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7 MITIGATING THE IMPACT

7.1 Introduction

Although a pandemic could potentially have a serious impact in the UK in terms of illness and deaths and the consequent impact on the provision of services, we are far better placed to handle the consequences of a pandemic now than we have been in the past. This is as a result of a number of factors - better health and nutrition standards amongst the population, improved health and community care services, better communication links and advanced technology and scientific research which will allow us to respond rapidly to treat the virus. In previous pandemics, poorer general standards of health and nutrition were a factor in the extent of illness and deaths caused.

Added to this, the Scottish Executive and UK Government response to a pandemic is based on a number of strategies which are designed to mitigate the impact of a pandemic.

Due to the uncertain nature of a pandemic and the heavy demands it will place on available resources, a flexible strategy which combines a number of measures will be used. This strategy includes:

• the use of medicines - both vaccines and anti-viral drugs;
• infection control;
• social distancing; and
• school closures

Although medicines may provide some protection from the more serious effects of the pandemic, we recognise that their use must go hand in hand with other measures which are equally important.

Final decisions about the application of all or some of these measures will be made by the Scottish Executive and UK Government as information about the nature of the pandemic emerges. This will be reflected in the messages which are given to the public and the media through the UK and national communications strategies.

7.2 Travel Restrictions

International travel

International travel is increasingly central to the way we live today and we are dependent on it at both a personal and a business level. Disruptions to travel can have widespread consequences. However, it is the ease and frequency of international travel which may also speed the spread of a pandemic.

As a major destination and international travel hub, the UK is particularly vulnerable to the importation of infectious diseases. Although the imposition of restrictions on travel to and from affected areas has made an important contribution to the control of some infectious diseases in the past, influenza is most infectious immediately after the onset of symptoms and has a short incubation period.

Modelling and evidence from previous outbreaks of infectious diseases suggest that no practical level of travel restriction is likely to allow a country to avoid a pandemic altogether. The imposition of restrictions on all travel to the UK would only be likely to delay arrival of the virus by one or two weeks if 90% effective and by some two months if 99.9% effective. Preventing those with symptoms travelling by using a system of exit screening would only be likely to delay the spread of infection by one to two weeks. Conducting additional entry screening for travellers arriving in the UK would have no additional advantage.

The possible limited health benefits from imposing international travel restrictions or border closures have to be weighed against their practicality, proportionality and potential effectiveness and wider social and economic consequences. We would also, of course, take account of any new advice or developments from the World Health Organization, European Community or other governments

However, both the Scottish Executive and the UK Government recognise that there is a need to review and potentially strengthen our existing arrangements for port health. Health Protection Scotland is currently engaged in a review of port health arrangements in Scotland. Port and airport operators, carriers and those authorities with specific responsibility for port health arrangements should also be reviewing the robustness of their own arrangements

The planning presumption should be that the UK Government is unlikely to recommend or impose international travel restrictions, border closures or entry/exit screening unilaterally. The Government would monitor the development of the pandemic and may advise against unnecessary travel. Advice to British nationals in - or intending to travel to- affected areas would be available from the Foreign and Commonwealth Office and from Health Protection Scotland.

Port Health Arrangements

At present NHS Boards and Local Authorities have responsibility for Port Health at designated ports in the United Kingdom. The response to a potential communicable disease risk at a port is usually the responsibility of the local NHS board who will provide a designated medical officer ( DMO) to lead the response supported by medical and environmental staff from NHS Boards and Local Authorities, respectively. The regulations that define the powers of the health authorities are The Public Health (Aircraft) (Scotland) regulations 1971 and The Public Health (Ships) (Scotland) regulations 1971. This response is dependent of notification of a risk by the commander of the aircraft or the master of a vessel. A risk may also be notified by officers of HM Customs & Excise, HM Immigration Service ( UKIS) or by Medical Inspectors ( MIs) called in by officer of UKIS where necessary. Both the above mentioned regulations give powers of detention and detention of vessels, aircraft and persons with additional measures for diseases covered by the International Health Regulations 1969; namely plague, cholera, yellow fever and small pox.

The International Health Regulations have recently been revised (2005) and are to be implemented by WHO member countries, of which the United Kingdom is one, over the next few years. Changes in these regulations will naturally affect the regulations under which the port health is guided. In addition, the implementation of the International Health Regulation affords an opportunity to review Port Health and Medical inspection (under the Immigration Act 1971) to find out whether it is fit-for-purpose. This review is currently ongoing and is considering such issues as communication, guidance, skill mix and facilities. In particular is important that the DMOs, MIs, as well as UKIS, HM Customs & Excise, and Local Authorities are informed of risks as they arise. In addition it will also be important to involve the British Airports Authority ( BAA), who will be involved in providing additional facilities and services, and in the case of shipping the Maritime & Coastguard Agency who have additional powers with respect to shipping, as well as the relevant English and UK authorities who are currently defining their own guidance and legislation.

National Travel

Modelling suggests that internal travel restrictions would have little positive impact on the total number infected by influenza over the entire course of a pandemic. Even a 60% reduction in all travel - including commuting to work - would only result in a small flattening of the profile of the pandemic across the country - reducing the national peak incidence by 5-10% and lengthening its period by a week - but also exacerbating the economic impact, increasing social disruption and adding to business/service continuity problems.

On balance, the planning presumption should be that the Government is unlikely to impose any restrictions on internal travel unless it becomes necessary to do so for public health reasons in which case it is likely to be on an advisory basis. The public will be advised to minimise non-essential (leisure/social) travel as a personal precautionary measure but to continue using public transport for essential journeys, adopting personal hygiene measures and staggering journeys where possible.

7.3 Medicines

Pre pandemic vaccination

Pre-first wave immunisation with an influenza vaccine, related but not specific to the pandemic strain might offer some limited, but nonetheless useful, cross protection. If a suitable vaccine were available but in limited supply, it could be used to provide partial protection for health and other staff likely to be frequently exposed to symptomatic patients. The UK has very limited stocks of A/H5N1 vaccine that might be used in this way should a pandemic virus emerge from this source. Immunisation with pre-pandemic vaccine could also provide partial protection for others crucial to the maintenance of essential services. It could possibly also help reduce hospitalisations and deaths in vulnerable groups. However this would require larger stocks of such a vaccine than are currently held. Decisions on use would follow assessments of the likely degree of cross-protection afforded (if any) and risk/benefits as the pandemic alert phases change. In the meantime, response plans should assume that arrangements for limited pre-pandemic vaccination for healthcare workers and possibly for other targeted groups, if further supplies are available, might be necessary.

More widespread immunisation with a pre-pandemic vaccine could have a substantial effect, but would require still larger stocks of such a vaccine and is not currently part of the UK Health Departments' plans. Anticipating a suitable vaccine strain also has the inherent risk of it being ineffective against the ultimate pandemic strain. The Department of Health working with SEHD and other UK Health Departments continues to monitor the evolution of viral strains and options for pre-pandemic vaccination. It will inform planners of any policy changes.

Pandemic specific vaccination

Vaccination is widely used in the UK to offer protection against the seasonal influenza strains most likely to be circulating that particular year. As a pandemic will result from the emergence of a new or modified strain, these routine vaccines are unlikely to offer protection. It is not possible to develop a matching vaccine for a matching strain until the emerging influenza strain can be identified and the UK Government is working actively with the international community, pharmaceutical industry and EMAE to speed the development, testing and licensing of vaccines and secure the earliest possible supply. However, it may take four to six months before an effective vaccine is available and considerably longer before it can be manufactured in sufficient quantities for the entire population given that international demand will be high. Realistically, it is therefore unlikely that a specific vaccine will contribute much to dealing with the initial wave of a pandemic - unless its evolution, or the effectiveness of early control measures, result in a significantly slower developing pandemic than anticipated.

For planning purposes, the presumption should be that a vaccination campaign with a specific pandemic vaccine before or during the first pandemic wave is unlikely, but may contribute to reducing the impact of subsequent waves if they occur.

Anti-viral medicines

The targeted and effective use of antiviral medicines is an important countermeasure and the UK has established a stockpile of oseltamivir (Tamiflu) sufficient to treat 25% of the population. Oseltamivir is a neuraminidase inhibitor which works by preventing the influenza virus from reproducing and leaving the host cell. When used to treat seasonal influenza, antiviral medicines reduce the length of symptoms (by around a day) and usually their severity, as long as they are started within two days of the onset of symptoms. It is impossible to predict whether antiviral medicines will be equally effective against a new or modified pandemic virus, but reasonable to anticipate a similar effect and associated substantial reductions in severe morbidity.

Although a number of alternative strategies are being evaluated, scientific advice confirms that prompt treatment of all symptomatic patients is currently the most effective use of the antiviral stocks available. The existing UK stockpile allows for a single course of treatment of all symptomatic patients at clinical attack rates of up to 25% and arrangements to make those rapidly available are a critical part of the health response. Operational plans should initially aim to make antiviral medicines available to all patients who have been symptomatic for less than 48 hours, preferably within 12 to 24 hours from reporting symptoms indicative of influenza.

The prompt use of antiviral medicines will benefit individual patients and may also produce public health benefits by decreasing the overall clinical attack rate, shortening the period that individuals are able to shed virus and thus able to pass on the infection to others. Although there is considerable uncertainty over the level of reduction possible, one model suggests a relative lowering of the attack rate by up to one third over the course of a pandemic.

Health protection agencies will implement measures to monitor the susceptibility of the virus to antiviral medicines, assess their effectiveness in reducing complications and deaths and inform policy decisions. The Medicines and Healthcare Products Regulatory Agency ( MHRA) will identify the incidence and patterns of any adverse reactions.

It is also possible to use antiviral medicines as a preventive measure (prophylaxis) to protect against infection. Although some prophylactic use may help contain spread from initial cases and thus slow the development of the pandemic, protecting significant numbers for its entire duration would consume large numbers of treatment courses and still leave those treated susceptible to infection as soon as they stopped taking the medicine. Therefore, apart from attempts to contain initial spread, general prophylaxis is not regarded as an effective or practical response strategy at this stage. An alternative may be 'household prophylaxis' which provides 'post-exposure' prophylaxis to immediate contacts at the same time as treating a symptomatic patient on the grounds that some of the contacts may already be incubating the infection. This could mitigate and delay the progress of a pandemic - particularly as part of a combination of measures such as school closures. However, such a strategy would consume significantly greater stocks of antiviral medicines than currently available in the UK. Its practicalities will be reviewed should the supply position change.

Antibiotics and essential pharmaceutical supplies

Demand for essential medicines and over the counter remedies is likely to be high in a pandemic and re-supply may be uncertain. The Department of Health is working with the pharmaceutical sector to enhance stocks and increase the resilience of the supply chain. Clinical guidance on prescribing and use during the pre pandemic and pandemic periods will be issued and changes to medicines legislation and related regulations implemented to ensure adequate patient access.

Social distancing

Whilst it might be possible to isolate initial cases and quarantine their immediate contacts, such an approach will become unsustainable after the first hundred or so cases. Geographic quarantining measures have been used in an attempt to isolate affected communities in the past, but are unlikely to be effective against pandemic influenza in the UK as infection is expected to affect all major population centres within one to two weeks of initial cases being identified.

Whilst those without symptoms will be encouraged to carry on as normal, symptomatic patients will be asked to stay at home or in their place of residence (voluntary home isolation and quarantine). If staying at home becomes impossible, for example because of the need to be assessed and treated for complications or transferred to hospital, symptomatic patients should wear a disposable face mask (ordinary surgical mask) to reduce transmission of infection.

Influenza is likely to spread rapidly in closed establishments such as prisons, residential homes and boarding schools where people are in close contact and may also be in higher risk groups. Such establishments may also be more vulnerable to higher levels of staff absenteeism, supply disruption or transport difficulties. As opportunities for closure, quarantine, isolation or social distancing may be limited, it is vital that resilient arrangements are developed in advance of an outbreak.

Infection control and personal protective equipment

Once efficient person-to-person transmission is established, preventing an influenza pandemic developing is unlikely to be possible as most people are likely to be exposed to the virus at some stage during normal activities. In order to protect others and reduce the spread of infection, anyone with influenza-like symptoms should stay at home, minimise social/family contact and go out only if absolutely necessary until symptoms have resolved. Those who are not symptomatic should continue normal activities and can reduce - but not eliminate - the risk of catching or spreading influenza by avoiding unnecessary close contact with others and adopting high standards of personal and respiratory hygiene.

Applying simple infection control measures and encouraging compliance with public health advice are likely to make an important contribution to the UK's overall response. Simple measures will help individuals to protect themselves and others. The necessary measures include:

• covering the nose and mouth with a tissue when coughing or sneezing
• disposing of dirty tissues promptly and carefully - bagging and binning them
• washing hands frequently with soap and water to reduce the spread of the virus from the hands to the face, or to other people, particularly after blowing your nose or disposing of tissues
• making sure children follow this advice
• cleaning hard surfaces ( e.g. kitchen worktops, door handles) frequently using a normal cleaning product
• avoiding crowded gatherings where possible, especially in enclosed spaces

Adopting such measures can help mitigate the overall health and wider impact of a pandemic by lowering the clinical attack rate and slowing its development thereby spreading peak demand and enabling services to respond more effectively.

The use of face masks and respirators

Facemasks and respirators (masks that incorporate a filter) provide a physical barrier against the influenza virus if of an appropriate type, worn correctly, changed frequently, removed properly, disposed of safely and used in combination with good universal hygiene behaviour. They can be used to help protect the facial mucosa by wearers who may for example be at occupational risk from close or frequent contact with symptomatic patients. Face masks may also be used by those who are symptomatic to avoid contaminating others if they have no choice but to leave their home. Disposable masks or respirators should generally only be worn once, for no longer than the time recommended by the manufacturer and then discarded in an appropriate receptacle.

Although the widely held perception is that wearing a facemask in public places may be beneficial, current evidence of benefit from widespread use by the public is not convincing and unless worn, handled and disposed of correctly, such masks may actually exacerbate the risk. Wearing masks at all times is not practical so decisions must take account of the degree of risk associated with particular occupations or activities and should be based on risk assessments carried out by the employer in occupational settings.

The planning presumption should be that the general wearing of facemasks by those who are not symptomatic will not be recommended whilst undertaking normal activities. Judgements in occupational settings will need to be based on a risk assessment. Guidance to employers is available via the HSE website:

www.hse.gov.uk/biosafety/diseases/pandemic.htm

Public gatherings

Large public gatherings and events are an important indicator of 'normality' and can help maintain public morale during a pandemic. Whilst close contact with others - especially in a confined space - accelerates the spread of an influenza virus, there is little direct evidence of the benefits or effects of cancelling such gatherings or events. Results similar to those for closing schools (see below) might be expected, albeit on a more limited scale if events are indoors. Individuals may benefit from reduced exposure by not attending such events but there would be very little benefit for the overall community. Reduction in travel to such events may also reduce the spread although the benefits of even major reductions in all travel are small.

These conclusions are consistent with the lack of important observable differences between the course of seasonal flu outbreaks in London - where there is considerable mixing on commuter trains and underground railways - and the course in other parts of the UK. Whilst evidence does not suggest a blanket ban on such events, individuals might well choose to avoid the potential infection risk from attending them and organisers to cancel to avoid any economic risks. Transport difficulties, public order, crowd safety or other similar considerations may also affect decisions on staging such events, which can only be taken by organisers and/or governing bodies and licensing authorities (where relevant) in the light of information and the circumstance at the time.

For planning purposes, the presumption should be that the Government is unlikely to recommend a blanket ban on public gatherings. However, informed judgements by the event organiser and/or governing body in conjunction with the regulatory authority may become necessary at the time. If international events are due to be held in the UK with participants from affected areas, the Government may recommend postponement.

Possible closure of schools, nurseries and group childcare settings

Influenza transmits readily wherever people are in close contact and is likely to spread particularly rapidly in schools. As children will have no residual immunity they could be amongst the groups worst affected and can be regarded as 'super-spreaders'. In the 1957 pandemic up to 50% of schoolchildren developed influenza and in residential schools attack rates reached 90%, often affecting the whole school within a fortnight.

Closing schools and nurseries to pupils as an adjunct to the antiviral treatment planned for a pandemic might reduce its peak impact by an additional 10% and the total number of clinical cases could also reduce by 10% compared to antiviral treatment alone. Most of this reduction would be in school age children, where the reduction in the number of clinical cases might be as high as 50%.

Closing all schools and nurseries in an affected area may offer the most practical option. While this would disrupt education and have a significant negative effect on services and businesses, particularly those highly dependent on working parents, such disadvantages would be outweighed by the children's lives saved. The same would apply to group childcare settings where groups of children (and often parents) mix. Though there is less evidence relating to this sector than to schools, the same principles would apply, and if schools were to close it would be logical to extend the closure to group childcare settings. This would nevertheless increase the impact of closures upon services and businesses where working parents are employed. Reducing mixing between children outside school or other childcare settings would also be necessary for maximum benefit and is likely to prove challenging during any extended closure.

The Scottish Executive has issued detailed guidance for schools, childcare and children's services in Scotland, which advised them to plan both for schools, nurseries and group childcare settings staying open and for possible closure, for some or all of a pandemic. Closure could either be very localised and brief - for example, a school with too few staff to operate safely - or more widespread and for a longer period if national public health advice confirms that this will reduce the spread of infection among children. The Executive would take national decisions on whether or not to advise closures based on an assessment of the emerging characteristics and impact as the pandemic develops. The trigger for local decisions by Strategic Co-ordination Groups on closure would be confirmation of initial cases in the area.

On balance, plans should be prepared on the basis that

• some school, nursery and group childcare closures are likely to be necessary
• decisions on school, nursery and childcare closures can only be made in the light of emerging information as a pandemic develops
• schools, nurseries and childcare settings will only be advised to close if it is anticipated that this will produce significant health benefits
• if the Executive and Strategic Co-ordination Groups advise schools, nurseries and childcare settings to close to pupils, the initial closure would be reviewed after 2-3 weeks, after which the closure may be extended
• any advice to close schools and childcare settings would be communicated to them through the local authority, who would be advised by Strategic Co-ordinating Groups
• even if there is no general advice to schools and childcare settings in an area to close, some may need to do so because of staff shortages or local health and safety reasons.

Planning for a Human Flu Pandemic - Guidance for Schools, Childcare and Children's Services in Scotland is available from http://www.scotland.gov.uk/Publications/2006/07/05121311/0

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