September 2011 Non-Pharmaceutical Measures to Prevent Transmission: The Evidence for Individual Protective Measures Alexis Crabtree, MPH, 1 and Bonnie Henry,MD, MPH, FRCP(C)1,2 1University of British Columbia; 2British Columbia Centre for Disease Control Key Points Introduction • Mask use by cases and/or household contacts may be efficacious A wealth of knowledge has become in reducing the transmission of influenza, but that effectiveness available concerning influenza is likely reduced by poor compliance. Mask use in the community prevention and control in the wake of setting is of dubious benefit, as is the use of N95 respirators rather the 2009 H1N1 pandemic. The purpose than surgical masks outside of health care settings. of this review is to summarize the recent • Isolation and quarantine are effective and acceptable interventions literature on several non-pharmaceutical to reduce the spread of influenza, particularly pandemic influ- interventions: masks; quarantine, enza. measures (excluding school closures and isolation, and social distancing; and prohibitions on mass gatherings, which are covered in another hand hygiene, respiratory hygiene, and paper in this series (Roth, 2011)), however, are of unproven value cleaning of fomites. and associated with low uptake. Special attention should be paid to providing tools and supports to those in quarantine or isolation, particularly to vulnerable groups. Masks A recently updated Cochrane review • Moderate evidence exists to support recommendations for hand concluded that mask use can interrupt and respiratory hygiene, especially in children. Further research is the transmission of influenza (1). While needed to show benefits from cleaning and disinfection of surfac- es in household and public spaces. the review found evidence for the efficacy of this approach, the study did not examine the real-world effectiveness of public spaces. Recommendations for mask-wearing, given the inconvenience Mask Use by Symptomatic mask use among health care personnel and costs of the strategy. Individuals and Their Household are summarized elsewhere (e.g. see Contacts Mask use to prevent influenza Carlson et al, 2010 (2)). Here, we review transmission can be divided into four recent literature on mask use for ill and A systematic review (3) found some categories of users: health care personnel, healthy individuals in the community evidence to support the use of masks by symptomatic individuals, well individuals and summarize recent recommendations symptomatic individuals. Most of the exposed to household contacts with regarding the utility of N95 respirators studies reviewed had both index cases influenza, and well individuals in versus surgical masks. and household contacts instructed to

knowledge that’s contagious! Des saviors qui se transmettent! wear masks, thereby creating difficulty recommendations for household contacts weekly ILI attack rate during some weeks identifying where an interruption in only to wear them. Although there was no of the trial, but found no difference in the influenza transmission occurred. They significant difference in the transmission cumulative attack rate (10). do, however, cite an experimental study risk of ILI between the three study arms As with mask use by cases and household of infectious volunteers with influenza, in an intention-to-treat analysis, adherent contacts, poor compliance could decrease supporting the conclusion that surgical use of either surgical masks or N95- the effectiveness of mask use in public masks provide outward protection (i.e. equivialent masks was the only variable settings. Observed rates of mask wearing mask-wearing by a case reduces the that was significantly associated with on Mexico City public transportation early likelihood that the case will infect others) a reduced risk of ILI infection among in the 2009 H1N1 pandemic were above (4). The review finds less evidence to household contacts of cases (7). 60%, but declined to below 40% within a support the use of masks in household Among possible interventions to reduce week (11), although only a slight decrease contacts of cases and suggests that such the spread of influenza, mask-wearing was reported in Hong Kong (12). Two interventions would result in difficulties by students was rated the lowest median Australian surveys, conducted before and with compliance (3). acceptability in a survey of teachers, and after the pandemic, found a significant Several recent randomized controlled mask-wearing while caring for ill children decrease in subjects’ willingness to wear trials (RCTs) have attempted to a mask in public (13, 14). A pandemic determine the effectiveness of masks and model, however, suggests that even if hand hygiene in preventing primary and/ Debate over the utility masks were only 20% effective and only or secondary transmission of influenza of N95 respirators versus 10% of the population wore them during compared to hand hygiene alone and surgical masks for the a pandemic, cases of influenza would be to a usual practice control group. One prevention of influenza reduced by 20%; masks that were 6% study found no decrease in overall effective worn by 50% of the population rates of upper respiratory infections in transmission is based would reduce cumulative cases by only those houses using masks, but did find to a large extent on 6% (15). mask wearing associated with reduced uncertainty about the secondary transmission (despite poor relative importance adherence) (5). Another trial also found Mask Type no significant difference in influenza of various modes of Debate over the utility of N95 respirators infection between the three arms of their transmission. versus surgical masks for the prevention study (where households with a member of influenza transmission is based to a presenting to clinic with influenza-like large extent on uncertainty about the illness [ILI] were assigned to the control was the least acceptable of interventions relative importance of various modes of group, the soap/hand sanitizer supplies proposed to parents (8). Similarly, transmission. Supporters of the key role and education group, or the third group surveyed university students were more of aerosol transmission, such as in a recent which received soap/hand sanitizer resistant to wearing a mask in public if expert-led review (16) and mathematical supplies and education plus surgical experiencing influenza-like symptoms model (17), encourage the use of N95 mask provision and education), but did than to any other proposed strategy respirators because they provide better see a reduction in influenza transmission (including isolation and vaccination) (9). filtration of small particles under ideal in the mask plus hand hygiene group conditions. Critics can point to a recent when the intervention was implemented model citing contact between virus- within 36 hours of symptom onset (6). Mask Use in Public Spaces laden hands and facial membranes as In these studies both index cases and Mask use in the general public is predicated the key transmission route (18), which is household contacts were instructed on the assumption that a significant supported by reviews finding no difference to wear masks, making it difficult to proportion of transmission events will in attack rates for influenza between isolate the effectiveness of mask-wearing occur in public spaces. Evidence for this masks and respirators (1, 19). Given that by index cases versus contacts. A final assumption is limited. Among recent the RCT comparing the two types of RCT recruited households of children literature on the subject, a RCT found masks in households was underpowered presenting to clinics with ILI and assigned mask-wearing plus hand hygiene in to detect a difference (7), resolution of them to the control intervention, surgical university dormitories decreased the this debate is still forthcoming. masks, or N95-equivalent masks, with

2 National Collaborating Centre for Infectious Diseases Overall, these results suggest mask use by strategies, according to a systematic given interventions. Two models from the cases and/or household contacts may be review of pandemic models (20). School UK found that the expected impact of a efficacious in reducing transmission of closures, social distancing of adults and pandemic was small (0.5%-2% of GDP) influenza, but that effectiveness is likely children, and targeted antivirals were and that the bulk of the economic impact reduced by poor compliance. Mask use associated with lowering the attack rate would come from quarantine and school in the community setting is of dubious from 35% to 10% when the reproduction closures (27, 28).

benefit, as is the use of N95 respirators number (R0) was greater than 2.1 in rather than surgical masks outside of one model; the preferred strategy for an Focus Groups, Interviews, and Surveys health care settings. R0 below 1.6 was social distancing and antivirals alone (21). Another study found Even if efficacious under ideal that, for an R0 of 1.5, a combination of circumstances, quarantine, isolation, Quarantine, Isolation, and Social school closures, in-household isolation, and social distancing will be ineffective Distancing workplace non-attendance, and reduction at controlling pandemic influenza if Measures to reduce interactions between of community contacts implemented adherence to these measures is low. ill and healthy individuals are some of the 6 weeks after identification of the first A variety of studies have examined oldest interventions in the battle against case could lower the cumulative attack individuals’ attitudes and intentions infectious diseases. For the purposes of regarding such strategies through focus this paper, these measures will be defined groups, interviews and surveys. A smaller as follows: The primary barriers to number of studies have examined the • Isolation is the separation of ill indi- undertaking quarantine reported behaviours of those who have viduals from others for the period of and isolation were experienced pandemic influenza in their infectiousness. region. economic disincentives, • Quarantine is the separation of ex- as many subjects did not The primary barriers to undertaking posed individuals until it is clear they quarantine and isolation were economic are not infectious (generally for the in- have sick leave and disincentives, as many subjects did not cubation period of the illness). could not afford periods have sick leave and could not afford • Social distancing includes measures without pay. periods without pay (13, 29-32). Another to reduce contacts with individuals of important barrier for those considering unknown illness status, such as avoid- quarantine or isolation was the lack of ing public transit and telecommuting. rate from 33% to 10% (22). In the same access to essential goods and services (29, School closures and prohibitions on model, case isolation alone could achieve 32). Participants in one series of focus mass gatherings are included in this a comparable outcome if implemented groups suggested that isolation of an ill definition, but are covered in depth within 3 weeks of introducing the first family member within the house would in another paper in this series (Roth, case (22); an alternative model found be hindered by the need to care for that 2011). case isolation associated with a one-third person and by space constraints due to As these measures are often explored reduction in the attack rate (23). the size of the home (33). together in the literature, they will be The majority of subjects questioned in presented together here by study design. Combined interventions are most surveys and focus groups indicated a effective at lower values of 0R (22, 24). To have an impact on overall attack rates, willingness to take part in quarantine and/or isolation if necessary, often out of Models these interventions must be implemented early (22, 25) and kept in place until a a desire to protect others or to fulfill their Most models explore combinations vaccine is available (22, 24). Targeting civic duties (8, 13, 34-36). Researchers of strategies to reduce the impact interventions to the age groups with the conducting focus groups in Canada and of pandemic influenza, including highest incidence of infection provides the UK reported that their participants quarantine, isolation, school closures, optimum effectiveness (26). looked more favourably on these workplace closures, antiviral treatment interventions, perhaps because of greater and prophylaxis, and vaccination. Not Economic models balance the costs of trust in the government and expectation surprisingly, combined preventive pandemic-associated morbidity and that provisions would be made for their methods are more effective than solitary mortality against the cost of implementing basic needs (37,38), although Canadian

Centre de collaboration nationale des maladies infectieuses 3 survey respondents also reported a need watching television with the index case. systematic review (43). for safeguards to prevent the inappropriate Members of households who discussed In focus groups with Australian application of quarantine (36). Groups influenza prevention had a 40% reduction Aboriginals, barriers to social distancing that were more likely to intend to in the risk to individual contacts (41). included the need to attend cultural and comply with these recommendations Special Populations religious events, and the lack of clear were women, the elderly, low-income communication about influenza that was earners and the unemployed, as well as The implications of quarantine, isolation, culturally appropriate. Subjects suggested people who attend religious services (13, and social distancing vary for different engaging local leaders as contacts to help 32, 34, 35). However, one Australian subsets of the population, and several tailor strategies and messages, and to survey found that 27.1% of health and authors have attempted to explore the engage with the whole community in community service workers would not conditions necessary for such measures designing pandemic plans (44). follow physician directions to stay at to be successful in these groups. At an home with seasonal influenza (35). The Australian university, surveyed students same study found that, in general, people were more likely than staff to avoid social Prospective Studies were more willing to self-isolate with events and public transportation but pandemic influenza than with seasonal were also more likely to attend school The recent pandemic provided an influenza or a common cold (35). opportunity to observe the effects of proximity on the transmission of Several surveys were conducted during pandemic influenza. Using cohorts of the 2009 H1N1 pandemic about the The recent Cochrane households with an index case, authors quarantine and isolation procedures review of physical inter- found conflicting results regarding how followed by the public. Cruise ship household size influences the secondary passengers universally complied with ventions to reduce the transmission of respiratory transmission rate. An Edmonton-based requests to self-isolate and mostly study of households with early laboratory- complied with requests to self-quarantine illness found that there is confirmed cases found larger households (39). Using information self-reported evidence to recommend had increased secondary attack rates (45). by patients who had been diagnosed handwashing, particularly A study of the households of students with pH1N1, a study in the UK found in young children. infected with influenza from a New York that patients made fewer daily contacts high school found that household size when they were ill than when they were was not associated with secondary attack well, particularly among those who rate (46), and in two other American missed work or were severely ill (40). A if unwell, particularly if they had an studies following early pandemic cases, follow-up to an earlier Australian study, exam or assignment due. Enthusiasm for larger household size was associated with in which the authors re-surveyed their online course delivery was higher among a decrease in the secondary attack rate original subjects, showed that they were students than teachers (9). (47, 48). still willing to comply with quarantine requests but were less likely to avoid public Migrant workers in the U.S. were A Korean study found that classmates, spaces and transportation (14). In Hong posited, in a non-systematic review and and especially roommates, of sick Kong, social distancing efforts declined series of consultations with experts, to students at a school residence were more as the pandemic progressed. The authors have potential difficulty isolating or likely to become ill than non-classmates also found that those who complied with quarantining themselves due to lack and roommates at the same school social distancing were more likely to have of sick days, fear of unemployment for (49). A report from two American navy other illnesses and to perceive having a missing work days, financial inability to vessels supported this finding, noting higher risk of infection (12). A survey stockpile supplies, and crowded living that isolating an ill crew member off- of families with a child who contracted conditions in dormitories or hotel ship likely prevented one vessel from a influenza during an outbreak at a New rooms where isolation is impossible widespread outbreak experienced on her York high school found that the highest (42). Social housing residents and low- sister ship (50). secondary infection rate occurred among income populations face similar issues, In summary, isolation and quarantine are parents providing care to the index case, particularly regarding the consequences effective and acceptable interventions to those providing care who slept in the of missing work and difficulty stockpiling reduce the spread of influenza, particularly same room as the index case, and siblings supplies, according to another non- pandemic influenza. Social distancing

4 measures (excluding school closures and prohibitions on mass gatherings, which are covered in another paper in this series (Roth, 2011)), however, are of unproven value and associated with low uptake. Special attention should be paid to providing tools and supports to those in quarantine or isolation, particularly to vulnerable groups.

Hand Hygiene, Respiratory Hygiene, and Fomite Disinfection Hand hygiene, respiratory hygiene (i.e. covering the mouth and nose with a tissue or sleeve when coughing or sneezing), and disinfection of fomites are all interventions with the potential to interrupt the transmission of influenza in households and in public spaces such as workplaces and schools. Surprisingly, despite the extensive recommendation to adopt these preventive measures, influenza. However, the effectiveness their hands twice daily and provided significant attention has only recently of other antibacterial products outside information on hand hygiene. The number been given to studying their effectiveness the hospital setting remains unproven of laboratory-confirmed influenza cases in outside the health care settings. (52). A literature review notes that such the intervention schools decreased by 47% interventions may be difficult for those (53). A similar study in Pittsburgh found living in poverty, as they lack the financial that good adherence by children to hand Reviews and Expert Opinion resources to purchase supplies and may and respiratory hygiene continued even The recent Cochrane review of physical live in inadequate housing without 4 months after the intervention period interventions to reduce the transmission access to warm water for handwashing or (54) and that the number of laboratory- of respiratory illness found that there is cleaning household surfaces (43). confirmed influenza A cases decreased by evidence to recommend handwashing, 52% (55). A before-and-after comparison particularly in young children (who are in a Thai preschool found a decrease Randomized Controlled Trials the least able to wash hands on their in ILI after implementing hand and own and have greater social contact A number of RCTs exploring the respiratory hygiene education, mandatory and infections of longer duration) (1). effectiveness of hand hygiene at home vaccination, and enforced absenteeism for A review of national guidelines for or school have been published in recent ill students (56). Compared to students in non-pharmaceutical interventions for years. Several of these studies found no the control (no intervention) group of a pandemic influenza noted that hand difference in primary and/or secondary trial conducted in a university dormitory hygiene and cough etiquette were transmission between those households setting, study participants who used face universally recommended by the 10 randomized to hand hygiene (where masks and practiced hand hygiene and countries examined, and 7 of 10 also soap and/or hand sanitizer was provided those who used face masks alone showed recommended that individuals avoid with instructions) compared to controls a statistically non-significant reduction touching their eyes and mouths (51). This given educational materials about healthy (~10%) in cumulative ILI incidence over recommendation is supported by a recent lifestyles (6) or prevention and treatment a 6-week study period. However, when Canadian non-systematic review which of influenza (5). considering the latter half of the study concluded that with an period only (weeks 4-6), reductions in ILI An RCT in Egypt found decreases in alcohol-based sanitizer or soap and water incidence in the mask and hand hygiene absenteeism and ILI in schools where can provide adequate protection against group did achieve statistical significance, teachers instructed children to wash

Centre de collaboration nationale des maladies infectieuses 5 Table 1 Summary of current findings of studies on public health measures for the prevention of seasonal and pandemic influenza, and suggestions for future research priorities

Public Health Measure Study Findings Suggested Research Priorities Masks • Mask use by cases and/or household • RCTs that examine the effective- contacts may be efficacious in reducing ness of mask use by index cases and transmission. their household contacts separately. • Effectiveness of masks is likely • RCTs comparing the effectiveness reduced by poor compliance. of N95 vs. surgical masks with suf- • Mask use in the community setting is ficient power to detect a difference. of dubious benefit. • N95 respirators have not been proven superior to surgical masks outside of health care settings. Quarantine, isolation, and social • Isolation and quarantine are both • Cohort studies of social contacts of distancing effective and acceptable, particularly ILI cases and ILI exposed individuals with regard to pandemic influenza. during incubation/infectious periods. • Voluntary social distancing measures • Prospective studies of household (e.g. avoiding public transit, telecom- and social network factors that influ- muting) are of unproven value and are ence secondary transmission. associated with low uptake. • Special attention should be paid to providing tools and supports to those in quarantine or isolation, particularly to vulnerable groups. Hand hygiene, • Moderate evidence supports recom- • Evaluation of the effectiveness of respiratory hygiene, and fomite mendations for hand and respiratory communication strategies for hand disinfection hygiene, especially in children. and respiratory hygiene. • There is insufficient evidence to sup- • Effectiveness studies (laboratory port recommendations for cleaning and and/or others) of fomite disinfection. disinfection of surfaces in household and public spaces. in contrast to the mask-only group (10). covered by sleeves or tissues, suggesting to solutions of 1% , 10% malt that respiratory hygiene messages had not vinegar, or 0.01% dish soap (59). reached their intended audience (57). The Surveys and Focus Groups Observational and Laboratory Studies use of hand sanitizer also dropped in the Public opinion about the effectiveness Investigators in New Zealand found the wake of the pandemic in New Zealand and feasibility of hand hygiene and other majority of respiratory events (coughs (58). personal protective measures in preventing and sneezes) that took place in public Regarding cleaning products, investigators pandemic influenza was mixed. For settings (i.e. railway transport system, found that commercially available anti- example, an Australian telephone survey hospital and shopping mall) were covered microbial wipes outperformed the non- showed hand hygiene was seen as an by subjects’ hands, followed by uncovered anti-microbial variety at reducing virus ineffective means of preventing pandemic events. Very few respiratory events were viability, but that neither was superior

6 National Collaborating Centre for Infectious Diseases influenza (32). UK focus groups identified or exposed individuals’ social contacts 15;49(2):275-7. (Cited by: Cowling three major barriers to hand hygiene: in the periods before, during, and after, BJ, Zhou Y, Ip DK, Leung GM, Aiello AE. Face masks to prevent difficulty remembering, belief that their infectious or incubation periods. transmission of influenza virus: A others should take more responsibility Prospective studies examining the social systematic review . Epidemiol Infect and embarrassment at being seen as and household factors that contribute 2010, Apr;138(4):449-56.) 5. Larson EL, Ferng YH, Wong- engaging in “extreme measures”(33). to secondary transmission would assist McLoughlin J, Wang S, Haber M, Conversely, other studies revealed the in identifying households at highest Morse SS. Impact of non-pharmaceu- endorsement of hand hygiene by certain risk and tailoring quarantine, isolation, tical interventions on URIs and influ- enza in crowded, urban households. sectors of the general population. Use and social distancing strategies to the Public Health Rep 125(2):178-91, of hygiene products (e.g. face masks needs of different types of households. 2010, Mar;125(2):178-91. and hand hygiene products) was the Finally, there is a need to evaluate 6. Cowling BJ, Chan KH, Fang VJ, step that university students had most the communication strategies used to Cheng CK, Fung RO, Wai W, et al. Facemasks and hand hygiene to commonly taken to protect themselves promote respiratory and hand hygiene prevent influenza transmission in from pandemic influenza (9). Parents and to study the effectiveness of fomite households: A cluster randomized and teachers were confident in their disinfection in interrupting influenza trial. Ann Intern Med 2009, Oct abilities to encourage children in hand transmission. 6;151(7):437-46. 7. MacIntyre CR, Cauchemez S, Dwyer and respiratory hygiene (8). Lastly, the Investing in such research is key to DE, Seale H, Cheung P, Browne majority of survey respondents in Hong developing evidence-based guidelines for G, et al. Face mask use and control Kong reported practicing hand hygiene, of respiratory virus transmission the prevention and control of influenza. in households. Emerg Infect Dis with numbers declining only slightly as Non-pharmaceutical measures have 2009;15(2):233-41. the pandemic progressed (12). formed the cornerstone of the public 8. Stebbins S, Downs JS, Vukotich CJ. Using nonpharmaceutical interven- There is evidence to supporthealth response to influenza for centuries, tions to prevent influenza transmis- recommendations for hand and and as we continue to learn how best sion in elementary school children: respiratory hygiene, especially in children, to employ these measures, we are Parent and teacher perspectives. Journal of Public Health Manag but further research is needed to show increasingly better-equipped to protect Pract 2009, Mar;15(2):112-7. benefits from cleaning and disinfection of the health of the public during regular 9. Van D, McLaws ML, Crimmins J, surfaces in household and public spaces. influenza seasons and pandemics alike. MacIntyre CR, Seale H. University life and pandemic influenza: Attitudes and intended behaviour of staff and students towards pandemic Future Directions References (H1N1) 2009. BMC Public Health Non-pharmaceutical methods have 1. Jefferson T, Del Mar C, Dooley L, 2010;10:130. been, and will continue to be, Ferroni E, Al Ansary LA, Bawazeer 10. Aiello AE, Murray GF, Perez V, Coulborn RM, Davis BM, Uddin M, important elements of any strategy to GA, et al. Physical interventions to interrupt or reduce the spread et al. Mask use, hand hygiene, and limit pandemic influenza. While the of respiratory viruses. [Update seasonal influenza-like illness among 2009 H1N1 pandemic provided an of cochrane Database Syst Rev. young adults: A randomized inter- important opportunity to investigate the 2007;(4):CD006207; PMID: vention trial. J Infect Dis 2010, Feb 17943895]. Cochrane Database of 15;201(4):491-8. effectiveness of these approaches, much Syst Rev 2010(1):CD006207. 11. Condon BJ, Sinha T. Who is that research remains to be done (Table 1). 2. Carlson AL, Budd AP, Perl TM. masked person: The use of face masks Control of influenza in healthcare on Mexico City public transporta- There is a particular need for RCTs to settings: Early lessons from the 2009 tion during the influenza A (H1N1) investigate the effectiveness of mask use pandemic. Curr Opin Infect Dis outbreak. Health Policy 2010, by cases separately from mask use by 2010, Aug;23(4):293-9. Apr;95(1):50-6. 3. Cowling BJ, Zhou Y, Ip DK, Leung 12. Cowling BJ, Ng DM, Ip DK, Liao Q, their household contacts, as well as for GM, Aiello AE. Face masks to pre- Lam WW, Wu JT, et al. Community trials comparing the effectiveness of N95 vent transmission of influenza virus: psychological and behavioral re- and surgical masks outside of health care A systematic review. Epidemiol Infect sponses through the first wave of the 2009 influenza A(H1N1) pandemic settings. To better understand adherence 2010, Apr;138(4):449-56. 4. Johnson DF, Druce JD, Birch C, in Hong Kong. J Infect Dis 2010, to quarantine, isolation, and social Grayson ML. A quantitative assess- Sep 15;202(6):867-76. distancing measures (and to provide more ment of the efficacy of surgical and 13. Eastwood K, Durrheim D, Francis accurate parameters for transmission N95 masks to filter influenza virus JL, d’Espaignet ET, Duncan S, in patients with acute influenza in- Islam F, et al. Knowledge about models), it would be helpful to have fection. Clin Infect Dis 2009, Jul pandemic influenza and compliance studies that collect information on cases with containment measures among

Centre de collaboration nationale des maladies infectieuses 7 Australians. Bull World Health to non-pharmaceutical interventions. Public perceptions of quarantine: Organ 2009, Aug;87(8):588-94. BMC Infect Dis 2010;10:32. Community-based telephone sur- 14. How the H1N1 pandemic has 26. Wallinga J, van Boven M, Lipsitch vey following an infectious dis- changed Australian’s willingness to M. Optimizing infectious disease ease outbreak. BMC Public Health comply with public health measures; interventions during an emerging 2009;9:470. 2010 International Conference on epidemic. Proceedings Natl Acad 37. Joint Centre for Bioethics Pandemic Infectious Diseases. 2010. Sci U S A 107(2):923-8, 2010, Jan Ethics Working Group. Public en- 15. Tracht SM, Del Valle SY, Hyman JM. 12;107(2):923-8. gagement on social distancing in a Mathematical modeling of the effec- 27. Keogh-Brown MR, Smith RD, pandemic: A Canadian perspective. tiveness of facemasks in reducing the Edmunds JW, Beutels P. The macro- Am J Bioeth 2009, Nov;9(11):15-7. spread of novel influenza A (H1N1). economic impact of pandemic influ- 38. Sorell T, Draper H, Damery S, Ives PLoS One 2010;5(2):e9018. enza: Estimates from models of the J. “Dunkirk spirit:” Differences be- 16. Tellier R. Aerosol transmission of United Kingdom, France, Belgium tween United Kingdom and United influenza A virus: A review of new and the Netherlands. Eur J of Health States responses to pandemic influen- studies. J R Soc Interface 2009, Dec Econ 2010 Dec;11(6):543-54. za. Am J Bioeth 2009, Nov;9(11):21- 6;6(Suppl 6):S783-90. 28. Smith RD, Keogh-Brown MR, 2. 17. Wein LM, Atkinson MP. Assessing Barnett T, Tait J. The economy-wide 39. Ward KA, Armstrong P, McAnulty infection control measures for pan- impact of pandemic influenza on the JM, Iwasenko JM, Dwyer DE. demic influenza. Risk Anal 2009, UK: A computable general equilib- Outbreaks of pandemic (H1N1) Jul;29(7):949-62. rium modelling experiment. BMJ 2009 and seasonal influenza A 18. Nicas M, Jones RM. Relative contri- 2009;339:b4571. (H3N2) on cruise ship. Emerg Infect butions of four exposure pathways 29. Baum NM, Jacobson PD, Goold SD. Dis 2010;16(11):1731. to influenza infection risk. Risk Anal “Listen to the people”: Public delib- 40. Eames KT, Tilston NL, White PJ, 2009, Sep;29(9):1292-303. eration about social distancing mea- Adams E, Edmunds WJ. The im- 19. Daniels TL, Talbot TR. Unmasking sures in a pandemic. Am J of Bioeth pact of illness and the impact of the confusion of respiratory protec- 2009, Nov;9(11):4-14. school closure on social contact pat- tion to prevent influenza-like illness 30. Blake KD, Blendon RJ, Viswanath terns. Health Technol Assess 2010, in crowded community settings. J K. Employment and compliance Jul;14(34):267-312. Infect Dis 2010;201(4):483-5. with pandemic influenza mitigation 41. France AM, Jackson M, Schrag S, 20. Lee VJ, Lye DC, Wilder-Smith A. recommendations. Emerg Infect Dis Lynch M, Zimmerman C, Biggerstaff Combination strategies for pandemic 2010, Feb;16(2):212-8. M, et al. Household transmission of influenza response - a systematic re- 31. Horney JA, Moore Z, Davis M, 2009 influenza A (H1N1) virus after view of mathematical modeling stud- MacDonald PD. Intent to receive a school-based outbreak in New York ies. BMC Medicine 2009;7:76. pandemic influenza A (H1N1) vac- City, April-May 2009. J Infect Dis 2010(7):984-92. 21. Perlroth DJ, Glass RJ, Davey VJ, cine, compliance with social distanc- Cannon D, Garber AM, Owens DK. ing and sources of information in NC, 42. Steege AL, Baron S, Davis S, Torres- Health outcomes and costs of com- 2009. PLoS One 2010;5(6):e11226. Kilgore J, Sweeney MH. Pandemic munity mitigation strategies for an 32. Seale H, McLaws ML, Heywood AE, influenza and farmworkers: The ef- influenza pandemic in the United Ward KF, Lowbridge CP, Van D, et fects of employment, social, and eco- States. Clin Infect Dis 2010, Jan al. The community’s attitude towards nomic factors. Am J Public Health 15;50(2):165-74. swine flu and pandemic influenza. 2009, Oct;99(Suppl 2):S308-15. 22. Kelso JK, Milne GJ, Kelly H. Med J Aust 2009, Sep 7;191(5):267- 43. Bouye K, Truman BI, Hutchins S, Simulation suggests that rapid acti- 9. Richard R, Brown C, Guillory JA, et vation of social distancing can arrest 33. Morrison LG, Yardley L. What infec- al. Pandemic influenza preparedness epidemic development due to a novel tion control measures will people car- and response among public-housing strain of influenza. BMC Public ry out to reduce transmission of pan- residents, single-parent families, Health 2009;9:117. demic influenza? A focus group study. and low-income populations. Am J BMC Public Health 2009;9:258. Public Health 2009, Oct;99(Suppl 23. Yasuda H, Suzuki K. Measures 2):S287-93. against transmission of pandem- 34. Bauerle Bass S, Burt Ruzek S, Ward L, ic H1N1 influenza in Japan in Gordon TF, Hanlon A, Hausman AJ, 44. Massey PD, Pearce G, Taylor KA, 2009: Simulation model. Euro et al. If you ask them, will they come? Orcher L, Saggers S, Durrheim Surveillance: Bulletin Europeen Predictors of quarantine compliance DN. Reducing the risk of pandemic Sur Les Maladies Transmissibles = during a hypothetical avian influenza influenza in aboriginal communi- European Communicable Disease pandemic: Results from a statewide ties. Rural Remote Health 2009, Bulletin 2009;14(44). survey. Disaster Med Public Health Jul;9(3):1290. 24. An der HM, Buchholz U, Krause Prep 2010(4):135-44. 45. Sikora C, Fan S, Golonka R, G, Kirchner G, Claus H, Haas WH. 35. Brown LH, Aitken P, Leggat PA, Sturtevant D, Gratrix J, Lee BE, et al. Breaking the waves: Modelling the Speare R. Self-reported anticipated Transmission of pandemic influenza potential impact of public health compliance with physician advice to A (H1N1) 2009 within households: measures to defer the epidemic peak stay home during pandemic (H1N1) Edmonton, Canada. J Clin Virol of novel influenza A/H1N1. PLoS 2009: Results from the 2009 2010, Oct;49(2):90-3. One 2009;4(12):e8356. Queensland Social Survey. BMC 46. Lessler J, Reich NG, Cummings DA, 25. Lin F, Muthuraman K, Lawley M. Public Health 2010;10:138-43. New York City Department of Health An optimal control theory approach 36. Tracy CS, Rea E, Upshur RE. and Mental Hygiene Swine Influenza

8 National Collaborating Centre for Infectious Diseases Investigation Team. Outbreak of Prevention and control of infections 2010. 2009 pandemic influenza A (H1N1) in the home. Can Med Assoc J 2009, 58. Manning S, Barry T, Wilson N, at a New York City school. N Engl May 26;180(11):E82-6. Baker M. Update: Follow-up study J Med 2009, Dec 31;361(27):2628- 53. Impact of intensive hand hygiene showing post-pandemic decline in 36. campaigns on the incidence of lab- hand sanitiser use, New Zealand, 47. Cauchemez S, Donnelly CA, Reed oratory-confirmed influenza and December 2009. Euro Surveill 2010, C, Ghani AC, Fraser C, Kent CK, et absenteeism in schoolchildren in Jan 21;15(3). al. Household transmission of 2009 Cairo governorate: A randomized 59. Greatorex JS, Page RF, Curran MD, pandemic influenza A (H1N1) virus controlled trial; 2010 International Digard P, Enstone JE, Wreghitt T, et in the United States. N Engl J Med Conference on Infectious Diseases. al. Effectiveness of common house- 2009;361(27):2619-27. 2010. hold cleaning agents in reducing 48. Morgan OW, Parks S, Shim T, 54. Stebbins S, Stark JH, Vukotich CJ. the viability of human influenza A/ Blevins PA, Lucas PM, Sanchez R, et Compliance with a multilayered H1N1. PLoS One 2010;5(2):e8987. al. Household transmission of pan- nonpharmaceutical intervention demic (H1N1) 2009, San Antonio, in an urban elementary school set- Texas, USA, April--May 2009. ting. J Public Health Manag Pract Emerg Infect Dis 2009;16(4):631-7. 2010;16(4):316-24. 49. Kim JH, Lee HS, Park HK, Kim 55. Stebbins S, Cummings DAT, JS, Lee SW, Kim SS, et al. An out- Stark JH, Vukotich C, Mitruka K, break of novel influenza A (H1N1) Thompson W, et al. Reductions in in the English Language Institute. the incidence of influenza A associ- J Prev Med Public Health 2010, ated with use of hand sanitizer and May;43(3):274-8. cough hygiene in schools: A ran- 50. Dill CE, Favata MA. Novel influ- domized controlled trial; Available enza A (H1N1) outbreak on board a from: http://www.pipp.pitt.edu/pdf/ US navy vessel. Disaster Med Public PIPP-Abstract1.pdf. Accessed 15 Health Prep 2009, Dec;3(Supple November 2010. 2):S117-20. 56. Apisarnthanarak A, Apisarnthanarak 51. Wlad; Schuck-Paim, Cynthia. Public P, Cheevakumjorn B, Mundy LM. preparedness guidance for a severe in- Intervention with an infection con- fluenza pandemic in different coun- trol bundle to reduce transmission tries: a qualitative assessment and of influenza-like illnesses in a Thai critical overview [Internet]. Version preschool. Infect Control Hosp 16. PLoS Currents: Influenza. Epidemiol 2009, Sep;30(9):817-22. 2009 Nov 5 [revised 2010 Apr 57. Respiratory hygiene practices during 15]:PMC2775164. an influenza pandemic: An obser- 52. Embil JM, Dyck B, Plourde P. vational study; 2010 International Conference on Infectious Diseases.

413-445 Ellice Aveune, Winnipeg, MB R3B 3P5 204.943.0051 [email protected] www.nccid.ca

Production of this document has been made possible through a financial contribution from the Public Health Agency of Canada. The views expressed herein do not necessarily represent the views of the Public Health Agency of Canada.

Centre de collaboration nationale des maladies infectieuses 9