A virus to be taken seriously

A funny thing happened when bird flu first emerged in Thailand in 2003.

People initially said their chickens were perfectly healthy.

As the human death toll mounted, word started coming out that, actually, the chickens had been pretty crook.

Lance Jennings, one of New Zealand's top virologists, suspects something similar might start happening with pigs.

Jennings is talking in the early morning hours from France where he is, coincidentally, attending a gathering of international experts at a conference aptly titled in these flu-scare times, "Influenza Vaccine for the World."

Jennings, who received the Queen's Service Order in 2006 for services to virology, isn't about to pin anything as yet on pig farms neighbouring a small village in rural Mexico where a third of the villagers reportedly became ill weeks ago with severe flu-like symptoms, and where the first confirmed case of the so-called swine flu was discovered.

But residents of La Gloria, in the Veracruz mountains, who live near huge pig farms co-owned by United States pig producer Smithfield, are reportedly convinced their town is ground zero for the outbreak.

In February, 5-year-old Edgar Hernandez went down with fever and "a headache so bad his eyes hurt" but recovered after a few days of antibiotics.

Though hundreds of residents also complained of severe respiratory problems, the little boy is the first person to have been confirmed as falling ill from a new strain of H1N1 infection, a mix of pig, bird and human flu virus, which has the world on high pandemic alert.

The residents of La Gloria believe the blame for their illnesses lie with a pig farm upwind of them about five miles away.

They have long been worried about swarms of flies which feed on pig manure and the stink coming from the farm. They believe their water and air is contaminated with pig waste.

The world's media has now converged on La Gloria, along with United Nations teams who are investigating.

But so far authorities say they have found no evidence of illness in pigs.

As the pork industry moved to reject claims that such factory farms are implicated, others say the opposite.

The very suggestion of a link, writes Stephen Foley of the Independent "has sent a shudder through the ranks of campaigners who have long argued that the sort of industrialised pig farming that has turned Smithfield into one of the most powerful corporations in the US, with a market value of $2.47 billion , was a disaster waiting to happen".

Jennings thinks the pigs may yet turn out to be sick.

"I think as there is increased awareness about the circulation of this virus, what we'll be hearing is increasing reports of outbreaks of sorts of respiratory illness among pigs which, because investigations are being carried out, will surface.

"At the start of the outbreak of avian influenza in 2003 in Thailand, they were saying their chickens were perfectly well, and yet reports of their high mortality were coming out from that country.

"You have to remember," says Jennings, "the poultry industry at that time was an extremely important part of the economy in a part of the world which was also just recovering from Sars (Severe Acute Respiratory Syndrome), and people did not want to do

or say anything which would affect that industry."

As with the pork industry now. Pork is an important part of the economy in many countries, so local farmers and authorities will not want to report accounts of illness in pigs and jeopardise their industry.

That's just human nature, says Jennings.

"So this is why I say as investigations are carried out we will gain more information about events that may have related to the initial emergence of this virus."

Jennings, like most world experts, says it is still early days in this outbreak and we have much to discover.

But one thing scientists do know about this virus - and swine viruses in general - is that up until about 1998, viruses circulating in pigs had been very stable.

That has changed.

There has been much sharing of genetic material between different viruses and the variety of viruses discovered in pigs has increased substantially, he says.

This "restlessness" of the virus has meant it has been crossing the species barrier from pigs into humans and the first human outbreaks that scientists are aware of have now occurred in Mexico.

"What is different from the other viruses that have undergone genetic material exchange among pigs is that this one has the right combination to a) infect humans and b) be transmissible to humans.

"Exactly when this event occurred or where it occurred, I suspect once there is more retrospective analysis of the viruses out of Mexico and other viruses that are recovered by research teams, we will have a slightly better idea."

Further investigations will also, he hopes, reveal why people in Mexico seem to have been hit harder by the flu bug than people in other parts of the world.

This is an enigma for which there is no satisfactory answer so far, he says.

But theories are emerging. Some experts say the recorded number of cases in Mexico could be merely the tip of the iceberg.

Oxford University Professor Elspeth Garman, who is at the same conference as Jennings, told the Witney Gazette that perhaps many more people had contracted the virus but had not fallen as ill.

Or, she said, the virus could have mutated downwards and become less deadly as it travelled.

Public reaction to the virus has see-sawed. Pharmacies in New Zealand are selling face-masks but as those afflicted seem to be recovering quickly, some commentators are writing the fuss off as fear-mongering.

Lance Jennings doesn't think has been an over-reaction.

He says this virus must be taken seriously, and we must understand the history of the emergence of novel influenza viruses.

The 1918 pandemic virus, which wiped out an estimated 50 million people worldwide, among them thousands of New Zealanders,

was avian in origin, though pigs may have been involved in its evolution.

Though that pandemic was a long time ago, Jennings says there is good evidence to suggest it had been around for some time before people started dying.

The virus, also an H1N1 virus, circulated in the Western Front of World War I in 1916 and 1917, causing mild disease before, for some reason, it increased in pathogenicity and became associated with severe disease and high mortality.

Canterbury University history professor Geoffrey Rice says we are right to be extremely wary of flu viruses. He points out that he is an historian - not a virologist. Still, he knows more than most lay people about the workings of the H1N1 virus.

Rice wrote Black November, a book about the dark days of 1918 when 8500 New Zealanders died from the flu in just six weeks.

There are lessons to be learned from history, Rice says.

The 1918 flu came in two waves. The first was a mild wave where people recovered, then came a second highly infectious wave where people died - and died fast.

We don't know yet if what we are seeing in Mexico other countries is the start of a mild first wave and whether worse is to come, he says.

Actually, he doesn't think so this time, partly because the world is much better prepared for pandemics, but also because the situation in 1918 was unique.

The brutal and bloody World War was coming to an end when the flu hit.

The epicentre of the second wave was beyond doubt the Western Front, in northeastern France, Rice says.

"One of the theories is that it was because that was the year both sides were firing thousands of mustard gas shells at each other and experiments that they did during [World War II] have shown that diluted mustard gas does have an influence on simple organisms like moulds and bacteria and speeds up their reproductive rate.

"There was this suggestion that it might have been because the troops on both sides had the mild flu, that the mustard gas somehow produced a kind of superflu."

Rice is not totally sold on this theory and thinks a more likely explanation for what turned a mild flu into a big killer was the fact that millions of fit young men in the prime of their life came together in a confined area.

Only the toughest and nastiest of the viruses survived fighting their way through such a population and the ones which emerged via natural selection were the smart breeders which were then spread around the world by natural transmission.

There are positives and negatives to the world we live in now, he says.

What killed people in 1918 was not so much the primary influenza but the secondary pneumonic complications, and today we have better medicines.

And thanks to previous scares - such as bird flu and Sars - the world is on high alert for what to do, and most developed countries now have a pandemic plan.

New Zealand's pandemic plan - identify, isolate, stamp it out - swung into action quickly and has been top-class, says Rice.

It was a different story in 1918. The Health Department was tiny, its senior officers were seconded to the army so they weren't even around, and then key officials caught the flu themselves.

Developed nations today will probably be able to contain this flu, he thinks, but he does fear for third world countries which don't have a fully developed medical system and don't have stocks of the drug Tamiflu, which stops the virus replicating if taken early enough.

In an Aids-compromised continent like Africa, the flu could really cause havoc, he says.

Rice's big message from history is don't be complacent about flu.

"Flu pandemics have an amazing capacity to surprise you and to puzzle you. Unlike most other infectious diseases, which will run a very predictable course, influenza is peculiarly unpredictable."

We need to remain vigilant for many months to come, perhaps even fora year, he says. Jet travel has turned the world into a "viral village" and where flu has traditionally started in the northern hemisphere and not appeared in the southern hemisphere for another four to six months, that is no longer the case.

These scares will become more regular, Rice thinks, "for the simple reason that jet travel makes the distribution of viruses so much faster now than it has ever been in human history".

- Additional reporting, agencies