Water, Sanitation, Hygiene, and Soil-Transmitted Helminth Infection: A Systematic Review and Meta-Analysis

ANTECEDENTES

La quimioterapia preventiva representa una estrategia de control para las helmintiasis transmitidas por el suelo de gran alcance pero a corto plazo. Dado que los humanos a menudo se vuelven a infectar rápidamente, las soluciones a largo plazo requieren mejoras en agua, saneamiento e higiene (WASH) . El propósito de este estudio fue resumir cuantitativamente la relación entre el acceso o prácticas WASH y la transmisión con helmintos del suelo (STH) .
Se realizó una revisión sistemática y meta-análisis para examinar las asociaciones de mejora de WASH en la infección por helmintos del suelo (Ascaris lumbricoides, Trichuris trichiura, ancylostoma [Ancylostoma duodenale y Necator americanus] y Strongyloides stercoralis). PubMed, Embase, Web of Science, y LILACS se buscaron desde el inicio al 28 de octubre de 2013, sin restricciones de idioma. Los estudios fueron elegibles para su inclusión si presentó una estimación del efecto del acceso o las prácticas sobre la infección por geohelmintos WASH. Se evaluó la calidad de los estudios publicados con los grados de recomendación, Evaluación, Desarrollo y Evaluación (GRADE). Un total de 94 estudios cumplieron con los criterios de elegibilidad, y cinco eran ensayos controlados aleatorios, mientras que la mayoría de los otros fueron estudios transversales. Utilizamos de efectos aleatorios meta-análisis y se analizaron sólo los presupuestos ajustados a ayudar a explicar la heterogeneidad y posibles factores de confusión, respectivamente.

REFERENCE
Strunz EC, Addiss DG, Stocks ME, et al. (2014). Water, Sanitation, Hygiene, and Soil-Transmitted Helminth Infection: A Systematic Review and Meta-Analysis. PLoS Med 11(3): e1001620. doi:10.1371/journal.pmed.1001620
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Reporte Nacional y Estatal (USA) de Infecciones Hospitalarias 2012 #HAI #nosocomiales

Publicado en Marzo 2014

Las infecciones nosocomiales son una importante, aunque a menudo prevenible, amenaza a la seguridad del paciente. El Informe Nacional y Estatal de Infecciones Nosocomiales se expande y ofrece una actualización de los informes anteriores que detallan el progreso hacia el objetivo final de eliminar las infecciones nosocomiales.
El Informe muestra que se reportaron reducciones significativas en 2012 para casi todas las infecciones. Infecciones del torrente sanguíneo asociadas a vías centrales y las infecciones del sitio quirúrgico continúan para acercarse a los objetivos 5 años establecidos en el Plan de Acción Nacional para Prevenir la salud asociadas con la atención hospitalaria.
REFERENCIA:
Centers for Disease Control and Prevention 2012. National and State Healthcare-Associated Infections Progress. Report Published March 26, 2014
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Evaluation of a Virucidal Quantitative Carrier Test for Surface Disinfectants

ABSTRACT

Surface disinfectants are part of broader preventive strategies preventing the transmission of bacteria, fungi and viruses in medical institutions. To evaluate their virucidal efficacy, these products must be tested with appropriate model viruses with different physico-chemical properties under conditions representing practical application in hospitals.
The aim of this study was to evaluate a quantitative carrier assay. Furthermore, different putative model viruses like adenovirus type 5 (AdV-5) and different animal parvoviruses were evaluated with respect to their tenacity and practicability in laboratory handling. To evaluate the robustness of the method, some of the viruses were tested in parallel in different laboratories in a multi-center study. Different biocides, which are common active ingredients of surface disinfectants, were used in the test. After drying on stainless steel discs as the carrier, model viruses were exposed to different concentrations of three alcohols, peracetic acid (PAA) or glutaraldehyde (GDA), with a fixed exposure time of 5 minutes. Residual virus was determined after treatment by endpoint titration.
All parvoviruses exhibited a similar stability with respect to GDA, while AdV-5 was more susceptible. For PAA, the porcine parvovirus was more sensitive than the other parvoviruses, and again, AdV-5 presented a higher susceptibility than the parvoviruses. All parvoviruses were resistant to alcohols, while AdV-5 was only stable when treated with 2-propanol. The analysis of the results of the multi-center study showed a high reproducibility of this test system.
In conclusion, two viruses with different physico-chemical properties can be recommended as appropriate model viruses for the evaluation of the virucidal efficacy of surface disinfectants: AdV-5, which has a high clinical impact, and murine parvovirus (MVM) with the highest practicability among the parvoviruses tested.
REFERENCE
Rabenau HF, Steinmann J, Rapp I, et al. Evaluation of a Virucidal Quantitative Carrier Test for Surface Disinfectants. PLoS One. 2014; 9(1): e86128.

Exhaled Air Dispersion during Coughing #N95

Abstract
Objectives: We compared the expelled air dispersion distances during coughing from a human patient simulator (HPS) lying at 45u with and without wearing a surgical mask or N95 mask in a negative pressure isolation room.
Methods: Airflow was marked with intrapulmonary smoke. Coughing bouts were generated by short bursts of oxygen flow at 650, 320, and 220L/min to simulate normal, mild and poor coughing efforts, respectively. The coughing jet was revealed by laser light-sheet and images were captured by high definition video. Smoke concentration in the plume was estimated from the light scattered by smoke particles. Significant exposure was arbitrarily defined where there was $ 20% of normalized smoke concentration.
Results: During normal cough, expelled air dispersion distances were 68, 30 and 15 cm along the median sagittal plane when the HPS wore no mask, a surgical mask and a N95 mask, respectively. In moderate lung injury, the corresponding air dispersion distances for mild coughing efforts were reduced to 55, 27 and 14 cm, respectively, p , 0.001. The distances were reduced to 30, 24 and 12 cm, respectively during poor coughing effort as in severe lung injury. Lateral dispersion distances during normal cough were 0, 28 and 15 cm when the HPS wore no mask, a surgical mask and a N95 mask, respectively.
Conclusions: Normal cough produced a turbulent jet about 0.7 m towards the end of the bed from the recumbent subject. N95 mask was more effective than surgical mask in preventing expelled air leakage during coughing but there was still significant sideway leakage.

Reference

David S. Hui, Benny K. Chow, Leo Chu, Susanna S. Ng, Nelson Lee, Tony Gin, Matthew T. V. Chan. Exhaled Air Dispersion during Coughing with and without Wearing a Surgical or N95 Mask. PLoS One. 2012; 7(12): e50845.

Poorly processed reusable surface disinfection tissue dispensers may be a source of infection

ABSTRACT
Background: Reusable surface disinfectant tissue dispensers are used in hospitals in many countries because they allow immediate access to pre-soaked tissues for targeted surface decontamination. On the other hand disinfectant solutions with some active ingredients may get contaminated and cause outbreaks. We determined the frequency of contaminated surface disinfectant solutions in reusable dispensers and the ability of isolates to multiply in different formulations.
Methods: Reusable tissue dispensers with different surface disinfectants were randomly collected from healthcare facilities. Solutions were investigated for bacterial contamination. The efficacy of two surface disinfectants was determined in suspension tests against two isolated species directly from a contaminated solution or after 5 passages without selection pressure in triplicate. Freshly prepared use solutions were contaminated to determine survival of isolates.
Results: 66 dispensers containing disinfectant solutions with surface-active ingredients were collected in 15 healthcare facilities. 28 dispensers from nine healthcare facilities were contaminated with approximately 107 cells per mL of Achromobacter species 3 (9 hospitals), Achromobacter xylosoxidans or Serratia marcescens (1 hospital each). In none of the hospitals dispenser processing had been adequately performed. Isolates regained susceptibility to the disinfectants after five passages without selection pressure but were still able to multiply in different formulations from different manufacturers at room temperature within 7 days.
Conclusions: Neglecting adequate processing of surface disinfectant dispensers has contributed to frequent and heavy contamination of use-solutions based on surface active ingredients. Tissue dispenser processing should be taken seriously in clinical practice.

Reference

Kampf G, Degenhardt S, Lackner S, et al. Poorly processed reusable surface disinfection tissue dispensers may be a source of infection. BMC Infect Dis. 2014; 14: 37.

Nueva página de #Facebook para el Blog!

Hola a todos. A partir de hoy, las publicaciones del blog sólo podrán seguirse en facebook en la siguiente página: https://www.facebook.com/pages/seguridadbiologicablogspotcom/138640189529850
Buen Día..

Availability, consistency and evidence-base of policies and guidelines on the use of mask and respirator

Abstract
Background: Currently there is an ongoing debate and limited evidence on the use of masks and respirators for the prevention of respiratory infections in health care workers (HCWs). This study aimed to examine available policies and guidelines around the use of masks and respirators in HCWs and to describe areas of consistency between guidelines, as well as gaps in the recommendations, with reference to the WHO and the CDC guidelines.
Methods: Policies and guidelines related to mask and respirator use for the prevention of influenza, SARS and TB were examined. Guidelines from the World Health Organization (WHO), the Center for Disease Control and Prevention (CDC), three high-income countries and six low/middle-income countries were selected.
Results: Uniform recommendations are made by the WHO and the CDC in regards to protecting HCWs against seasonal influenza (a mask for low risk situations and a respirator for high risk situations) and TB (use of a respirator). However, for pandemic influenza and SARS, the WHO recommends mask use in low risk and respirators in high risk situations, whereas, the CDC recommends respirators in both low and high risk situations. Amongst the nine countries reviewed, there are variations in the recommendations for all three diseases. While, some countries align with the WHO recommendations, others align with those made by the CDC. The choice of respirator and the level of filtering ability vary amongst the guidelines and the different diseases. Lastly, none of the policies discuss reuse, extended use or the use of cloth masks.
Conclusion: Currently, there are significant variations in the policies and recommendations around mask and respirator use for protection against influenza, SARS and TB. These differences may reflect the scarcity of level-one evidence available to inform policy development. The lack of any guidelines on the use of cloth masks, despite widespread use in many low and middle-income countries, remains a policy gap. Health organizations and countries should jointly evaluate the available evidence, prioritize research to inform evidence gaps, and develop consistent policy on masks and respirator use in the health care setting.
Reference
Abrar Ahmad Chughtai, Holly Seale, Chandini Raina MacIntyre. Availability, consistency and evidence-base of policies and guidelines on the use of mask and respirator to protect hospital health care workers: a global analysis. BMC Res Notes. 2013; 6: 216.

New Antimicrobial Surgical Glove

ABSTRACT

Background: Perforations of surgical gloves are common and increase with the duration of glove wear. Skin flora, re-grown after pre-operative disinfection of the hands, may contaminate a surgical site. An antimicrobial surgical glove with chlorhexidine on its inner surface has been developed. We hypothesized that by suppressing the re-growth of skin flora during the complete course of a surgical procedure, antimicrobial gloves may reduce the risk of surgical site contamination in the event of an intra-operative glove breach.
Methods: We conducted a randomized, double-blind, single-center trial, to measure any differences in the bacterial skin populations of surgeons' hands during surgical procedures done with antimicrobial and non-antimicrobial surgical gloves [ISRCTN71391952]. In this study, 25 pairs of gloves were retrieved from 14 surgeons who donned them randomly on their dominant or non-dominant hand. The number of bacteria retrieved from glove fluid was measured and expressed as colony forming units (CFU)/mL.
Results: The median cfu/mL of antimicrobial gloves was 0.00 (LQ: 0.00 CFU/mL; UQ: 0.00 cfu/mL), with a mean log10 cfu/mL=0.02 (range: 0.00–0.30). The median CFU/mL of non-antimicrobial gloves was 54.00 (LQ: 3.00 cfu/mL; UQ: 100.00 cfu/mL) with a mean log10 CFU/mL=1.32 (range: 0.00–2.39). After a mean operating time of 112 min, the difference in the log10 CFU/mL was 1.30 (p<0.001).
Conclusions: A new antimicrobial surgical glove suppressed surgeons' hand flora during operative procedures. In the event of a glove breach, the use of such a glove may have the potential to prevent bacterial contamination of a sterile surgical site, thereby decreasing the risk of surgical site infection (SSI) and increasing patient safety. Further clinical studies are needed to confirm this concept.
Reference
Assadian O, Kramer A, Ouriel K et al. Suppression of Surgeons' Bacterial Hand Flora during Surgical Procedures with a New Antimicrobial Surgical Glove. Surg Infect (Larchmt). Feb 1, 2014; 15(1): 43–49.

How and when to write policies and procedures ?

This book was created to:

← Help you work out what to write and when and

← Make writing and reviewing easier

The writing of policies and procedures takes time and can be disliked by busy people focussed on providing a service. Policy and procedure manuals fall into disuse because they are too big and out of date.

This booklet has been designed to help you identify when you ought to have a written policy or procedure, thereby reducing the risk of manuals so large as to be useless. It will serve to reduce the time commitment associated with the writing of policies and procedures, through the provision of framework for the writing and you will be provided with a structure for reviewing your policies and procedures.  

Reference

How and when to write policies and procedures.

Kinetics of ozone inactivation of infectious prion protein

ABSTRACT
The kinetics of ozone inactivation of infectious prion protein (PrPSc, scrapie 263K) was investigated in ozone-demand-free phosphate-buffered saline (PBS). Diluted infectious brain homogenates (IBH) (0.01%) were exposed to a predetermined ozone dose (10.8 ± 2.0 mg/liter) at three pHs (pH 4.4, 6.0, and 8.0) and two temperatures (4°C and 20°C). The inactivation of PrPSc was quantified by determining the in vitro destruction of PrPSc templating properties using the protein misfolding cyclic amplification (PMCA) assay and bioassay, which were shown to correlate well. The inactivation kinetics were characterized by both Chick-Watson (CW) and efficiency factor Hom (EFH) models. It was found that the EFH model fit the experimental data more appropriately. The efficacy of ozone inactivation of PrPSc was both pH and temperature dependent. Based on the EFH model, CT (disinfectant concentration multiplied by contact time) values were determined for 2-log10, 3-log10, and 4-log10 inactivation at the conditions under which they were achieved. Our results indicated that ozone is effective for prion inactivation in ozone-demand-free water and may be applied for the inactivation of infectious prion in prion-contaminated water and wastewater.

Reference

Ding N, Neumann NF, Price LM, Braithwaite SL, Balachandran A, Mitchell G, Belosevic M, Gamal El-Din M. Kinetics of ozone inactivation of infectious prion protein. Appl Environ Microbiol. 2013 Apr;79(8):2721-30.

Clinical Documentation and Data Transfer from #Ebola and #Marburg #Virus Disease Wards in Outbreak Settings

Abstract

Understanding human filovirus hemorrhagic fever (FHF) clinical manifestations and evaluating treatment strategies require the collection of clinical data in outbreak settings, where clinical documentation has been limited. Currently, no consensus among filovirus outbreak-response organisations guides best practice for clinical documentation and data transfer. Semi-structured interviews were conducted with health care workers (HCWs) involved in FHF outbreaks in sub-Saharan Africa, and with HCWs experienced in documenting and transferring data from high-risk areas (isolation wards or biosafety level 4 laboratories). Methods for data documentation and transfer were identified, described in detail and categorised by requirement for electricity and ranked by interviewee preference. Some methods involve removing paperwork and other objects from the filovirus disease ward without disinfection. We believe that if done properly, these methods are reasonably safe for certain settings. However, alternative methods avoiding the removal of objects, or involving the removal of paperwork or objects after non-damaging disinfection, are available. These methods are not only safer, they are also perceived as safer and likely more acceptable to health workers and members of the community. The use of standardised clinical forms is overdue. Experiments with by sunlight disinfection should continue, and non-damaging disinfection of impregnated paper, suitable tablet computers and underwater cameras should be evaluated under field conditions.

Reference

Bühler S, Roddy P, Nolte E, Borchert M. Clinical documentation and data transfer from ebola and marburg virus disease wards in outbreak settings: health care workers' experiences and preferences. Viruses. 2014 Feb 19;6(2):927-37.

Análsis genético de la Plaga de Justiniano

Abstract

BACKGROUND:

Justiniano. Emperador
del Imperio Bizantino. 

Yersinia pestis has caused at least three human plague pandemics. The second (Black Death, 14-17th centuries) and third (19-20th centuries) have been genetically characterised, but there is only a limited understanding of the first pandemic, the Plague of Justinian (6-8th centuries). To address this gap, we sequenced and analysed draft genomes of Y pestis obtained from two individuals who died in the first pandemic.

METHODS:

Teeth were removed from two individuals (known as A120 and A76) from the early medieval Aschheim-Bajuwarenring cemetery (Aschheim, Bavaria, Germany). We isolated DNA from the teeth using a modified phenol-chloroform method. We screened DNA extracts for the presence of the Y pestis-specific pla gene on the pPCP1 plasmid using primers and standards from an established assay, enriched the DNA, and then sequenced it. We reconstructed draft genomes of the infectious Y pestis strains, compared them with a database of genomes from 131 Y pestis strains from the second and third pandemics, and constructed a maximum likelihood phylogenetic tree.

FINDINGS:

Radiocarbon dating of both individuals (A120 to 533 AD [plus or minus 98 years]; A76 to 504 AD [plus or minus 61 years]) places them in the timeframe of the first pandemic. Our phylogeny contains a novel branch (100% bootstrap at all relevant nodes) leading to the twoJustinian samples. This branch has no known contemporary representatives, and thus is either extinct or unsampled in wild rodent reservoirs. TheJustinian branch is interleaved between two extant groups, 0.ANT1 and 0.ANT2, and is distant from strains associated with the second and third pandemics.

INTERPRETATION:

We conclude that the Y pestis lineages that caused the Plague of Justinian and the Black Death 800 years later were independent emergences from rodents into human beings. These results show that rodent species worldwide represent important reservoirs for the repeated emergence of diverse lineages of Y pestis into human populations.

References

• Wagner DM, Klunk J, Harbeck M, Devault A, et al. Yersinia pestis and the Plague of Justinian 541-543 AD: a genomic analysis. Lancet Infect Dis. 2014 Jan 27. pii: S1473-3099(13)70323-2.
• Harbeck M, Seifert L, Hänsch S, et al. Yersinia pestis DNA from skeletal remains from the 6(th) century AD reveals insights into  Justinianic Plague. PLoS Pathog. 2013;9(5):e1003349.
• The Death Toll of Justinian’s Plague and Its Effects on the Byzantine Empire
• 1,500-year-old plague victims shed light on disease origins

VIDEO: Contamination of Stethoscopes and Physicians' Hands After a Physical Examination

Abstract 
Objectives: To compare the contamination level of physicians’ hands and stethoscopes and to explore the risk of cross-transmission of microorganisms through the use of stethoscopes.
Patients and Methods: We conducted a structured prospective study between January 1, 2009, and May 31, 2009, involving 83 inpatients at a Swiss university teaching hospital. After a standardized physical examination, 4 regions of the physician’s gloved or ungloved dominant hand and 2 sections of the stethoscopes were pressed onto selective and nonselective media; 489 surfaces were sampled. Total aerobic colony counts (ACCs) and total methicillin-resistant Staphylococcus aureus (MRSA) colony-forming unit (CFU) counts were assessed.
Results: Median total ACCs (interquartile range) for fingertips, thenar eminence, hypothenar eminence, hand dorsum, stethoscope diaphragm, and tube were 467, 37, 34, 8, 89, and 18, respectively. The contamination level of the diaphgm was lower than the contamination level of the fingertips (P<.001) but higher than the contamination level of the thenar eminence (P1⁄4.004). The MRSA contamination level of the diaphragm was higher than the MRSA contamination level of the thenar eminence (7 CFUs/25 cm2 vs 4 CFUs/25 cm2; P1⁄4.004). The correlation analysis for both total ACCs and MRSA CFU counts revealed that the contamination level of the diaphragm was associated with the contamination level of the fingertips (Spearman’s rank correlation coefficient, r1⁄40.80; P<.001 and r1⁄40.76; P<.001, respectively). Similarly, the contamination level of the stethoscope tube increased with the increase in the contamination level of the fingertips for both total ACCs and MRSA CFU counts (r1⁄40.56; P<.001 and r1⁄4.59; P<.001, respectively).
Conclusion: These results suggest that the contamination level of the stethoscope is substantial after a single physical examination and comparable to the contamination of parts of the physician’s dominant hand.

Reference

Longtin Y, Schneider A, Tschopp C, Renzi G, Gayet-Ageron A, Schrenzel J, Pittet D. Contamination of Stethoscopes and Physicians’ Hands After a Physical Examination. Mayo Clin Proc. n March 2014;89(3):291-299