Avian Flu Pandemic Adivice continued ....

Department of Health influenza pandemic planning assumptions

Based on previous pandemics and current internationally agreed arrangements co-ordinated by the WHO, UK Health Departments have agreed the following planning assumptions (further details in Chapter 4 of main Plan):

(i) Spread from the source country to the UK will take no more than three months. Once in the UK, it is unlikely that we will be able to stop the spread of pandemic influenza. Our aims are to slow its spread, at least in the short term, in order to buy time and spread the load on health and other services, and to reduce its impact.

(ii) Most people will be susceptible to the new virus, although not all will necessarily develop clinical illness. All ages will be affected, but children and otherwise fit adults could be at relatively greater risk should elderly people have some residual immunity from exposure to a similar virus earlier in their lifetime.

(iii) Vaccine will not be available in the early stages. A pandemic vaccine cannot be stockpiled in advance: it must be produced specifically for the virus concerned so development cannot start until the virus is known. Everything will be done to produce a vaccine as quickly as possible, but it is likely to take at least 6 months.

(iv) As vaccine becomes available it will be given according to nationally agreed priorities, starting with health care and other essential workers. Beyond that, the final decisions will be based on early information about the age groups being affected most severely. When vaccine supplies become more widely available, vaccination will be offered to the general population.

(v) Antiviral drugs are available for treating influenza, but even with a national stockpile, there will not be an unlimited supply. They may be used initially to try to contain small outbreaks. Later they will be used to treat certain narrowly-defined priority groups according to agreed guidelines in order to achieve the maximum health benefits.

(vi) Planning should be based on a cumulative total of 25% of workers taking some time off – possibly 5-8 working days - over a period of 3 months. This first wave is likely to be followed by a second wave of similar duration. The interval between each wave could be several weeks or months. Absenteeism may be more than this either due to a higher rate of illness, the need to care for sick family members or fear of exposure to infection. Past pandemic experience indicates that between 10-35% of the workforce may be absent from work. The absentee rate is expected to peak for 1-2 weeks at the height of the outbreak (around weeks 8 to 9).

(vii) Total deaths in the UK normally run at around 12,000 per week. During a pandemic, without effective interventions, total deaths are likely to gradually rise to 50% higher than normal at the peak of a pandemic wave, and then gradually decline. However, there is the potential for as many deaths in 12 weeks of a pandemic as in the rest of the year (around 600,000 excess deaths across the UK).

(viii) Slowing down the spread and reducing the number that will be affected in the first wave may be achieved by implementation of :

- Hygiene including respiratory hygiene and hand washing
- Travel advisories to restrict international travel to or from affected areas
- Health screening at UK ports
- Voluntary home isolation of cases
- Voluntary quarantine of contacts of known cases
- Staff rostering to minimise the impact on staffing if all contacts of a case in a work team are asked to remain in voluntary quarantine
- Local restrictions on the movement of people, eg in a local community or town
- Restriction of public gatherings, especially international mass gatherings
- School closures (recognising the impact this will have on maintaining the workforce in other sectors)
- The use of face masks by infected people (to reduce droplet spread), by those in contact with infected people or by the general public

These measures are being kept under review as public health interventions during a pandemic, and clear guidance will be issued by Health Departments, based on the advice of the UK National Influenza Pandemic Committee or guidance from the WHO or real time modelling as the evidence evolves or as need arises.

Some of these measures may be required as a result of staff absence or the general disruption, or may occur by default because of public concern or other considerations, such as concerns about possible exposure to infection when using public transport. Voluntary co-operation with recommended measures would be sought. Mandatory quarantine and curfews are generally not considered necessary and are not currently covered by public health legislation.

General advice to local authorities, educational establishments and businesses

For the purposes of business continuity planning, local authorities, educational establishments and businesses will wish to consider the likely effects of a pandemic on their organisations outlined above and the measures that may need to be taken to manage these. For example, by:

¨ Considering the likely impact on their organisations and businesses;

¨ Considering their needs to maintain continuity of core business activities and putting appropriate plans in place taking into account high levels of staff absences;

¨ Providing information to staff and students (this will be available on the Department of Health website and in printed form);

In addition, research on the spread of infectious diseases suggests that the spread of an influenza pandemic may be slowed down by:

¨ cancellation of public events; for example this may include large-scale national or international events held in the UK (involving inter-regional/UK and international travel by participants), such as sporting fixtures, concerts, competitions, conferences, agricultural shows, exhibitions. In practice, possible lack of ambulance cover due to increased health care pressures associated with a pandemic might result in the cancellation of such events;

¨ curbing unnecessary travel; for example this may include encouraging people to travel intra- and inter-regionally in UK only if absolutely necessary (as part of nationally-produced communication messages);

¨ if there was a particular flu hotspot in a region, local authorities may need to issue advice to the public about not travelling to and from that region.

Decisions on such actions will normally remain for local determination, based on advice and recommendations issued by Health Departments.

Particular advice to educational establishments

The pandemic virus may spread readily in schools and other education establishments (attack rates of up to 90% were reported in some boarding schools in previous pandemics). If this is confirmed as a characteristic of the virus, Health Departments will inform Education Departments to advise local education authorities and the education sector about measures to be taken to slow down spread of the virus. This advice would particularly apply to younger children, childcare settings and education establishments and may include closing down for a short period, and management of pupils/students travelling within, to and from the UK. Education Departments will assist in disseminating the advice to the various education sectors.

The decision on such closures will normally remain for local determination having regard for the possibility that such establishments may have insufficient staff and/or pupils/students to remain open and for the possible implications for increased work absence because of workers’ child-care responsibilities.

Department of Health
February 2005