Contamination, disinfection, and cross-colonization: are hospital surfaces reservoirs for nosocomial infection?
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Despite documentation that the inanimate hospital environment (e.g., surfaces and medical equipment) becomes contaminated with nosocomial pathogens, the data that suggest that contaminated fomites lead to nosocomial infections do so indirectly. Pathogens for which there is more-compelling evidence of survival in environmental reservoirs include Clostridium difficile, vancomycin-resistant enterococci, and methicillin-resistant Staphylococcus aureus, and pathogens for which there is evidence of probable survival in environmental reservoirs include norovirus, influenza virus, severe acute respiratory syndrome-associated coronavirus, and Candida species. Strategies to reduce the rates of nosocomial infection with these pathogens should conform to established guidelines, with an emphasis on thorough environmental cleaning and use of Environmental Protection Agency-approved detergent-disinfectants. (+info)
Dementia-specific risks of scabies: retrospective epidemiologic analysis of an unveiled nosocomial outbreak in Japan from 1989-90.
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BACKGROUND: Although senile dementia patients in long-term care facilities are at leading risk of scabies, the epidemiologic characteristics of this disease have yet to be fully clarified. This study documents the findings of a ward-scale nosocomial outbreak in western Japan from 1989-90, for which permission to publish was only recently obtained. METHODS: A retrospective epidemiologic study was performed to identify specific risk factors of scabies among patients with dementia. Analyses were based on a review of medical and nursing records. All inpatients in the affected ward at the time of the outbreak were included in the study. Observational and analytical approaches were employed to assess the findings. RESULTS: Twenty of 65 inpatients in the ward met the case definition of scabies. The outbreak lasted for almost 10 months and as a result, the spatial distribution of infections showed no localized patterns in the latter phase of the outbreak. The duration of illness significantly decreased after initiation of control measures (P = 0.0067). Movement without assistance (Odds Ratio [OR] = 11.3; 95% Confidence Interval [CI]: 2.9, 44.8) and moving beyond the room (but within the ward) (OR = 4.1; 95% CI: 1.4, 12.5) were significantly associated with infection, while types of room (Western or Japanese) and sleeping arrangement (on beds or futons laid directly on the floor) appeared not to be risk factors. CONCLUSION: Univariate analysis demonstrated the importance of patients' behaviours during daily activities in controlling scabies among senile dementia patients. The findings also support previous evidence that catching scabies from fomites is far less common. Moreover, since cognitive disorders make it difficult for individuals to communicate and understand the implications of risky contacts as well as treatment method, and given the non-specific nature of individual contacts that are often unpredictable, real-time observations might help improve control practices. (+info)
Efficacy of machine laundering to eradicate head lice: recommendations to decontaminate washable clothes, linens, and fomites.
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The efficacy of machine laundering to eradicate head lice should be determined. Viable lice and nits were machine laundered using 3 washing programs (with water temperatures of 40 degrees C, 50 degrees C, and 60 degrees C), with and without detergent, and the results were compared with results for control lice and nits. A drying program was also used. Either washing done with a water temperature of at least 50 degrees C or drying is necessary to kill head lice and nits. (+info)
Non-pharmaceutical interventions for pandemic influenza, international measures.
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Since global availability of vaccine and antiviral agents against influenza caused by novel human subtypes is insufficient, the World Health Organization (WHO) recommends non-pharmaceutical public health interventions to contain infection, delay spread, and reduce the impact of pandemic disease. Virus transmission characteristics will not be completely known in advance, but difficulties in influenza control typically include peak infectivity early in illness, a short interval between cases, and to a lesser extent, transmission from persons with incubating or asymptomatic infection. Screening and quarantining entering travelers at international borders did not substantially delay virus introduction in past pandemics, except in some island countries, and will likely be even less effective in the modern era. Instead, WHO recommends providing information to international travelers and possibly screening travelers departing countries with transmissible human infection. The principal focus of interventions against pandemic influenza spread should be at national and community levels rather than international borders. (+info)
Survival of meningococci outside of the host: implications for acquisition.
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Meningococci are regarded as being unlikely to survive outside of their human host although this has possibly been more assumed than demonstrated. Seven strains of meningococci were tested for their ability to survive on glass or plastic while retaining expression of their capsule and important outer membrane proteins. A known number of colony-forming units of each strain were dried onto glass and onto plastic and tested for viability over time. Survival on glass was significantly better than on plastic (P<0.0001). Isolates of the New Zealand epidemic strain, B:4:P1.7-2,4 survived better on glass than all other strains tested. Recovered isolates still expressed their capsules and outer membrane proteins. These findings raise the question of whether meningococci can be transferred from person to person via fomites contaminated with oropharyngeal secretions containing meningococci. (+info)
How long do nosocomial pathogens persist on inanimate surfaces? A systematic review.
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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. (+info)
Acquisition of Helicobacter pylori infection in rhesus macaques is most consistent with oral-oral transmission.
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Socially housed rhesus monkeys rapidly acquired Helicobacter pylori infection, although the organism was rarely cultivated from saliva, feces, or the environment. Since the concentrations of H. pylori in vomit were compatible with what is known about the infectious dose, our results are most consistent with an oral-oral means of transmission. (+info)
Disrupting the transmission of influenza a: face masks and ultraviolet light as control measures.
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In the event of an influenza pandemic, where effective vaccine and antiviral drugs may be lacking, disrupting environmental transmission of the influenza virus will be the only viable strategy to protect the public. We discuss 2 such modalities, respirators (face masks) and ultraviolet (UV) light. Largely overlooked, the potential utility of each is underappreciated. The effectiveness of disposable face masks may be increased by sealing the edges of the mask to the face. Reusable masks should be stockpiled, because the supply of disposable masks will likely prove inadequate. UV light, directed overhead, may be beneficial in hospitals and nursing homes. (+info)