Aerosol-phase activity of iodine captured from a triiodide resin filter on fine particles containing an infectious virus.

AIMS: To avoid interference by water-iodine disinfection chemistry and measure directly the effect of iodine, captured from a triiodide complex bound to a filter medium, on viability of penetrating viral particles. METHODS AND RESULTS: Aerosols of MS2 coli phage were passed through control P100 or iodinated High-Efficiency Particulate Air media, collected in plastic bags, incubated for 0-10 min, collected in an impinger containing thiosulphate to consume all unreacted iodine, plated and enumerated. Comparison of viable counts demonstrated antimicrobial activity with an apparent half-life for devitalization in tens of seconds; rate of kill decreased at low humidity and free iodine was captured by the bags. CONCLUSIONS: The results support the mechanism of near-contact capture earlier proposed; however, the disinfection chemistry in the aerosol phase is very slow on the time scale of inhalation. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that disinfection by filter-bound iodine in the aerosol phase is too slow to be clinically significant in individual respiratory protection, but that it might be of benefit to limit airborne transmission of infections in enclosed areas.

Standard method for deposition of dry, aerosolized, silica-coated Bacillus spores onto inanimate surfaces.

AIMS: To evaluate a standard aerosolization method for uniformly depositing threat-representative spores onto surfaces. METHODS AND RESULTS: Lyophilized Bacillus anthracis ΔSterne spores, coated in silica, were aerosolized into a containment chamber and deposited onto nine surface types by two independent laboratories. Laboratory A produced a mean loading concentration of 1·78 × 10(5) CFU cm(-2) ; coefficient of variation (CV) was <40% for 96% of samples. Laboratory B produced a mean loading concentration of 7·82 × 10(6) CFU cm(-2) ; 68% of samples demonstrated CV <40%. CONCLUSIONS: This method has been shown to meet the goal of loading threat-representative spores onto surfaces with low variability at concentrations relevant to the Department of Defense. SIGNIFICANCE AND IMPACT OF THE STUDY: As demonstrated in 2001, a biological attack using anthrax disseminated as a dry powder is a credible threat. This method will provide a means to load spores onto surfaces that mimic a 'real-world' scenario of an aerosolized anthrax attack. The method has utility for evaluating sporicidal technologies and for nondecontamination studies, for example fate and transport or reaerosolization.

Analysis of residual chemicals on filtering facepiece respirators after decontamination.

The N95 filtering facepiece respirator (FFR) is commonly used to protect individuals from infectious aerosols. Health care experts predict a shortage of N95 FFRs if a severe pandemic occurs, and an option that has been suggested for mitigating such an FFR shortage is to decontaminate and reuse the devices. Before the effectiveness of this strategy can be established, many parameters affecting respiratory protection must be measured: biocidal efficacy of the decontamination treatment, filtration performance, pressure drop, fit, and toxicity to the end user post treatment. This research effort measured the amount of residual chemicals created or deposited on six models of FFRs following treatment by each of 7 simple decontamination technologies. Measured amounts of decontaminants retained by the FFRs treated with chemical disinfectants were small enough that exposure to wearers will be below the permissible exposure limit (PEL). Toxic by-products were also evaluated, and two suspected toxins were detected after ethylene oxide treatment of FFR rubber straps. The results provide encouragement to efforts promoting the evolution of effective strategies for decontamination and reuse of FFRs.

Efficacy of uvulopalatopharyngoplasty in unselected patients with mild obstructive sleep apnea.

OBJECTIVES: Uvulopalatopharyngoplasty (UPPP) is widely used as a first-step procedure for the surgical management of obstructive sleep apnea (OSA) syndrome but best manages obstruction occurring at the level of the oropharynx alone and not the hypopharynx. Previous publications have noted mediocre results with use of this procedure in unselected patients with OSA, but less clear is the effectiveness of this procedure in the unselected patient with mild OSA (respiratory event index [REI] 5-25). Using objective and subjective criteria, we retrospectively analyzed the results of UPPP in patients with mild OSA. METHODS: We examined 37 patients with mild OSA (REI 13.5 +/- 5.1, range 5.6-23.1) who had been operated on during 1996 with UPPP with or without tonsillectomy and/or septoplasty. Follow-up polysomnography was obtained in 25 (68%) an average of 40.5 weeks after surgery and compared with findings before surgery. Subjective assessment of sleepiness was performed with the Sleep-Wake Activity Inventory. RESULTS: Ten patients (40%) had a postoperative reduction in the REI of more than 50%, comparable with the improvements reported in those with more severe apnea. Those who did not have a reduction in REI after surgery actually saw an increase in average REI from 16.6 +/- 5 to 26.7 +/- 18.4. Similarly, subjective assessment of sleepiness with the Sleep-Wake Activity Inventory showed no statistically significant improvement after surgery. CONCLUSION: Overall, these results indicate that UPPP alone in the unselected patient provides little benefit in the management of mild OSA, similar to findings for more severe OSA. Surgeons must use great care in discerning the level of obstruction in the patient with mild OSA to tailor the appropriate retropalatal and/or retrolingual procedures and thereby achieve excellent surgical outcomes.

CPAP therapy in patients with mild OSA: implementation and treatment outcome.

Objectives: To determine continuous positive airway pressure (CPAP) treatment compliance and reversal of excessive daytime sleepiness in patients with mild OSA.Background: CPAP therapy is the most widely accepted and used intervention in patients with a diagnosis of obstructive sleep apnea (OSA). There are, however, no widely accepted protocols to help guide the rational use of CPAP therapy. Patients with mild OSA (respiratory event index (REI) >5 or

The behavioral morbidity of obstructive sleep apnea.

The behavioral morbidity associated with obstructive sleep apnea (OSA) includes symptoms of excessive daytime sleepiness (EDS), neurocognitive deficits, psychological problems, and possibly an increased chance of accidents. EDS is among the most frequently reported symptoms in patients diagnosed with OSA. The available data suggest that the primary cause of EDS is sleep fragmentation. The subjective measures of sleepiness include the sleep wake activity inventory and the epworth sleepiness scale. Sleepiness can also be evaluated objectively in the sleep laboratory using the multiple sleep latency test or the maintenance of wakefulness test. The neurocognitive manifestations of OSA include impairments in vigilance, concentration, memory, and executive function. There is no agreed on consensus as to how to best quantify neurocognitive deficits in this population. Symptoms consistent with depression or personality changes have also been described, but are likely to be correlates of EDS and/or the chronicity of the disorder. Manifestations of the behavioral morbidity of OSA are reversible, but dependent on the degree of normalization in sleep-disordered breathing and the individual's sleep habits.