02 December 2008

A new killer-flu pandemic?

The current outbreaks of bird flu in Asian countries may seem remote, but it may have a direct impact on your life.


The current outbreaks of bird flu in Asian countries may seem remote, but it may have a direct impact on your life.

The new, virulent strain of bird flu could be the predecessor to a new human flu virus as lethal as that which caused the devastation of the 1918 Spanish Influenza. The human population has grown so much in the interim that such a flu pandemic would cause the 1918 pandemic to pale by comparison.

According to the World Health Organisation (WHO), it may take as long as a whole year before the current Asian bird flu epidemic can be contained.

At any moment during these 365 days, the genes of the H5N1 bird influenza virus – already able to jump from animals to humans – may mix with the genes of an existing human influenza A-type virus. This can create a new human influenza virus that is easily transmittable.

These drastic genetic changes in the influenza A virus have over the past century occurred at irregular intervals of 10 years or more. Each newly emerged influenza A virus led to worldwide influenza pandemics, because no-one had been previously exposed to the new virus, and so no-one had any built-in resistance to this form of the disease.

This is what happened in 1918, and four times again since then (notably the Hong Kong flu of 1968). These huge changes occur on top of smaller changes, which occur every one to three years to create slightly different influenza virus strains virtually every year.

It is impossible to predict when the next pandemic will occur, but most scientists believe it is 100% certain that there will be one soon.

In 1918, when transportation was still by rail and boat and painfully slow, the pandemic circled the globe in a matter of months. Travelling by jet, a new killer virus originating in the East (as usual), could reach Tokyo in three hours and Cape Town within a day or two. It could circle the globe in four days, not four months as in 1918.

Flu pandemics then and now

  What happened What could happen
Year 1918 2006/2007
World population 1.8 billion 6.5 billion
Primary mode of transportation Troop ship, railroad Jets
Time to circle the globe Four months Four days
Preventative measures Gauze masks, disinfectants Vaccines
Treatments Bed rest, aspirin Some antiviral drugs
Estimated death 20 million 60 million

Take action:
You can take several steps to try and prevent flu.

Get vaccinated. Last year, as every year, one or more of the human influenza virus strains underwent small changes and new virus strains emerged. The new vaccine composition for 2006 has already been changed to incorporate significant new strains. It is important for all high-risk people to get vaccinated as soon as possible.

Don’t catch the virus. If you stand closer than five metres to an infected person when he/she is speaking, sneezing or coughing, you may inhale the virus. This is why one infected person in a lift, bus, aeroplane, school, cinema, old age home, or army barrack can infect others quite easily. However, the virus is often transmitted when you touch your nose, mouth or eyes after touching an object which has been touched by an infected person or ‘sprayed’ by infected droplets. These objects include the rails of escalators, the insides of lifts, computer mouses and keyboards of other people, public telephones, utensils, pens and pencils belonging to other people. It is therefore important to wash your hands regularly.

Protect your child: Discourage your child from sharing food, utensils, handkerchiefs, napkins and towels with classmates. Childcare centres should wash plastic toys daily and stuffed toys weekly. Rather keep your toddler at home if a child at the crèche has flu and yours is still healthy, and protect other children by not sending your child to crèche when he or she is ill. Daycare personnel handling your baby or toddler should place a new cloth over their shoulder every time they hold a different baby. The flu virus is not transmitted through the mother’s bloodstream or her breast milk and she should continue breastfeeding. However, a breastfeeding mother should try not to sneeze or kiss her baby when she has a respiratory infection. She should also wash her hands frequently.

Protect your body: Eat correctly to help your immune system function at its best. Prevent heaters from drying out the air by using humidifiers. Quit smoking, because smokers are more susceptible to respiratory illnesses.

Who should be vaccinated?
All adults should be vaccinated against flu, especially sportspeople and the self-employed, or those who have other strong reasons to avoid being ill! However, people in the high-risk group for complications should get vaccinated.

They are:

  • The elderly (people aged 65 or older), especially if living in a retirement home.
  • Anyone with a heart problem, lung problem, or with chronic illnesses such as anaemia, diabetes or kidney failure.
  • The immune-suppressed, including people who are HIV-positive, people treated for lengthy periods with steroids, and cancer patients.
  • Anybody over the age of six months who required regular doctor visits during the preceding year.
  • Children and teenagers (six months to 18 years) on long-term aspirin therapy, because of the dangers of Reye’s syndrome.
  • Women in their second and third trimester of pregnancy, because the functions of their hearts and lungs are compromised by the extra burden of pregnancy.
  • Caregivers and close contacts of any of the above.
  • Smokers, who are more susceptible to respiratory illnesses.

Who shouldn’t be vaccinated?

  • People allergic to eggs (the protein albumin), because the vaccine virus is grown in eggs, or to thiomersal (a vaccine preservative).
  • Those with a history of side effects.
  • Those who are acutely ill.
  • Pregnant moms in their first trimester of pregnancy, although there are no known adverse affects to the foetus.

Reviewed (2006) by Dr Jane Yeats MBChB, BSc(Med)(Hons)Biochem, FCPathSA(Virology).


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