Identification of a mutant bovine herpesvirus-1 (BHV-1) in post-arrival outbreaks of IBR in feedlot calves and protection with conventional vaccination. (33/878)

Outbreaks of infectious bovine rhinotracheitis (IBR) have recently been observed in vaccinated feedlot calves in Alberta a few months post-arrival. To investigate the cause of these outbreaks, lung and tracheal tissues were collected from calves that died of IBR during a post-arrival outbreak of disease. Bovine herpesvirus-1 (BHV-1), the causative agent of IBR, was isolated from 6 out of 15 tissues. Of these 6 isolates, 5 failed to react with a monoclonal antibody specific for one of the epitopes on glycoprotein D, one of the most important antigens of BHV-1. The ability of one of these mutant BHV-1 isolates to cause disease in calves vaccinated with a modified-live IBR vaccine was assessed in an experimental challenge study. After one vaccination, the majority of the calves developed humoral and cellular immune responses. Secondary vaccination resulted in a substantially enhanced level of immunity in all animals. Three months after the second vaccination, calves were either challenged with one of the mutant isolates or with a conventional challenge strain of BHV-1. Regardless of the type of virus used for challenge, vaccinated calves experienced significantly (P < 0.05) less weight loss and temperature rises, had lower nasal scores, and shed less virus than non-vaccinated animals. The only statistically significant (P < 0.05) difference between the 2 challenge viruses was the amount of virus shed, which was higher in non-vaccinated calves challenged with the mutant virus than in those challenged with the conventional virus. These data show that calves vaccinated with a modified-live IBR vaccine are protected from challenge with either the mutant or the conventional virus.  (+info)

Reproductive performance of a cow-calf herd following a Neospora caninum-associated abortion epidemic. (34/878)

This study examines the long-term impact of a Neospora caninum-associated abortion outbreak in a large cow-calf herd in northern Alberta. Blood samples were collected 4 times from all bred females and heifer calves born during the spring before the outbreak: (1) at the time of the outbreak, (2) the following spring, (3) the subsequent fall, and, finally, (4) the second spring after the outbreak. The samples were analyzed using a commercially available enzyme-linked immunosorbent assay for N. caninum. Calves born immediately following the outbreak were also monitored. Individual calving or abortion records were available from all cows for 2 calving seasons. All cows and heifers were pregnancy tested after the 2 subsequent breeding seasons. At the time of the abortion outbreak in 1997, 81% of all bred females and 87% of the heifer calves were serologically positive. In spring 1998, 49% of the cows and 47% of the heifer calves remained positive. In fall 1998, 48% of the remaining cows and heifers were serologically positive. After the first breeding season following the outbreak (1998), 13.5% of the heifers and 22.2% of the cows were open (not pregnant). Animals that were serologically positive in the spring were more likely to be open in the fall (odds ratio, 2.0; 95% confidence interval, 1.1 to 3.7). No subsequent associations with increased risk of abortion, stillbirth, or nonpregnancy were identified.  (+info)

Influenza vaccination in Alberta long-term care facilities. (35/878)

BACKGROUND: Canada's National Advisory Committee on Immunization recommends that both staff and residents of long-term care facilities be vaccinated against influenza. This paper describes the influenza vaccination policies and programs, as well as vaccination rates, for staff and residents of long-term care institutions in Alberta. Such data have not previously been reported. METHODS: Data were collected by means of an anonymous mail survey (with 2 reminders) sent to Alberta nursing homes and auxiliary hospitals in spring 1999. RESULTS: Of 160 facilities providing long-term care during the study period, 136 responded to the survey (85%). Of these, only 85 provided data on staff vaccination rates, whereas 118 provided data on resident vaccination rates. For institutions reporting this information, the median proportion of staff vaccinated was 29.9% and the median proportion of residents vaccinated was 91.0%. Only 2 facilities reported that staff vaccination was mandatory; however, only one of these had a written policy consistent with the self-report period. Using a travelling vaccination cart, offering vaccination on night shift, and monitoring and providing feedback about staff vaccination rates were infrequently employed as elements of staff vaccination programs, although all were positively correlated with staff vaccination rates. Standing orders for resident vaccination were reported by only 84 facilities. Fourteen institutions required written consent for vaccination from the resident or a relative. Facility requirements for consent to vaccinate from the resident or a relative were significantly associated with mean vaccine coverage: 90.5% coverage for institutions requiring verbal consent, 86.5% coverage for institutions requiring written consent and 95.0% for institutions not requiring written or verbal consent. INTERPRETATION: Staff vaccination rates in Alberta long-term care facilities are unacceptably low. Changes in staff vaccination programs may improve the situation even in the absence of mandatory vaccination or work exclusion rules. Requirements for written consent for vaccination of residents of long-term care facilities may be a barrier to immunization.  (+info)

A case study of hospital closure and centralization of coronary revascularization procedures. (36/878)

BACKGROUND: Despite nation-wide efforts to reduce health care costs through hospital closures and centralization of services, little is known about the impact of such actions. We conducted this study to determine the effect of a hospital closure in Calgary and the resultant centralization of coronary revascularization procedures from 2 facilities to a single location. METHODS: Administrative data were used to identify patients who underwent coronary artery bypass grafting (CABG), including those who had combined CABG and valve procedures, and patients who underwent percutaneous transluminal angioplasty (PTCA) in the Calgary Regional Health Authority from July 1994 to March 1998. This period represents the 21 months preceding and the 24 months following the March 1996 hospital closure. Measures, including mean number of discharges, length of hospital stay, burden of comorbidity and in-hospital death rates, were compared before and after the hospital closure for CABG and PTCA patients. Multivariate analyses were used to derive risk-adjustment models to control for sociodemographic variables and comorbidity. RESULTS: The number of patients undergoing CABG was higher in the year following than in the year preceding the hospital closure (51.6 per 100,000 before v. 67.3 per 100,000 after the closure); the same was true for the number of patients undergoing PTCA (129.8 v. 143.6 per 100,000). The burden of comorbidity was significantly higher after than before the closure, both for CABG patients (comorbidity index 1.3 before v. 1.5 after closure, p < 0.001) and for PTCA patients (comorbidity index 1.0 before v. 1.1 after, p = 0.04). After adjustment for comorbidity, the mean length of hospital stay was significantly lower after than before the closure for CABG patients (by 1.3 days) and for PTCA patients (by 1.0 days). The adjusted rates of death were slightly lower after than before the closure in the CABG group. The adjusted rates of death or CABG in the PTCA group did not differ significantly between the 2 periods. INTERPRETATION: Hospital closure and the centralization of coronary revascularization procedures in Calgary was associated with increased population rates of procedures being performed, on sicker patients, with shorter hospital stays, and, for CABG patients, a trend toward more favourable short-term outcomes. Our findings indicate that controversial changes to the structure of the health care system can occur without loss of efficiency and reduction in quality of care.  (+info)

Antibodies to capsular polysaccharides of group B Streptococcus in pregnant Canadian women: relationship to colonization status and infection in the neonate. (37/878)

In a cohort study of 1207 pregnant women in Alberta, Canada, the serotype distributions of vaginal-rectal group B Streptococcus (GBS) isolates were compared with all isolates from neonates with invasive GBS disease identified by population-based surveillance. Serum concentrations of Ia, Ib, II, III, and V capsular polysaccharide (CPS)-specific IgG also were determined, according to serotype of the vaginal-rectal colonizing GBS strain. GBS colonization was detected in 19.5% (235 of 1207) of women. Serotype III accounted for 20.6% (48 of 233) of colonizing strains available for typing but for 37% (27 of 73) of invasive isolates from neonates (P<.01). Maternal colonization with type III was least likely to be associated with moderate concentrations of III CPS-specific IgG. Serotype III GBS is more invasive than other serotypes in this population; this may be due, at least in part, to poor maternal type III CPS-specific antibody response.  (+info)

The pseudomonas hot-foot syndrome. (38/878)

BACKGROUND: Between March and May 1998, there was an outbreak of a clinically distinct skin eruption on the soles of the feet of children who used a community wading pool. METHODS: We reviewed the medical records of 40 children in whom this syndrome developed between March and May 1998. We treated 17 children and advised the attending physicians on the care of the other 23. Follow-up data were obtained for up to one year. RESULTS: Exquisitely painful erythematous plantar nodules developed in 40 children (age, 2 to 15 years) within 40 hours after they had used a wading pool whose floor was coated with abrasive grit. Culture of the plantar pustules from one child yielded Pseudomonas aeruginosa with a pattern on pulsed-field gel electrophoresis that was identical to that of a strain of P. aeruginosa cultured from the pool water. A skin-biopsy specimen from this patient showed a perivascular and perieccrine neutrophilic infiltrate, and a specimen from another patient showed a dermal microabscess. Thirty-seven patients were treated symptomatically; three others were treated with cephalexin. All patients recovered within 14 days, but three children had recurrences of the painful plantar nodules within 24 hours after using the pool again. Folliculitis developed in one patient. CONCLUSIONS: The "pseudomonas hot-foot syndrome" is characterized by the acute onset in children of exquisitely tender plantar nodules and a benign, self-limited course. This community outbreak developed after exposure to pool water containing high concentrations of P. aeruginosa.  (+info)

Case-control study of lifetime physical activity and breast cancer risk. (39/878)

A population-based case-control study of 1,233 incident breast cancer cases and 1,237 controls was conducted in Alberta, Canada, in 1995-1997 to examine the effect of lifetime physical activity patterns on breast cancer risk. No associations between physical activity and breast cancer were found for premenopausal women. For postmenopausal women in the highest quartile (> or =161 metabolic equivalent (MET)-hours/week per year) versus the lowest quartile (<104.8 MET-hours/week per year) of lifetime total physical activity, the adjusted odds ratio was 0.70 (95% confidence interval (CI): 0.52, 0.94). When the risks associated with each type of activity were examined for postmenopausal women, household and occupational activity conferred the largest risk reductions (odds ratio (OR) = 0.57, 95% CI: 0.41, 0.79 and OR = 0.59, 95% CI: 0.44, 0.81, respectively, for highest vs. lowest quartiles of activity), while recreational activity was not associated with any risk reductions. For postmenopausal women, the authors found stronger risk reductions for those who were also nonsmokers (OR = 0.64, 95% CI: 0.46, 0.88), non-alcohol-drinkers (OR = 0.39, 95% CI: 0.11, 0.77), or nulliparous (OR = 0.22, 95% CI: 0.07, 0.70) when they compared the highest with the lowest quartile of lifetime total physical activity. This study provides evidence that lifetime total activity reduces risk of postmenopausal breast cancer.  (+info)

Environmental sources and transmission of Escherichia coli O157 in feedlot cattle. (40/878)

A study was conducted in 2 feedlots in southern Alberta to identify environmental sources and management factors associated with the prevalence and transmission of Escherichia coli O157:H7. Escherichia coli O157:H7 was isolated in preslaughter pens of cattle from feces (0.8%), feedbunks (1.7%), water troughs (12%), and incoming water supplies (4.5%), but not from fresh total mixed rations. Fresh total mixed rations did not support the growth of E. coli O157:H7 and E. coli from bovine feces following experimental inoculation. Within a feedlot, the feces, water troughs, and feedbunks shared a few indistinguishable subtypes of E. coli O157:H7. A few subtypes were repeatedly isolated in the same feedlot, and the 2 feedlots shared a few indistinguishable subtypes. The prevalence of E. coli O157:H7 in water troughs of preslaughter cattle in 1 feedlot was associated with season, maximum climatic temperatures the week before sampling; total precipitation the week before sampling, and coliform and E. coli counts in the water trough.  (+info)