Ebola virus infection among western healthcare workers unable to recall the transmission route

Introduction. During the 2014-2016 West-African Ebola virus disease (EVD) outbreak, some HCWs from Western countries became infected despite proper equipment and training on EVD infection prevention and control (IPC) standards. Despite their high awareness toward EVD, some of them could not recall the transmission routes. We explored these incidents by recalling the stories of infected Western HCWs who had no known directly exposures to blood/bodily fluids from EVD patients. Methodology. We carried out conventional and unconventional literature searches through the web using the keyword "Ebola" looking for interviews and reports released by the infected HCWs and/or the healthcare organizations. Results. We identified fourteen HCWs, some infected outside West Africa and some even classified at low EVD risk. None of them recalled accidents, unintentional exposures, or any IPC violation. Infection transmission was thus inexplicable through the acknowledged transmission routes. Conclusions. We formulated two hypotheses: inapparent exposures to blood/bodily fluids or transmission due to asymptomatic/mildly symptomatic carriers. This study is in no way intended to be critical with the healthcare organizations which, thanks to their interventions, put an end to a large EVD outbreak that threatened the regional and world populations

The face of Ebola: changing frequency of haemorrhage in the West African compared with Eastern-Central African outbreaks

BACKGROUND: The West-African (WA) Zaire Ebolavirus disease (EVD) outbreak was characterized by an exceptionally high number of cases and deaths as compared with the Eastern-Central African (ECA) outbreaks. Despite the Zaire Ebolavirus being the most lethal for humans, case-fatality rate, close to 80 % in ECA outbreaks, almost halved to 47 % in Guinea-Liberia-Sierra Leone (WA). Such an improvement was due to the remarkable implementation of international humanitarian aids. Some studies also suggested that the long human-to-human transmission cycle occurred in WA, gave rise to human adaptation and consequent immune escape. Haemorrhage, the main feature in seriously infected EVD patients, is due to the immune system that triggers the infected endothelial cells which expose the spike-like glycoprotein (GP) of the virion on their surface. If the human adaptation hypothesis holds true, the proportion of EVD patients with haemorrhage in the WA outbreak should be lower than in the ECA outbreaks due to immune escape. Therefore, the aim of this meta-analysis was to compare the relative frequencies of three typical haemorrhagic symptoms (conjunctival -CB, nasal -NB, gingival -GB- bleedings) in the ECA and WA outbreaks. METHODS: Literature searches were performed through PubMed and Scopus using generic keywords; surveys including at least ten patients reporting CB, NB, GB relative frequencies were extracted and split into ECA and WA. The meta-analytical methods chosen were based on the levels of between-study heterogeneity and publication bias. Pooled CB, NB, GB relative frequencies in ECA and WA were estimated and compared. Subgroup analysis including only studies on Zaire Ebolavirus also was performed. RESULTS: Fifteen studies (10 ECA, 5 WA) were located with 4,867 (CB), 3,859 (NB), 4,278 (GB) EVD patients overall. GB pooled relative frequency was 45.3 % (95 % confidence interval -95 CI, 34.7-56.1 %) and 18.0 % (95 CI, 6.0-34.5 %), in ECA and WA; NB was 10.6 % (95 CI, 5.7-16.8 %) and 1.3 % (1.0-1.8 %); GB was 24.2 % (95 CI, 11.9-39.2 %) and 1.9 % (95 CI, 1.4-2.4 %). Subgroup analysis confirmed these results. CONCLUSIONS: During the WA outbreak the relative frequency of GB decreased by two thirds, while NB and GB almost disappeared, suggesting that the Zaire Ebolavirus human adaptation hypothesis is plausible

Nano-TiO2-based photocatalytic disinfection of environmental surfaces contaminated by meticillin-resistant Staphylococcus aureus

Background: Traditional cleaning and disinfection methods are inefficient for complete decontamination of hospital surfaces from meticillin-resistant Staphylococcus aureus (MRSA). Additional methods, such as nano-TiO2-based photocatalytic disinfection (PCD), could be helpful. Aim: To evaluate anti-MRSA activity of PCD on polyvinyl chloride (PVC) surfaces in naturallike conditions. Methods: Two identical PVC surfaces were used, and nano-TiO2 was incorporated into one of them. The surfaces were contaminated with MRSA isolated from hospitalized patients using a mist sprayer to simulate the mode of environmental contamination caused by a carrier. MRSA cell density was assessed before contamination until 180 min after contamination using Rodac plates. The differences between test and control surfaces in terms of MRSA density and log MRSA density reduction were assessed using parametric and non-parametric statistical tests. Five strains were tested, and each strain was tested five times. Findings: The highest median MRSA densities [46.3 and 43.1 colony-forming units (cfu)/ cm2 for control and test surfaces, respectively] were detected 45 min after contamination. Median MRSA densities 180 min after contamination were 10.1 and 0.7 cfu/cm2 for control and test surfaces, respectively (P<0.01). Log MRSA density reduction attributable to PCD was 1.16 log cfu/cm2 , corresponding to 93% reduction of the baseline MRSA contamination. Conclusions: The disinfectant activity remained stable throughout the 25 testing occasions, despite between-test cleaning and disinfection. The anti-MRSA activity of PCD was compatible with the benchmark for surface hygiene in hospitals (<1 cfu/cm2 ), but required 3 h of exposure to photocatalysis. Thus, PCD could be considered for non-clinical surfaces. However, for clinical surfaces, PCD should be regarded as supplemental to conventional decontamination procedures, rather than an alternative

General dental practitioners and hearing impairment

Objective: Hearing impairment (HI) remains a problem among dentists Hearing loss at speech frequencies was recently reported among dentists and dental hygienists. This study aimed to investigate prevalence and factors associated with perceived HI among dentists. Methods: In 2009-2010, 100 general dental practitioners (GDPs) and 115 general (medical) practitioners (GPs) (mean ages, 43.7 and 44.4 years) from Rome (Italy), who commenced practice &gt;= 10 years ago, were interviewed on a series of occupation- and recreation-related HI risk factors and on HI-associated symptoms (tinnitus, sensation of fullness, hypoacusis). Prevalence of presumptive HI (&gt;= 1 symptom perceived during workdays and weekends) was assessed and factors associated with presumptive HI were investigated. Results: Prevalence was 30.0% (95% confidence interval, 21.0-39.0%) and 14.8% (95% confidence interval, 8.3-21.3%) among GDPs and GPs, respectively. Occupation (GDP vs. GP), family history of hypoacusis, hypertension, ear diseases and smoking were significantly associated with presumptive HI. Within GDPs alone, significant associations were found for frequent use of ultrasonic scalers, use of dental turbines aged &gt;= 1 year and prosthodontics as prevalent specialty. Conclusions: GDPs experienced HI risk than GPs. Such a risk was not generalized to all dentists, but was specific for those who frequently used noisy equipment (aged turbines, ultrasonic scalers) during their daily practice. Clinical significance: GDPs with 10 or more years of practice who routinely use potentially noisy equipment, could be at risk of HI. In order to prevent such condition, daily maintenance and periodical replacement of dental instruments is recommended. (c) 2012 Elsevier Ltd. All rights reserved

Dentists' awareness toward vaccine preventable diseases

Effective infection control in dentistry is unfeasible without an adequate immunization program for dental health care providers (DHCPs). Such an assumption is demonstrated for some vaccine preventable infectious diseases (VPIDs), such as Hepatitis B. Influenza and Varicella. However, excluding Hepatitis B vaccine, immunization programs for DHCPs are few and often unclear about which vaccinations are recommended, thus leading to generally low awareness and consequent low vaccination rates. This survey investigated dentists' awareness toward VPIDs. At the moment of registration to a dental congress, a questionnaire regarding the immunization status toward VPIDs was anonymously filled in by 379 Italian dentists (86% of the contacted dentists), with at least fifteen years of activity. DHCP specific awareness was considered high if dentists reported to have controlled the serum level of anti-HBs during the last ten years and have received seasonal influenza vaccine annually. Awareness toward VPIDs was classified high if dentists reported to be immune against six or seven of the following V1PDs, Hepatitis B, Influenza, Varicella, Measles, Mumps, Rubella and Tetanus. DHCP specific awareness resulted high for 32.5% of subjects and low for 31.1%. None of the subjects reported high awareness toward VPIDs. while for 60% of them, such awareness was low (immunization status reported for none or one of the seven VPIDs). Low dentists' awareness stresses the need for a transparent immunization program which is effective in controlling VPID transmission in the dental health care settings and focuses on those VPIDs which pose a true risk of infection for DHCPs and patients. (C) 2011 Elsevier Ltd. All rights reserved

Quality of air and water in dental healthcare settings during professional toothcleaning

Introduction: Professional toothcleaning with ultrasonic scaler produces microbial aerosols. These microorganisms come from dental unit waterlines (DUWLs) -thus potentially including opportunistic pathogens, or from patients -thus potentially including human pathogens. Aim: To investigate the association between levels and quality of contamination of air samples and DUWLs during professional toothcleaning, thus providing information regarding the nature of air contamination produced by ultrasonic scaler use. Material and methods: Before treating the first patient of the day, 100 mL of water was aseptically collected from the DUWL designated for the ultrasonic scaler, water was not disinfected or flushed. Aliquots were plated on Plate Count Agar to determine total viable flora (TVF) and Charcoal-Yeast Extract Agar supplemented with a Growth Supplement to determine Legionella. Two sets of settle plates were placed on the tray in front of the patient, one before and another during patient treatment to determine TVF and Legionella. The association between TVF and Legionella levels and prevalence in DUWLs and in air samples was assessed using correlation coefficients. Results. 82 testing occasions were performed. The mean TVF levels in DUWLs and air were 21.2 (95% confidence interval, 95CI, 13.8-32.6) CFU/mL and 12.4 (95CI, 9.7-15.8) CFU/plate/h, respectively. The mean Legionella detection rates were 1.2% (DUWLs) and 0% (air). Correlations between air and water TVF and Legionella were not significant. Conclusion: Air contamination during ultrasonic scaler use was frequent and high, but it was not associated with DUWL contamination, suggesting that airborne microorganisms could come from patients and be potentially pathogens for humans. © 2013 Medicinski fakultet Niš