sodium-dodecyl-sulfate and Influenza--Human

A randomized field trial was conducted in Tecumseh, Michigan, to test the efficacy of virucidal nasal tissues in interrupting transmission of respiratory agents in the household. In the double-blinded trial, 296 households were stratified by household size and randomly assigned to the group using treated tissues and the group using placebo tissues. Households were recruited in late August to early September 1984, and the tissues were distributed in November 1984. A 10-week influenza A(H3N2) period was identified from January 13 to March 23, 1985, although there was also evidence of rhinovirus circulation during that period. A household-level infection transmission model was used to assess the effectiveness of the virucidal tissue in the household. The model was used to estimate the secondary attack rate for the placebo and treated tissue households during the influenza A(H3N2) period. The efficacy of the treated tissue in interrupting secondary transmission was found to vary from 30.1% to 36.9%, although it could be as high as 39.4% when historical comparisons are used. However, these differences were not statistically significant. In general, the use of virucidal nasal tissue in the household appears to result in the partial interruption of transmission of influenzavirus from an infected household member to another household member during an influenza epidemic.

Topics: Adult; Antisepsis; Antiviral Agents; Citrates; Citric Acid; Disease Outbreaks; Double-Blind Method; Humans; Influenza A virus; Influenza, Human; Malates; Michigan; Paper; Picornaviridae Infections; Random Allocation; Sodium Dodecyl Sulfate

Healthcare workers (HCWs) are at significantly higher risk of exposure to influenza virus during seasonal epidemics and global pandemics. During the 2009 influenza pandemic, some healthcare organizations recommended that HCWs wear respiratory protection such as filtering facepiece respirators, while others indicated that facemasks such as surgical masks (SMs) were sufficient. To assess the level of exposure a HCW may possibly encounter, the aim of this study was to (1.) evaluate if SMs and N95 respirators can serve as "personal bioaerosol samplers" for influenza virus and (2.) determine if SMs and N95 respirators contaminated by influenza laden aerosols can serve as a source of infectious virus for indirect contact transmission. This effort is part of a National Institute for Occupational Safety and Health 5-year multidisciplinary study to determine the routes of influenza transmission in healthcare settings. A coughing simulator was programmed to cough aerosol particles containing influenza virus over a wide concentration range into an aerosol exposure simulation chamber virus/L of exam room air), and a breathing simulator was used to collect virus on either a SM or N95 respirator. Extraction buffers containing nonionic and anionic detergents as well as various protein additives were used to recover influenza virus from the masks and respirators. The inclusion of 0.1% SDS resulted in maximal influenza RNA recovery (41.3%) but with a complete loss of infectivity whereas inclusion of 0.1% bovine serum albumin resulted in reduced RNA recovery (6.8%) but maximal retention of virus infectivity (17.9%). Our results show that a HCW's potential exposure to airborne influenza virus can be assessed in part through analysis of their SMs and N95 respirators, which can effectively serve as personal bioaerosol samplers.

Topics: Aerosols; Animals; Dogs; Health Personnel; Humans; Influenza A virus; Influenza, Human; Madin Darby Canine Kidney Cells; Masks; Occupational Exposure; Particle Size; Respiratory Protective Devices; RNA, Viral; Serum Albumin, Bovine; Sodium Dodecyl Sulfate; Surface-Active Agents

An influenza epidemic is still a problem despite the development of vaccines and anti-influenza drugs. Preventive measures such as handwashing are fundamental and important for counteracting influenza virus infection. In this study, we clarified the anti-influenza virus effects of surfactants, which are the main components of hand soaps for hand washing: potassium oleate (C18:1), sodium laureth sulfate (LES) and sodium lauryl sulfate (SDS). For a human influenza virus strain (H3N2), C18:1 reduced the infectivity by 4 logs or more, whereas LES and SDS reduced the infectivity by 1 log or less. Similar results were obtained when an avian influenza virus strain (H5N3) was used. The interaction between the surfactant and virus was then investigated by isothermal titration calorimetry. The LES-virus system showed a positive value of enthalpy changes (ΔH), meaning an exothermic interaction that indicated a hydrophobic interaction. In contrast, both the C18:1-virus system and the SDS-virus system showed negative values of ΔH, meaning an endothermic interaction that indicated an electrical interaction. The ΔH value of the C18:1-virus system was much higher than that of the SDS-virus system. A mixture of C18:1 and HA proteins similarly showed negative values of ΔH. These results indicate that influenza virus inactivation by a hydrophobic interaction of a surfactant with the viral envelope is insufficient to prevent infection, whereas inactivation by an electrical interaction of a surfactant with HA proteins is sufficient to prevent influenza virus infection.

Topics: Animals; Chick Embryo; Chickens; Dogs; Humans; Influenza A Virus, H3N2 Subtype; Influenza A Virus, H5N8 Subtype; Influenza in Birds; Influenza, Human; Madin Darby Canine Kidney Cells; Oleic Acid; Soaps; Sodium Dodecyl Sulfate; Virus Inactivation