Regional differences in the fescue toxicosis response of Bos taurus cattle.

Cattle of the same breed from different regions of the USA may have altered responses to heat stress and fescue toxicosis. Angus steers from Missouri (MO ANG, n = 10, 513.6 ± 13.6 kg BW) and Oklahoma (OK ANG, n = 10, 552.8 ± 12.0 kg BW) were fed a diet containing either endophyte-infected (E+, 30 µg ergovaline/kg BW/day) or endophyte-uninfected (E-, 0 µg ergovaline/kg BW/day) tall fescue seed for 23 days. Diet treatment began on day 2. Animals were maintained at thermoneutrality (TN, 19-22 °C, days 1-8) and then exposed to heat stress (HS, cycling 26-36 °C, days 9-22). On day 23, ambient temperature was returned to TN and used as a recovery day. Feed intake (FI) was measured daily, with rectal and skin temperatures determined six times daily. Feed intake reduction from pretreatment levels was greater (P < 0.01) for E + (13.9 ± 0.9 versus 11.9 ± 0.3 kg/day) compared to E - (12.6 ± 0.9 versus 12.4 ± 0.3 kg/day) steers over the entire TN period, regardless of Angus group. During HS, E + cattle had reduced FI (P < 0.02; 6.9 ± 0.2 versus 8.4 ± 0.2 kg/day) compared to E - animals, independent of region of origin. A greater decrease in FI (P < 0.01) was observed for OK (12.1 ± 0.3 versus 6.2 ± 0.2 kg/day) compared to MO ANG (12.2 ± 0.3 versus 7.9 ± 0.2 kg/day) when ambient temperature was increased from TN to HS. On day 13 and days 15-22, OK ANG (E+) had reduced FI (P < 0.01, -2.21 kg) compared to OK ANG (E-), while there was no effect on MO ANG. From day 12 to day 22 of HS, daily minimum temperatures for ear, rump, and tail skin were less for E + (P < 0.05) when compared with E-treated steers, signifying peripheral vasoconstriction in E + animals. This was supported by reduced shoulder and lower tail temperatures (P < 0.01) for E + compared to E-treated OK ANG on the recovery day. In summary, regional differences in the response to fescue toxicosis exist, with peripheral vasomotor effects becoming most evident when animals are subjected to rapid changes in their environment.

Enumerative, Bayesian, and analytic statistical analysis of nosocomial infection for quality improvement: first of two parts.

Readmission rates are used by the Health Care Financing Administration (HCFA) as an indicator of a hospital's quality of care. Specifically, HCFA seeks to relate readmission to complications of the primary admission. A recent study at the Cleveland Clinic Foundation examined patients readmitted within 30 days of dismissal during two non-consecutive months to the cardiovascular surgery, cardiology, and gastroenterology services at this 1,008 bed hospital, accounting for 31% (1640-5342) of all hospital discharges. Only 17% (25/149) of readmissions were due to a complication of the previous hospital admission. Examining those who were readmitted for complications of their primary admission, we found that 36% (9/25) of such readmitted patients had infections that occurred during their primary admission. Otherwise stated, 5.4% (9/149) of readmissions were for nosocomial infections. These patients were compared with 20 retrospectively matched, non-readmitted patients chosen randomly from a group of 100 patients retrospectively matched for gender, age, type, and date of surgery. Using these controls, a computer-based expert system was used to help identify patient variables that are associated with readmission due to nosocomial infection. We found if a patient had (1) a weight less than 66 Kilograms or (2) had a first postoperative total serum protein greater than 6.1 or (3) was reoperated, we could predict with 100% specificity and 60% sensitivity that the patient would have an unplanned readmission. Total readmission rates do not accurately reflect complications of the primary admission.(ABSTRACT TRUNCATED AT 250 WORDS)

Reliability of blood cultures collected from intravascular catheter versus venipuncture.

This is a study of 130 matched venipuncture and intravascular blood cultures collected from 53 patients. In 99 cultures (76.1%), both the venipuncture and the catheter specimens were negative. There were six matched cultures yielding significant isolates: in three both the venipuncture and intravascular specimens were positive; in two only the intravascular specimen was positive; and in one only the venipuncture specimen was positive. Twenty-five cultures were positive from the intravascular specimen only, and 23 of these were classified as contaminated cultures. Thus, the contamination rate was significantly higher in the intravascular catheter blood culture specimens (P less than 0.001). These results indicate that blood culture specimens should not be routinely collected from intravascular catheters unless collection by venipuncture is impossible.

Septicemia secondary to urinary tract infection with colony counts less than 10(5) CFU/mL.

This study evaluates the importance of low-colony-count bacteriuria (less than 10(5) CFU/mL) in septicemia originating from urinary tract infections. In a 14-month period, 260 episodes of septicemia occurred. No clinical or microbiologic evidence for a source other than the urinary tract was evident in 68 (26.2%) cases. Of these 68 patients, 13 (19.1%) had colony counts less than 10(5) CFU/mL, and 6 of the 13 had colony counts less than 10(4) CFU/mL. Nine of the infections were community acquired and four were nosocomial. None of the nosocomial cases were associated with an indwelling catheter; four of the 13 patients were receiving chemotherapy and/or steroid therapy. These data support the thesis that some cases of septicemia in patients other than acutely dysuric women, can be caused by UTIs with low colony counts.

Evaluation of the BACTEC resin blood-culture medium.

A study to determine the value of the BACTEC resin-containing medium, 16B, used in conjunction with radiometric detection of bacteremia using three media was conducted. During a six-month period, 2,104 blood-culture sets consisting of the four media (6B, 7C, 8B, and 16B) were collected. There were 158 significant positive cultures (excluding contaminants) that yielded 168 pathogenic isolates. The data were divided into two patient groups: patients receiving antibiotics and patients not receiving antibiotics. In contrast to previous studies, there was no significant difference in the detection rate of significant positive cultures by the different media in either group of patients. However, in patients receiving antimicrobial therapy, 41 of 55 significant positive cultures (74.5%) were detected by 16B medium, while 34 of 55 (61.8%) were detected by 6B medium. Although this difference is not statistically significant, this trend suggests that 16B medium may be useful in these patients. However, the isolation rate of significant positive cultures is the same for the resin medium and the hypertonic aerobic medium for both groups of patients. Thus, it is possible that the hypertonic medium is as efficacious as resin-containing media in blood culturing.

An outbreak of Norwalk gastroenteritis associated with swimming in a pool and secondary person-to-person transmission.

In June 1977 an outbreak of acute gastroenteritis affected 103 students and teachers at an elementary school in Ohio. The illness typically lasted 24 hours or less and was characterized by vomiting (86%) and cramping (70%), but more than half of the persons involved also reported having nausea, diarrhea, and headache. Similar illness frequently followed in household members (29%) of families with primary cases. Investigation revealed that 70% of the children and teachers who swam in a pool at an all day outing June 1 (4 classrooms) and 55% of those who swam during a similar outing June 2 (2 classrooms) had the onset of acute illness from 12--48 hours later. None of the children who attended the outings but did not swim had a similar illness. The evidence suggested that the primary outbreak was caused by contaminated water in the pool and that person-to-person spread of illness followed. Results of a microbiologic study of pool water were negative for bacterial and viral pathogens. Throat washings, stool specimens, and paired blood samples studied for evidence of pathogens were negative initially, but subsequent serologic studies suggested that infection by Norwalk virus was the cause of the outbreak. The pool chlorinator which was inadvertently unconnected at the time of the school visits was reconnected and an underground leak in the water supply pipes was corrected. No more cases were reported after the pool was drained, cleaned, and reopened.

Nosocomial Pseudomonas aeruginosa urinary tract infections.

Two separate outbreaks of Pseudomonas aeruginosa urinary tract infections (UTIs) were associated with cystoscopy or transurethral prostate resection. The first outbreak was identified after routine bacteremia surveillance demonstrated four cases of P aeruginosa septicemia in a three-month period. A six-month retrospective review of the microbiology records identified 14 cases of P aeruginosa UTI associated with urologic surgery instrumentation. The outbreak terminated after the implementation of two major control measures: (1) replacement of hexachlorophene solution with an iodophor solution for preparing patients and cleaning instruments before disinfection, and (2) weekly gas sterilization of cystoscopy instruments. The second outbreak, consisting of 11 cases of P aeruginosa UTI after transurethral resection of the prostate gland, occurred in a 187-bed community hospital. All available patient isolates were serotype 011, and culture of a rubber adaptor attached to the resectoscope also yielded growth of that serotype. The outbreak promptly terminated when the rubber adaptor was sterilized between cases.