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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Increased concern over the transmission of acquired immunodeficiency syndrome, hepatitis B, herpes, and other diseases has prompted research into the disinfection of dental impressions. Among the factors to be considered when dental impressions are disinfected is the stability of the disinfectant solutions during storage and use. This study is concerned with the effect on disinfectant solutions of repeated immersion of alginate dental impressions taken in metal trays. The effects of the impression materials, metal trays, and dilution were evaluated, and the impact of light, heat, and storage were also addressed. The findings indicated that in the test solutions, although considerable chlorine was consumed during the disinfection procedures, bactericidal activity was maintained, while in the control solution both chlorine content and bactericidal activity were remarkably stable.
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PMID:Factors affecting the stability of sodium hypochlorite solutions used to disinfect dental impressions. 188 53

The effects of heat, sodium hypochlorite, diethyl ether, and ethyl alcohol on the activity of DNA polymerase (DNA-P) associated with hepatitis B virsus (HBV) in serum were evaluated. The response of DNA-P to heating at 60 degrees C for 15, 30, 45, 60, 90, 120, 180, and 240 minutes was studied and the data suggested that there may be two types of DNA-P. The majority of DNA-P was type 'a', and it showed a one log reduction (D60) at 60 degrees C in 36 minutes, while the remaining activity was type 'b' that showed a one log reduction (D60) in 340 minutes. Treatment of DNA-P with sodium hypochlorite at concentrations of 250 and 500 parts per million (ppm) of available chlorine resulted in a 20 to 25% reduction in DNA-P activity within one minute. Complete loss in detectable DNA-P activity occurred within one minute when available Cl- was 2500 ppm or greater. Various concentrations of ethyl alcohol (ranging from 10 to 70%) caused gradually increasing inactivation of DNA-P activity in ten minutes at 4 degrees C. Ninety percent inactivation occurred with 60% alcohol. Overnight treatment of DNA-P-reactive material with diethyl ether at 4 degrees C led to loss of detectable activity. A reduction in the titer of HBsAg was found following treatment with alcohol or ether. The possible use of DNA-P assay as an indicator of the rate of inactivation of HBV is proposed.
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PMID:Inactivation of DNA-polymerase associated with hepatitis B virus. 714 78

Sodium hypochlorite (NaOCl) was examined as an effective disinfectant in hepatitis laboratories. Concentrations of NaOCl containing 5,600 ppm (5,600 microgram/ml) of available chlorine were found to be effective in destroying the antigenicity of hepatitis B surface antigen (HBsAg) in virion-rich plasma after an exposure time of 1 min or more. In the treatment of protein-deficient solutions containing HBsAg, smaller concentrations of available chlorine (less than 500 pm) are equally effective. Neither 17-to 25-nm HBsAg particles nor 45-nm virion particles could be detected by electron microscopy after treatment. chemical interaction of protein and NaOCl was confirmed by isoelectrofocusing of 125I-labeled HBsAg. More than 90% of the labeled material was found at pH 3.0 or lower, indicating complete antigen oxidation. Labeled HBsAg was reduced in density from 1.21 g/cm3 in CsCl to approximately 1.07 g/cm3 after treatment with NaOCl. Both hepatitis B core antigen and deoxyribonucleic acid polymerase activity were significantly reduced after interaction with hypochlorite solutions. These results show that NaOCl destroys hepatitis B antigenicity and virus structures and therefore may be utilized as a disinfectant for the virus.
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PMID:Immunological and biophysical alteration of hepatitis B virus antigens by sodium hypochlorite disinfection. 731 5

Polymerase chain reaction-ethidium bromide (PCR-EB) method for detecting hepatitis B virus DNA (HBV-DNA) was established with good specificity and a detection limit of 1 pg HBV-DNA, minimum HBV infection dose in susceptible animal, chimpanzees, could be detected with it. Determination of inactivation of HBV-DNA could be inactivated with active chlorine 1,250 mg/L for 60 minutes, or 2,500 mg/L for 30 minutes, 10 pg HBV-DNA in purified Dane particles could be inactivated by active chlorine 625 mg/L for 10 minutes. Accordingly, use of PCR to evaluate the effects of chlorine disinfectant in inactivating HBV was feasible, and HBV-DNA was a more reliable index for inactivation of HBV than HBsAg.
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PMID:[Studies on inactivation of hepatitis B virus with polymerase chain reaction]. 764 53

The susceptibility of duck hepatitis B virus (DHBV) to the virucidal effects of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) was compared to hepatitis B virus (HBV) with the aim of using the duck as a model for studying HBV disinfection. Using viral DNA polymerase (DNAP) as a target, inhibition of DNAP activity by chlorine disinfectants was found to be concentration-dependent but independent of contact time. Two minute exposure of minimal effective concentrations of sodium hypochlorite (domestic bleach: 3600 ppm and industrial bleach: 3180 ppm) and sodium dichloroisocyanurate (3000 ppm available chlorine) to DHBV- and HBV-rich plasma totally inhibited DNA polymerase activity. DHBV particles in DHBV-carrier duck plasma (10(4.5) ID50/mL) were treated with these concentrations and inoculated intravenously into 18 one-day old ducklings (six animals/disinfectant). Analysis of plasma (0, 7 and 14 days post-infection) and post-mortem liver (14 days post-infection) by DNA hybridization techniques showed that DHBV DNA was undetectable in samples from all animals inoculated with disinfected virus particles. However, post-inoculation plasma and liver of 18 of 18 control ducklings inoculated with untreated virions were positive for DHBV DNA. These results show for the first time that total inhibition in vitro of hepadnavirus DNA polymerase activity by chemical disinfectants is predictive of inactivation of infectivity in vivo.
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PMID:Chemical disinfection of duck hepatitis B virus: a model for inactivation of infectivity of hepatitis B virus. 822 34

The effects of sodium dichloroisocyanurate (NaDCC) and Solprogel (Laboratorios Inibsa, S.A., Barcelona, Spain), a compound that contains NaDCC plus a biodegradable polymer of acrylic acid, on the activity of DNA polymerase (DNA-P) associated with hepatitis B virus in serum were evaluated. DNA-P positive and negative pools of human serum samples were used as positive and negative stock virus. Inhibition of DNA-P activity by NaDCC and the commercial product was found to be concentration-dependent. Two minutes exposure to the minimum effective concentration of NaDCC (1000 ppm available chlorine) or Solprogel 16% (960 ppm available chlorine) totally inhibited DNA-P activity.
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PMID:Inactivation of hepatitis B virus: evaluation of the efficacy of the disinfectant 'Solprogel' using a DNA-polymerase activity assay. 926 60

Two per cent glutaraldehyde is the most commonly used disinfectant in endoscopy units within the UK. Unfortunately adverse reactions to glutaraldehyde are common among endoscopy personnel and the Health and Safety Commission has recommended substantial reductions in atmospheric levels of glutaraldehyde in order to comply with the Control of Substances Hazardous to Health Regulations, 1994. The Working Party addressed ways of eliminating or minimising exposure to glutaraldehyde in endoscopy units by reviewing alternative disinfectants and the use of automated washer/disinfectors. Alternatives to glutaraldehyde must be at least as microbicidal as glutaraldehyde, non-irritating and compatible with endoscope components and decontamination equipment. Peracetic acid is a highly effective disinfectant and may be a suitable alternative to glutaraldehyde. Peracetic acid has a vinegary-like odour and is claimed to be less irritating than glutaraldehyde. Experience with this agent remains relatively limited and the Working Party recommends that peracetic acid should be used in sealed or exhaust ventilated facilities until further experience is obtained. It is considerably more expensive than glutaraldehyde, is less stable and large volumes have to be stored. It causes cosmetic (but not functional) damage to endoscopes and is not compatible with some washer/ disinfectors. Chlorine dioxide is a powerful oxidising agent and highly effective as a disinfectant. Once activated it must be stored in sealed containers with little head space. Fumes cause irritation and sealed or exhaust ventilated facilities are necessary. The agent may damage some metallic and polymer components of endoscopes and automated washer/disinfectors and compatibility should be established with equipment manufacturers before the agent is used. Other disinfectants such as peroxygen compounds and quaternary ammonium derivatives are less suitable because of unsatisfactory mycobactericidal and/or virucidal activity, or incompatibility with endoscopes and automated washer/disinfectors. Alcohol is effective but, on prolonged contact, is damaging to lens cements. It is also flammable and therefore unsuitable for use in large quantities in automated systems. Superoxidised water (Sterilox) is an electrochemical solution (anolyte) containing a mixture of radicals with strong oxidising properties. It is highly microbicidal when freshly generated, provided items are thoroughly clean and strict generation criteria are met--that is, current, pH, redox potential. It seems to be safe for users and provided field trials substantiate laboratory efficacy tests, and the agent is non-damaging, it too may become an alternative to glutaraldehyde. When 2% glutaraldehyde is used for manual and automated disinfection, 10 minutes' immersion is recommended for endoscopes before the session and between patients. This will destroy vegetative bacteria and viruses (including hepatitis B virus (HBV) and HIV). A five minute contact period is recommended for 0.35% peracetic acid and for chlorine dioxide (1100 ppm av ClO2), but if immersed for 10 minutes sporicidal activity will also be achieved. At the end of each session 20 minutes' immersion in glutaraldehyde or five minutes in peracetic acid or chlorine dioxide is recommended. Microbiological studies show that 20 minutes of exposure to 2% glutaraldehyde destroys most organisms, including Mycobacterium tuberculosis. The Working Party concludes therefore that immersion of the endoscope in 2% glutaraldehyde for 20 minutes is sufficient for endoscopy involving patients with AIDS and other immunodeficiency states or pulmonary tuberculosis. Similarly, 20 minutes' immersion is recommended at the start of the list and between cases for endoscopic retrograde cholangiopancreatography (ERCP) when high level disinfection is required. Cleaning and disinfection of endoscopes should be undertaken by trained staff in a dedicated room. Thorough cleaning with detergent
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PMID:Cleaning and disinfection of equipment for gastrointestinal endoscopy. Report of a Working Party of the British Society of Gastroenterology Endoscopy Committee. 961 26

Electrolyzed products of sodium chloride solution were examined for their disinfection potential against hepatitis B virus (HBV) and human immunodeficiency virus (HIV) in vitro. Electrolysis of 0.05% NaCl in tap water was carried out for 45 min at room temperature using a 3 A electric current in separate wells installed with positive and negative electrodes. The electrolyzed products were obtained from the positive well. The oxidation reduction potential (ORP), pH and free chlorine content of the product were 1053 mV, pH 2.34 and 4.20 ppm, respectively. The products modified the antigenicity of the surface protein of HBV as well as the infectivity of HIV in time- and concentration-dependent manner. Although the inactivating potential was decreased by the addition of contaminating protein, recycling of the product or continuous addition of fresh product may restore the complete disinfection against bloodborne pathogens.
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PMID:Disinfection potential of electrolyzed solutions containing sodium chloride at low concentrations. 1071 49

(1) Infections following invasive endoscopy are rare and are usually of endogenous origin. Nevertheless, infections do occur due to inadequate cleaning and disinfection and the use of contaminated rinse water and processing equipment. (2) Rigid and flexible operative endoscopes and accessories should be thoroughly cleaned and preferably sterilized using properly validated processes. (3) Heat tolerant operative endoscopes and accessories should be sterilized using a vacuum assisted steam sterilizer. Use autoclavable instrument trays or containers to protect equipment during transit and processing. Small bench top sterilizers without vacuum assisted air removal are unsuitable for packaged and lumened devices. (4) Heat sensitive rigid and flexible endoscopes and accessories should preferably be sterilized using ethylene oxide, low temperature steam and formaldehyde (rigid only) or gas plasma (if appropriate). (5) If there are insufficient instruments or time to sterilize invasive endoscopes, or if no suitable method is available locally, they may be disinfected by immersion in 2% glutaraldehyde or a suitable alternative. An immersion time of at least 10 min should be adopted for glutaraldehyde. This is sufficient to inactivate most vegetative bacteria and viruses including HIV and hepatitis B virus (HBV). Longer contact times of 20 min or more may be necessary if a mycobacterial infection is known or suspected. At least 3 h immersion in glutaraldehyde is required to kill spores. (6) Glutaraldehyde is irritant and sensitizing to the skin, eyes and respiratory tract. Measures must be taken to ensure glutaraldehyde is used in a safe manner, i.e., total containment and/or extraction of harmful vapour and the provision of suitable personal protective equipment, i.e., gloves, apron and eye protection if splashing could occur. Health surveillance of staff is recommended and should include a pre-employment enquiry regarding asthma, skin and mucosal sensitivity problems and lung function testing by spirometry. (7) Possible alternative disinfectants to glutaraldehyde include peracetic acid (0.2-0.35%), chlorine dioxide (700-1100 ppm) and superoxidized water. These are very effective, killing vegetative bacteria, including mycobacteria, and viruses in 5 min and bacterial spores in 10 min. An endorsement of compatibility with endoscopes, accessories and processing equipment is required from both the solution/device manufacturer and the endoscope manufacturer. Other important considerations are stability, cost and safety from the user and environmental standpoints. (8) Cleaning and disinfection or sterilization should be undertaken by trained staff in a dedicated area, e.g., SSD or TSSU. A suitable training programme is described. (9) If endoscopes are processed by immersion in disinfectants, harmful residues must be removed by thorough rinsing. Sterile or bacteria free water is essential for rinsing all invasive endoscopes and accessories to prevent recontamination. (10) If an automated washer disinfector is used it must be effective, non-damaging, reliable, easy to use and its performance regularly monitored. (11) If used, washer disinfectors and other processing equipment should be disinfected on a regular basis, i.e., between patients or at the start of each session. This will prevent biofilm formation and recontamination of instruments during rinsing. Disinfection should include the water treatment system, if present. (12) To comply with the Medical Devices Directive, manufacturers are obliged to provide full details on how to decontaminate the reusable devices they supply. This should include details of compatibility with heat, pressure, moisture, processing chemicals and ultrasonics. (13) The Infection Control Team should always be involved in the formulation and implementation of decontamination policies. Wherever possible, the national good practice guidelines produced by the Medical Devices Agency and/or professional societies shoul
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PMID:Decontamination of minimally invasive surgical endoscopes and accessories. 1143 15

Because of the difficulties of the chimpanzee model and the genetic differences using the duck model, we developed a cell culture method to measure human hepatitis B virus (HBV) inactivation in vitro. Pooled HBV-infected human plasma that had been exposed to a disinfectant was left in contact for three days with a cell culture of the human hepatoma cell line, HepG2, with 4% polyethyleneglycol and 3 mM sodium butyrate. The mean log10 of the viral titre of unexposed plasma was 4.87 infectious units per mL. Our results showed that 1% glutaraldehyde, sodium hypochlorite at 4700 ppm free chlorine and an iodophor-detergent disinfectant containing 3.6% povidone-iodine reduced viral titres by factors exceeding 10(3)-10(4). However, sodium hypochlorite at 1000 ppm free chlorine had minimal activity and povidone-iodine at 9, 5 and 3.6% had no measurable activity (less than 10-fold reduction). This is the first study using a cell culture model to assess disinfectant activity against HBV. It demonstrates more rapidly than the chimpanzee model that glutaraldehyde and sodium hypochlorite, using standard concentrations and exposure times compatible with clinical practice, were highly active against HBV. However, unexpectedly for an enveloped virus, we found no antiviral activity for iodine in the absence of detergent.
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PMID:Inactivation of hepatitis B virus in plasma by hospital in-use chemical disinfectants assessed by a modified HepG2 cell culture. 1128 71


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