Killer can come disguised as a cold

The flu season is approaching and many of us are lining up for vaccinations. ALISON HORWOOD looks at the cost of the disease and how we fight it.

Headache. Aches. Fever. Fatigue.

It's the influenza virus, and between next month and September it will be coming to a workplace, school or home near you. And so will the battle against it - controversially headed by vaccination campaigns.

Flu is often confused with the common cold, but its potential danger should not be underestimated. It can carry the risk of death.

The Ministry of Health rates it as a significant health problem, and it moves swiftly through the population base.

Its epidemic quality is its hallmark. No other acute respiratory disease is capable of rapidly affecting large numbers of the population.

This winter, about one in 18 New Zealanders will go to a doctor with flu-like symptoms.

When a large population with at least partial natural immunity is affected, about 20 per cent will not experience apparent signs of infection. A further 30 per cent will have the symptoms of an upper respiratory tract infection, without the fever.

About half will suffer chills, sore throat, a sudden onset of fever, malaise, headache and a cough. And for an unlucky 5 per cent, the flu is much more serious.

For those people - usually the elderly or those already ill - the virus will develop into pneumonia or tracheobronchitis.

The chance of chest complications in people aged over 70 is as high as 73 per cent, and bacterial pneumonia is the most common cause of death from the flu.

Between 1980 and 1992, an average of 59 deaths a year were attributed to the flu. However, it is suggested that for every death certificate citing flu as the cause of death, a further 7.7 deaths were caused by the virus but not reported as such. That would put the annual death rate nearer 450.

In addition to the social disruption, the flu is a heavy burden on healthcare and workplace productivity.

In 1994 alone, the Ministry of Health estimates, there were more than 12,000 hospital discharges with pneumonia and the flu as a primary or secondary diagnosis. On average, those patients stayed 18 nights in hospital.

In the workplace, the cost is huge.

A Ministry of Health report last year said one-tenth of all absences from work were attributed to the flu.

Recent calculations estimate the total annual cost of influenza is $3 billion to $5 billion a year in the United States and $65 million to $190 million a year in Australia.

Because of its impact on the economy and society, it comes as no surprise that New Zealand and other countries try to arm themselves heavily in the war against the virus.

In recent years, the most favoured weapon has been the influenza vaccine.

Capsules and inhalers are also on the market but require a doctor's prescription and attract no Government subsidies.

For supporters of the vaccine, the shot is a safe and effective way of controlling costly and dangerous complications of the flu.

Canterbury Health virologist Dr Lance Jennings says the side-effects are negligible. A small number of people suffer a soreness at the site of the injection, and others complain of flu-like symptoms.

It is impossible, he says, to get the flu from the vaccine because it is made up of disrupted and killed virus.

However, there are also hundreds of websites dedicated to the criticism of mass vaccination. Some claim an increased risk of cancer, others say the shots do not work and are nothing more than profit-based scams between pharmaceutical giants and the doctors who administer them.

General practitioners in New Zealand can make about $11 per free vaccination and the cost of the vaccine is reimbursed.

The vaccinations are free for people over 65 and for people with certain specified conditions.

One American website quotes an investigation by Money Magazine saying the vaccine industry is worth $US1 billion a year, up from $US500 million in 1990.

The Ministry of Health says vaccine sales in New Zealand increased by 53 per cent between 1996 and 1997.

But the big question is, does the vaccine work?

Ministry of Health figures show the death rate from the flu has fallen since the vaccine became free for over-65s in 1997. But consultation and hospitalisation rates have increased markedly in the last year the figures were recorded, between 1998 and 1999.

For that period, the consultation rate rose from 1400 people per 100,000 to 2400. The hospitalisation rate increased from 13 people per 100,000 to 22.

Dr Paul Bohmer, ministry spokesman on influenza, said the figures did not fully reflect the situation. Those who contracted the virus often had other complicating respiratory factors, influenza was highly variable from year to year and there was an unexplained increase of hospital admissions around the world.

"It's very complicated. The evidence from studies is that it [the vaccine] has made an impact, but the figures don't easily show that.

"All studies indicate the vaccine is effective in reducing complications and deaths from influenza."

Companies often provide vaccination for their workers, but there are no centrally collected statistics on the numbers involved or the success of such private schemes.

Dr Jennings says the influenza vaccination does not guarantee you will not get the flu.

What it means it that between 70 and 90 per cent of recipients will not get the virus, but in over-65s that rate may be as low as 60 per cent.

The vaccine did not aim to stamp out the spread of the virus, but rather to control the complications, he said.

For that reason it was aimed at the people most at risk - such as the elderly and sick - and not children and pre-schoolers in day-care who were known to be the carriers.

If you are not on the free list, a shot will cost about $5 plus the GP consultation fee.

The Ministry of Health says the number of people over 65 receiving a free shot has increased every year since 1997.

Last year 59 per cent in that category made use of the free offer.

Dr Katy Godfrey, infectious diseases physician with South Auckland Health, said the optimist in her wanted to believe increased public awareness and vaccinations were behind the last two mild winters for flu.

She is a firm believer that if enough people get vaccination it will help slow the spread.

Dr Godfrey said the statistics for the flu were no worse at Middlemore than in other parts of Auckland, although the symptoms could be worse.

She said the area seemed to have a high proportion of smokers, which could be associated with the virus leading to greater complications.

Last year, in an attempt to target a wider group of people at risk, a scheme was run in South Auckland giving free vaccinations at churches and marae.

New Zealand has a relatively low level of flu vaccine use. In 1997, we rated 13th among 22 developed countries.

The National Influenza Immunisation Strategy Group was set up in December 1999 to coordinate flu vaccine promotion, increase awareness of the flu and its seriousness, and communicate with health professionals about flu prevention and treatment.

Its key message for the 2001 campaign is: "Influenza is a serious disease - it is not like having a cold."

One of the reasons the flu is so serious, says Dr Jennings, is its shifting form.

"You are dealing with a virus that is always changing."