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Pandemic Flu

Pandemic Flu 窶・MICKS April 2008

Background

For this edition of MICKS, I wish to address and discuss pandemic flu which has the potential of being a very significant public health issue and which has major infection control implications in hospitals and the wider community. This subject has received much media attention and is widely discussed amongst many professional groups, which is why I believe it is valuable for us to discuss this as part of MICKS.

The term "flu" is a non-specific name often used to refer to a range of different general symptoms, whereas influenza is an acute infectious respiratory disease caused by an influenza virus, characterised by fever, sudden onset of chills, headache, muscle pains, severe prostration and, usually, a cough with or without a sore throat or other respiratory symptoms. Typical incubation period is 1-3 days (typically 2 days), acute symptoms last for about 1 week but full recovery may take longer and adults can be infectious from the onset of symptoms for 4-5 days. Influenza is mainly spread by the respiratory route, through droplets of infected respiratory secretions produced when an infected person talks, coughs or sneezes (direct droplet spread); it may also be spread by hand/face contact after touching a person or surface contaminated with infectious respiratory droplets. Airborne transmission through finer respiratory aerosols (which stay in the air for longer and are therefore more effective at spreading infection) may occur in some circumstances.

A pandemic means an epidemic of any disease over a wide geographic area affecting a large proportion of the population. Therefore, pandemic influenza refers to emergence of a major new type of influenza A for which the entire population has little or no immunity. It spreads the same way that ordinary influenza does, but is more likely to cause severe disease or death.

The actual risk of a flu pandemic!

There is no pandemic human influenza virus currently in circulation. The risk of a human influenza pandemic is distinct from seasonal flu, and avian influenza (bird flu). Human cases of avian influenza in Asia are not part of an influenza pandemic. Seasonal influenza outbreaks are caused by subtypes of influenza virus that have already circulated among people and can cause serious illness in some people. However, fewer people are infected because of the effectiveness of the vaccines and many people will already have developed some immunity. Avian influenza, or "bird flu", is an infectious disease of birds caused by influenza virus that normally cause mild or no symptoms in birds and is found worldwide. However, some virus strains such as the H5N1 cause more severe disease in birds and maybe lethal, the avian flu, H5N1 virus rarely infects humans. Most, if not all human cases to date involved people who have had direct contact with infected poultry. There is no evidence of sustained human-to-human transmission that would be necessary for the avian flu virus to become pandemic influenza.

Internationally, there have been an increasing number of media stories focusing on pandemic fears and speculating that the current increase in birds with avian flu virus is the warning sign that a human flu pandemic is imminent.

Pandemic flu affecting humans may occur due to the emergence of a new flu virus which is markedly different from recently circulating strains. It could happen if:

(a) avian flu combines with 'ordinary' flu;

(b) avian flu virus mutates and a completely new flu strain that can be transmitted directly from one person to another is created or

(c) a new flu virus emerges from circulating strains.

It hasn't happened yet, but if pandemic flu did occur, it would be a significant problem. Few, if any people will have immunity to the new virus, which will allow it to spread widely, and to cause more serious illness. Experts predict another pandemic will occur but cannot say exactly when. Each pandemic is different and, until the virus starts circulating, it is impossible to predict its full effects.

Pandemic flu will only be considered imminent when a new virus has shown it can spread easily between people. In practice, this means when a new strain of the virus has been identified as the cause of chains of illness passed from one person to another or illness in more than one country, with no obvious links. This has not yet happened.

Although it is inevitable that there will be major changes in the human influenza virus again in the future, no one can say for certain when this will occur, or how severe the resulting disease will be. The current avian flu would have to evolve to a type capable of efficient human-to-human transmission before a pandemic could occur. This may or may not happen. In the event of an outbreak in one part of the world, modern travel patterns makes the quick spread of the virus to other countries quite likely. Where humans have caught H5N1, it is because of close and prolonged contact with infected poultry or poultry products. There is no confirmed evidence that H5N1 has acquired the ability to pass easily from person to person. A human flu pandemic would only be triggered if a flu virus gains the ability to spread effectively and quickly between people. This has not yet happened.

National and International Government Planning:

Governments are responsible human health, and therefore for planning for a human flu pandemic. Because the impact of any outbreak is unpredictable, national Governments should be sure they are:

・Prepared - planning is well developed i.e a national strategy and operational policy for responding to an influenza pandemic; stockpiling anti-virals and other infection control equipment, acquiring vaccines and the capacity to acquire new vaccines quickly.

・Flexible - there are robust generic arrangements for community emergency response. Organisations at the local, regional and central levels have prepared options and strategies for dealing with an outbreak of human flu pandemic, and making sure pertinent action plans.

・Decisive - there clear arrangements in place for directing, planning and responding decisively to a pandemic. Agreed strategies should be evidence based, trialed and include lead departments/personal responsible for the planning and response work necessary.

・International - both avian flu and pandemic flu have global impacts, and must be tackled globally. Therefore international collaboration together with epidemiological intelligence are very important in international control and outbreak management.

The World Health Organization refers to six phases:

Phase 1: No new influenza virus subtypes detected in humans.

Phase 2: Animal influenza virus subtype poses substantial risk

Phase 3: Human infection(s) with new subtype, but no (or rare) person-to-person spread to close contact.

Phase 4: small cluster(s) with limited person-to-person transmission but spread is highly localized, suggesting that the virus is not well adapted to humans.

Phase 5: Large cluster(s) but person-to person spread still localised, suggesting that the virus is becoming increasingly better adapted to humans.

Phase 6: increased and sustain transmission in general population.

Individual nations have adopted additional levels of alert for example, in the UK 1 窶・4. ( DH 2007) which range from virus cases only outside the UK (Level 1) to widespread activity across the UK (Level 4).

Significant about each of these phases/levels of spread, is that they directly relate to the response and extent of planning required by each government and country, which are generally detailed in national policies and guidance frameworks for pandemic flu.

The guidance provides advice for acute hospitals, healthcare in community settings, schools, businesses, transport and large public events. It is recommended that these documents are obtained from government websites.However for this edition of MICKS I wish only to examine the guidance for hospitals. In a subsequent edition I hope to examine control measures for the community and schools.

Guidance for hospital practitioners: recommended infection control measures Fundamentally the infection control precautions that should be adopted include Standard Precautions and airborne precautions.

Its mode of spread is:

・From person to person through close contact

・Large droplet and indirect contact

・Airborne or fine droplet especially during aerosol generating procedures

General Infection control Management of Cases

・Where ever possible patients with influenza should be managed within their home.

・Patients with symptoms of pandemic influenza should be segregated from non-influenza patients as rapidly as possible.

・Patients in ITU should be nursed in designated side room. Patient should wear a surgical mask. If the patient requires a CxR( chest x-ray) this should be a portable Xray in the side room.

・Verify with the patient’s community doctor that the patient actually needs admission or further assessment.

・If patient requires admission they should be admitted directly to the area of the hospital designated in Pandemic Influenza Operational Plan. Inpatients who develop symptoms or laboratory proven influenza must be transferred to the designated pandemic influenza cohort area.

・The patient should wear a surgical mask to be transported through the hospital.

Management of coughing and sneezing

・Encourage patient to cover nose and mouth with a disposable single-use tissue when coughing and sneezing or blowing nose.

・Dispose of used tissue in paper locker bag at bedside.

・All waste should be placed in clinical waste bin.

・Encourage patient to use alcohol hand gel.

・Keep hands away from mucous membranes of nose and eyes

・The patient should wear a surgical mask during transport and in common waiting areas.

Handwashing

・Hand hygiene is the single most important practice to reduce the risks of transmission of pandemic influenza

・Hands must be decontaminated with soap and water or alcohol based hand disinfectants.

Personal Protective Equipment (PPE)

・PPE should be worn to protect staff from contamination with body fluids and thus reduce the risk of transmission of pandemic influenza between service users and staff and from one service users to another

・It is likely that PPE might quickly become in short supply; advanced planning is required to build up and manage adequate stock

・PPE must be donned and removed with care to reduce the risk of contamination, and disposed of after use

・If using surgical masks or respirators these should be removed last

・All PPE must meet the relevant international and/or national standards

・Staff must be trained in the appropriate use of PPE

・PPE must be removed before leaving a cohort area

Surgical FFP1 masks

・Must be worn by care practitioners for close contact (< 1 metre) of patients with symptoms or pandemic flu.

・Must cover the nose and mouth and not be allowed to dangle around the neck

・Must not be touched once put on

・Masks are a single use item.

・Mask should be worn for a maximum of four hours only and then changed.

・Mask should be changed immediately if they become moist.

・It may be practical for staff working in cohorted areas to wear a mask on entry and wear it for the duration of the activity in this area.

・Must be discarded as clinical waste.

・Must be removed last when leaving an area

・Decontaminate hands after removing mask.

Respiratory mask

・A respiratory mask providing the highest protection (EN149:2001 FFP3) should be worn by health care workers when performing patient procedures where aerosol may be generated e.g. intubation, nasopharyngeal aspiration, tracheostomy care, chest physiotherapy, bronchoscopy, nebuliser therapy.

・Respiratory mask should be replaced after each use.

・If the respirator becomes damaged or distorted or contaminated by body fluids it should be changed immediately.

・Decontaminate hands after removing mask.

・Fit testing of FFP3 respiratory masks should be provided for staff in high-risk clinical areas e.g. intensive care units and/or Pandemic flu cohort area.

Gloves

・Gloves are required as part of Standard Infection Control precautions only. There is no need to use gloves for patients with pandemic influenza unless indicated as part of these standard precautions

・Disposable non-sterile soft vinyl gloves should be worn for procedures where contact with respiratory secretions is likely.

・Latex gloves are only required if the respiratory secretions are heavily blood stained.

・Gloves should be removed immediately after use and disposed of as clinical waste

・Gloves are single use items and should not be re-used

Aprons

・Disposable plastic aprons must be worn whenever there is a risk of clothing coming into contact with blood or body fluids (including respiratory secretions)

・They are single use items and must be disposed of immediately after use

Gowns

・Gowns are required if extensive soiling of clothing or uniform with respiratory secretions is anticipated

・Fluid repellent gowns are preferred but if these are unavailable then a plastic apron should be worn underneath.

・Single use, disposable gowns are preferred as the CT does not have laundering facilities

・Gowns should fully cover the area to be protected

Eye protection

・Standard eye protection (goggles or face visors) should be worn when there is a risk of contamination of the eyes by splashes and droplets.

Linen

・Linen from service users with pandemic influenza should be classed as infected and washed separately. It should be bagged in an Aquafilm alginate bag at point of use and sealed before removing from the area.

・Linen should be washed on the hottest wash for the fabric

・In community clinics and day care centres , the same procedure be adopted using a hot wash on a domestic washing machine. If not possible consideration should be given to using disposable items.

Crockery & Utensils

・No special requirements beyond standard precautions are required

・Where possible, use a dishwasher for washing items

・Disposable items are not required

Environmental cleaning

・Undertake routine cleaning with freshly prepared neutral detergent and hot water.

・Detergent wipes should be used on frequently touched surfaces i.e. bed tables, medical equipment.

・The use of vacuum cleaners should be avoided.

・Spillages and contamination should be dealt with in line with local policy.

・Cleaning staff should be allocated to specific areas and not moved between influenza and non-influenza areas.

・Cleaning staff should wear gloves, apron and a surgical mask in the immediate patient environment in cohorted areas.

・Cleaning staff should decontaminate their hands after removal of PPE and when leaving an area where influenza patients are nursed.

・Hypochlorite solution 1,000 ppm available chlorine should be used for terminal cleaning of a bed area in the cohort ward.

・Privacy bed curtains must be changed following patient transfer to pandemic cohort area if visibly contaminated.

Visitors

・Should be restricted to close family.

・Family members who have symptoms of influenza should not visit.

・Visitors entering a cohort area must be instructed on hand hygiene and the wearing of protective clothing as appropriate.

・If visitors or volunteers become carers they will need instruction in infection control principles.

Further Information and Guidance:

To assist practitioners, health authorities and the public in developing their local plans most governments provide a range of further guidance e.g.

1. Pandemic Flu 窶・A national framework for responding to an influenza pandemic. UK Deaprtment of Health 2007. www.dh.gov.uk/pandemicflu

2. Pandemic Influenza Guidance for Primary care trusts and primary care professionals on the provision of healthcare in a community setting in England. UK Department of Health 2007

3. CDC Pandemic Influenza Operational Plan (OPLAN) 2008 www.cdc.gov/flu/pandemic/cdcplan.htm

Information is generally also available from professional organisations, and international bodies such as the World Health Organisation and the Centres for Disease Control.

Jg/2008

University of Wales
Dr. John Gammon
Profile


Dr Gammon is recognised as an international authority on infection prevention and control. Currently, he is a Non -Executive Director of Carmarthenshire NHS Hospital Trust and Deputy Head of the School of Health Science, at Swansea University, Wales, UK. He has practiced as an infection control practitioner for many years and been instrumental in Wales in establishing infection control services. Furthermore he has lead on the establishment infection control courses, and national guidance on hospital and community infection prevention strategies. He has been central to the development of, evidence based, international guidance on patient isolation. His research interests include patient isolation, standard precautions and hand decontamination. He has published a number of research papers and continues to advise the Welsh Government on infection control practice and strategy. He acts as key advisor to a number of commercial companies involved in infection control. His focus of academic interest for the last few years has been the education and professional development of practitioners and specifically infection control practitioners. This has included e-learning course as well as Masters programmes in infection control.