Prospective surveillance applying the national nosocomial infection surveillance methods in a Brazilian pediatric public hospital.

BACKGROUND: A hospital-wide, traditional prospective surveillance for nosocomial infections was commenced in 1992 in Centro Geral de Pediatria in Minas Gerais, Brazil, to describe the epidemiology of nosocomial infection in this pediatric hospital and to implement cross-infection prevention and control policies. METHODS: We performed a prospective cohort nosocomial infection surveillance of all patients receiving acute care according to the hospital-wide and intensive care unit components of the National Nosocomial Infections Surveillance System from January 1993 to December 1997 (14,892 discharges; 131,764 patient-days). The Centers for Disease Control and Prevention (Atlanta) 1988-definitions and the Brazilian Ministry of Health-Legislation 930 (1992) were used. RESULTS: The average overall nosocomial infection rate per 1000 patient-days was 8.9 in units 2 and 3 and 16.4 in the pediatric intensive care unit. Over time, the overall hospital infection rate decreased from 16.6 nosocomial infections per 1000 patient-days in 1993 to 7.0 in 1997 (P <.05). We believe this can be attributed to interventions and data reporting during the period. The five most frequent sites of infections were eye-ear-nose-throat (38%), skin (22%), pneumonia (12%), soft tissue (5%) and laboratory-confirmed bloodstream infection (4%). In the pediatric intensive care unit, the most frequent nosocomial infection sites were pneumonia related to mechanical ventilators (22%), with rates ranging from 0 to 42 per 1000 ventilator-days; and sepsis related to central lines (11%), with rates ranging from 0 to 32 per 1000 central line-days. CONCLUSIONS: Describing the epidemiology of nosocomial infections in this hospital enabled us to establish infection occurrence, distribution, and expected incidence, as well as to recognize trends and keep track of possible outbreaks. The knowledge acquired through this surveillance allowed us to target more specific and continuous quality improvement projects, to upgrade health care quality in pediatric public hospitals in Brazil, and to implement preventive strategies. Methods from the National Nosocomial Infections Surveillance System can be successfully applied in pediatric public hospitals in Brazil.

Prevention of lung eosinophilic inflammation by oral tolerance.

Airway inflammation plays a major role in human asthma. Increasing evidence points to a close correlation between eosinophil infiltration and allergic lung disease. A new murine model of eosinophilic lung inflammation has recently been developed; it consists of immunizing mice with small fragments of solidified hen egg white implanted (EWI) into the subcutaneous tissue. In this model, which is further characterized here, mice challenged with ovalbumin (OVA) present an intense and persistent lung eosinophilia, as well as histopathological findings that resemble human asthma. In the present work, the effect of oral tolerance on the development of allergic lung inflammation in B6 mice immunized with antigen plus adjuvant or with EWI is investigated. It was found that in mice rendered orally tolerant by previous exposure to antigen in the drinking water, the T-helper type 2 cell (Th2)-associated allergic responses in both protocols of immunization were almost completely abolished. The allergic responses were assessed by pulmonary and bone marrow eosinophilia, lung histopathology and antigen-specific IgE and IgG1 production. These findings provide the first indication that Th2-associated lung pathology can be prevented by oral tolerance.

A new murine model of pulmonary eosinophilic hypersensitivity: contribution to experimental asthma.

BACKGROUND: We have recently described a model of hypersensitivity reaction in the mouse paw, which induces a typical late-phase reaction with a marked eosinophilic infiltrate. OBJECTIVE: In the search for a murine model of asthma, this model was adapted to the lungs and compared with other models of pulmonary hypersensitivity. METHODS: A fragment of heat-coagulated hen's egg white was implanted subcutaneously, and 14 days later, the mice were challenged intratracheally with aggregated ovalbumin. Comparison was made with a group that received subcutaneous injection of soluble ovalbumin in alumen, challenged as described above and with four additional protocols of immunization and challenge. RESULTS: Forty-eight hours after challenge, the percentage of eosinophils was higher in the egg white implant group (35%) than in the group immunized with ovalbumin in alumen (10.4%). The eosinophil peroxidase activity in lung homogenates of the first group was also significantly higher (529 ng/ml) than that of the second group (43 ng/ml). These results were reproduced in five different mouse strains. Compared with five different models of lung hypersensitivity, the egg white implant model was unique in terms of persistence of the pulmonary eosinophilia. Histopathologic analysis of the lungs of mice immunized with egg white implant showed peribronchial, perivascular, and intraepithelial eosinophil infiltration; morphologic characteristics of bronchoconstriction; and patchy epithelial shedding. At 21 days, in addition to persistence of eosinophil infiltrate, enlarged alveoli, reflecting air trapping, were observed. CONCLUSION: On the basis of the characteristics of the model described here, we propose it as a suitable murine model of asthma.

A novel murine model of late-phase reaction of immediate hypersensitivity.

We describe here a novel experimental model of late-phase reaction of immediate hypersensitivity developed in mice. It consists of introducing small fragments of heat-coagulated hen egg white into the subcutaneous tissue of mice. After 14 days, animals challenged with purified ovalbumin into the footpad presented an immediate swelling of the paw peaking at 30 min, followed by two peaks of swelling at 6 and 24 h. Histological examination of the paws showed a massive eosinophil infiltration (more than 800 cells/5 microscopic fields). This intense infiltration persisted for more than 14 days after the challenge. Furthermore, in mice immunized with coagulated egg white the delayed swelling of the paws and eosinophilic infiltration were significantly higher than in mice immunized with the classical protocol of ovalbumin in alumen adjuvant. Transfer of lymph node cells obtained from mice implanted with heat-coagulated hen egg white induced footpad swelling and eosinophil infiltration in response to ovalbumin. High levels of ovalbuminspecific IgG1 but not of IgE were detected in the serum of these animals. The advantages of this model for the experimental study of late-phase reaction per se and its relevance to the study of allergic diseases such as asthma are discussed.

Noise and the quality of sleep in two hospitals in the city of Belo Horizonte, Brazil.

Male patients of two hospitals in Belo Horizonte completed a questionnaire during an interview on the day of discharge in order to evaluate sleeping conditions related to noise during the previous night and were retested 24 h later. Patients had a worse perception of sleep at the noisier hospital, the University Hospital of the Federal University of Minas Gerais (N = 13), whose internal mean nocturnal noise level was Leq = 53.7 db(A), than at the quieter hospital, Baleia (N = 22), whose internal mean nocturnal noise level was Leq = 45.5 db(A). Noise was the only sleep-disturbing factor which was statistically significant.

Noise and the quality of sleep in two hospitals in the city of Belo Horizonte, Brazil

Male patients of two hospitals in Belo Horizonte completed a questionnaire during an interview on the day of discharge in order to evaluate sleeping conditions related to noise during the previous night and were retested 24 h later. Patients had a worse perception of sleep at the noisier hospital, the University Hospital of the Federal University of Minas Gerais (N = 13), whose internal mean nocturnal noise level was Leq = 53.7 db(A), than at the quieter hospital, Baleia (N = 22), whose internal mean nocturnal noise level was Leq = 45.5 db(A). Noise was the only sleep-disturbing factor which was statistically significant.

Effect of external carbon dioxide concentration on electric organ dischargge frequency by the gymnotiform fish Apteronotus albifrons

A model is described for the instantaneous frequency (F) of electric organ discharge in Apteronotus albifrons: F=H/(aH + b), where a and b are linear parameters and H, hydrogen ion concentration, pH from 7.10 to 4.89 was modified by increasing external carbon dioxide concentrations. With the increase in pH from 5.17 to 7.40, corresponding to a decrease of carbon dioxide concentration, the equation was as follows: F=(logH)/(a ,log H=b). The model search consisted of the adjustment of a simple linear regression using fucntion transformation for the most adequate residue analysis by the Durbin-Watson test. The parallelism was checked by comparing regression lines with homogeneous variances and using other tests for non-homogeneous variances