Individual and Community Based Measures to Help Prevent Transmission of Influenza-Like-Illness (ILI), Including the Pandemic Influenza (H1N1) 2009 Virus, in the Community

Purpose

The goals of Canada’s pandemic preparedness and response are to minimize serious illness and deaths, and to minimize societal disruption as a result of an influenza pandemic. This document has been developed to provide guidance for public health authorities regarding non-pharmaceutical measures that may contribute to the reduction of transmission of the pandemic (H1N1) 2009 influenza virus in the community. Public health and other health professionals may adapt this guidance as necessary to address their local circumstances.

The guidance in this document should be used in combination with individual infection prevention measures such as proper hand hygiene and respiratory etiquette and immunization.

Canadian Situation Analysis/Introduction

The pandemic (H1N1) 2009 influenza virus has rapidly spread across the world. Canadians experienced the first wave in the spring and early summer of 2009 with the peak appearing in June.  While influenza activity is normally expected to wane during the summer months, the pandemic (H1N1) 2009 influenza virus continued to circulate at low levels in Canada throughout the summer and resurged in the fall.  The epidemiology of this second wave is consistent with the first wave with pandemic (H1N1) 2009 influenza virus infections resulting in influenza like illness (ILI) similar to seasonal influenza.

The surveillance case definition for ILI in the general population is defined as the acute onset of respiratory illness with fever and cough with one or more of the following - sore throat, muscle aches, joint pain or weakness which could be due to influenza virus. In children under 5, gastrointestinal symptoms may also be present. In patients under 5 or 65 and older, fever may not be prominent.

It has been observed that gastrointestinal symptoms have been present in at least one third of the cases and a wider age range of individuals may not experience fever.

The clinical case definition for ILI for treatment or isolation purposes in a given setting should be adapted to ensure appropriate sensitivity and specificity for this setting.

This pandemic (H1N1) 2009 influenza virus is thought to be spread from person to person in the same way as seasonal influenza where transmission occurs predominantly through droplets produced from coughing or sneezing. Indirect transmission may also occur through self-inoculation after contact with surfaces or objects contaminated with the virus from infected persons.

The incubation period for pandemic (H1N1) 2009 influenza virus is understood to be approximately four days (range: one to seven days).  The period of communicability is estimated to be seven days in uncomplicated cases; however, it may be longer in children (up to 10 days) and other individuals in whom symptoms and virus shedding may persist (i.e. immunocompromised and severely ill). Consistent with seasonal influenza, transmission of the pandemic (H1N1) 2009 influenza virus is most likely during the initial days of infection when cases are typically symptomatic and have higher viral loads.

Like seasonal influenza, the pandemic influenza (H1N1) 2009 influenza infection in humans can vary in severity from mild to severe, with approximately two-thirds of hospitalized cases to date occurring in individuals with known risk factors for complications from influenza such as chronic illness, immunosuppression or pregnancy. This virus also appears to result in more severe disease in the 5-64 year old age group than does seasonal influenza; however, most individuals with pandemic (H1N1) 2009 influenza have not required hospitalization and have recovered in the community.

Most individuals with pandemic (H1N1) 2009 influenza have not required hospitalization and have recovered in the community.

Description of Community Settings

The unique characteristics of certain settings (e.g., homeless shelters) and communities (e.g., remote or isolated or communities with a large proportion of high risk individuals) may require that these recommendations be adapted to individual circumstances. For example, communal settings such as shelters may wish to develop processes for identifying ill individuals, for isolating ill individuals that do not require hospitalization, for education on respiratory and hand hygiene, and for connecting to medical care if needed. Additional information pertaining to communal settings can be found at:
http://www.phac-aspc.gc.ca/alert-alerte/h1n1/guidance_lignesdirectrices/commun-eng.php

Recommendations

The following are non-pharmaceutical measures to help mitigate the spread of the pandemic (H1N1) 2009 influenza virus within communities.

Self-Isolation of Ill Individuals

To help reduce transmission between ill persons and those who are healthy, prompt recognition of symptoms and early self-isolation (stay home) of symptomatic individuals is key. Individuals with ILI should self-isolate until they are feeling well and able to return to their normal activities.

It is recommended that persons who are ill with ILI who must go out into the community (for example, to seek medical care) take proper infection prevention measures (i.e., respiratory etiquette and hand hygiene) and avoid crowds (like mass transit) to prevent exposing others to the virus. If this is not possible or if preferred, a surgical mask could be worn to reduce the risk of spreading the virus within the community.

Family and other household members in homes with ill persons can continue their normal daily activities but should self-isolate, (e.g., stay home/go home) if they develop symptoms of ILI.

Although there is only limited evidence to support the use of masks in households as a means to reduce influenza transmission within the household, there may be some benefit in having the ill individual wear a mask when in a room with well individuals in an effort to help reduce the risk of spreading the virus to others.

Currently, there is insufficient evidence to suggest that the wearing of masks by asymptomatic individuals (e.g., caregivers) will help to reduce the transmission of influenza in the household setting.

While asymptomatic caregivers may choose to use a facial or surgical mask when caring for someone with ILI who is not wearing a face mask, this may not provide any benefit unless strict adherence to proper mask use and good personal hygiene practices are followed, including regular hand washing.

Hand Hygiene and Respiratory Etiquette

Proper hand hygiene and respiratory etiquette (covering coughs and sneezes) are important means of preventing the transmission of pandemic (H1N1) 2009 influenza virus. Information on hand hygiene and cough etiquette can be found at: http://www.phac-aspc.gc.ca/alert-alerte/h1n1/index-eng.php.

Respiratory etiquette involves coughing and sneezing into a disposable tissue, discarding tissue immediately and cleaning one’s hands afterwards or coughing/sneezing into one’s elbow or sleeve rather than one’s bare hands, if tissues are unavailable.

Hand washing with plain soap and water is the preferred method of hand hygiene in the community as the mechanical action is effective at removing visible soil as well as microbes. Where hand washing is not possible, use of alcohol-based hand rubs (with at least 60% alcohol) is recommended; however, alcohol-based hand rubs alone may not be effective at eliminating the influenza virus on hands that are visibly soiled.

It is recommended that businesses and other community settings where people congregate provide adequate hand washing supplies in the washrooms, kitchens and other sink areas in their facilities. They may also consider providing additional hand hygiene stations in highly visible locations, particularly where people congregate (e.g., entrances, food courts, etc.). Hand hygiene stations in non-supervised public settings (e.g., transit stations, parks etc.) are not recommended as evidence shows they are logistically difficult to maintain in such settings.  Product specific Material Safety Data Sheets (MSDS) and product labels provide additional information regarding placement, storage and warnings associated with alcohol-based hand rubs.

It is also recommended that supplies of tissues and waste receptacles be provided throughout facilities. Waste receptacles should be emptied frequently into the regular trash disposal containers.

Environmental Cleaning

Influenza viruses can survive on some surfaces from a period of several hours to days, but are rapidly destroyed by cleaning. Cleaning of high-touch objects and surfaces (e.g. doorknobs, faucet handles, work surfaces, computer keyboards, telephones, hand rails, etc.) will help to prevent the transmission of the influenza virus from person-to-person through contaminated hands.

To help mitigate the risk of individuals becoming infected through self-inoculation after touching contaminated surfaces, it is recommended that businesses and community organizations increase the frequency of cleaning of high touch surfaces (at least twice daily) and ensure that adequate hand hygiene supplies are available at all times.

Typically, no special disinfectants or waste handling practices are required for influenza. Waste handling would be according to usual practices and many readily available household or commercial disinfectant cleaning products are effective against influenza viruses. Product specific information, including its effectiveness against the H1N1 influenza virus, may be found on the cleaning product label and/or the manufacturer’s web site.¹ If household or commercial disinfectant cleaning products are not readily available, hard surfaces can be cleaned using a mixture of 1 part bleach and 9 parts water.  Always use caution when using bleach as undiluted bleach is corrosive and could damage the skin, fabrics and others surfaces. Dishes, clothing, and sheets used by an individual with ILI can be washed using ordinary detergent and water.    

Public Education

Public health messages that target all sectors of the public, including at risk and marginalized populations, will help to inform the general public in regards to illness prevention and management.

Key messages regarding prevention of transmission of the pandemic (H1N1) 2009 influenza virus should include information regarding:

• Getting immunized as soon as possible;
• Early identification and isolation of ill persons exhibiting ILI symptoms:
  • Be aware of signs and symptoms of ILI;
  • Stay home when sick with ILI until feeling well enough to be able to fully participate in all normal day to day activities;
  • When ill, staying away from others as much as possible to help prevent infecting others; and,
  • Plan ahead on how to return home as soon as possible by a means that will minimize exposure to others, should symptoms of ILI develop while at work or school.
• Use of appropriate hand hygiene and respiratory etiquette at all times;;
• Avoiding touching one’s eyes, nose and mouth; not sharing drinks, eating utensils, cigarettes, etc., to help prevent the virus from entering the body; and
• Avoiding contact with people who are sick with ILI and, if unable to do so, maintaining a 2-metre separation from others as much as possible.

Other important public messaging might include:

• Information on where to call for/seek medical advice (e.g., health information hot lines, vaccination centres, flu assessment clinics) and when to seek medical care;
• Implementing a “Flu Buddy” system whereby neighbours would check on each other, particularly the elderly, singles, and single parent families to help ensure assistance is available, if required;
• Information for individuals at high risk for serious illness or complications from influenza regarding the importance of:
  • consulting with their physicians to plan what they can do to protect themselves, what to do if they do become ill, where and when to get immunized and how to access anti-viral medication rapidly, should it be needed; and
  • consider avoiding large gatherings when ILI is circulating in their community in order to minimize potential exposure to the virus.
• Advice to all individuals regarding the importance of planning for the possibility of getting sick and ensuring an adequate in-house supply of groceries and other necessities should they be isolated at home for several days.

Some useful web-based information to support public education includes:

• How to recognize symptoms of ILI: Symptoms and Information
  http://www.fightflu.ca/sym-eng.html
• Practise cough and sneeze etiquette: Protect Yourself and Others
  http://www.fightflu.ca/prot-eng.html
• Use the correct hand washing technique: Get the dirt on clean hands! Your top questions answered. http://www.phac-aspc.gc.ca/alert-alerte/h1n1/public/handtech-eng.php

• Hand Hygiene Recommendations for Remote and Isolated Community Settings http://www.phac-aspc.gc.ca/alert-alerte/h1n1/public/handhygiene-eng.php

• How to look after someone at home with H1N1 flu virus.
  http://www.phac-aspc.gc.ca/alert-alerte/swine-porcine/guidance-orientation-05-03-eng.php
• Public Health Agency of Canada Travel Health Notices
  http://www.phac-aspc.gc.ca/tmp-pmv/index-eng.php

Faith-Based Organizations/Settings

It is recommended that faith-based organizations consider how the guidance provided within this document may apply to their settings and to determine if there may be a need to temporarily modify some faith based practices in an effort to prevent ILI transmission within their settings, especially when influenza is circulating in their community.
  
Additionally, faith-based organizations can contribute to public health efforts to prevent the transmission of influenza. Through their extensive networks, they can provide a venue to communicate key influenza prevention messages and, through their outreach programs, may also provide additional assistance such as Flu-Buddies who can check on vulnerable individuals within their communities.

Potential Community Based Interventions NOT Recommended at this Time

Use of Masks in the General Population

The Public Health Agency of Canada does not recommend that healthy people wear masks as they go about their daily lives in the community. There is no evidence to suggest that wearing masks will prevent the spread of infection in the general population and improper use of masks may in fact increase the risk of infection as removing the mask incorrectly can spread the virus to one’s hands and face.

Additional information regarding mask use in the community and home settings can be found at:

• Public Health Agency of Canada Recommendations on Use of Masks in Public Settings to Prevent Transmission of the H1N1 Flu Virus (Human Swine Flu)
  http://www.phac-aspc.gc.ca/alert-alerte/h1n1/info-mask-masque-eng.php
• How to look after someone at home with H1N1 flu virus.
  http://www.phac-aspc.gc.ca/alert-alerte/swine-porcine/guidance-orientation-05-03-eng.php

Widespread School and Daycare Closures

Neither proactive (in anticipation of illness/outbreak) nor reactive (in response to illness/outbreak) school closures are recommended at this time. More detailed information regarding schools and daycares can be found at:

Public Health Guidance for Child Care Programs and Schools (K to Grade 12)
http://www.phac-aspc.gc.ca/alert-alerte/h1n1/interim-provisoires0819-eng.php

Public Health Guidance for Post Secondary and Boarding Schools
http://www.phac-aspc.gc.ca/alert-alerte/h1n1/hp-ps/psili-eng.php

Workplace and Community Setting Closures

Widespread closures of businesses and community settings (e.g., libraries, recreational centres, government offices, etc.) are not recommended at this time. There is limited evidence regarding the effectiveness of these measures to stop the spread of the virus.  Most evidence comes from modelling studies where such measures are implemented as part of broad community closures. The societal disruption and economic consequences of these measures are thought to far outweigh the benefits of any potential reduction in transmission of influenza at this point in the pandemic in Canada.

In addition to the mitigation measures outlined in this document, some businesses may consider measures such as separating workstations by at least 2 metres and reducing face-to-face meetings or staggering arrival times as part of their internal pandemic planning. These measures are not yet supported by evidence.

Travel Restrictions

Due to the widespread transmission of the H1N1 virus, travel restrictions are not considered to be an effective measure to stop the spread of the virus; however, advice regarding individuals who are ill with symptoms of ILI remains the same – stay home (or in your accommodations, if not at home) if ill.

For specific travel health advice regarding H1N1 and international travel, please visit the PHAC travel health websites at http://www.phac-aspc.gc.ca/tmp-pmv/2009/h1n1_global-090722-eng.php#rec.

Broad Restrictions on Other Public Gatherings

Community outbreaks have been detected throughout Canada with the virus primarily causing mild illness; therefore, at this point in time widespread closures/cancellations or other broad restrictions are not recommended as there would be insufficient benefit to warrant the high cost these measures would entail. Encouraging ill people not to attend gatherings and ensuring processes are in place to safely isolate and transport people who become ill on-site remain the most important measures to prevent transmission.

If the epidemiology of the disease changes and the virus becomes more virulent, particularly in certain age groups, these recommendations will be reconsidered along with other social distancing strategies.

The evidence supporting measures such as widespread closures and broad restrictions on public gatherings (e.g., theatres, parades, sporting events, etc.) is limited and therefore potential benefits remain theoretical. Some modelling studies have shown that widespread and prolonged closures of settings such as schools, businesses, etc., when implemented early in the pandemic, have the potential to reduce transmission resulting in “flattening” of the peak of an epidemic wave, especially if implemented in series with other interventions. In addition, historical data from the 1918 pandemic suggests that cities that cancelled public gatherings early in the pandemic had reduced epidemic peaks; however, it is impossible to discern if this measure alone had a significant impact.

The potential benefit of cancellation should be weighed against the known high economic and social costs of these measures. Additionally, ethical issues including undue burden on specific populations and the possible disruption of key services such as healthcare and public transit should also be considered when determining whether to implement broad restrictions on public gatherings.

Reference List and Additional Resources

1. Aledort J.E., et al. Non-pharmaceutical public health interventions for pandemic influenza: an evaluation of the evidence base. BMC Public Health 7:208. 2007. http://www.biomedcentral.com/1471-2458/7/208
2. Centers for Disease Control and Prevention. CDC Guidance for Businesses and Employers To Plan and Respond to the 2009-2010 Influenza Season. 2009. http://www.cdc.gov/h1n1flu/business/guidance/
3. European Centre for Disease Prevention and Control. ECDC Interim Risk Assessment Influenza A(H1N1) 2009 Pandemic, 20 July 2009     http://www.reliefweb.int/rw/RWFiles2009.nsf/FilesByRWDocUnidFilename/SODA-7U5TH8-full_report.pdf/$File/full_report.pdf
4. MacIntyre C.R., et al. Face mask use and control of respiratory virus transmission in households. Emerging Infectious Diseases vol 15, no.2. February 2009
5. Perez-Padilla, R., et al. Pneumonia and Respiratory Failure from Swine-Origin Influenza A (H1N1) in Mexico. New England Journal of Medicine 361;7. August 2009. http://content.nejm.org/cgi/reprint/361/7/680.pdf
6. Public Health Agency of Canada. Canadian Pandemic Influenza Plan for the Health Sector; Annex M: Public Health Measures., Oct. 2006. http://www.phac-aspc.gc.ca/cpip-pclcpi/ann-m-eng.php
7. Public Health Agency of Canada. Public Health Guidance for Child Care Programs and Schools (K to grade 12) regarding the Prevention and Management of Influenza-Like-illness (ILI), Including the Pandemic (H1N1) 2009 influenza Virus. 2009. http://www.phac-aspc.gc.ca/alert-alerte/h1n1/interim-provisoires0819-eng.php
8. Public Health Agency of Canada. Guidance for Ambulatory Care of Influenza-Like Illness in the context of H1N1 influenza virus. 2009. http://www.phac-aspc.gc.ca/alert-alerte/h1n1/guidance-orientation-amb-07-16-eng.php
9. Public Health Agency of Canada. Business Continuity Planning Resources and Checklists. http://www.phac-aspc.gc.ca/influenza/bcp-eng.php
10. Public Health Agency of Canada. Pandemic (H1N1) 2009 Epidemiological Summary for  Canadian Laboratory-Confirmed Hospitalized Cases and Deaths. Unpublished (October 24, 2009)