Foot-and-mouth - a virus that could cripple a nation

The fact that what is almost certainly a hoax should detonate such an immediate and huge response is testimony to the threat that foot-and-mouth disease poses to this country.

A confirmed outbreak could bring New Zealand to its knees. Even the suggestion of it was enough to set the sharemarket shuddering.

The disease is such a scourge that no major trading partner would entertain importing products from an infected country, fearing it would bring havoc to their own livestock industries in its wake.

The virus is phenomenally infectious and can hit all major food-producing livestock, including cattle, sheep, pigs and goats.

It can spread as far as 200km on the wind and can contaminate clothing, vehicles and roads. It can survive freezing temperatures.

Once established, it can render any host nation an agricultural pariah and kill an export trade overnight. Any comprehensive overseas ban by trading partners has the potential to cripple a country such as ours, which is so dependent on animal-product exports.

Even domestic production would be devastated if the disease was widespread and farms and processing plants were in long-term quarantine.

The tourism industry, so linked to our clean, green image, would be severely tarnished and movement within the country could be drastically restricted.

Only a month or two ago, realistic foot-and-mouth simulation exercises reduced some participants to tears when they realised the catastrophic consequences of an outbreak in this country.

Twenty-four years after New Zealand's last major exotic disease alert at Temuka in the South Island, Exercise Taurus involved a broad range of Government departments and agencies, as well as people from the private sector. In March and April the capabilities of the Exotic Disease Response Centre and field teams were tested thoroughly, with international observers from Canada, the United States, Ireland, Australia and Britain monitoring the exercise.

A Reserve Bank report in 2003 estimated that a foot-and-mouth outbreak would wipe $6 billion off New Zealand's GDP in the first year.

Foot-and-mouth is a curse in many countries and there is a constant risk of it entering New Zealand.

We have every reason to fear such a fate. Who can forget the graphic photographs of slaughtered animals during the 2001 outbreak in Britain?

Shattered farmers, their livelihoods and their futures destroyed, undertook an horrendous animal cull. Nearly five million sheep, 764,000 cattle, 428,000 pigs and 7500 goats were killed, the carcasses burned on huge funeral pyres.

By the time the outbreak had run its course the cost had reached many billions of dollars.

In May 2002, South Korea had to destroy tens of thousands of livestock after foot-and-mouth was diagnosed in the weeks leading up to the soccer World Cup finals.

If the dreaded disease was ever confirmed here, all animals on affected farms would immediately be slaughtered.

Inspections would be made of neighbouring properties and movements of all stock and vehicles over past weeks would be traced.

A control area of at least a 10km radius would be placed round the farm and stock, with goods movements stopped throughout the region.

Community and sporting events in the surrounding countryside would be cancelled.

That procedure was activated in 1968 when a possibly "highly infectious disease" was discovered on a farm at Warkworth north of Auckland.

Tissue samples from about two dozen pigs, with clear blisters on their mouths, snouts and feet, were flown to Britain for analysis.

Meanwhile, police road blocks were set up and stock movements were banned as a precaution. Cats and dogs in cars were allowed through provided the vehicles did not stop.

No evidence was found of infection in other animals - mainly sheep and cattle - on 65 farms round the restricted zone.

But the reaction to this event showed what would happen if there was a real outbreak. Australia barred imports of all raw animal products from New Zealand until the disease was diagnosed. People living within 8km of Warkworth were temporarily forbidden to enter Australia.

Fortunately, the British test proved negative and the precise cause of the blisters was never officially stated. There was some suggestion they may have been caused by the stings of wasps attracted to pears the pigs had been eating.

There have been other scares, the biggest 13 years later when a pig farm in the South Canterbury town of Temuka was under siege and in world focus for a few days. Local farmers' hearts sank into their gumboots as a grim-faced community considered what a possible foot-and-mouth outbreak would mean to them.

Although only 28 pigs showed symptoms, all 800 on the property - along with a pet sheep - were slaughtered and burned.

Traffic through or leaving the area was stopped, inspected, driven through a disinfectant bath and sprayed underneath. Movement of animals in and out of the South Island was suspended.

Everyone breathed a sigh of relief when confirmation came that the disease was not foot-and-mouth and trading partners lifted import bans.

The Ministry of Agriculture and Forestry receives reports of one or two foot-and-mouth scares a month, though few are publicised.

Usually they come from veterinarians handling livestock on farms or at meatworks, who notice symptoms such as mouth or feet blisters.

After years of study, Government scientists came to the conclusion the 1968 and 1981 scares were water blisters, similar to those contracted by market gardeners harvesting parsnips in the sun.

The harmless skin condition phytophotodermatitis is a common disease with an uncommon cause and symptoms frighteningly close to those of foot-and-mouth.

Parsnip and related plant leaves contain furocoumarins which cause skin cell damage when activated by ultraviolet light.

But when it comes to foot-and-mouth New Zealand cannot afford to take chances.

Disease's ravages

Human effects

* It is rare for humans to contract foot-and-mouth. There has been only one recorded case in Britain and that was in 1966.

* The effects of the disease in that case were similar to influenza, with some blisters.

*There has never been a case of foot-and-mouth in New Zealand, either in people or animals.

* Hand, foot and mouth disease is an unrelated disease found in humans.

Effects on livestock

* While foot-and-mouth is not normally fatal to adult animals, it is debilitating and causes significant loss of productivity.

* In young animals it can be fatal on a large scale.

* The most serious effects are seen in dairy cattle, which cannot properly produce milk and suffer abortion, sterility and chronic lameness.