DESPITE the media hype, Britain was not hit by a flu epidemic this month. In
England and Wales, just 203 people out of every 100 000 turned up at their
doctor鈥檚 surgery with flu in the first full week in January, when the outbreak
peaked. This is far short of the 400 per 100 000 that marks an epidemic. This
nasty, nationwide bout of flu simply showed how stretched and inflexible
Britain鈥檚 National Health Service is when faced with a sudden drain on its
emergency beds.
When a really serious flu pandemic strikes, January 2000 will look like a
picnic by comparison. The worst flu pandemic ever, in 1918, hit 23 per cent
(that鈥檚 23 000 per 100 000) of the British population, and 150 000 died in
England and Wales. The global death toll exceeded 20 million. Last year,
scientists at the Centers for Disease Control and Prevention in Atlanta
estimated that during the next flu pandemic there could be 200 000 deaths and 40
million hospital admissions in the US alone. Another one could strike at any
time.
鈥淣obody鈥檚 thinking `if鈥� this happens but rather `when鈥�,鈥� says Gregory Poland,
a vaccine expert and adviser to the US government at the Mayo Clinic in
Rochester, Minnesota. The World Health Organization has called on every country
in the world to plan what it will do when a quarter of the population comes down
with flu. So how well prepared are we?
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Not if, but when
If history is any guide, the next flu pandemic may well arise in China, with
Singapore, South Korea and Japan the next countries to suffer. The WHO is geared
up to respond to reports that people are dying of an unusually severe
respiratory illness. If patients test positive for influenza type A virus, the
kind associated with pandemics, officials will send samples to WHO labs to
determine the precise subtype. They will also want to know whether it spreads
from person to person. A new, transmissible subtype will set alarm bells
ringing: if it causes several deadly outbreaks in the country of origin and then
spreads abroad, the WHO will declare a pandemic.
From then on it will then be up to individual countries to put their
emergency plans into action. A crucial element is to quickly vaccinate as many
people as possible, especially workers in key services. But flu experts such as
Arnold Monto of the University of Michigan at Ann Arbor note that very few
countries make the vaccine. The WHO lists just 17 that do
(see Figure).
The question is, if these manufacturing countries were struggling to provide
enough vaccine for their own citizens, would they meet their export contracts?
鈥淚 suspect that many of these contracts would not be honoured in the face of a
pandemic,鈥� Monto says.
Daniel Lavanchy, head of the WHO鈥檚 influenza programme, says that countries
that do not make their own vaccine or antiviral drugs should try to address that
issue by making arrangements now. But he warns: 鈥淗ow valid in the case of
emergency these arrangements will be remains to be determined.鈥� Observers point
to what happened in 1976, when the US vaccinated millions of people against a
possible swine flu, while Canada, which in those days needed to import vaccine,
was denied supplies from its usual US sources.
Even in the 17 manufacturing countries, there is a real possibility that many
people won鈥檛 be vaccinated until the worst is over. The production of an
effective vaccine can鈥檛 begin until the particular subtype of flu virus causing
an outbreak has been identified. Even then, the manufacturing process is slow
and old-fashioned.
Manufacturers inject the virus into fertilised chicken eggs, harvest the
resulting virus particles from the embryos and inactivate them to create a
vaccine. It takes months to build up a reasonable supply. Ideally, health
officials would have other options, such as a recombinant DNA vaccine or, even
better, a universal influenza vaccine. But despite promising reports last year
(Nature Medicine, vol 5, p 1157), an effective vaccine along these
lines is still some way off.
Britain was one of the first countries to develop a flu pandemic plan and had
it in place even before the Hong Kong chicken flu scare of 1997
(快猫短视频, 31 January 1998, p 18).
That close call reminded the rest of the
world that a pandemic might be just around the corner, and the WHO finalised its
guidelines in April 1999. So far, less than a dozen countries have pandemic
plans anywhere near completed. The US has only a draft plan, due to be made
public within months.
Australia, which completed its plan in June 1999, is perhaps the only country
to consider the idea of stockpiling drugs. Its pandemic planning committee has
spoken to at least one company about maintaining a stock of antiviral drugs,
says Graham Rouch, chief health officer of the Department of Human Services in
Victoria.
The drugs zanamivir and oseltamivir, which came onto the market in the past
six months, can cut the duration of flu and reduce symptoms. But to be effective
these drugs must be given within 48 hours鈥攁nd ideally within 24
hours鈥攐f the onset of symptoms. This would be very difficult with a
pandemic in full swing, so countries need to consider what part these new drugs
will play in their plans.
There is in any case a limit to what even the best of plans can achieve.
鈥淲hat would you have in the face of a pandemic? Chaos,鈥� says Alan Hay, a flu
expert at the National Institute for Medical Research in London. Early on, there
may be calls to quarantine passengers arriving by plane from affected areas.
Poland, who is on the committee responsible for drafting the American plans,
says that if people started to drop dead in Hong Kong, it鈥檚 conceivable that
flights might be restricted. But he points out that flu is so contagious that
鈥渢here鈥檚 no real way鈥� to seal international borders.
As the epidemic takes hold, hospitals will be overwhelmed. Essential services
will be disrupted as health workers, police officers and air-traffic controllers
succumb to the virus.
A guide put together by the Centers for Disease Control and Prevention in
Atlanta warns officials to expect shortages of ventilators for patients who
develop pneumonia and outrage from relatives of those who have died. Even
looting could be a hazard, as sickness among the police prevents effective law
enforcement.
In Britain, experts predict that an epidemic will last six to eight weeks.
When a pandemic threatens, a national Influenza Advisory Committee will be set
up to monitor its progress, the extent to which public services are disrupted,
the availability of vaccines and any adverse reactions to vaccines and antiviral
drugs. The committee will keep the public informed through regular press
conferences and a round-the-clock telephone helpline. It will also advise the
government on whether the outbreak amounts to a national emergency.
Local health authorities will be expected to set up their own pandemic
committees estimate local needs, distribute the vaccine and antiviral and
antibacterial drugs, and make mortuary arrangements.
With the rich countries preoccupied with the effect of flu on their citizens,
the developing nations are likely to be especially hard hit. 鈥淭he majority of
the world does not have access to good hospital facilities, drugs or vaccines,鈥�
says Hay. 鈥淎s with any of these illnesses, it鈥檚 the underdeveloped countries
that will suffer the worst.鈥� That was certainly the case in 1918, when around
half the Spanish flu deaths occurred in India.
Experts agree that real progress has been made in planning for pandemics in
the past two years. But until the gap between rich and poor nations is narrowed,
and until vaccine technology improves, few expect the next pandemic to be
something we鈥檙e prepared for.