How long do nosocomial pathogens persist on inanimate surfaces? A systematic review

BACKGROUND: Inanimate surfaces have often been described as the source for outbreaks of nosocomial infections. The aim of this review is to summarize data on the persistence of different nosocomial pathogens on inanimate surfaces. METHODS: The literature was systematically reviewed in MedLine without language restrictions. In addition, cited articles in a report were assessed and standard textbooks on the topic were reviewed. All reports with experimental evidence on the duration of persistence of a nosocomial pathogen on any type of surface were included. RESULTS: Most gram-positive bacteria, such as Enterococcus spp. (including VRE), Staphylococcus aureus (including MRSA), or Streptococcus pyogenes, survive for months on dry surfaces. Many gram-negative species, such as Acinetobacter spp., Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, Serratia marcescens, or Shigella spp., can also survive for months. A few others, such as Bordetella pertussis, Haemophilus influenzae, Proteus vulgaris, or Vibrio cholerae, however, persist only for days. Mycobacteria, including Mycobacterium tuberculosis, and spore-forming bacteria, including Clostridium difficile, can also survive for months on surfaces. Candida albicans as the most important nosocomial fungal pathogen can survive up to 4 months on surfaces. Persistence of other yeasts, such as Torulopsis glabrata, was described to be similar (5 months) or shorter (Candida parapsilosis, 14 days). Most viruses from the respiratory tract, such as corona, coxsackie, influenza, SARS or rhino virus, can persist on surfaces for a few days. Viruses from the gastrointestinal tract, such as astrovirus, HAV, polio- or rota virus, persist for approximately 2 months. Blood-borne viruses, such as HBV or HIV, can persist for more than one week. Herpes viruses, such as CMV or HSV type 1 and 2, have been shown to persist from only a few hours up to 7 days. CONCLUSION: The most common nosocomial pathogens may well survive or persist on surfaces for months and can thereby be a continuous source of transmission if no regular preventive surface disinfection is performed

Cyclophosphamide effect on coccidioidomycosis in the rat

Coccidioidomycosis is a systemic mycosis, endemic in arid areas of the American continent. The rat was employed as an experimental host, since it had been shown to reproduce human lesions and present a chronic course of disease with granulomas mainly restricted to lungs. Given the influence of immunosuppressive therapy on the clinical course of human coccidioidomycosis, we studied the effect of cyclophosphamide (CY) in the experimental rat model. Accordingly, animals were inoculated with 400 Coccidioides immitis arthroconidia of the Acosta strain, by intracardiacal route. As single CY doses failed to alter the course of disease, three schedules were used: A) 4 daily doses of 20 mg/kg each, prior to C. immitis inoculation; B) 4 similar daily doses after infection; and C); 6 doses of 20 mg/kg each, given from day +1 to +4, then on days +8 and +9, post infection (pi), taking day 0 as the time of fungal inoculation. The first two schedules inhibited antibody formation up to day 28 pi, without modifying cellular response to coccidioidin as measured by foodpad swelling. Initially, there was greater fungal spread than in controls receiving C. immitis alone, which proved self-limiting in the latter. In contrast, schedule C led to 559r mortality, with both humoral and cellular response abrogation, accompanied by extensive C. immitis dissemination. Histology disclosed significant alterations, such as the persistence of primary infection sporangia, corresponding to the acute stage of coccidioidomycosis in the absence of granuloma development. Therefore, the observed depression in cellular immunity seems responsible for the lack of inflammatory reaction capable of restricting sporangia proliferation in tissues which, in turn, enhances pathogen spread and mortality rate.El propósito de este trabajo fue estudiar el efecto de la inmunosupresión causada por la droga ciclofosfamida (CY) sobre la infección de la rata con Coccidioides immitis por vía intracardíaca. Este huésped fue empleado como modelo experimental, ya que presenta una evolución de la enfermedad semejante a la del hombre, alcanzando una etapa crónica con granulomas principalmente restringidos a los pulmones. Se utilizaron tres esquemas de CY: A) 4 dosis de 20 mg/kg cada una, antes de la inoculación de Ci; B) 4 dosis de igual cantidad de CY, luego de la infección; y C) 6 dosis de 20 mg/kg cada una, administradas desde el día +1 hasta +4 y continuando los días + 8 y +9 post-infección (pi). Los dos primeros esquemas inhibieron la formación de anticuerpos hasta el día 28 pi, sin modificar la respuesta celular a la coccidioidina, medida como hinchazón de la almohadilla plantar. Se observó una mayor diseminación fúngica inicial, autolimi-tándose más tarde. Por el contrario, el esquema C provocó un 55% de mortalidad, disminución de la respuesta humoral y celular, acompañada de una extensa diseminación del Ci. La histología mostró alteraciones significativas, tales como persistencia de esporangios de primoinfección, correspondientes al estadio agudo de la coccidioidomicosis, con ausencia de desarrollo de granulomas. Por lo tanto, la depresión observada en la respuesta celular debido al tratamiento con CY sería la responsable de la ausencia de la reacción inflamatoria capaz de restringir la proliferación de esporangios en los tejidos, lo cual a su vez favorece la diseminación del microorganismo patógeno y el aumento de morta lidad

Salvation Through Storytelling: Examining Storytelling in Modern Children’s Literature

Storytelling traditions from all corners of the globe are active experiences that involve both teller and listener. We tell stories to keep history alive, to impart lessons, to awake cathartic emotions, and to be simply entertained. Storytelling, therefore, is an act of self-preservation. Not only do we keep our ancestors in our memory, but as we see with the famous tale of Shahrazad (or Scheherazade), we also tell stories to save ourselves and those we love within our families and community. The characters in modern twentieth and twenty-first century children’s literature further this tradition of salvation through storytelling by using stories to save their own lives or those of others, or even that of the reader. The texts examined are The Capture by Kathryn Lasky, The Tale of Despereaux by Kate DiCamillo, Where the Mountain Meets the Moon and Starry River of the Sky by Grace Lin, Haroun and the Sea of Stories by Salman Rushdie, and Shadow Spinner by Susan Fletcher. By showing young readers how valuable the storytelling experience is, we keep it alive and reaffirm that this it is vital to our spiritual and physical survival. Through Shahrazad’s ongoing tradition, we can find salvation through storytelling

Relationships Between Students' Course Grades and Value-Added Scores

Value-added assessment holds the promise of separating the effects of teachers and schools from non-educational factors in order to show large differences in effectiveness among teachers; however, the course grade is still widely used and is one of the most entrenched traditions in American education. The overarching question for this study: Is there a relationship between summative internal student assessment within the classroom (course grades) and external assessment through standardized testing (value-added scores)? Educators hope to see a strong, positive relationship between classroom assessment of learning and standardized test performance. The purpose of this study was to evaluate the relationship between course grades in both mathematics and English/Language Arts and value-added scores derived from standardized test scores from eighth and 10th grade students in one Midwestern school district during the 20082009 school year. A non-experimental, correlational research design was used in this quantitative study to determine if and to what degree, a relationship existed between the variables of value-added residual scores and course grades. Overall, all correlations were positive but weak and no real patterns were found in the overall results or among or between the quintiles. The strongest correlation in this study was in Quintile 1 for the eighth Grade OAT Reading (rs = 0.379) and the second was Quintile 5 of 10th Grade Reading (rs = 0.378). The weakest correlation in this study was Quintile 1 for 10th Grade OGT Reading ( rs = 0.047). The correlations from this study showed a positive (but weak) relationship compared to the strong, positive relationship from other studies by Darling-Hammond (2007), Dittmar (2005), and Johnson (2001), which examined the correlation of internal and external assessments, though not value-added. The lack of patterns in the results and weak correlations could have been impacted by the delimitations such as value-added methodology itself, the ability to generalize the results, and the scope of the study. This suggests the need for further studies. Recommendations for future studies could include: school districts replicating this study, correlating course grades and value-added scores by specific teachers, and further examining how different subgroups would perform in a similar study