Each time he steps out of his ground floor laboratory, veterinary scientist Hare Krishna Pradhan has to take three hot showers. If he doesn’t, the door won’t open. It’s an airtight building from where the smallest of microbes cannot escape and where every drop of water is sterilised at 120° C for 30 minutes before it leaves the building. In this little-known laboratory in Bhopal, the search for the deadly bird flu virus in India began three years ago. And should it ever strike in India — whether it infects poultry or people — Pradhan will be the first to know.

At the High Security Animal Disease Laboratory (HSADL), the 58-year old pathologist and his colleagues have screened hundreds of samples of blood and faeces of chicken from poultry farms across India looking for the bird flu virus that biologists have named ‘H5N1’. Over the past few weeks, the virus has infected poultry in eight Asian countries and killed eight people in Vietnam and Thailand.

With the virus appearing to head closer to India, last week the government banned the import of all birds — alive or dead — and ordered a high alert on the borders. Security forces will now also have to look out for people trying to smuggle in poultry or other birds.

The crisis that may, or may not, reach Indian shores has prompted its share of high-level government meetings. On Friday, at Pune’s National Institute of Virology, the nation’s top laboratory responsible for investigating viral outbreaks, scientists huddled with state veterinary officers and officials of organised poultry farms to discuss ‘action to be taken’ in the event that H5N1 pops up in India.

“For India, H5N1 is an exotic disease — it has never been detected here,” said HSADL director Pradhan, who has been investigating bird viruses in India for the past 30 years. “It has the potential to spread very fast, it has no treatment, and it could cause major epidemics,” he said. With stringent biosafety systems in place, the HSADL is the only laboratory in the country today equipped to isolate the H5N1 virus. Last week, Pradhan called a special meeting and distributed tasks to his 12 scientists — just in case.

If the virus does enter India, it could severely hurt India’s poultry industry which is currently thriving, breeding nearly 350 million chickens annually. To prevent any kind of a crisis, the Bhopal laboratory has stocked up testing equipment and chemicals that would allow it to conduct up to 30 diagnostic tests each day to look for the presence of the H5N1 virus.

But the fuss isn’t about poultry alone. Avian influenza, or bird flu viruses have demonstrated their potential to jump from birds into people and cause life-threatening illnesses. The death rate associated with the H5N1 virus is uncomfortably high.

Eight out of ten people infected in the current outbreak are dead. “Preventing its entry into India should be a top priority,” said Pradhan. With poultry reared in backyards in rural areas and open slaughterhouses and trucks ferrying live chickens in cities, many Indians would find it hard to avoid some contact with chickens.

Scientists are even more worried about the possibility that the H5N1 virus may change and acquire the ability to spread from person to person just like the common cold viruses are passed through handshakes or sneezes. Medical scientists are concerned that such a transformation could trigger a fast-spreading global pandemic of influenza that could be fatal to humans. The 20th century witnessed three global flu pandemics and some scientists believe another one is inevitable, perhaps imminent.

“The real fear is that the bird flu virus may exchange genes with another human flu virus and evolve into a new and virulent virus that spreads from person to person and against which people have no immunity,” said Albert Osterhaus, head of Institute of Virology at the Erasmus Medical Centre in The Netherlands. No matter where it emerged, if the virus can be transmitted easily between people, passengers flying across the continents would help the virus spread across the planet in less than a year.

The Spanish flu pandemic during the winter of 1918-19 demonstrated how fast a virus could travel even in the era before commercial air travel. The virus killed more than 20 million people within a year. Some estimates put the toll at 40 million. Flu pandemics again claimed human lives in 1957 and 1968. “The issue is not whether another pandemic will happen, but when it will happen,” Osterhaus told The Telegraph.

Although the H5N1 virus is lethal to people, all people infected so far have got it from close contact with poultry. They might have touched infected chickens and then rubbed their eyes or inhaled tiny particles of chicken faeces laced with the virus. “The longer the infection persists in poultry, the greater are the chances that the virus will get an opportunity to exchange genes with a human flu virus,” said Shahid Jameel, head of virology at the International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi.

Osterhaus has coined a name for such double-infected people — ‘mixing vessels’. The double-infection allows viruses to reassort their genes and turn more virulent than before.

Some influenza experts believe that deadly influenza pandemics may have been nipped in the bud at least twice in the past seven years in different parts of the world through good disease surveillance and the mass slaughter of infected birds. In the summer of 1997, a three-year-old boy died in the intensive care unit of the Queen Mary Hospital in Hong Kong five days after he was admitted there with pneumonia and severe respiratory distress.

Wellina Lim, a medical researcher at the virus unit of the hospital, isolated the virus from the body and sent it to Osterhaus to help understand what had killed the boy. Osterhaus and colleagues in the US were astonished to discover that it was an influenza virus usually found in birds.

Until the 1997 outbreak, it was believed that birds passed viruses to pigs, which, in turn, passed them on to people. But H5N1 had never been seen in pigs. The only explanation was that the boy had contracted the virus directly from birds. That first H5N1 outbreak in humans killed seven out of 18 infected people.

Just eight months ago, another bird flu virus called H7N7 that hit poultry farms in The Netherlands also slipped into people. In the weeks following the outbreak, 86 people who had been exposed to the chickens and three of their family members fell sick, most had severe conjunctivitis while some had flu-like symptoms.

The virus claimed the life of a 57-year-old veterinarian. Two days after he had visited a poultry farm with sick birds, the veterinarian was struck by high fever and severe headache. A few days later, he was in hospital and on a ventilating machine because of a severe respiratory problem. Then his kidneys failed and within two weeks after his farm visit he was dead. An autopsy revealed evidence of viral pneumonia.

The World Health Organisation says mass slaughter of infected birds is the major line of defence to prevent further cases of human infection and to avert the emergence of a new virus. During the Dutch epidemic, for instance, nearly 30 million poultry birds were destroyed. Infectious disease specialists believe that no country in the world is prepared for a new influenza pandemic. Current stocks of neither vaccines nor anti-viral drugs will be sufficient in the event of a pandemic, renowned influenza experts Robert Webster and Richard Webby warned just two months ago.

In any case, existing flu vaccines will not work against the current strain of the H5N1 virus. Studies by influenza laboratories investing the current outbreak show that the virus has genetically changed and significantly enough to render existing vaccines ineffective. “It’s going to take time. We have had to start from scratch. We don’t expect to have anything close to a vaccine ready for weeks or months,” said Julie Gerberding, director of the US Centres for Disease Control.

But some scientists argue that even a new flu virus is unlikely to extract the kind of toll that the influenza pandemics did during the 20th century. The combination of surveillance, mass slaughter of infected birds each time a virus outbreak occurs, and anti-viral drugs will dampen its spread. “The 1918 scenario is unlikely today,” said Jameel of the ICGEB. Influenza sometimes leads to bacterial pneumonia which can be treated with antibiotics. It is suspected that some proportion of patients who died during the 1918 pandemic succumbed to bacterial infections and not to the virus itself. “But a virus transmitted from person to person could travel much faster now than it did back then,” he said.

Although there is no evidence of avian flu in India yet, the entry of the virus was averted at least once by the animal disease laboratory in Bhopal. Three years ago, a traveller from Saudi Arabia flew into Chennai airport with 80 pigeons with the intention of giving them away as pets. The laboratory which has the mandate to screen all imported birds and animals discovered that some of the pigeons were infected with a virulent bird flu virus, although the virus was not H5N1. All 80 pigeons were killed and incinerated.

The quest to understand how the virus has managed to jump from birds into humans continues. International influenza experts are now trying to isolate viruses that have infected people and pinpoint genetic differences between them and viruses that have infected birds. Since bird or animal viruses do not normally cause disease or death in humans, Osterhaus is trying to seek out the genetic alterations that make bird flu viruses turn specially virulent.

And influenza experts are also urging governments to prepare for the next pandemic. As a recent paper in the journal Science said: “Nature’s ongoing experiments with H5N1 in Asia and H7N7 in Europe may be the greatest bioterror threat of all.”