Personal clothing as a potential vector of respiratory virus transmission in childcare settings.

Previous investigations of fomite transmission have focused on the presence of pathogens on inanimate objects in clinical settings. There has been limited investigation of fomite transmission in non-clinical pediatric settings where there is a high prevalence of respiratory virus infections. Over a 5 week period, this study investigated whether the personal clothing of teachers working in childcare centers was contaminated with viral RNA, and potentially could mediate virus transmission. Matched morning and evening clothing and nasal samples were collected for 313 teacher work days (TWDs). Human rhinoviruses (hRV) RNA were detected from samples using real-time PCR. Human rhinovirus RNA was detected in clothing samples on 16 TWDs and in nasal samples on 32 TWDs. There were no TWDs when teachers provided both positive nasal and clothing samples and only three TWDs when hRV persisted on clothing for the entire day. The detection of hRV RNA was significantly predicted by self-recognition of symptomatic illness by the teacher 2 days prior to detection. These findings suggest that teachers' personal clothing in childcare settings is unlikely to facilitate the transmission of hRV.

Face touching: a frequent habit that has implications for hand hygiene.

BACKGROUND: There is limited literature on the frequency of face-touching behavior as a potential vector for the self-inoculation and transmission of Staphylococcus aureus and other common respiratory infections. METHODS: A behavioral observation study was undertaken involving medical students at the University of New South Wales. Their face-touching behavior was observed via videotape recording. Using standardized scoring sheets, the frequency of hand-to-face contacts with mucosal or nonmucosal areas was tallied and analyzed. RESULTS: On average, each of the 26 observed students touched their face 23 times per hour. Of all face touches, 44% (1,024/2,346) involved contact with a mucous membrane, whereas 56% (1,322/2,346) of contacts involved nonmucosal areas. Of mucous membrane touches observed, 36% (372) involved the mouth, 31% (318) involved the nose, 27% (273) involved the eyes, and 6% (61) were a combination of these regions. CONCLUSION: Increasing medical students' awareness of their habituated face-touching behavior and improving their understanding of self-inoculation as a route of transmission may help to improve hand hygiene compliance. Hand hygiene programs aiming to improve compliance with before and after patient contact should include a message that mouth and nose touching is a common practice. Hand hygiene is therefore an essential and inexpensive preventive method to break the colonization and transmission cycle associated with self-inoculation.

Respiratory virus RNA is detectable in airborne and droplet particles.

Aerosol transmission routes of respiratory viruses have been classified by the WHO on the basis of equilibrium particle size. Droplet transmission is associated with particles sized >5 µm in diameter and airborne transmission is associated with particles sized ≤5 µm in diameter. Current infection control measures for respiratory viruses are directed at preventing droplet transmission, although epidemiological evidence suggests concurrent airborne transmission also occurs. Understanding the size of particles carrying viruses can be used to inform infection control procedures and therefore reduce virus transmission. This study determined the size of particles carrying respiratory viral RNA produced on coughing and breathing by 12 adults and 41 children with symptomatic respiratory infections. A modified six-stage Andersen Sampler collected expelled particles. Each stage was washed to recover samples for viral RNA extraction. Influenza A and B, parainfluenza 1, 2 and 3, respiratory syncytial virus (RSV), human metapneumovirus and human rhinoviruses (hRV) were detected using RT-PCR. On breathing, 58% of participants produced large particles (>5 µm) containing viral RNA and 80% produced small particles (≤5 µm) carrying viral RNA. On coughing, 57% of participants produced large particles containing viral RNA and 82% produced small particles containing viral RNA. Forty five percent of participants produced samples positive for hRV viral RNA and 26% of participants produced samples positive for viral RNA from parainfluenza viruses. This study demonstrates that individuals with symptomatic respiratory viral infections produce both large and small particles carrying viral RNA on coughing and breathing.

Health care workers' perceptions predicts uptake of personal protective equipment.

BACKGROUND: Health care workers' (HCW) compliance with infection control measures is influenced by organizational, environmental and individual factors. However, it is unknown whether HCWs' perceptions of transmission risk and protectiveness of infection control measures influences the uptake of infection control measures. METHODS: A questionnaire of perceptions and intentions to use infection control measures was completed by 74 HCWs at 2 hospitals. HCWs also indicated a 1-m transmission risk zone and their perceived transmission risk zone. Responses were used in logistic regression models to predict intended behaviors. RESULTS: Poor recognition of the importance of employing a 1-m transmission risk zone predicted intention not to don a mask in single rooms where patient contact was unexpected (adjusted odds ratio [AOR], 0.5; P = .032). When contact was expected, perceived protectiveness of pre-exposure prophylaxis (AOR, 7.9; P < .001), vaccination (AOR, 3.6; P = .023), and a minimum 1-m risk zone (AOR, 9.8; P = .022) predicted mask use. HCWs perceived transmission risk zones within 2.45 m from attending an adult and 1.12 m from attending pediatric patients. CONCLUSION: Intention to use a facemask was poor for care in single rooms but improved if patient contact was expected and in multibed rooms. HCWs attending pediatric patients measured a smaller transmission risk zone than what is currently recommended under droplet precautions.

Using evidence-based medicine to protect healthcare workers from pandemic influenza: Is it possible?

OBJECTIVE: To use evidence-based principles to develop infection control algorithms to ensure the protection of healthcare workers and the continuity of health service provision during a pandemic. DESIGN: : Evidence-based algorithms were developed from published research as well as "needs and values" assessments. Research evidence was obtained from 97 studies reporting the protectiveness of antiviral prophylaxis, seasonal vaccination, and mask use. Needs and values assessments were undertaken by international experts in pandemic infection control and local healthcare workers. Opportunity and resources costs were not determined. SETTING: The Australian government commissioned the development of an evidence-based algorithm for inclusion in the 2008 revision of the Australian Health and Management Plan for Pandemic Influenza. PARTICIPANTS: Two international infection control teams responsible for healthcare worker safety during the Severe Acute Respiratory Syndrome outbreak reviewed the evidence-based algorithms. The algorithms were then reviewed for needs and values by eight local clinicians who were considered key frontline clinicians during the contain and sustain phases. The international teams reviewed for practicability of implementation, whereas local clinicians reviewed for clinician compliance. RESULTS: Despite strong evidence for vaccination and antiviral prophylaxis providing significant protection, clinicians believed they required the additional combinations of both masks and face shields. Despite the equivocal evidence for the efficacy of surgical and N95 masks and the provision of algorithms appropriate for the level of risk according to clinical care during a pandemic, clinicians still demanded N95 masks plus face shields in combination with prophylaxis and novel vaccination. CONCLUSIONS: Conventional evidence-based principles could not be applied to formulate recommendations due to the lack of pandemic-specific efficacy data of protection tools and the inherent unpredictability of pandemics. As an alternative, evidence-based principles have been used to formulate recommendations while giving priority to the needs and values of healthcare workers over the research evidence.

The role of particle size in aerosolised pathogen transmission: a review.

Understanding respiratory pathogen transmission is essential for public health measures aimed at reducing pathogen spread. Particle generation and size are key determinant for pathogen carriage, aerosolisation, and transmission. Production of infectious respiratory particles is dependent on the type and frequency of respiratory activity, type and site of infection and pathogen load. Further, relative humidity, particle aggregation and mucus properties influence expelled particle size and subsequent transmission. Review of 26 studies reporting particle sizes generated from breathing, coughing, sneezing and talking showed healthy individuals generate particles between 0.01 and 500 µm, and individuals with infections produce particles between 0.05 and 500 µm. This indicates that expelled particles carrying pathogens do not exclusively disperse by airborne or droplet transmission but avail of both methods simultaneously and current dichotomous infection control precautions should be updated to include measures to contain both modes of aerosolised transmission.

Protecting healthcare workers from pandemic influenza: N95 or surgical masks?

OBJECTIVE: The successful management of an influenza pandemic will be reliant on the expertise of healthcare workers at high risk for occupationally acquired influenza. Recommended infection control measures for healthcare workers include surgical masks to protect against droplet-spread respiratory transmissible infections and N95 masks to protect against aerosol-spread infections. A literature review was undertaken for evidence of superior protective value of N95 masks or surgical masks for healthcare workers against influenza and extraneous factors influencing conferred protection. METHODS: Four scientific search engines using 12 search sequences identified 21 mask studies in healthcare settings for the prevention of transmission of respiratory syncytial virus, Bordetella pertussis, and severe acute respiratory syndrome. Each was critically assessed in accordance with Australian National Health Medical Research Council guidelines. An additional 25 laboratory-based publications were also reviewed. RESULTS: All studies reviewed used medium or lower level evidence study design. In the majority of studies, important confounders included the unrecognized impact of concurrent bundling of other infection control measures, mask compliance, contamination from improper doffing of masks, and ocular inoculation. Only three studies directly compared the protective value of surgical masks with N95 masks. The majority of laboratory studies identified both mask types as having a range of filtration efficiency, yet N95 masks afford superior protection against particles of a similar size to influenza. CONCLUSIONS: World Health Organization guidelines recommend surgical masks for all patient care with the exception of N95 masks for aerosol generating procedures. Because of the paucity of high-quality studies in the healthcare setting, the advocacy of mask types is not entirely evidence-based. Evidence from laboratory studies of potential airborne spread of influenza from shedding patients indicate that guidelines related to the current 1-meter respiratory zone may need to be extended to a larger respiratory zone and include protection from ocular inoculation.

Sleep disturbance in persistent allergic rhinitis measured using actigraphy.

BACKGROUND: Tiredness, fatigue, and impaired quality of life are common in patients with persistent allergic rhinitis (PAR). These symptoms may also be associated with reduced sleep quality in individuals with rhinitis. OBJECTIVE: To determine whether sleep disturbance can be detected using actigraphy in patients with PAR. METHODS: Ten house dust mite-allergic rhinitic patients and 10 nonallergic nonrhinitic control subjects were studied for 5 consecutive days and night. Continuous activity monitoring during the study period using actigraphy was used to obtain markers of sleep quality, such as sleep onset, sleep duration, and sleep fragmentation. In addition, participants recorded in a sleep diary the time they went to bed, the time they went to sleep, the time they awoke, and the quality of their sleep. RESULTS: Allergic rhinitic patients were found to have an increased fragmentation index value, indicative of reduced sleep quality and increased sleep disturbance, compared with the control group (P = .007). CONCLUSIONS: Using actigraphy, we identified specific sleep disturbances in patients with PAR that may result in the increased tiredness, fatigue, and impaired quality of life typically experienced in such patients.

The community's attitude towards swine flu and pandemic influenza.

OBJECTIVE: To ascertain the beliefs, perceived risks and initial attitudes of the Australian community towards the influenza pandemic declared by the World Health Organization in response to the emergence of an A(H1N1) influenza subtype. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional survey of Sydney residents during WHO Phase 5 of pandemic (H1N1) 2009. Members of the public were approached in shopping and pedestrian malls in seven areas of Sydney between 2 May and 29 May 2009 to undertake the survey. The survey was also made available by email. MAIN OUTCOME MEASURES: Perceived personal risk and seriousness of the disease, opinion on the government and health authorities' response, feelings about quarantine and infection control methods, and potential compliance with antiviral prophylaxis. RESULTS: Of 620 respondents, 596 (96%) were aware of pandemic (H1N1) 2009, but 44% (273/620) felt they did not have enough information about the situation. More than a third (38%; 235/620) ranked their risk of catching influenza during a pandemic as low. When asked how they felt pandemic influenza would affect their health if they were infected, only a third (33%; 206/620) said "very seriously". Just over half of the respondents (58%; 360/620) believed the pandemic would be over within a year. Respondents rated quarantine and vaccination with a pandemic vaccine as more effective than hand hygiene for the prevention of pandemic influenza. CONCLUSIONS: Emphasising the efficacy of recommended actions (such as hand hygiene), risks from the disease and the possible duration of the outbreak may help to promote compliance with official advice.