Comparing non-safety with safety device sharps injury incidence data from two different occupational surveillance systems.

The United States Occupational Safety and Health Administration (OSHA) Bloodborne Pathogens Standard as amended by the Needlestick Safety and Prevention Act requiring the use of safety-engineered medical devices to prevent needlesticks and sharps injuries has been in place since 2001. Injury changes over time include differences between those from non-safety compared with safety-engineered medical devices. This research compares two US occupational incident surveillance systems to determine whether these data can be generalized to other facilities and other countries either with legislation in place or considering developing national policies for the prevention of sharps injuries among healthcare personnel.

Methods for the recovery of a model virus from healthcare personal protective equipment.

AIMS: To develop methods for recovering a model virus (bacteriophage MS2) from healthcare personal protective equipment (PPE). METHODS AND RESULTS: Nine eluents were evaluated for recovery of infectious MS2 from PPE: 1.5% beef extract (BE) pH 7.5 with and without 0.1% Tween 80, 1.5% BE pH 9.0 with and without 0.1% Tween 80, 3% BE pH 7.5 with and without 0.1% Tween 80, 3% BE pH 9.0 with and without 0.1% Tween 80 and PBS with 0.1% Tween 80. Methods were applied to experimentally contaminated PPE. Elution followed by two-step enrichment assay could recover virus inputs as low as 1.5 log(10), and could recover >90% of inoculated virus from used items of experimentally contaminated PPE worn by human volunteers. CONCLUSIONS: BE was effective for recovering infectious viruses from a range of PPE materials. SIGNIFICANCE AND IMPACT OF THE STUDY: PPE plays a crucial role in interrupting transmission of infectious agents from patients to healthcare workers (HCWs). The fate of micro-organisms when PPE is removed and disposed of has important consequences for infection control. Methods described here can be used to conduct rigorous studies of viral survival and transfer on PPE for risk assessments in infection control and HCW protection.

Reprocessing endoscopes: United States perspective.

Endoscopes are used frequently for the diagnosis and therapy of medical disorders. For example, greater than 10000000 gastrointestinal endoscopic procedures are performed each year in the United States. Failure to employ appropriate cleaning and disinfection/sterilization of endoscopes has been responsible for multiple nosocomial outbreaks and serious, sometimes life-threatening, infections. Flexible endoscopes, by virtue of the site of use, have a high bioburden of microorganisms after use. The bioburden found on flexible gastrointestinal endoscopes following use has ranged from 10(5) to 10(10)CFU/ml, with the highest levels being found in the suction channels. Cleaning dramatically reduces the bioburden on endoscopes. Several investigators have shown a mean log(10) reduction factor of 4 (99.99%) in the microbial contaminants with cleaning alone. Cleaning should be done promptly following each use of an endoscope to prevent drying of secretions, allow removal of organic material, and decrease the number of microbial pathogens. Because the endoscope comes into intimate contact with mucous membranes, high-level disinfection is the reprocessing standard after each patient use. High-level disinfection refers to the use of a disinfectant (e.g., FDA-cleared chemical sterilant or high-level disinfectant) that inactivates all microorganisms (i.e., bacteria, viruses, fungi, mycobacteria) but not high levels of bacterial spores. The disinfection process requires immersion of the endoscope in the high-level disinfectant and ensuring all channels are perfused for the approved contact time (e.g., for ortho-phthaladehyde this is 12 min in the US). Following disinfection, the endoscope and channels are rinsed with sterile water, filtered water, or tapwater. The channels are then flushed with alcohol and dried using forced air. The endoscope should be stored in a manner that prevents recontamination. A protocol that describes the meticulous manual cleaning process, the appropriate training and evaluation of the reprocessing personnel, and a quality assurance program for endoscopes should be adopted and enforced by each unit performing endoscopic reprocessing.

The emerging nosocomial pathogens Cryptosporidium, Escherichia coli O157:H7, Helicobacter pylori, and hepatitis C: epidemiology, environmental survival, efficacy of disinfection, and control measures.

New and emerging infectious diseases pose a threat to public health and may be responsible for nosocomial outbreaks. Cryptosporidium parvum and Escherichia coli are gastrointestinal pathogens that have caused nosocomial infections via person-to-person transmission, environmental contamination, or contaminated water or food. Helicobacter pylori has been transmitted via inadequately disinfected endoscopes. Finally, hepatitis C may be acquired by healthcare personnel by percutaneous or mucous membrane exposure to blood or between patients by use of contaminated blood products or via environmental contamination. Rigorous adherence to Standard Precautions, Contact Precautions for patients with infectious diarrhea, disinfection of environmental surfaces, and appropriate disinfection of endoscopes are adequate to prevent nosocomial acquisition of these pathogens.

A review of single-use and reusable gowns and drapes in health care.

Gowns and drapes are used widely in healthcare facilities. Gowns have been used to minimize the risk of disease acquisition by healthcare providers, to reduce the risk of patient-to-patient transmission, and during invasive procedures to aid in maintaining a sterile field. Drapes have been used during invasive procedures to maintain the sterility of environmental surfaces, equipment, and patients. This article reviews the use of gowns and drapes in healthcare facilities, including the characteristics, costs, benefits, and barrier effectiveness of single-use and reusable products. Currently, gowns protect healthcare personnel performing invasive procedures from contact with bloodborne pathogens. Although gowns have been recommended to prevent patient-to-patient transmission in certain settings (eg, neonatal intensive care unit) and for certain patients (eg, those infected with vancomycin-resistant enterococci), scientific studies have produced mixed results of their efficacy. While appropriate use of drapes during invasive procedures is recommended widely as an aid in minimizing contamination of the operative field, the efficacy of this practice in reducing surgical-site infections has not been assessed by scientific studies. Based on an evaluation of the functional requirements, environmental impact, and economics of gowns and drapes, clear superiority of either reusable or single-use gowns and drapes cannot be demonstrated. The selection of particular gowns and drapes by individual healthcare facilities requires an assessment of the facility's requirements, available products, and costs and should be based on the desired characteristics of an ideal gown or drape as defined in this paper.

New disinfection and sterilization methods.

New disinfection methods include a persistent antimicrobial coating that can be applied to inanimate and animate objects (Surfacine), a high-level disinfectant with reduced exposure time (ortho-phthalaldehyde), and an antimicrobial agent that can be applied to animate and inanimate objects (superoxidized water). New sterilization methods include a chemical sterilization process for endoscopes that integrates cleaning (Endoclens), a rapid (4-hour) readout biological indicator for ethylene oxide sterilization (Attest), and a hydrogen peroxide plasma sterilizer that has a shorter cycle time and improved efficacy (Sterrad 50).

Creutzfeldt-Jakob disease: recommendations for disinfection and sterilization.

Prion diseases constitute a unique infection control problem because prions exhibit unusual resistance to conventional chemical and physical decontamination methods. Recommendations to prevent cross-transmission of infection from medical devices contaminated by Creutzfeldt-Jakob disease (CJD) have been based primarily on prion inactivation studies. The recommendations in this article consider inactivation data but also use epidemiological studies of prion transmission, infectivity of human tissues, and efficacy of removing microbes by cleaning. On the basis of the scientific data, only critical (e.g., surgical instruments) and semicritical devices contaminated with high-risk tissue (i.e., brain, spinal cord, and eye tissue) from high-risk patients--those with known or suspected infection with CJD--require special treatment.

Risks and prevention of nosocomial transmission of rare zoonotic diseases.

Americans are increasingly exposed to exotic zoonotic diseases through travel, contact with exotic pets, occupational exposure, and leisure pursuits. Appropriate isolation precautions are required to prevent nosocomial transmission of rare zoonotic diseases for which person-to-person transmission has been documented. This minireview provides guidelines for the isolation of patients and management of staff exposed to the following infectious diseases with documented person-to-person transmission: Andes hantavirus disease, anthrax, B virus infection, hemorrhagic fevers (due to Ebola, Marburg, Lassa, Crimean-Congo hemorrhagic fever, Argentine hemorrhagic fever, and Bolivian hemorrhagic fever viruses), monkeypox, plague, Q fever, and rabies. Several of these infections may also be encountered as bioterrorism hazards (i.e., anthrax, hemorrhagic fever viruses, plague, and Q fever). Adherence to recommended isolation precautions will allow for proper patient care while protecting the health care workers who provide care to patients with known or suspected zoonotic infections capable of nosocomial transmission.

Surface disinfection: should we do it?

The effective use of disinfectants constitutes an important factor in preventing hospital-acquired infections. Surfaces are considered non-critical items as they come in contact with intact skin. Use of non-critical items or contact with non-critical surfaces carries little risk of transmitting a pathogen to patients. Thus, the routine use of disinfectants to disinfect hospital floors and other non-critical items is controversial. However, surfaces may potentially contribute to cross-transmission by acquisition of transient hand carriage by health care personnel due to contact with a contaminated surface or by patient contact with contaminated surfaces or medical equipment. This paper reviews the epidemiological and microbiological data regarding the use of disinfectants on non-critical surfaces. It concludes that while non-critical surfaces are uncommonly associated with transmission of infections to patients, one should clean and disinfect surfaces on a regularly scheduled basis.

Efficacy of a washer-pasteurizer for disinfection of respiratory-care equipment.

We evaluated the efficacy of a commercial washer-pasteurizer. Carriers were inoculated with 10(4) to 10(6) test organisms and pasteurized at 170 degrees F for 30 minutes. Pasteurization eliminated all test organisms with the exception of Bacillus subtilis spores. Pasteurization appears efficacious for the disinfection of respiratory-care equipment and could result in a cost savings of approximately $30,000 per year.

Antimicrobial activity of home disinfectants and natural products against potential human pathogens.

OBJECTIVE: To assess the efficacy of both natural products (vinegar, baking soda) and common commercial disinfectants (Vesphene IIse, TBQ, Clorox, Lysol Disinfectant Spray, Lysol Antibacterial Kitchen Cleaner, Mr. Clean Ultra, ethanol) designed for home or institutional use against potential human pathogens, including selected antibiotic-resistant bacteria. DESIGN: A quantitative suspension test was used to assess the efficacy of selected disinfectants following exposure times of 30 seconds and 5 minutes. Activity was assessed against Staphylococcus aureus, Salmonella choleraesuis, Escherichia coli O157:H7, and Pseudomonas aeruginosa. Selected disinfectants were also tested against poliovirus, vancomycin-susceptible and -resistant Enterococcus species, and methicillin-susceptible and -resistant S. aureus. RESULTS: The following compounds demonstrated excellent antimicrobial activity (>5.6-8.2 log10 reduction) at both exposure times: TBQ, Vesphene, Clorox, ethanol, and Lysol Antibacterial Kitchen Cleaner. Mr. Clean eliminated 4 to >6 logs10 and Lysol Disinfectant approximately 4 logs10 of pathogenic microorganisms at both exposure times. Vinegar eliminated <3 logs10 of S. aureus and E. coli, and baking soda <3 logs10 of all test pathogens. All tested chemical disinfectants completely inactivated both antibiotic-resistant and -susceptible bacteria at both exposure times. Only two disinfectants, Clorox and Lysol, demonstrated excellent activity (>3 log10 reduction) against poliovirus. CONCLUSIONS: A variety of commercial household disinfectants were highly effective against potential bacterial pathogens. The natural products were less effective than commercial household disinfectants. Only Clorox and Lysol disinfectant were effective against poliovirus.

The effect of blood on the antiviral activity of sodium hypochlorite, a phenolic, and a quaternary ammonium compound.

OBJECTIVE: To assess the virucidal activity of three disinfectants (sodium hypochlorite, a phenolic, and a quaternary ammonium compound) in the presence and absence of blood. METHODS: Disinfectants at varying concentrations (hypochlorite: 5,000, 500, or 50 ppm; phenolic: 1:10 or 1:128 dilution; quaternary ammonium compound: 1:10 or 1:128 dilution) were added to either saline or whole blood (final concentration, 80% or 20% blood) and mixed. Test organisms included an attenuated vaccine strain of poliovirus type 1 (prototype for relatively resistant hydrophilic viruses) and herpes simplex virus (HSV) type 1 (prototype for relatively susceptible lipophilic viruses). Virus was added to create a viral-blood suspension. Viral survival was tested at room temperature at the following times: 0, 15 seconds, 30 seconds, 1 minute, 2 minutes, 5 minutes, and 10 minutes. A neutralizer stopped the reaction, and virus was assayed using a plaque technique. RESULTS: In the absence of blood, complete inactivation of HSV was achieved within 30 seconds with 5,000 (1:10 dilution of bleach) and 500 (1:100 dilution of bleach) ppm chlorine, 1:10 and 1:128 diluted phenolic (use dilution), and 1:10 and 1:128 diluted quaternary ammonium compound (use dilution). In the presence of 80% blood, only 5,000 ppm hypochlorite, 1:10 phenolic, and 1:10 or 1:128 quaternary ammonium compound were effective. In the absence of blood, complete inactivation of polio was achieved within 30 seconds by 5,000 and 500 ppm chlorine and 1:10 quaternary ammonium compound. In the presence of 80% blood, no solution tested was capable of completely inactivating poliovirus within 10 minutes. CONCLUSIONS: Our data suggest that, in the absence of visible blood, environmental surfaces may be disinfected with a diluted hypochlorite solution (1:10 or 1:100), a phenolic, or a quaternary ammonium compound. Based on our studies using HSV, which has similar susceptibilities to disinfectants as human immunodeficiency virus (HIV), phenolics at their use dilution and 1:100 diluted hypochlorite are unlikely to inactivate HIV or hepatitis B virus reliably in the presence of blood. Hypochlorite at a final concentration of 5,000 ppm (1:10 dilution) should be used to decontaminate blood spills, but, even after decontamination, care should be used to avoid sharps injuries.

Sporicidal activity of a new low-temperature sterilization technology: the Sterrad 50 sterilizer.

This study was undertaken to evaluate the efficacy of a new low-temperature sterilization system that recently has been cleared by the Food and Drug Administration, the Sterrad 50. Flat stainless steel carriers were inoculated with approximately 10(6) Bacillus stearothermophilus spores. These carriers were placed aseptically in the middle of 40-cm-long stainless steel-lumened test units of varying diameters (1 mm, 2 mm, and 3 mm). After inoculation, the test units were processed in the Sterrad 50. After sterilization, the carriers were assayed for growth of the B. stearothermophilus spores. Our data demonstrated that the Sterrad 50 was highly effective in killing the B. stearothermophilus spores (no positive carriers with 30 tests of each lumen-diameter test unit). The Sterrad 50 is likely to be clinically useful for the sterilization of heat-sensitive medical equipment.

Inactivation of Cryptosporidium parvum oocyst infectivity by disinfection and sterilization processes.

BACKGROUND: Cryptosporidium parvum is a common cause of self-limited gastroenteritis in the normal host but may cause severe disease in immunocompromised persons. Person-to-person transmission has been well documented in households, child care centers, and hospitals. Because contaminated environmental surfaces and medical devices such as endoscopes may play a role in disease transmission, we studied the susceptibility of C parvum to chemical agents commonly used for disinfection and evaluated the efficacy of sterilization processes. METHODS: Seven disinfectants were studied at their use dilution using a suspension test. Antimicrobial activity was assessed with the use of a cell infectivity assay. RESULTS: All sterilization processes tested (steam, ethylene oxide, Sterrad 100) inactivated 3 logs or greater of C parvum. The only liquid disinfectant/sterilant able to inactivate greater than 3 logs of C parvum was 6% and 7.5% hydrogen peroxide. Agents that did not completely inactivate C parvum included hydrogen peroxide at lower concentrations or exposure times, peracetic acid, sodium hypochlorite, a phenolic, a quaternary ammonium compound, 2% glutaraldehyde, and ortho-phthalaldehyde. CONCLUSIONS: Most high-level disinfectants used on endoscopes have limited efficacy against C parvum. However, the infectivity of C parvum on dry surfaces decreases rapidly. Therefore, current cleaning and high-level disinfection guidelines are adequate to prevent nosocomial transmission of C parvum by means of endoscopes.

Zoonotic infections.

More than 200 diseases are transmitted from animals to humans. Zoonotic infections can be transmitted via animal bites, arthropod vectors, especially ticks and mosquitoes, and direct contact with animals. Infections also can be contracted indirectly by ingestion of contaminated food or water or contact with contaminated hides, wool, or fur. Persons at risk of zoonotic infections include people who enjoy outdoor leisure activities such as hiking, camping, hunting, spelunking, and fishing. Occupational groups at risk include animal control officers, hunters, abattoir workers, farmers, fisherpersons, persons working with hides or wool, and laboratory workers working with zoonotic pathogens. The risk of infection can be reduced by appropriate use of personal protective equipment, immunizations, and measures to avoid insect bites.