Human infections associated with wild birds.

IntroductionWild birds and especially migratory species can become long-distance vectors for a wide range of microorganisms. The objective of the current paper is to summarize available literature on pathogens causing human disease that have been associated with wild bird species.MethodsA systematic literature search was performed to identify specific pathogens known to be associated with wild and migratory birds. The evidence for direct transmission of an avian borne pathogen to a human was assessed. Transmission to humans was classified as direct if there is published evidence for such transmission from the avian species to a person or indirect if the transmission requires a vector other than the avian species.ResultsSeveral wild and migratory birds serve as reservoirs and/or mechanical vectors (simply carrying a pathogen or dispersing infected arthropod vectors) for numerous infectious agents. An association with transmission from birds to humans was identified for 10 pathogens. Wild birds including migratory species may play a significant role in the epidemiology of influenza A virus, arboviruses such as West Nile virus and enteric bacterial pathogens. Nevertheless only one case of direct transmission from wild birds to humans was found.ConclusionThe available evidence suggests wild birds play a limited role in human infectious diseases. Direct transmission of an infectious agent from wild birds to humans is rarely identified. Potential factors and mechanisms involved in the transmission of infectious agents from birds to humans need further elucidation

A Bibliometric Analysis in the Fields of Preventive Medicine, Occupational and Environmental Medicine, Epidemiology, and Public Health

Background: Research in the fields of Preventive Medicine, Occupational/Environmental Medicine, Epidemiology and Public Health play an important role in the advancement of knowledge. In order to map the research production around the world we performed a bibliometric analysis in the above fields. Methods: All articles published by different world regions in the above mentioned scientific fields and cited in the Journal Citation Reports (JCR) database of the Institute for Scientific Information (ISI) during the period 1995 and 2003, were evaluated. The research production of different world regions was adjusted for: a) the gross domestic product in 1995 US dollars, and b) the population size of each region. Results: A total of 48,861 articles were retrieved and categorized. The USA led the research production in all three subcategories. The percentage of articles published by USA researchers was 43%, 44% and 61% in the Preventive Medicine, Epidemiology, and Public Health subcategories, respectively. Canada and Western Europe shared the second position in the first two subcategories, while Oceania researchers ranked second in the field of Public Health. Conclusion: USA researchers maintain a leadership position in the production of scientific articles in the fields of Preventive Medicine, Occupational/Environmental Medicine and Epidemiology, at a level similar to other scientific disciplines, while USA contribution to science in the field of Public Health is by all means outstanding. Less developed regions would need to support their researchers in the above fields in order to improve scientific production and advancement of knowledge in their countries

Toxicity of polymyxins: a systematic review of the evidence from old and recent studies

BACKGROUND: The increasing problem of multidrug-resistant Gram-negative bacteria causing severe infections and the shortage of new antibiotics to combat them has led to the re-evaluation of polymyxins. These antibiotics were discovered from different species of Bacillus polymyxa in 1947; only two of them, polymyxin B and E (colistin), have been used in clinical practice. Their effectiveness in the treatment of infections due to susceptible Gram-negative bacteria, including Pseudomonas aeruginosa and Acinetobacter baumannii, has not been generally questioned. However, their use was abandoned, except in patients with cystic fibrosis, because of concerns related to toxicity. METHODS: We reviewed old and recent evidence regarding polymyxin-induced toxicity by searching Pubmed (from 1950 until May 2005). RESULTS: It was reported in the old literature that the use of polymyxins was associated with considerable toxicity, mainly nephrotoxicity and neurotoxicity, including neuromuscular blockade. However, recent studies showed that the incidence of nephrotoxicity is less common and severe compared to the old studies. In addition, neurotoxic effects of polymyxins are usually mild and resolve after prompt discontinuation of the antibiotics. Furthermore, cases of neuromuscular blockade and apnea have not been reported in the recent literature. CONCLUSION: New evidence shows that polymyxins have less toxicity than previously reported. The avoidance of concurrent administration of nephrotoxic and/or neurotoxic drugs, careful dosing, as well as more meticulous management of fluid and electrolyte abnormalities and use of critical care services may be some of the reasons for the discrepancy between data reported in the old and recent literature

Attributable mortality of Acinetobacter baumannii: no longer a controversial issue

There has been controversy regarding the mortality directly attributed to Acinetobacter baumannii infections. Data from six case–control studies have been recently added to the literature regarding the attributable mortality of A. baumannii infections during the past months. The information from these studies, added to the previous knowledge on this issue, provides evidence that A. baumannii infections are indeed associated with increased mortality. In addition, there is relevant evidence from studies examining the effect of inappropriate treatment on mortality; specifically, inappropriate treatment of A. baumannii infections has been associated with excess mortality. We believe that the accumulated data suggest that attributable mortality due to A. baumannii infections should no longer be a controversial issue. The efforts of the scientific community interested in this pathogen should therefore be directed to the development and introduction of new antibiotics effective against multidrug-resistant and pandrug-resistant A. baumannii as well as the implementation of infection control measures that may help us in the control of the increasing problem of A. baumannii infections

Frequency, prevention, outcome and treatment of ventilator-associated tracheobronchitis: Systematic review and meta-analysis

SummaryObjectiveTo clarify issues regarding the frequency, prevention, outcome, and treatment of patients with ventilator-associated tracheobronchitis (VAT), which is a lower respiratory tract infection involving the tracheobronchial tree, while sparing the lung parenchyma.MethodsWe performed a systematic review and meta-analysis of relevant available data, gathered though searches of PubMed, Scopus, and reference lists, without time restrictions. A conservative random effects model was used to calculate pooled odds ratios (OR) and 95% confidence intervals (CI).ResultsOut of the 564 initially retrieved articles, 17 papers were included. Frequency of VAT was 11.5%. Selective digestive decontamination was not proved an effective preventive strategy against VAT (OR: 0.62, 95% CI: 0.31–1.26). Presence, as opposed to the absence, of VAT was not associated with higher attributable mortality (OR: 1.02, 95% CI: 0.57–1.81). Administration of systemic antimicrobials (with or without inhaled ones), as opposed to placebo or no treatment, in patients with VAT was not associated with lower mortality (OR: 0.56, 95% CI: 0.27–1.14). Most of the studies providing relevant data noted that administration of antimicrobial agents, as opposed to placebo or no treatment, in patients with VAT was associated with lower frequency of subsequent pneumonia and more ventilator-free days, but without shorter length of intensive care unit stay or shorter duration of mechanical ventilation.ConclusionsApproximately one tenth of mechanically ventilated patients suffer from VAT. Antimicrobial treatment of patients with VAT may protect against the development of subsequent ventilator-associated pneumonia and improve weaning outcome

Attributable mortality of Acinetobacter baumannii infections in critically ill patients: a systematic review of matched cohort and case-control studies

INTRODUCTION: There has been a continuing controversy about whether infection with Acinetobacter baumannii increases morbidity and mortality independently of the effect of other confounding factors. METHODS: We performed a systematic review of matched case-control and cohort studies examining the mortality attributable to infection with or acquisition of A. baumannii (infection or colonization). We included in our review studies that compared mortality and/or morbidity of patients with acquisition of or infection with A. baumannii (cases) with the outcomes of matched patients without A. baumannii isolation from clinical specimens (controls). The relevant studies were identified from searches of the PubMed and the Cochrane Library databases. Two independent reviewers performed the literature search, study selection, and data extraction from nine identified relevant studies. RESULTS: The attributable mortalities, in the hospital and in the intensive care unit, of patients with A. baumannii infection in six matched case-control studies included in our review ranged from 7.8% to 23% and from 10% to 43%, respectively. In addition, a statistically significantly higher mortality was reported for patients with A. baumannii acquisition; that is, colonization or infection (cases) compared with controls without such an acquisition in all four reviewed studies that reported data on this comparison. CONCLUSION: Although definitive statements about the mortality attributable to the acquisition of A. baumannii cannot be made from the available studies because of their methodological heterogeneity, the reviewed data suggest that infection with or acquisition of A. baumannii seems to be associated with increased mortality