Surveillance of antibiotic resistance in invasive isolates of Neisseria meningitidis in Australia 1994-1999

A total of 1434 strains of Neisseria meningitidis isolated from cases of invasive meningococcal disease (IMD) in Australia between 1994 and 1999 were examined by standard methods for susceptibility to antibiotics used for treatment and prophylaxis. The proportion of isolates fully susceptible to penicillin decreased from 45% in 1994 to 26% in 1999 (P<0.001). All the other isolates were less sensitive to penicillin except for two meningococci with a penicillin MIC of 1 mg/l. The geometric mean penicillin MIC increased from 0.045 to 0.065 mg/l from 1994 to 1999. There was no significant difference in the geometric mean penicillin MICs of serogroup B and serogroup C meningococci. Penicillin susceptibility was significantly associated with a poorer outcome. Isolates from survivors of IMD had a higher geometric mean penicillin MIC (0.06 mg/l) than those from fatal cases (0.048 mg/l) (P< 0.001). This suggests that factors other than the decrease in susceptibility to penicillin observed were more relevant to outcome in IMD. All isolates were fully susceptible to ceftriaxone. Rifampicin resistance was infrequent (eight isolates in 6 years) and sporadic. A single isolate had decreased quinolone susceptibility. Despite the significant shift in susceptibility to penicillin recorded, this group of antibiotics remains a suitable treatment for IMD in Australia.

Children's hospitals collaborate to improve quality of care

The Child Health Accountability Initiative brought together 35 chief executive officers, physicians, and researchers representing 12 children's hospitals and charged them with what most would think is a lofty goal: to improve health outcomes for America's children. After a rigorous and often highly debated selection process, two data-driven performance improvement projects were rapidly set in motion and implemented in each of the hospitals, with significant results--all within the first year. The initiative's breadth, scope, and speed may serve as a model for other healthcare collaboratives.

Clinical trial of an air-circulating cooling blanket for fever control in critically ill neurologic patients

OBJECTIVE

To evaluate the efficacy of an air-circulating cooling blanket for reducing body temperature in febrile neuro-ICU patients treated with acetaminophen.

METHODS

Two-hundred twenty consecutively admitted neuro-ICU patients whose tympanic membrane temperature reached or exceeded 101 degrees F (38.3 degrees C) were randomly assigned to receive acetaminophen (650 mg every 4 hours) alone (n = 107) or acetaminophen plus air blanket therapy (n = 113). After 24 hours of treatment, the authors compared the proportion of subjects who attained treatment success (T < or = 99 degrees F) or treatment failure (T > or = 101 degrees F for 2 consecutive hours) using the chi(2) test and the time to reach these endpoints using Kaplan-Meier survival analysis.

MAIN RESULTS

Air blanket therapy resulted in a small increase in the proportion of subjects with treatment success (44% versus 36%, chi(2) p = 0.19, log rank p = 0.10) and a similar small reduction in the proportion of patients with treatment failure (42% versus 53%, chi(2) p = 0.11, log-rank p = 0.21), compared with treatment with acetaminophen alone. Approximately one third of patients in both groups remained febrile after randomization and "failed" after the first 2 hours of treatment. Twelve percent of patients assigned to air blanket therapy refused or were unable to tolerate treatment, compared with 2% of patients treated with acetaminophen alone (p = 0.005).

CONCLUSIONS

Treatment with an air-circulating cooling blanket did not effectively reduce body temperature in febrile neuro-ICU patients treated with acetaminophen. More effective interventions are needed to maintain normothermia in patients at risk for fever-related brain damage.

A randomized, double blind study in young healthy adults comparing cell mediated and humoral immune responses induced by influenza ISCOM vaccines and conventional vaccines

Although current influenza vaccines have been shown to reduce influenza-related morbidity and mortality, there is a desire to develop more efficacious products. Vaccines which can induce CD8(+) cytotoxic T cell (CTL) responses in addition to strong antibody responses may be more effective in preventing disease since it has been demonstrated that CTL contribute to protective immunity, even against drift variants of influenza A viruses. The immunogenicity of two types of experimental influenza vaccines, which were based on immune stimulating complexes (ISCOM), were evaluated and compared with a conventional non-adjuvanted inactivated split virion vaccine, after immunization of human volunteers. In this randomized, double blind study, it was shown that the ISCOM vaccines altered the kinetics of the serum antibody response, resulting in more rapid titer rises against the vaccine strains. This accelerated antibody response coincided with enhanced in vitro proliferative T cell responses, which were observed shortly after vaccination. In addition, CTL responses were observed in a higher proportion of the vaccinees receiving an ISCOM vaccine, than in vaccinees receiving the conventional influenza vaccine.

Specification for signal processing and data handling used for infant pulmonary function testing. ERS/ATS Task Force on Standards for Infant Respiratory Function Testing. European Respiratory Society/American Thoracic Society

The aim of this present paper is to define minimal performance criteria for the separate items comprising signal processing and data handling used to measure respiratory function in infants. These guidelines cover numerous aspects including: signal processing, data handling and subsequent analysis, reporting of results, demographics and handling of reference values. Adherence to these guidelines should ensure that infant lung function measurements can be performed with an acceptable degree of safety, precision, and reproducibility. Furthermore, they will facilitate multicentre collection of data and the performance of clinical investigations.

Specifications for equipment used for infant pulmonary function testing. ERS/ATS Task Force on Standards for Infant Respiratory Function Testing. European Respiratory Society/ American Thoracic Society

The aim of this position paper is to define minimal performance criteria for the separate items comprising equipment used to measure respiratory function in infants together with overall performance criteria for the assembled pieces of such equipment. These guidelines cover numerous aspects including: 1) safety, 2) documentation and maintenance of equipment, 3) physical characteristics of mechanical parts and signal transducers, and 4) data acquisition. Further, validation procedures for individual components as well as for the integrated equipment are recommended. Adherence to these guidelines should ensure that infant lung function measurements can be performed with an acceptable degree of safety, precision and reproducibility. They will also facilitate multicentre collection of data and performance of clinical investigations. Manufacturers of infant respiratory function equipment should make every effort to comply with these guidelines, which represent the current standards of paediatric health professionals in this field.

Azithromycin vs cefuroxime plus erythromycin for empirical treatment of community-acquired pneumonia in hospitalized patients: a prospective, randomized, multicenter trial

OBJECTIVE

To compare the efficacy and safety of azithromycin dihydrate monotherapy with those of a combination of cefuroxime axetil plus erythromycin as empirical therapy for community-acquired pneumonia in hospitalized patients.

METHODS

Patients were enrolled in a prospective, randomized, multicenter study. The standard therapy of cefuroxime plus erythromycin was consistent with the American Thoracic Society, Canadian Community-Acquired Pneumonia Consensus Group, and Infectious Disease Society of America consensus guidelines. The doses were intravenous azithromycin (500 mg once daily) followed by oral azithromycin (500 mg once daily), intravenous cefuroxime (750 mg every 8 hours), followed by oral cefuroxime axetil (500 mg twice daily), and erythromycin (500-1000 mg) intravenously or orally every 6 hours. Randomization was stratified by severity of illness and age. Patients who were immunosuppressed or residing in nursing homes were excluded.

RESULTS

Data from 145 patients (67 received azithromycin and 78 received cefuroxime plus erythromycin) were evaluable. Streptococcus pneumoniae and Haemophilus influenzae were isolated in 19% (28/145) and 13% (19/145), respectively. The atypical pathogens accounted for 33% (48/145) of the etiologic diagnoses; Legionella pneumophila, Chlamydia pneumoniae, and Mycoplasma pneumoniae were identified in 14% (20/ 145), 10% (15/145), and 9% (13/145), respectively. Clinical cure was achieved in 91% (61/67) of the patients in the azithromycin group and 91% (71/78) in the cefuroxime plus erythromycin group. Adverse events (intravenous catheter site reactions, gastrointestinal tract disturbances) were significantly more common in patients who received cefuroxime plus erythromycin (49% [30/78]) than in patients who received azithromycin (12% [8/67]) (P<.001).

CONCLUSIONS

Treatment with azithromycin was as effective as cefuroxime plus erythromycin in the empirical management of community-acquired pneumonia in immunocompetent patients who were hospitalized. Azithromycin was well tolerated.

Elective versus symptomatic antibiotic treatment in cystic fibrosis patients with chronic Pseudomonas infection of the lungs

BACKGROUND

A previous retrospective study suggested that a policy of regular anti-pseudomonal antibiotic treatment improved pulmonary function and increased survival in patients with cystic fibrosis chronically infected with Pseudomonas species. The results of a prospective multicentre study to compare the effects on pulmonary function and mortality of three monthly elective anti-pseudomonal antibiotic treatment with conventional symptomatic treatment are reported.

METHODS

Sixty patients with cystic fibrosis, chronically infected with P aeruginosa, were randomised to the two treatment arms (elective or symptomatic) and followed clinically at yearly reviews. The major end points were changes in forced expiratory volume in one second (FEV(1)) and forced vital capacity (FVC). Survival was a secondary end point.

RESULTS

Patients in the symptomatic group received a mean of three antibiotic treatments each year and those in the elective group received four antibiotic treatments during each year of the study. No significant differences in FEV(1) and FVC were found between the two groups after three years. There was a statistically non-significant higher rate of deaths in the elective group (n = 4), three of which were associated with B cepacia infection, compared with the symptomatic group (n = 0).

CONCLUSIONS

This study did not demonstrate an advantage of a policy of elective antibiotic treatment over symptomatic treatment in patients with cystic fibrosis chronically infected with Pseudomonas species.

Program for licensure for international medical graduates in British Columbia: 7 years' experience

British Columbia has funded a program for licensure for international medical graduates since 1992, providing 2 entry positions per year for postgraduate training. Each year 25-35 candidates are eligible for the program, 13-16 enter the evaluation process, 4 go on to a clinical evaluation and 2 are offered funding by the Ministry of Health. Other candidates may access community funding if they meet the requirements of the program. Twenty of 26 candidates have successfully completed the postgraduate training and achieved full licensure; 6 are still in training. In this article we describe the development of the program, the evaluation and selection process, characteristics of the candidates and the outcomes of the program.

An outbreak of Campylobacter enteritis on an island resort, north Queensland

An outbreak of Campylobacter enteritis among staff on a resort island in north Queensland is reported. Untreated rainwater and food from the staff dining room were initially suspected as possible sources of infection but Campylobacter species were not isolated from any environmental samples. Faecal contamination was detected in four rainwater tanks. A case control study involved a total of 23 cases (7 confirmed and 16 probable), 3 of whom required hospitalisation. There was a strong association between gastrointestinal illness and consumption of water from a dispenser in the staff restaurant that had probably been filled from one of the contaminated tanks. We conclude that this was probably a waterborne outbreak and postulate that Campylobacter species were introduced into one or more of the tanks by contamination with the faeces of wild animals.

Measurement of sputum Mycobacterium tuberculosis messenger RNA as a surrogate for response to chemotherapy

Effective treatment regimens for pulmonary tuberculosis are difficult to assess because of the slow growth rate of Mycobacterium tuberculosis in culture and its protracted clearance from sputum. A rapid method that reflects effective antimicrobial activity would markedly advance evaluation of treatment and promote the assessment of new antituberculosis drugs. Conventional methods measure the progressive reduction of numbers of acid-fast bacilli in the sputum smear and the clearance of organisms in sputum culture. In this study, we measured levels of M. tuberculosis 85B (alpha antigen) messenger RNA (mRNA), 16S ribosomal RNA (rRNA), and IS6110 DNA in patients' sputa to ascertain whether they could serve as potential surrogate markers of response to chemotherapy. Sputum specimens were sequentially collected for up to a year from 19 smear-positive pulmonary tuberculosis patients receiving an optimal drug treatment regimen. Nucleic acids were isolated from these specimens, and two M. tuberculosis molecular targets (mRNA, DNA) were quantified, using the ABI Prism 7700 Sequence Detection System. The Mycobacterium genus-specific 16S rRNA was quantified with a limiting dilution RT-PCR assay. Results show that levels of 85B mRNA declined after initiation of therapy, as did viable M. tuberculosis colony counts, with 90% of patients becoming negative for both markers after 2 mo of treatment. The rapid disappearance of M. tuberculosis mRNA from sputum suggests that it is a good indicator of microbial viability and a useful marker for rapid assessment of response to chemotherapy.

Telephone triage in acute oncology

Cancer patients experience a variety of complex problems over the course of their illness. Shorter hospital stays and fewer inpatient beds have created additional challenges for patients diagnosed with cancer, as they often continue complicated treatment protocols as outpatients. As one result, patients and their families often telephone their physician or cancer clinic to seek advice.

Immunopotentiation of humoral and cellular responses to inactivated influenza vaccines by two different adjuvants with potential for human use

Two quite different adjuvants, currently under development for use in humans, have been examined for their effects on the magnitude and type of immunity elicited in response to inactivated influenza vaccine. Immunostimulating complexes (ISCOM adjuvant) contain the saponin ISCOPREP 703, and SPT is an oil-in-water emulsion of squalane, non-ionic block copolymer (L121) and Tween 80. Influenza virus vaccines formulated in either adjuvant were far superior to the non-adjuvanted aqueous vaccine in eliciting antibody and T-cell responses in mice, particularly at lower doses of antigen. In addition, the vaccines containing adjuvant were superior in eliciting protective immunity. One of the shortcomings of the unadjuvanted inactivated influenza vaccine was its inability to elicit a primary proliferative T-cell response. However, after one dose of either adjuvanted vaccine, strong proliferative responses were achieved. We also show that subcutaneous vaccination with inactivated vaccines is capable of modulating the isotype profile of antibody secreting cells generated in the lungs of mice in response to intranasal challenge with live virus. In this system, the isotype of antibody elicited after challenge of mice that had received ISCOM vaccine more closely mimicked that of animals vaccinated with live virus.

Effects of clozapine on auditory event-related potentials in schizophrenia

BACKGROUND

Schizophrenia is associated with cognitive deficits that are an intrinsic component of the disorder. Clozapine is an atypical antipsychotic that is superior to typical agents in the treatment of positive symptoms. The degree to which clozapine ameliorates cognitive deficits, however, is still controversial. Mismatch negativity (MMN), N200 (N2), and P300 (P3) are cognitive event-related potentials (ERPs) that index preattentive (MMN) and attention-dependent information processing (N2, P3) and provide a measure of cognitive deficits associated with schizophrenia. In schizophrenic patients deficient generation of MMN, N2, and P3 has been observed, suggesting impairments of discrete stages of information processing.

METHODS

This study investigates the effects of clozapine treatment on MMN, N2, and P3 generation. Patients were recruited from a haloperidol-controlled, double-blind treatment study of clozapine in chronic schizophrenia. ERPs were obtained at the beginning of the study and after 9 weeks (4 patients) and 16 weeks (13 patients) of treatment.

RESULTS

Clozapine treatment was associated with a significant increase of P3 amplitude, which was not observed in the haloperidol group; however, clozapine treatment did not affect deficits in MMN and N2.

CONCLUSIONS

These findings suggest that clozapine--in contrast to conventional antipsychotics--improves electrophysiological measures of attention-dependent information processing, but does not ameliorate preattentive deficits.

Studies on experimental adjuvanted influenza vaccines: comparison of immune stimulating complexes (Iscoms) and oil-in-water vaccines

Detergent-disrupted influenza virus vaccines, formulated as Iscoms, or oil-in-water (o/w) emulsions, were administered parenterally to mice and evaluated for immunogenicity and protective efficacy. Both formulations enhanced both primary and secondary serum antibody responses. The magnitude of these responses with o/w emulsions was further enhanced by the addition of the non-ionic block copolymer L121 in the emulsion. Four weeks after primary immunization, mice were challenged by exposure to an aerosol containing infectious virus. Resistance to challenge in terms of survival rate and weight change correlated well with serum antibody titre for all formulations. Two major differences were observed between the adjuvant formulations. Iscom vaccines, formulated with Quil-A or the less toxic Quillaia saponin preparation Iscoprep 703, induced specific cytotoxic T-lymphocyte responses, whereas the o/w-based vaccines did not. In addition, dose-site reactivity studies in sheep showed that Iscom vaccines were less reactive than o/w-based vaccines, the degree of reactivity of the latter increasing sharply with increasing L121 concentration. On the basis of these studies, Iscoms were chosen for development as a potential adjuvant for human influenza vaccines.

Gyri of the human neocortex: an MRI-based analysis of volume and variance

This magnetic resonance imaging (MRI)-based morphometric analysis of cortical topography in the human brain is based upon the segmentation and parcellation of volumetric T1-weighted MRI data for a set of 20 young adult brains including 10 males and 10 females. For the most part, each parcellation unit (PU) of the neocortex corresponds to a single or a portion of a single gyrus. The volumes of each PU were computed for each brain. Subsets of PUs were also grouped so as to represent the neocortex for the frontal, temporal, parietal and occipital lobes. The coefficient of variation of the mean volume of total neocortex and that of the neocortex assigned to individual lobes cluster around 10%, whereas that of neocortex assigned to the individual gyri (PU) is more than twice that value. Approximately 80% of the total variance in gyral volume arises from determinants interactive for individual and specific gyri, while only approximately 10% of the total variance appears to be a reflection of uniform scaling to total neocortical volume. Sexual dimorphism contributes a pervasive though relatively small component of this variance. These results have implications for the study of structure-function correlation, and the proper statistical methods of handling volumetric data in morphometric studies. In addition, the nature of the covariance structure of the data will lead to future hypotheses regarding the relationships between the various potential genetic and epigenetic gyral influencing factors.

Clinical value of CYFRA 21.1, carcinoembryonic antigen, neurone-specific enolase, tissue polypeptide specific antigen and tissue polypeptide antigen in the diagnosis of lung cancer

In this study we looked at what useful information cytokeratin fragment detected by antibodies BM 19-21 and KS 19-1 (CYFRA 21.1), carcinoembryonic antigen (CEA), neurone-specific enolase (NSE), tissue polypeptide specific antigen (TPS), and tissue polypeptide antigen (TPA) gave when measured prospectively. All patients who were suspected of having lung cancer and who underwent diagnostic bronchoscopy in this hospital between July 1994 and May 1995 were included in the study. Of 184 patients, 87 were subsequently found to have intrathoracic malignancy, 93 were found to have benign lung disease and four were lost to follow-up. CYFRA 21.1 was the most efficient marker in differentiating benign from malignant disease, with a sensitivity of 54% and a positive predictive value of 96%. Thirty seven patients who had a negative bronchoscopy subsequently turned out to have malignant disease. Either CYFRA 21.1 or CEA was elevated in 26 (70%) of such patients. Multivariate analysis showed that only CYFRA 21.1 and CEA contributed significantly to the discriminatory power of the data. We conclude that measurement of cytokeratin fragment detected by antibodies BM 19-21 and KS 19-1 and carcinoembryonic antigen at the time of bronchoscopy significantly increased the diagnostic yield in this population and was especially useful in those patients in whom tumour biopsy was not possible at bronchoscopy.

Epidemiology of vancomycin-resistant enterococci in the community and the relevance of farm animals to human infection

Several reports have documented the presence of vancomycin-resistant enterococci (VRE) in the stools of asymptomatic individuals from the community who have neither recently been in hospital nor received antibiotics. Such findings were contrary to the then existing perception of VRE as a strictly hospital-acquired infection of debilitated and immunocompromised patients on specialized units. Community-acquired infections with VRE are extremely rare but those that do occur may be conspicuous because of their serious nature, for example, endocarditis. If asymptomatic faecal carriage of VRE is present in the community, individuals admitted to hospital and subjected to the selective pressures of antibiotics on the normal gut flora, may act as the source of hospital outbreaks. VRE have also been found in sewage, from stools of healthy farm animals and animal products. Avoparcin, a glycopeptide showing cross-resistance to medically important glycopeptides, has been used in the European Community as a growth promoter in animal feeds. A possible link between the use of avoparcin, the selection of VRE, and humans becoming colonized via the food chain exists. To prove such a link is beset with many difficulties: it is necessary to explain the presence of VRE in the United States where avoparcin is not used, and the predominance of the VanA gene over the VanB gene. It is also proving difficult to show that animal and human strains are identical by means of molecular typing. To date, molecular typing of strains is only suggestive of a link, but epidemiological studies of farms that use avoparcin have shown a significant association with the presence of VRE in animal stools. As long ago as 1969, the Swann report declared that an antibiotic of medical importance should not be used as a growth promoter in animal feeds. The vasy array of antibiotics now being used in animal husbandry and fish-farming, and the cross-resistance of some antibiotics to their medically important counterparts is a real cause for concern. The emergence of multi-resistant enterococci causing human infections and the possibility of the transfer of the VanA gene from VRE to methicillin-resistant Staphylococcus aureus (MRSA) emphasizes the importance of this problem.