IT has been more than five weeks since swine flu landed in Australia. Now more than 2400 people have tested positive and three people have died. Thousands have been quarantined, schools have been closed, and understaffed emergency departments have struggled with an influx of patients, suddenly highly conscious of every sniffle and cough.Since it was first detected in Mexico in March, the World Health Organisation says at least 52,160 people have been diagnosed and 230 have died. But the real figures will be much higher. The WHO says its statistics are unreliable because some countries are no longer counting and poor countries do not have the means to reliably detect cases.What we do know is that swine flu or the A(H1N1) virus seems to hit younger people hardest and, that while many people who died after contracting the virus had underlying medical conditions, some did not.When swine flu arrived in Australia on May 9, experts predicted it could kill up to 25,000 people, lay low up to half the workforce and cause "massive" economic damage.If it resembled the 1918 influenza pandemic, health bureaucrats warned, the nation could be crippled for up to 10 months, with the tourism industry being particularly hard hit.More than 2 million people would be infected and millions more affected by university, school and child-care centre closures, transport restrictions and health system chaos.But last week, the Federal Government downgraded Australia's swine flu alert phase, ending mandatory quarantine, thermal imaging at airports and compulsory testing.The "protect" phase was created after it became clear the Government's pandemic plan had been devised for a more virulent and deadly strain and the tough measures were not needed for such a mild virus.The new alert level means those with flu-like symptoms will no longer be routinely tested. Anyone who is sick is "strongly advised" to stay at home until their symptoms resolve. But they will not be forced into quarantine, nor will those who have had contact with a swine flu victim.Those moderately sick should see a GP and those who are severely ill should go to a hospital emergency department. Antiviral medications, such as Tamiflu and Relenza, will not be prescribed to people diagnosed with, or suspected of having, swine flu, unless they are at risk of developing serious complications. Pregnant women, the morbidly obese, people with respiratory illness and suppressed immune systems are considered to be at risk.Pregnant women can take antiviral medications, but Tamiflu and Relenza are relatively new drugs and yet to be declared safe in the long term. Those breastfeeding can take Relenza, but it will be prescribed only if there is a high risk of complications.Mass gatherings, such as football finals, will go ahead and schools will not be closed, even if many children are diagnosed.A Department of Education spokeswoman says the Board of Studies may award substitute marks to HSC students who contract swine flu and allow some students to complete assessment tasks at home.But the Government's sudden change of heart has left at least one influenza expert dubious.Calling the decision political, Nikolai Petrovsky, of Flinders University in Adelaide, said "doctors who look after the patients who die from influenza each year would never label it a 'mild' infection"."Influenza, through its ability to mutate and exchange genetic material with related viruses, has a potential to change its nature overnight from benign to highly lethal," Petrovsky said."The biggest concern of all will be when [it] becomes established in South-East Asia and particularly Indonesia and Vietnam where avian influenza remains a major concern. Should swine flu mix with H5N1 avian flu then all bets are off."Research published last year showed most new flu strains had their beginnings in northern Asia during October to March each year, moving to North America and Europe, then Australia a few months later, mutating constantly.Australia's most common strain of flu, H3N2, has been circulating annually in Australia for the past 40 years, peaking every three to four years.Thus swine flu is expected to return for decades, the head of clinical research at the National Centre for Immunisation Research and Surveillance at the University of Sydney, Robert Booy, says. "But most people will develop some immunity to it. The problem is that eventually it will gain an important mutation that we have no immunity to."Genetic similarities between pigs and humans made it easier for flu strains to jump between the two species, with the Asian and Hong Kong flus in 1957 and 1968 both originating in pigs in China, but Australians should not fear contracting other animal strains, Booy says."Even the avian flu didn't make the cross to humans easily. You basically had to sleep with a chicken in your bed to get it."But Peter Collignon, a professor of microbiology and infectious diseases at the Australian National University and a vocal opponent of the Government's hardline measures to stop the virus, says swine flu is proving to be less aggressive than the seasonal flu and "99 per cent of people just get better on their own".He says there is still no data to back up fears of a second or third more virulent wave in the next few months and years, and most of the deaths from the more virulent second wave of the Spanish flu in 1918 were caused by bacterial pneumonia, a secondary infection which can now be treated with antibiotics.Swine flu may not be the mass killer it was first feared, but there is no doubt it has left the NSW Health Department reeling and people confused and fearful. At times, communication between the federal and state health departments seemed limited, answers were thin on the ground and major mistakes were made, leaving NSW open to ridicule.Last month, about 1800 people aboard a cruise ship were allowed to disembark in Sydney without being tested, despite swine flu being on board.The ship was subsequently cleared to travel to the Whitsundays the same night, a move which infuriated Queensland authorities, forced to divert the ship while swabs were taken.Another cruise ship was denied access to dock in New Caledonia because crew members developed swine flu, but the ship did dock in Vanuatu and Fiji.In Sydney, some hospitals turned suspected swine flu sufferers away because they believed they had been designated as "clean", but NSW Health said no emergency department had been given that status.Federal Government guidelines to avoid mass gatherings and stockpile food and water were quickly discarded, anti-discrimination experts warned against shunning swine flu victims and GPs complained they had not been given enough information on dealing with suspected cases in busy waiting rooms.One doctor, who did not want to be named, said NSW Health's rigid bureaucratic protocols had denied his colleagues the right to make any decisions on testing and medication, forcing them to call the Public Health Unit on each occasion. "GPs have had six years of university training and an additional four to five years of postgraduate training," the doctor said. "They have far more knowledge and expertise than most of the federal and state bureaucrats who rule over them with an iron fist."Others said that antivirals were being wasted and testing was too slow.Lindsay Grayson and Paul Johnson, both from the infectious diseases department of Austin Health in Melbourne, told the Medical Journal of Australia that testing was restricted to patients who fitted the specific case definition, and tests on all other patients who had a clinical illness suspected of being swine flu were initially refused or given low priority."This is the opposite of what should have occurred," they wrote.Practical issues such as the adequacy of the protective mask stockpile or the means of distributing drugs and equipment to GPs did not appear to have been planned in detail, they said.Roche, the manufacturer of antiviral drug Tamiflu, was forced to suspend deliveries for two weeks for fear that the drug was being prescribed indiscriminately by GPs, while sales of masks and anti-bacterial handwash soared.Flight manifests were scoured every time an international traveller was diagnosed, but quarantine rules seemed arbitrary.Some people were told to stay at home for seven days; others were never told they had been in contact with the virus.One couple left an infected cruise ship to visit a newborn grandchild because they weren't told they had been exposed.Anecdotal evidence of people self-quarantining abounded.Suddenly, swine flu became the desired diagnosis for anyone wanting a week off work.But Booy warns: "I wouldn't recommend throwing influenza parties - you might be one of the unlucky ones that gets a severe case".About 30-50 per cent of deaths in North America were among those who had no underlying risk factors, he says.YOUR QUESTIONS ANSWEREDWhat are the symptoms?Swine flu resembles any other flu. Main symptoms: sore throat, cough, runny nose, fatigue, aching muscles.How can you tell if you have it?You can't, except by having a doctor take a throat swab for testing. Health authorities said last week they would no longer support testing of anyone likely to be infected, but only those with severe disease or risk factors such as pregnancy or asthma.How infectious is it?Every infected person infects an average of 1.5 others within 2 to 3 days. That is highly infectious, but on a par with other flu. Measles and whooping cough spread much more readily.How deadly is it?Swine flu causes more hospitalisations than human flu. Its death rate is about one in 1000 in developed nations - about double that of regular flu.Who is most likely tobe affected?It affects healthy, young adults and children disproportionately. Children are more at risk because they have not had previous flu infections which may confer partial immunity. Older adults seem better protected because they are more likely to have been exposed to flu types similar to swine flu that circulated in the 1950s.If it's like other flu andnot exceptionally deadly,why should we care?Regular human flu kills 1500 to 3000 Australians annually. Depending on how widely it spreads, swine flu could easily exceed that. Australia is moving into the peak flu season. Hospitals may struggle to cope.Are there other dangers?Swine flu in humans is a novel virus that could mutate further, combining with other forms of flu to become more infectious, more virulent or resistant to treatments. Because there is no vaccine, there is still no way of holding back that worst-case scenario.Is there any treatment?Anti-viral medicines such as Tamiflu can prevent flu or reduce severity and the likelihood of complications. But doctors have now determined they should be used only for those at increased risk of complications. Others should stay at home and use over-the-counter medicines.How can people avoidcatching or spreading it?Stand a metre or more away from people with respiratory symptoms. Wash your hands regularly; it makes a big difference. Use tissues and dispose of them promptly. Stay away from work and keep children away from school if you have symptoms. Support those around you, including employees, to do this.When will there be a vaccine?Scientists are making rapid progress towards a vaccine, but large-scale production will not start until late this year, at the earliest.