Longitudinal study of fecal shedding of Escherichia coli O157:H7 in feedlot cattle: predominance and persistence of specific clonal types despite massive cattle population turnover.

Identification of the sources and methods of transmission of Escherichia coli O157:H7 in feedlot cattle may facilitate the development of on-farm control measures for this important food-borne pathogen. The prevalence of E. coli O157:H7 in fecal samples of commercial feedlot cattle in 20 feedlot pens between April and September 2000 was determined throughout the finishing feeding period prior to slaughter. Using immunomagnetic separation, E. coli O157:H7 was isolated from 636 of 4,790 (13%) fecal samples in this study, with highest prevalence earliest in the feeding period. No differences were observed in the fecal or water trough sediment prevalence values of E. coli O157:H7 in 10 pens supplied with chlorinated drinking water supplies compared with nonchlorinated water pens. Pulsed-field gel electrophoresis of XbaI-digested bacterial DNA of the 230 isolates obtained from eight of the pens revealed 56 unique restriction endonuclease digestion patterns (REDPs), although nearly 60% of the isolates belonged to a group of four closely related genetic subtypes that were present in each of the pens and throughout the sampling period. The other REDPs were typically transiently detected, often in single pens and on single sample dates, and in many cases were also closely related to the four predominant REDPs. The persistence and predominance of a few REDPs observed over the entire feeding period on this livestock operation highlight the importance of the farm environment, and not necessarily the incoming cattle, as a potential source or reservoir of E. coli O157:H7 on farms.

Measles vaccination during the respiratory virus season and risk of vaccine failure.

OBJECTIVE: To determine whether measles vaccine failure is more common in persons who were vaccinated during the respiratory virus season, when they were more likely to have had concurrent minor illnesses. DESIGN: Population-based case series and case-control study. SETTING: Wisconsin and Ohio. SUBJECTS: The case series included all 545 of the states' residents who had confirmed measles reported during 1985 through 1990 and a history of receiving a single dose of measles vaccine during 1975 through 1988 at 15 to 59 months of age. In a case-control study restricted to 1984 through 1988 vaccinees, season of vaccination was compared in 170 case children and 6070 control students. MAIN OUTCOME MEASURE: Risk of clinical vaccine failure after measles vaccination during the respiratory virus season (September through May) or the peak season (November through March) compared with summertime (June through August), after adjustment for age at vaccination and place of residence. RESULTS: In the case series of persons with vaccine failure, the proportion who had been vaccinated during the respiratory virus season (74.7%) was no greater than expected (September through May = 74.8% of the year). In the case-control study, vaccination during the respiratory virus season (odds ratio, 0.92; 95% confidence interval, 0.66 to 1.30) or the peak season (odds ratio, 0.93) did not increase the risk of vaccine failure. CONCLUSION: Despite the high and strongly seasonal prevalence of viral respiratory illness in young children, routine childhood measles vaccination during the respiratory virus season does not increase their risk of vaccine failure. Findings provide epidemiologic support for recently strengthened recommendations that measles vaccination not be deferred in children with minor respiratory illnesses.

Efficacy of a feed-additive antibacterial combination for improving feedlot cattle performance and health.

The effectiveness of a feed-additive antimicrobial combination for improving feedlot performance and health was tested using 4325 high-risk feeder calves randomly allocated to a control group or an experimental group. The experimental group received the conventional ration plus a feed additive containing 700 mg per head/day of chlortetracycline and sulfamethazine from arrival at the feedlot to day 56 of the feeding period. The inclusion of the feed additive to the ration significantly improved average daily gain for days 0-28 (P = 0.0163) and 0-56 (P = 0.0001), and the feed conversion for days 0-28 (P = 0.0061) and 0-56 (P = 0.0004). Additionally, the use of the feed additive significantly reduced the rate of bovine respiratory disease morbidity for days 0-28 (P = 0.0014) and 0-56 (P = 0.0001), the rate of relapses and mortality for days 0-56 (P = 0.0151 and P = 0.0209, respectively), and the rate of animals diagnosed with chronic respiratory disease for days 0-28 and 0-56 (P = 0.0009 and P = 0.0002, respectively). Performance and health improvements produced by the use of the feed additive were cost-effective.

A Rorschach analysis: parallel disturbance in thought and in self/object representation.

The relationship between thought process disturbance and the structure of internal object relations was investigated by comparing Rorschach Special Scorings and content variables that reflected developmental levels of object relations. Selected Special Scorings from the Comprehensive System (Exner, 1990) and composite (WSum6) scores were correlated with Urist's (1977) Mutuality of Autonomy Scale (MOA) on the Rorschach protocols of 35 borderlines, 15 schizophrenics, and 19 narcissists. Correlations between composite scores of severe thought process disturbance and severe imbalance in internalized object representations were highly significant, p < .0001. The hypothesis that there is a significant relationship between disturbance in internalized self/object differentiation and thought process disturbance was supported. Implications of this study are discussed as they relate to empirical validation of theoretical constructs concerning ego function deficit and self/object disturbance.

Object relations, defensive operations, and affective states in narcissistic, borderline, and antisocial personality disorder.

Rorschach data were used to psychometrically "map" the internal psychological operations of three Cluster B personality disorders, listed in the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev. [DSM-III-R]; American Psychiatric Association, 1987), all of which may be organized at a borderline level. Psychopathic antisocial subjects (P-APDs) and narcissistic subjects (NPDs) were highly narcissistic. NPD subjects, however, produced more indices of anxiety and attachment capacity and fewer scores related to borderline object relations and damaged identity. P-APDs and borderline subjects (BPDs) produced similar mean numbers of borderline object relations; however, the BPDs were more anxious, produced more unsublimated aggressive and libidinal drive material, and evidenced greater potential for attachment. BPDs were also less narcissistic than both P-APDs and NPDs. Nonpsychopathic antisocial subjects (NP-APDs) were less borderline than P-APDs and BPDs, less narcissistic in terms of a stable grandiose self-structure than NPD and P-APDs, produced less evidence of attachment capacity than NPDs and BPDs but more than P-APDs, and were similar to BPDs in their proneness to anxiety. The outpatient NPDs and BPDs produced more idealization responses than the incarcerated antisocial personality disorder (APD) groups. We conclude that the behavioral descriptions offered for these three Cluster B personality disorders, when used in conjunction with information such as level of personality organization (Kernberg, 1984), level of psychopathy (Hare, 1980, 1985), and outpatient versus inpatient research settings, may have greater intrapsychic specificity than previously thought.

A pertussis outbreak in a Wisconsin nursing home.

The epidemiologic features and clinical spectrum of pertussis in the elderly are poorly understood. In October 1985, the Wisconsin Division of Health investigated an outbreak of pertussis in residents of a nursing home in rural Wisconsin. Clinical information and nasopharyngeal swab and acute- and convalescent-phase serum specimens were obtained from all consenting residents and employees. Of 105 residents, 38 (36.2%) were seropositive, including four who were culture-positive for Bordetella pertussis. Culture-positive residents (age range, 52-81 years) had cough lasting 43-54 days. Three of these residents had paroxysmal cough, and all four had cough that interrupted sleep; none of the residents had cough with apnea or vomiting, and all recovered without sequelae. Of six seropositive residents with clinical pertussis, five lived on the south wing of the facility. Of 104 employees, 8 (7.7%) were seropositive, but none were culture-positive for B. pertussis. The higher attack rate for residents and the clustering of clinical cases were consistent with ongoing transmission within the nursing home.

Risk factors for measles in a previously vaccinated population and cost-effectiveness of revaccination strategies.

Using data from a large measles outbreak that occurred in Dane County (Wisconsin) in 1986, we conducted a case-control study to evaluate risk factors for vaccine failure and assessed the cost-effectiveness of school-based revaccination strategies. Vaccination before a change in the measles vaccine stabilizer in 1979 (odds ratio, 5.5; 95% confidence interval, 1.05 to 28.9) and vaccination before age 15 months (odds ratio, 13.9; 95% confidence interval, 5.9 to 32.6) were identified as risk factors. Revaccination strategies for all students ($3444 per case prevented), students vaccinated before 1980 ($3166 per case prevented), and students vaccinated before age 15 months ($2546 per case prevented) were evaluated, assuming use of measles-mumps-rubella vaccine after the initial case was detected in a school. However, a large proportion of cases (43% to 53%) may not have been preventable using these strategies. Therefore, revaccination in all schools assessed to be at risk for measles may be necessary to prevent large outbreaks until a two-dose vaccination schedule is fully implemented.

Mild measles and secondary vaccine failure during a sustained outbreak in a highly vaccinated population.

A prolonged school-based outbreak of measles provided an opportunity to study "vaccine-modified" mild measles and secondary vaccine failure. Thirty-six (97%) of 37 unvaccinated patients had rash illnesses that met the Centers for Disease Control clinical case definition of measles, but 29 (15%) of 198 vaccinated patients did not, primarily because of low-grade or absent fever. Of 122 patients with seroconfirmed measles, 10 patients (all previously vaccinated) had no detectable measles-specific IgM and significantly milder illness than either vaccinated or unvaccinated patients with IgM-positive serum. Of 108 vaccinated patients with seroconfirmed measles, 17 patients (16%) had IgM-negative serology or rash illnesses that failed to meet the clinical case definition; their mean age (13 years), age at the time of vaccination, and time since vaccination did not differ from those of other vaccinated patients. The occurrence of secondary vaccine failure and vaccine-modified measles does not appear to be a major impediment to measles control in the United States but may lead to underreporting of measles cases and result in overestimation of vaccine efficacy in highly vaccinated populations.

Differentiating ego functions of borderline and narcissistic personalities.

This study investigated differences in ego functions of borderline and narcissistic personality disorders through examining responses to Rorschach structural and content variables. Reality testing, thought process, affective regulation, impulse control, and the defenses of splitting and grandiosity were examined from Rorschach protocols of 50 borderlines and 26 narcissists. The borderlines produced greater distortion in reality testing, p less than .05; the narcissists produced more insidious thought process disturbance, p less than .05; and higher functioning groups demonstrated greater control of impulses, p less than .05. Borderlines in this sample demonstrated more affective constriction than the narcissists and used more splitting, p less than .05; narcissists used more grandiosity, p less than .05. Implications of this study are (a) ego functions mature inconsistently, (b) affective responsivity influences ego disorganization, and (c) level of functioning and IQ are related to the production of Rorschach variables.