroenteritis caused by Shigella sonnei. Onset of illness peaked 2 days after the festival ended, and patients were spread throughout the United States by the time the outbreak was recognized. An uncooked tofu salad served on the last day was implicated as the outbreak vehicle (odds ratio = 3.4, p less than 0.0001). Over 2,000 volunteer food handlers prepared the communal meals served during the festival. This large foodborne outbreak had been heralded by a smaller outbreak of shigellosis among staff shortly before the festival began and by continued transmission of shigellosis from staff to attendees during the festival. S. sonnei isolated from women who became ill before, during, and after the festival had identical antimicrobial susceptibility patterns and plasmid profiles. Limited access to soap and running water for handwashing was one of the few sanitary deficits noted at this gathering. This investigation demonstrates the need for surveillance and prompt public health intervention when Shigella infections are recognized in persons attending mass outdoor gatherings, the singular importance of handwashing in reducing secondary transmission of shigellosis, and the potential for explosive outbreaks when communal meals are prepared by large numbers of food handlers.

Adult↗

PubMed1991

Isolation of Escherichia coli serotype O157:H7 and other Shiga-like-toxin-producing E. coli from dairy cattle.

We examined 1,266 fecal specimens from healthy cattle during the investigations of two sporadic cases of hemolytic uremic syndrome associated with raw milk consumption and an outbreak of gastroenteritis and hemolytic uremic syndrome caused by Escherichia coli serotype O157:H7. We collected specimens from heifers, calves, and adult cows on 22 farms, in a stockyard, and in a packing house. We also collected 3 raw hamburger specimens from a restaurant and 23 raw milk samples from two farms. All specimens were examined for E. coli O157:H7 by using sorbitol-MacConkey agar, H immobilization, O157 agglutination, and tissue culture cytotoxicity. E. coli O157:H7 was isolated from 16 heifers or calves and 1 adult cow on 22 farms, 1 stockyard calf, 2 beef specimens, and 1 raw milk sample. Selected fecal specimens were also examined for the presence of other Shiga-like-toxin-producing E. coli (SLTEC) by testing polymyxin B extracts of colony sweeps and then testing individual colonies for toxin production. SLTEC other than O157 was isolated from 8 of 10 farms investigated and from the stockyard; 8% of adult cows and 19% of heifers and calves were positive for SLTEC. Several animals were positive for SLTEC by colony sweep only. This investigation demonstrates that dairy cattle are a reservoir of E. coli O157:H7 and other SLTEC.

Animals↗

PubMed1991

Surveillance of Escherichia coli O157 isolation and confirmation, United States, 1988.

In 1989, to examine patterns of testing for Escherichia coli O157:H7 in state public health laboratories (SPHLs), CDC conducted a survey to determine the availability and type of Escherichia coli O157:H7 testing in SPHLs during 1988 and the number of isolates confirmed at SPHLs if such testing was available. The results were compared with information on isolates submitted for confirmatory testing at CDC in 1988. Thirty-nine (78%) of the 51 SPHLs were testing for E. coli O157:H7 in 1988; 26 confirmed at least one E. coli O157 isolate in that year. CDC confirmed isolates from three additional states. A total of 489 E. coli O157:H7 or E. coli O157:NM isolates were identified, with the largest numbers being reported from Washington (156), Oregon (64), Minnesota (63), and Massachusetts (36). These results show that E. coli O157 has been detected in most areas of the United States. Infections are apparently concentrated in northern states; however, improved surveillance data are needed to determine regional incidence and trends.

Child↗

PubMed1990

A statewide outbreak of Escherichia coli O157:H7 infections in Washington State.

In November 1986, a statewide outbreak of Escherichia coli O157:H7 infections in Washington State was identified after a physician in an eastern Washington community hospitalized three patients with hemorrhagic colitis which progressed to thrombotic thrombocytopenic purpura. Epidemiologic investigation identified 37 cases in this community and linked the illnesses to a local restaurant which had served ground beef that was the suspected initial vehicle of transmission. The plasmid profile and toxin production pattern (Shiga-like toxin II alone) of the outbreak strain provided a unique strain marker. E. coli O157:H7 infections caused by this strain were simultaneously seen in other parts of the state among nursing home residents and in patients with the hemolytic-uremic syndrome, and an increase in sporadic cases of hemorrhagic colitis was noted at a Seattle health maintenance organization. It is suspected that a contaminated product, probably ground beef distributed statewide, was the common source. Tracing of this meat led to farms where rectal swabs from six (1%) of 539 cattle tested yielded E. coli O157:H7, although the plasmids and toxin production patterns of these isolates differed from the human outbreak strain. Introduction of a single strain of E. coli O157:H7 has the potential to cause widespread concurrent outbreaks. Such outbreaks are likely to escape recognition until heightened screening and surveillance for E. coli O157:H7 is established.

Adolescent↗

PubMed1989

Infections with Escherichia coli O157:H7 in Washington State. The first year of statewide disease surveillance.

In 1987, Washington became the first state to require that infection with Escherichia coli serotype O157:H7 be reported. In the first year of surveillance, 93 cases were reported, yielding an annual incidence of 2.1 cases per 100,000 population. The median age of case patients was 14 years (range, 11 months to 78 years), with the highest attack rate among children younger than 5 years (6.1 cases per 100,000 population per year). Bloody diarrhea was present in 95% of reported cases, 12% of patients developed either hemolytic-uremic syndrome or thrombotic thrombocytopenic purpura, and one patient died. Suspected secondary cases were seen in 5% of households. Fifty-six (60%) cases occurred during June through September, as did 73% of the cases of hemolytic-uremic syndrome or thrombotic thrombocytopenic purpura. Cases reported during the summer months were more likely than cases reported at other times of the year to be in children younger than 10 years. Medications, including antimicrobial medications, did not influence the duration of symptoms, nor did they appear to alter the risk of developing hemolytic-uremic syndrome or thrombotic thrombocytopenic purpura. This newly established surveillance system in Washington demonstrates that E coli O157:H7 is an important and common cause of bloody diarrhea in the United States.

Adolescent↗

PubMed1989

Toxin genotypes and plasmid profiles as determinants of systemic sequelae in Escherichia coli O157:H7 infections.

In 1987, 93 Escherichia coli O157:H7 isolates were collected during routine surveillance for this pathogen in the state of Washington. Toxin genotypes and plasmid profiles were correlated with the clinical sequelae of illness in 88 of the 93 patients from whom these strains were isolated. Thirteen plasmid patterns were observed among the 88 tested isolates; four patterns accounted for 82% of the isolates. Genetic probing for Shiga-like toxins (SLT) I and II demonstrated the presence of both genes in 67 (76%), SLT I alone in three (3%), and SLT II alone in 18 (20%). The hemolytic uremic syndrome or thrombotic thrombocytopenic purpura developed in seven (39%) of 18 patients infected with isolates having only the SLT II gene, while these complications occurred in only four (6%) of 70 patients infected with isolates having the other two genotypes (relative risk, 6.8; 95% confidence interval, 1.9, 26.4). This study shows that E. coli O157:H7 isolates systematically collected from a single geographic region over a defined time period exhibit considerable diversity in plasmid content and toxin genotype and that the toxin genotype of the infecting strain may influence the risk of developing microangiopathic sequelae.

Age Factors↗