Preventing the spread of hepatitis B and C viruses: where are germicides relevant?

The Promise and Potential of Metal-Organic Frameworks and Covalent Organic Frameworks in Vaccine Nanotechnology

The immune system's complexity and ongoing evolutionary struggle against deleterious pathogens underscore the value of vaccination technologies, which have been bolstering human immunity for over two centuries. Despite noteworthy advancements over these 200 years, three areas remain recalcitrant to improvement owing to the environmental instability of the biomolecules used in vaccines─the challenges of formulating them into controlled release systems, their need for constant refrigeration to avoid loss of efficacy, and the requirement that they be delivered via needle owing to gastrointestinal incompatibility. Nanotechnology, particularly metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), has emerged as a promising avenue for confronting these challenges, presenting a new frontier in vaccine development. Although these materials have been widely explored in the context of drug delivery, imaging, and cancer immunotherapy, their role in immunology and vaccine-related applications is a recent yet rapidly developing field. This review seeks to elucidate the prospective use of MOFs and COFs for biomaterial stabilization, eliminating the necessity for cold chains, enhancing antigen potency as adjuvants, and potentializing needle-free delivery of vaccines. It provides an expansive and critical viewpoint on this rapidly evolving field of research and emphasizes the vital contribution of chemists in driving further advancements.

Managing and preventing blood-borne viral infection transmission in assisted reproduction: a Canadian Fertility and Andrology Society clinical practice guideline

Fertility care providers have an obligation to provide safe and effective care to patients. When a user of assisted reproductive technology (ART) is living with a blood-borne viral infection (BBVI: HIV, hepatitis C or hepatitis B), physicians and ART laboratory personnel need to know the requirements for providing quality care. Recent developments in the treatment of BBVI and understanding of transmission have changed these requirements. This guideline from the Canadian Fertility and Andrology Society (CFAS) provides comprehensive, evidence-based guidelines for reducing horizontal transmission and cross-contamination in the ART setting.

Urban Waste Collectors in Belo Horizonte, Brazil: Their Perceptions of Occupational Health Risk

Frequent contact with hazardous materials makes waste collection a potentially unhealthy activity. This article assesses the perception of waste management workers regarding work-related accidents in domestic and health service contexts in Brazil. Six focus groups were performed between June 2014 and August 2015. The aims of this study were to apprehend different aspects of the participants' health, workers' experiences of work-related accidents and perception of risks. Cuts and puncture injuries were reported most frequently in the line of work and were often considered as irrelevant. Immunization against hepatitis B was not common among all workers, which increases the risk of infection for those individuals. Finally, it is considered urgent to consolidate an inclusive space in which workers can have discussions on their health.

Is waste collection associated with hepatitis B infection? A meta-analysis

This meta-analysis, which is based on a previously published systematic review, aims to contribute to the scientific discussion on hepatitis B virus (HBV) infection in workers who are exposed to domestic and healthcare wastes. Publications were sought which had been made available on the data used by December 2013 and updated to December 2016. The quality of the included studies was assessed according to the guidelines of Loney et al. for the critical appraisal of studies on the prevalence or incidence of a health problem. To verify the presence of heterogeneity between the papers, we used the Chi-squared test based on a Q statistic. A funnel plot was used to test for publication bias. All included studies had across-sectional study design. The association between exposure to waste and positive serology for the HBV surface antigen (HBsAg) showed a significant association [odds ratio (OR) 1.89, 95% confidence interval (CI) 1.27-2.86; p = 0.0019]. The prevalence rates of HBsAg and anti-HBc seropositivity was 0.04 (95% CI 0.03-0.05) and 0.21 (95% CI 0.14-0.28), respectively (p <0.0001). We found no evidence of publication bias. The results of this meta-analysis indicate a statistically significant association between exposure to solid waste, whether healthcare or domestic, and positive HBV infection markers. Therefore, the working conditions of waste collectors should be analyzed more closely. Immunization against HBV is recommended as the chief preventive measure for all solid waste workers.

Assessment of work-related accidents associated with waste handling in Belo Horizonte (Brazil)

As more urban solid waste is generated, managing it becomes ever more challenging and the potential impacts on the environment and human health also become greater. Handling waste - including collection, treatment and final disposal - entails risks of work accidents. This article assesses the perception of waste management workers regarding work-related accidents in domestic and health service contexts in Belo Horizonte, Brazil. These perceptions are compared with national data from the Ministry of Social Security on accidents involving workers in solid waste management. A high proportion of accidents involves cuts and puncture injuries; 53.9% among workers exposed to domestic waste and 75% among those exposed to health service waste. Muscular lesions and fractures accounted for 25.7% and 12.5% of accidents, respectively. Data from the Ministry of Social Security diverge from the local survey results, presumably owing to under-reporting, which is frequent in this sector. Greater commitment is needed from managers and supervisory entities to ensure that effective measures are taken to protect workers' health and quality of life. Moreover, workers should defend their right to demand an accurate registry of accidents to complement monitoring performed by health professionals trained in risk identification. This would contribute to the improved recovery of injured workers and would require managers in waste management to prepare effective preventive action.

Seroprevalence of hepatitis B and C among domestic and healthcare waste handlers in Belo Horizonte, Brazil

Infection with the hepatitis B and C viruses may occur through contact with infected body fluids, including injury with infected sharps. Collectors of domestic or healthcare wastes are potentially exposed to these infections. The aim of this article is to investigate the risk factors associated with the prevalence of hepatitis B and C viruses (HBV and HCV) infection among domestic and healthcare waste workers in Belo Horizonte, Brazil. A cross-sectional study of hepatitis B and C infection was conducted from November 2014 to January 2015, through blood sample collection and interviews about socio-demographic factors with 61 workers exposed to healthcare waste ('exposed') and 461 exposed only to domestic wastes ('unexposed'). The prevalence of antibodies to HCV (Anti-HCV) antibodies was 3.3% in 'exposed' workers and 0.9% in 'unexposed', and of antibody to hepatitis B core antigen (Anti-HBc) was 9.8% and 5.6% in 'exposed' and 'unexposed' workers, respectively. Only 207 (44.9%) of those exposed to domestic waste and 45 (73.8%) of those handling healthcare waste were effectively immunised against hepatitis B virus (HBV). Exposures to domestic waste and to healthcare wastes were associated with similar risks of infection with HBV. The risk of hepatitis C virus (HCV) infection was marginally higher among healthcare waste workers compared with domestic waste workers, probably because of needlestick accidents owing to deficient sharps management systems. Immunisation against hepatitis B and screening tests to ensure the success of vaccination should be a condition for recruitment for both groups of waste workers.

Comparison and optimization of detection methods for noroviruses in frozen strawberries containing different amounts of RT-PCR inhibitors

Frozen berries have been repeatedly identified as vehicles for norovirus (NoV) transmission causing large gastroenteritis outbreaks. However, virus detection in berries is often hampered by the presence of RT-PCR-inhibiting substances. Here, several virus extraction methods for subsequent real-time RT-PCR-based NoV-RNA detection in strawberries were compared and optimized. NoV recovery rates (RRs) between 0.21 ± 0.13% and 10.29 ± 6.03% were found when five different artificially contaminated strawberry batches were analyzed by the ISO/TS15216-2 method indicating the presence of different amounts of RT-PCR inhibitors. A comparison of five different virus extraction methods using artificially contaminated strawberries containing high amounts of RT-PCR inhibitors revealed the best NoV RRs for the ISO/TS15216 method. Further improvement of NoV RRs from 2.83 ± 2.92% to 15.28 ± 9.73% was achieved by the additional use of Sephacryl(®)-based columns for RNA purification. Testing of 22 frozen strawberry samples from a batch involved in a gastroenteritis outbreak resulted in 5 vs. 13 NoV GI-positive and in 9 vs. 20 NoV GII-positive samples using the original ISO/TS15216 method vs. the extended protocol, respectively. It can be concluded that the inclusion of an additional RNA purification step can increase NoV detection by the ISO/TS15216-2 method in frozen berries containing high amounts of RT-PCR inhibitors.

Is hepatitis B-virucidal validation of biocides possible with the use of surrogates?

The hepatitis B virus (HBV) is considered to be a major public health problem worldwide, and a significant number of reports on nosocomial outbreaks of HBV infections have been reported. Prevention of indirect HBV transmission by contaminated objects is only possible through the use of infection-control principles, including the use of chemical biocides, which are proven to render the virus non-infectious. The virucidal activity of biocides against HBV cannot be predicted; therefore, validation of the virucidal action of disinfectants against HBV is essential. However, feasible HBV infectivity assays have not yet been established. Thus, surrogate models have been proposed for testing the efficacy of biocides against HBV. Most of these assays do not correlate with HBV infectivity. Currently, the most promising and feasible assay is the use of the taxonomically related duck hepatitis B virus (DHBV), which belongs to the same Hepadnaviridae virus family. This paper reviews the application of DHBV, which can be propagated in vitro in primary duck embryonic hepatocytes, for the testing of biocides and describes why this model can be used as reliable method to evaluate disinfectants for efficacy against HBV. The susceptibility levels of important biocides, which are often used as ingredients for commercially available disinfectants, are also described.

Does limited virucidal activity of biocides include duck hepatitis B virucidal action?

BACKGROUND

There is agreement that the infectivity assay with the duck hepatitis B virus (DHBV) is a suitable surrogate test to validate disinfectants for hepatitis B virucidal activity. However, since this test is not widely used, information is necessary whether disinfectants with limited virucidal activity also inactivate DHBV. In general, disinfectants with limited virucidal activity are used for skin and sensitive surfaces while agents with full activity are more aggressive. The present study compares the activity of five different biocides against DHBV and the classical test virus for limited virucidal activity, the vaccinia virus strain Lister Elstree (VACV) or the modified vaccinia Ankara strain (MVA).

METHODS

Virucidal assay was performed as suspension test according to the German DVV/RKI guideline. Duck hepatitis B virus obtained from congenitally infected Peking ducks was propagated in primary duck embryonic hepatocytes and was detected by indirect immunofluorescent antigen staining.

RESULTS

The DHBV was inactivated by the use of 40% ethanol within 1-min and 30% isopropanol within 2-min exposure. In comparison, 40% ethanol within 2-min and 40% isopropanol within 1-min exposure were effective against VACV/MVA. These alcohols only have limited virucidal activity, while the following agents have full activity. 0.01% peracetic acid inactivated DHBV within 2 min and a concentration of 0.005% had virucidal efficacy against VACV/MVA within 1 min. After 2-min exposure, 0.05% glutardialdehyde showed a comparable activity against DHBV and VACV/MVA. This is also the case for 0.7% formaldehyde after a contact time of 30 min.

CONCLUSIONS

Duck hepatitis B virus is at least as sensitive to limited virucidal activity as VACV/MVA. Peracetic acid is less effective against DHBV, while the alcohols are less effective against VACV/MVA. It can be expected that in absence of more direct tests the results may be extrapolated to HBV.

Comparison on the Efficacy of Disinfectants Used in Automated Endoscope Reprocessors: PHMB-DBAC versus Orthophthalaldehyde

BACKGROUND/AIMS

Since endoscopes are reusable apparatus classified as semicritical item, thorough reprocessing to achieve high-level disinfection is of utmost importance to prevent spread of infection. To improve disinfection efficacy and safety, disinfectants and endoscope reprocessors are continuously evolving. This study aimed to compare the efficacy of the combination of polyhexamethylenebiguanide hydrochloride-alkyldimethylbenzylammonium chloride (PHMB-DBAC) and orthophthalaldehyde (OPA) used respectively in ultrasonographic cleaning incorporated automated endoscope reprocessors: COOLENDO (APEX Korea) or OER-A (Olympus Optical).

METHODS

A total of 86 flexible upper endoscopes were randomly reprocessed with either COOLENDO/PHMB-DBAC or OER-A/OPA. Culture samplings were done at two sites (endoscope tip and working channel) which were later incubated on blood agar plate. Bacterial colonies were counted and identified.

RESULTS

The culture-positive rate at the endoscope tip and working channel was 0% and 2.33% for COOLENDO/PHMB-DBAC and 4.65% and 0% for OER-A/OPA. Staphylococcus hominis was cultured from one endoscope reprocessed with COOLENDO/PHMB-DBAC and Pseudomonas putida was isolated from two endoscopes reprocessed with OER-A/OPA.

CONCLUSIONS

The reprocessing efficacy of COOLENDO/PHMB-DBAC was non-inferior to that of OER-A/OPA (p=0.032; confidence interval, -0.042 to 0.042). During the study period, significant side effect of PHMB-DBAC was not observed.

Qualitative accounts of needle and syringe cleaning techniques among people who inject drugs in Sydney, Australia

INTRODUCTION AND AIMS

Cleaning needles/syringes is an important second-line harm reduction strategy, yet there is limited information on practices employed by people who inject drugs in Australia. This study attempts to identify and assess cleaning practices in terms of the techniques involved and the social contexts in which cleaning takes place.

DESIGN AND METHODS

As part of an exploratory qualitative study in south-west Sydney, in-depth interviews and simulated cleaning exercises were conducted with 12 people who inject drugs. Interviews were digitally recorded and transcribed verbatim. Open coding was used to inductively classify data into themes, and data were examined for patterns and variations in the relationships within and between themes.

RESULTS

Data indicate that cleaning and reuse of needles/syringes was common in this small sample. The most frequently utilised reagent was cool water. While all participants reported cleaning and reusing only their own equipment, none of the techniques demonstrated would have been sufficient to deactivate human immunodeficiency virus or hepatitis C virus.

DISCUSSION AND CONCLUSIONS

Results suggest that even where cleaning of needles and syringes is widespread, people who inject drugs may not engage in efficacious cleaning. The combination of the complexity of current cleaning messages and a lack of accurate information about efficacious techniques are likely to contribute to poor cleaning practice. Australia could benefit from the development of a nationally consistent cleaning message; however, the evidence would suggest that this would need to be accompanied by strategies designed to simplify and disseminate this information in order to increase the uptake of efficacious cleaning methods by people who inject drugs.

Thermal stability and inactivation of hepatitis C virus grown in cell culture

Background

Hepatitis C virus (HCV) is a blood-borne flavivirus that infects many millions of people worldwide. Relatively little is known, however, concerning the stability of HCV and reliable procedures for inactivating this virus.

Methods

In the current study, the thermostability of cell culture-derived HCV (HCVcc, JFH-1 strain) under different environmental temperatures (37°C, room temperature, and 4°C) and the ability of heat, UVC light irradiation, and aldehyde and detergent treatments to inactivate HCVcc were evaluated. The infectious titers of treated viral samples were determined by focus-forming unit (FFU) assay using an indirect immunofluorescence assay for HCV NS3 in hepatoma Huh7-25-CD81 cells highly permissive for HCVcc infection. MTT cytotoxicity assay was performed to determine the concentrations of aldehydes or detergents at which they were no longer cytotoxic.

Results

HCVcc in culture medium was found to survive 37°C and room temperature (RT, 25 ± 2°C) for 2 and 16 days, respectively, while the virus was relatively stable at 4°C without drastic loss of infectivity for at least 6 weeks. HCVcc in culture medium was sensitive to heat and could be inactivated in 8 and 4 min when incubated at 60°C and 65°C, respectively. However, at 56°C, 40 min were required to eliminate HCVcc infectivity. Addition of normal human serum to HCVcc did not significantly alter viral stability at RT or its susceptibility to heat. UVC light irradiation (wavelength = 253.7 nm) with an intensity of 450 μW/cm² efficiently inactivated HCVcc within 2 min. Exposures to formaldehyde, glutaraldehyde, ionic or nonionic detergents all destroyed HCVcc infectivity effectively, regardless of whether the treatments were conducted in the presence of cell culture medium or human serum.

Conclusions

The results provide quantitative evidence for the potential use of a variety of approaches for inactivating HCV. The ability of HCVcc to survive ambient temperatures warrants precautions in handling and disposing of objects and materials that may have been contaminated with HCV.

Occupational exposure of health care personnel to hepatitis B and hepatitis C: prevention and surveillance strategies

Ensuring the safety of personnel working in health care environments can be challenging and requires a multifaceted approach to target reductions in occupational exposures to blood-borne pathogens, such as hepatitis B or hepatitis C. This article reviews the epidemiology of occupational exposures to hepatitis B and hepatitis C in health care personnel in hospital settings. The nature and likelihood of risk to health care personnel are evaluated along with estimates of seroconversion risk. The review focuses on prevention programs and available surveillance programs to aid in monitoring and reducing occupational exposures to blood-borne pathogens.

Possible risks of transmission of bloodborne infection via acupuncture needles in Guizhou province, southwest China

BACKGROUND

Acupuncture is in widespread use in China, a country where the prevalence of infection with hepatitis B (HBV) is high and that of other bloodborne viruses is growing. Policies to reduce iatrogenic transmission have so far focused on injections, overlooking the risks connected with acupuncture.

OBJECTIVE

To assess knowledge, attitudes, and practice relevant to the potential iatrogenic transmission of bloodborne viruses in Guizhou province, southwest China.

MATERIALS AND METHODS

Semi-structured interviews and focus groups were conducted (in 2005) with 80 health care workers, patients, and other key informants in health facilities at provincial, county, and village levels.

RESULTS

In village clinics, reusable acupuncture needles were disinfected with alcohol rather than being sterilized, because of concerns that sterilization might blunt the needles. Sterilization of equipment by acupuncturists in the informal sector may be inadequate, but official monitoring of their practice appears not to be taking place. Acupuncturists working in hospitals are not included in formal training on bloodborne diseases and do not routinely receive HBV immunization. Some health workers lack clear understanding of asymptomatic infections.

CONCLUSION

Policy on iatrogenic transmission of bloodborne viruses in China needs to place a greater emphasis on safe acupuncture, taking account of prevailing beliefs that may lead to hazardous practices, while enforcing safe procedures.

Molecular and contextual markers of hepatitis C virus and drug abuse

The spread of hepatitis C virus (HCV) infection involves a complex interplay of social risks, and molecular factors of both virus and host. Injection drug abuse is the most powerful risk factor for HCV infection, followed by sexual transmission and additional non-injection drug abuse factors such as co-infection with other viruses and barriers to treatment. It is clearly important to understand the wider context in which the factors related to HCV infection occur. This understanding is required for a comprehensive approach leading to the successful prevention, diagnosis, and treatment of HCV. An additional consideration is that current treatments and advanced molecular methods are generally unavailable to socially disadvantaged patients. Thus, the recognition of behavioral/social, viral, and host factors as components of an integrated approach to HCV is important to help this vulnerable group. Equally important, this approach is key to the development of personalized patient treatment - a significant goal in global healthcare. In this review, we discuss recent findings concerning the impact of drug abuse, epidemiology, social behavior, virology, immunopathology, and genetics on HCV infection and the course of disease.

Virucidal activity of ortho-phthalaldehyde solutions against hepatitis B and C viruses

Ortho-phthalaldehyde (OPA), a high-level disinfectant alternative to glutaraldehyde, was tested for efficacy against human hepatitis B virus (HBV) and hepatitis C virus (HCV) using surrogate animal viruses. HBV and HCV are the most prevalent human bloodborne viruses but have not yet been propagated in the laboratory. The surrogate viruses, duck hepatitis B virus (DHBV) and bovine viral diarrhea virus (BVDV), were used to assess the virucidal efficacy of OPA on HBV and HCV, respectively. After a timed exposure to the test disinfectant, the surrogate virus dried on a hard surface was neutralized and assayed to detect viable viruses using appropriate cell lines. A greater than 4-log(10) reduction in virus titer was demonstrated using dilute OPA solutions against dried DHBV and BVDV after 5 minutes of exposure at 20 degrees C. OPA was shown to be efficacious against surrogate viruses for human hepatitis B and hepatitis C virus. This is the first time that OPA efficacy has been demonstrated for HBV and HCV.

Microbiologic profile of flexible endoscope disinfection in two Brazilian hospitals

BACKGROUND

[corrected] Endoscopes are routinely used in hospitals and clinics of the world and they can be potential sources of cross-infection when the decontamination process is unsuitable

AIM

The routines of flexible endoscope (bronchoscopes, esophagogastroduodenoscopes and colonoscopes) disinfection procedures used in two Brazilian university hospitals were evaluated during a 3-year period

METHODS

Aleatory samples from internal channels of endoscopes were collected after patient examination and after cleaning/disinfection procedures

RESULTS

A contamination >3 log10 was achieved in samples recovered from endoscopes after patient examination. These samples yielded gram-negative bacilli (n = 142: 56%), gram-positive cocci (n = 43: 17%), yeast cells (n = 43: 17%), and gram-positive bacilli (n = 26: 10%). Approximately, 72 out of 149 samples (48.32%) collected after undergoing the cleaning and disinfection procedures disclosed gram-negative bacilli (n = 55: 61%), gram-positive cocci (n = 21: 23%), gram-positive bacilli (n = 8: 9%) and yeast cells (n = 6: 7%). Esophagogastroduodenoscopes and colonoscopes were the most frequently contaminated devices. Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterobacter spp, Serratia marcescens, Proteus mirabilis, Citrobacter freundii, Staphylococcus aureus, Staphylococcus coagulase negative, Micrococcus luteus, Candida albicans, C. tropicalis, C. glabrata, C. guilliermondii, Bacillus spp and Corynebacterium spp were predominantly identified

CONCLUSION

Inappropriate cleaning and low times of disinfection were respectively the major factors associated with the presence of microorganisms in colonoscopes and esophagogastroduodenoscopes. By analyzing the identified germs, hospital disinfection was considered of either intermediate or poor level. After this investigation, both university centers improved their previous protocols for disinfection and conditions for reprocessing endoscopes.

Suitability of vaccinia virus and bovine viral diarrhea virus (BVDV) for determining activities of three commonly-used alcohol-based hand rubs against enveloped viruses

BACKGROUND

A procedure for including activity against enveloped viruses in the post-contamination treatment of hands has been recommended, but so far no European standard is available to implement it. In 2004, the German Robert Koch-Institute (RKI) and the German Association for the Control of Virus Disease (DVV) suggested that vaccinia virus and bovine viral diarrhea virus (BVDV) should be used as test viruses in a quantitative suspension test to determine the activity of a disinfectant against all enveloped viruses.

METHODS

We have studied the activities of three commonly-used alcohol-based hand rubs (hand rub A, based on 45% propan-2-ol, 30% propan-1-ol and 0.2% mecetronium etilsulfate; hand rub B, based on 80% ethanol; hand rub C, based on 95% ethanol) against vaccinia virus and BVDV, and in addition against four other clinically relevant enveloped viruses: herpes simplex virus (HSV) types 1 and 2, and human and avian influenza A virus. The hand rubs were challenged with different organic loads at exposure time of 15, 30 and 60 s. According to the guidelines of both BGA/RKI and DVV, and EN 14476:2005, the reduction of infectivity of each test virus was measured on appropriate cell lines using a quantitative suspension test.

RESULTS

All three alcohol-based hand rubs reduced the infectivity of vaccinia virus and BVDV by > or = 4 log10-steps within 15 s, irrespective of the type of organic load. Similar reductions of infectivity were seen against the other four enveloped viruses within 15 s in the presence of different types of organic load.

CONCLUSION

Commonly used alcohol-based hand rubs with a total alcohol concentration > or = 75% can be assumed to be active against clinically relevant enveloped viruses if they effectively reduce the infectivities of vaccinia virus and BVDV in a quantitative suspension test.

Validation of biocides against duck hepatitis B virus as a surrogate virus for human hepatitis B virus

The use of a surrogate virus, namely duck hepatitis B virus (DHBV), has been recommended for testing the virucidal activity of chemical biocides against hepatitis B virus. To date, however, this model has not been recognized as a standard test in European countries, as its laboratory use is associated with considerable difficulties. As previous studies have demonstrated, several alternative procedures may improve the validation of DHBV infection in a cell culture system. Using indirect immunofluorescent antigen staining and the light cycler real-time polymerase chain reaction (PCR) technique, the virucidal activity of peracetic acid (PAA), povidone-iodine (PVP-I) and formaldehyde was tested against DHBV obtained from congenitally infected ducks or prepared from the transfected hepatoma D2 cell line. The results demonstrated that inactivation of DHBV from the D2 cell line was achieved with lower concentrations of the biocides and within shorter exposure time intervals. These lower concentration-exposure time values for DHBV from D2 cells in comparison with DHBV from infected ducks indicated a higher sensitivity of the virus derived from D2 cells. In addition, concentrations of PAA and PVP-I that significantly inactivated DHBV in suspension tests were not able to destroy the viral genome. In conclusion, DHBV from congenitally infected ducks should be used for virucidal testing of chemical biocides against DHBV; DHBV prepared from D2 cells is unsuitable due to its higher sensitivity to biocides. Indirect immunofluorescent staining allows reliable detection of DHBV infectivity, whereas the hepadnavirucidal effect can be evaluated by quantitative PCR.

Hand hygiene: an evidence-based review for surgeons

This review of the literature discusses the scientific evidence behind using different hand hygiene agents on the surgical ward, and in theatre for preoperative disinfection. It considers the mechanism of action of the agents and their effectiveness against different pathogens, as well as possible future agents, and how they are tested. It addresses problems such as the poor compliance with hand hygiene guidelines by healthcare workers (especially doctors) and investigates what can be done to improve compliance. Finally, it demonstrates the reduction in hospital acquired infection (HAI) rate that can be achieved by improving hand hygiene compliance, and shows that the savings associated with this easily outweigh the cost.

Microbicides and the environmental control of nosocomial viral infections

Viruses are important causes of acute and chronic diseases in humans. Newer viruses are still being discovered and those that are already known are being incriminated in the aetiology of clinical conditions with hitherto unknown causes. Apart from frequently causing infections in the general community, many types of viruses are also significant nosocomial pathogens. While it is generally agreed that we underestimate the proportion of nosocomial infections that are viral, due to a lack of routine monitoring, viruses easily account for more than 30% of the cases of hospital-acquired infections in many paediatric settings. Indeed, the relative importance of viruses in this respect is increasing due to a number of societal and demographic changes as well as alterations in healthcare practices. Safe vaccines against many common nosocomial viral agents are currently unavailable while there is also a virtual lack of effective and affordable chemotherapy against them. There is, therefore, renewed emphasis on preventive strategies by better understanding of the relative importance of various vehicles in the nosocomial spread of viruses and by infection control using microbicides. This, in turn, has stimulated considerable interest in the development of formulations that are not only safer but which also have demonstrated activity against major types of nosocomial viral pathogens. Further, much work is now underway to design better methods to assess the virucidal activity of microbicides used to decontaminate hands, reusable medical devices and environmental surfaces in critical areas of healthcare settings. It is anticipated that these approaches will result in reducing the health and economic impact of nosocomial infections due to viruses.

Viral hepatitis transmission in ambulatory health care settings

In the United States, transmission of viral hepatitis from health care-related exposures is uncommon and primarily recognized in the context of outbreaks. Transmission is typically associated with unsafe injection practices, as exemplified by several recent outbreaks that occurred in ambulatory health care settings. To prevent transmission of bloodborne pathogens, health care workers must adhere to standard precautions and follow fundamental infection-control principles, including safe injection practices and appropriate aseptic techniques. These principles and practices need to be made explicit in institutional policies and reinforced through in-service education for all personnel involved in direct patient care, including those in ambulatory care settings. The effectiveness of these measures should be monitored as part of the oversight process. In addition, prompt reporting of suspected health care-related cases coupled with appropriate investigation and improved monitoring of surveillance data are needed to accurately characterize and prevent health care-related transmission of viral hepatitis.

Nosocomial outbreak of norovirus gastroenteritis and investigation of ABO histo-blood group type in infected staff and patients

The blood groups were analysed of staff and patients (N=45) infected during two nosocomial outbreaks of norovirus gastroenteritis at a German University hospital. Persons with O phenotype were significantly less affected than was expected from the normal distribution of blood group types in Southwest Germany (OR 2.45; 95% CI 1.22-4.95; P=0.01).

Calcium hypochlorite as a disinfecting additive for dental stone

STATEMENT OF PROBLEM

Dental casts come into direct contact with impression materials and other items that are contaminated by saliva and blood from a patient's mouth, leaving the casts susceptible to cross-contamination. Topical methods of disinfecting casts are difficult to control, while immersion methods are potentially destructive. Thus, an additional method to control cross-contamination between patients and laboratory personnel is needed.

PURPOSE

This study was undertaken in an attempt to develop a dental stone with disinfecting properties and adequate compressive and tensile strengths.

MATERIAL AND METHODS

Calcium hypochlorite [Ca(OCl)(2)] in aqueous solution in concentrations from 0 to 1.5% was tested as a disinfecting additive to type V dental stone. The compressive and tensile strength properties of the modified stone were measured (MPa) using a universal testing machine at a consistency similar to unmodified stone. Strength data were analyzed by 1-way ANOVA and post hoc Tukey-Kramer procedure (alpha < or =.05). To measure the disinfecting ability, the effect on Bacillis subtilis bacteriophage phi29 was tested in triplicate to find the minimum concentration at which no phage was detected. Additionally, 3 impressions were disinfected with CaviCide, and 3 impressions rinsed in water served as controls.

RESULTS

In general, the effect of adding the disinfectant to the stone was a decrease in strength. Exceptions were the dry compressive strength, for which there was a significant increase in strength (P=.048) at 0.5%, and the wet compressive and wet tensile strength, which showed no significant difference between the 1.5% and the control. When Ca(OCl)(2) was added at the concentration 0.5% (2765 ppm available chlorine), the gypsum had acceptable mechanical properties; dry compressive strength was 78.86 +/- 4.12 MPa, and dry tensile strength was 10.64 +/- 1.27 MPa, compared to control values of 67.85 +/- 6.28 and 13.41 +/- 1.24 MPa, respectively. At concentrations of 0.3% and higher (36 1650 ppm of available chlorine), calcium hypochlorite was able to completely inactivate phi29.

CONCLUSION

It is possible to prepare a type V dental stone that contains a disinfectant, has adequate mechanical properties, and will reduce numbers of residual microorganisms. For example, stone mixed with water containing 0.5% Ca(OCl)(2) meets these criteria.

Traditional versus new needle retractable i.v. catheters in children: are they really safer, and whom are they protecting?

Retractable needle IV catheters are designed to reduce needle-stick injuries; their use is mandated by federal regulations. We undertook a prospective data collection with the "traditional" IV catheters (JELCO) versus the "new" (Angiocath Autoguard). Assignment of catheter type was randomized by week. Data collected included assessment of the difficulty of i.v. access; number of catheters used; and splatters or spills of blood on skin, linen, floor, clothing, and operating room table. There were 473 attempted insertions in 330 patients over 20 days. No needle-stick injuries occurred. Seventy-seven blood spills or splatters occurred in 42 patients. The number of splatters or spills was four times more with the new compared with the traditional catheters. There were significantly more total splatters or spills and patients who experienced splatters or spills with new catheters when they were placed by attendings but not when placed by trainees. Our study suggests that use of this technology by more experienced anesthesiologists may increase the risk of exposure of health care providers to blood-borne pathogens. Practitioners should choose the i.v. system that allows the most efficient venous access with the least potential for blood contamination. Hospitals should allow the choice to be made by the individuals using the devices.

Guideline for Hand Hygiene in Health-Care Settings. Recommendations of the Healthcare Infection Control Practices Advisory Committee and the HIPAC/SHEA/APIC/IDSA Hand Hygiene Task Force

The Guideline for Hand Hygiene in Health-Care Settings provides health-care workers (HCWs) with a review of data regarding handwashing and hand antisepsis in health-care settings. In addition, it provides specific recommendations to promote improved hand-hygiene practices and reduce transmission of pathogenic microorganisms to patients and personnel in health-care settings. This report reviews studies published since the 1985 CDC guideline (Garner JS, Favero MS. CDC guideline for handwashing and hospital environmental control, 1985. Infect Control 1986;7:231-43) and the 1995 APIC guideline (Larson EL, APIC Guidelines Committee. APIC guideline for handwashing and hand antisepsis in health care settings. Am J Infect Control 1995;23:251-69) were issued and provides an in-depth review of hand-hygiene practices of HCWs, levels of adherence of personnel to recommended handwashing practices, and factors adversely affecting adherence. New studies of the in vivo efficacy of alcohol-based hand rubs and the low incidence of dermatitis associated with their use are reviewed. Recent studies demonstrating the value of multidisciplinary hand-hygiene promotion programs and the potential role of alcohol-based hand rubs in improving hand-hygiene practices are summarized. Recommendations concerning related issues (e.g., the use of surgical hand antiseptics, hand lotions or creams, and wearing of artificial fingernails) are also included.

Guideline for Hand Hygiene in Health-Care Settings: recommendations of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force

The Guideline for Hand Hygiene in Health-Care Settings provides health-care workers (HCWs) with a review of data regarding handwashing and hand antisepsis in health-care settings. In addition, it provides specific recommendations to promote improved hand-hygiene practices and reduce transmission of pathogenic microorganisms to patients and personnel in health-care settings. This report reviews studies published since the 1985 CDC guideline (Garner JS, Favero MS. CDC guideline for handwashing and hospital environmental control, 1985. Infect Control 1986;7:231-43) and the 1995 APIC guideline (Larson EL, APIC Guidelines Committee. APIC guideline for handwashing and hand antisepsis in health care settings. Am J Infect Control 1995;23:251-69) were issued and provides an in-depth review of hand-hygiene practices of HCWs, levels of adherence of personnel to recommended handwashing practices, and factors adversely affecting adherence. New studies of the in vivo efficacy of alcohol-based hand rubs and the low incidence of dermatitis associated with their use are reviewed. Recent studies demonstrating the value of multidisciplinary hand-hygiene promotion programs and the potential role of alcohol-based hand rubs in improving hand-hygiene practices are summarized. Recommendations concerning related issues (e.g., the use of surgical hand antiseptics, hand lotions or creams, and wearing of artificial fingernails) are also included.

Hygienic hand antiseptics: should they not have activity and label claims against viruses?

Enteric and respiratory viruses are among the most frequent causes of human infections, and hands play an important role in the spread of these and many other viral diseases. Regular and proper hand hygiene by caregivers and food handlers in particular is essential to decontaminate hands and potentially interrupt such spread. What would be considered a proper decontamination of hands? Handwashing with regular soap and water is often considered sufficient, but what of hygienic handwash and handrub antiseptic products? Are they more effective? The evidence suggests that some clearly are. Activity against bacteria may not reflect the ability of hygienic hand antiseptics to deal with viruses, especially those that are nonenveloped. In spite of the acknowledged importance of hands as vehicles for viruses, there is a lack of suitable regulatory mechanism for handwash or handrub products to make claims of efficacy against viruses. This is in contrast with the ability of general-purpose disinfectants to make antiviral claims, although transmission of viruses from surfaces other than those of reusable medical devices may play only a minor role in virus transmission. This review discusses the (1). recent information on the relative importance of viruses as human pathogens, particularly those causing enteric and respiratory infections; (2). the survival of relevant viruses on human hands in comparison with common gram-negative and gram-positive bacteria; (3). the potential of hands to transfer or receive such contamination on casual contact; (4). role of hands in the spread of viruses; (5). the potential of hygienic measures to eliminate viruses from contaminated hands; (6). relative merits of available protocols to assess the activity of hygienic hand antiseptics against viruses; and (7). factors considered crucial in any tests to assess the activity of hygienic hand antiseptics against viruses. In addition, this review proposes surrogate viruses in such testing and discusses issues for additional consideration by researchers, manufacturers, end-users, and regulators.

Hepatitis C and the skin

Hepatitis C is an important and common cause of chronic hepatitis and cirrhosis. Cutaneous manifestations are often the first signs of infection. Dermatologists must be aware of these manifestations, because early diagnosis is the best treatment. HCV Ab by ELISA should be ordered in patients with LCV-urticarial vasculitis, cryoglobulinemia, lichen planus, Sjögren's syndrome, unexplained pruritus, PCT, PAN, chronic urticaria, patients starting methotrexate, unexplained pruritus, and any patient initiating therapy with a potentially hepatotoxic drug.