South Africans have no reason to panic about bird flu just yet, as the virus can only be transmitted from infected birds to humans at present.

But once the potent bird flu virus – identified as H5N1 – crosses the species barrier and is able to be transmitted by humans, it will spread fast because the human population will have no immunity to it and port cities of Durban and Cape Town will be particularly vulnerable, according to virologist Professor Alan Smith.

“Most virologists agree that it is simply a matter of time before the reassortment of the virus’s genetic material happens, allowing the virus to be transmitted by humans,” says Smith, head of Virology at the University of KwaZulu-Natal.

He explains that there are two kinds of influenza viruses, one occurring in birds and the other in mammals, including humans.

For bird flu to become transmitted by people, a person would have to be infected with both types of flu virus at the same time. The genetic material of the two flu viruses could then intermingle and change the viral genes, allowing what virologists call a “reassortment” – or the development of a mutated virus containing the genetic material of both bird and mammal flu capable of being transmitted by humans.

While it is impossible to predict when such a reassortment might happen, says Smith, once it does Durban and Cape Town will be particularly vulnerable to the vicious virus.

‘€œOur ports act as a conduit to the Far East, the present major source of H5N1,’€ says Smith. ‘€œSailors on these ships could become infected with the virus and pass it on to South Africans working on the docks,” says Smith.

To counteract this threat, Smith proposes that the port and health authorities set up surveillance systems to monitor all dockworkers.

“Any stevedore with flu should be monitored. We could take samples of the flu viruses and send unusual strains of flu to the National Institute for Communicable Diseases in Johannesburg to be analysed,” says Smith.

Should a person become infected with bird flu, they would need to be isolated in a hospital ward and all those who had come into contact with them would need to be vaccinated.

Tamiflu, said to be the best medicine available to treat the virus, is not yet registered in the country but its approval is being fast-tracked by the Medicines Control Council.

However, Smith warns that stockpiling massive amounts of flu vaccine may prove futile as the H5N1 virus, like all viruses, mutates fast and may become resistant to vaccines that are not updated to tackle the latest strain.

Smith is to meet with KwaZulu-Natal health authorities within the next few weeks to discuss plans to contain the bird flu threat.

In the past century, there have been three serious flu pandemics in the world, taking place   in 1918, 1957 and 1969. In all three cases, reassortment took place which resulted in the development of a completely new virus which then spread rapidly.

Millions of people died in the 1918 pandemic. The World Health Organisation – which has been monitoring the H5N1 virus since it first appeared in Hong Kong in 1997 – has warned that up to 7.4 million people could die from H5N1 which could be spread to all corners of the earth, thanks to globalisation. – Health-e News Service

 Brief history of bird flu

• The first humans to get the current strain of bird flu, called H5N1,were identified in Hong Kong in 1997. Eighteen people were infected and six died.
• Since then, about 120 people in Vietnam, Cambodia, Thailand and Indonesia have been infected and 63 have died. Vietnam has been   worst affected with 41 deaths.
• All people infected were in close contact with infected poultry, and contracted the virus either by inhaling the virus or from their faeces or by contamination during food preparation.
• Infected migratory birds have since spread the H5N1 virus from South East Asia to Central Asia, Russia and Eastern Europe.
• Millions of infected birds in Asia have died, while millions ofothers exposed to infection have been culled in an attempt to contain the epidemic.
• People typically acquire flu by inhaling the virus or by being indirect contact with the respiratory tract secretions of people who are infected.
• Typical symptoms of flu, which last about five to seven days, are adry cough, muscle pains, sore throat, raised temperature, headache and feeling weak and tired.
• The time between exposure to the flu virus and the onset of symptoms is usually two days, but it can vary from one to five days