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Past Pandemics |
Influenza pandemics are rare, but have occurred three times during the last century causing widespread illness, large numbers of deaths and huge disruption throughout society in a matter of weeks.
- In 1918, the ‘Spanish influenza’ pandemic caused 250,000 deaths in the UK alone and up to 20-40 million deaths worldwide.
- In 1957/1958 ‘Asian’ flu caused an estimated 33,000 deaths in the UK and 1 million worldwide
- In 1968/1969 ‘Hong Kong’ flu caused an estimated 30,000 deaths in England & Wales and 1-4 million worldwide.
Pandemics usually occur in waves of approximately 3-9 month intervals, each lasting between 2-3 months, with the second and third waves sometimes being more virulent than the first.
More recently in 2002/2003 an outbreak of Severe Acute Respiratory Syndrome (SARS) occurred. Although a different virus and not declared a pandemic, lessons can be learned from the SARS outbreak showing how an influenza pandemic might spread. It was not as virulent or infectious as flu and was successfully contained, but not before an estimated financial and economic cost of US$60 billion was brought about in East and South East Asia.
• SARS spread to 11 countries in three continents - within one week.
The rapid international spread of SARS and a previous outbreak of avian flu in Hong Kong in 1997 highlighted the need for countries to develop or improve existing contingency plans.
It is impossible to predict when the next flu pandemic will occur, but experts have warned that it is both ‘inevitable’ and ‘imminent’.
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Lessons Learned |
- Pandemics can arise at any time of the year
- The increased use of global travel will help the virus to spread more easily across continents possibly in less than 3 months
- If there are outbreaks of a pandemic flu virus in other parts of the world, it will almost certainly reach the UK
- Once it reaches the UK, the virus is expected to spread throughout the country in a matter of weeks causing much more illness and potentially higher death rates than those associated with ordinary flu
- The most severe pandemics can affect all age groups
- Estimates suggest the potential unavailability of 25-50% of staff
- Assume that anyone infected will take 5-10 working days off during a three-month period. Subsequent waves can occur at 3-9 month gaps and may be even more virulent than the first.
- During the actual Pandemic Outbreak phase, estimates suggest absenteeism will double in the private sector and increase by two thirds in the public sector
- Schools and other institutions may be closed to reduce the rapid spread of the virus through close-knit communities
- More workers will become absent as they are required to care for children and dependents, contributing to social and economic disruption
- Transport is likely to be disrupted
- There may be temporary fuel shortages (affecting power supplies)
- Personal hygiene such as washing hands frequently is fundamental to controlling infectious diseases (as seen during the SARS outbreak)
- Effective hygiene in buildings is essential to help reduce the spread of a virus
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Vaccines |
The two most important medical interventions for reducing illness and death during a pandemic are vaccines and antiviral drugs (e.g. Tamiflu). However, supplies of these will be inadequate in all countries at the start of a pandemic and for many months after.
Vaccines cannot be developed until the new strain of flu virus is identified and this could be 3-6 months from the day a pandemic is declared. Current vaccines for ordinary flu take an average of 6 months to develop. Once vaccines are developed, they will be given to priority groups identified by the Joint Committee on Vaccination and Immunisation in the first instance.
Antiviral drugs work by preventing the flu virus from reproducing however, the effectiveness of antiviral drugs in a pandemic, and in particular in reducing mortality in cases of severe disease is not known. Again it is likely that antivirals will be distributed to priority groups.
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Swine flu - how you can prepare for a pandemic |
| Swine flu has made it back to the headlines as the WHO raises the pandemic alert level to Phase 6 signifying that a global pandemic is now under way. More ... |
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