At the moment the only way to get bird flu is by dealing directly with poultry that have the infection. That means in Australia you are not going to get it at the moment. If you are overseas, there is a risk that you could become infected if you live intimately (sharing the house or yard) with chickens or ducks infected with the virus. That's not something that we commonly do in Australia.

Millions of people have had contact with infected birds but only about 200 people have contracted the virus from infected birds overseas, which indicates that the virus is not very transmissible. People caring for or killing infected birds in rural areas of Vietnam or China are at most risk.

—Professor Peter Collignon, Director of Infectious Diseases & Microbiology, Canberra Clinical School, Australian National University/University of Sydney

H5N1 is spread via infectious aerosol droplets from handling birds (eg plucking feathers). Spread has not occurred from properly cooked poultry meat. Human-to-human spread has not yet been proven and health care workers have not been infected even without proper precautions and controls.

—Tony Cunningham, Director, Westmead Millennium Institute

There are no real characteristics that differentiate H5N1 from other types of influenza in the early stages of infection. You have to be careful about describing particular symptoms because it depends at what stage the disease is at. It can also affect people differently, depending perhaps on genetic factors or the amount of the virus they were exposed to. The main initial symptoms are a cough and high temperature (greater than 38C), linked with a history of prior exposure to avian species, with no other possible explanation for the symptoms. For further information see the World Health Organisation's bird flu Factsheet.

— Ian Barr, Deputy Director WHO Influenza Centre

A high fever is the first symptom of both classic seasonal and bird flu. Seasonal flu predictable progresses to a cough and other common flu symptoms like a sore throat and tiredness. The symptoms of avian flu are not as consistent, with many patients not having a cough at all, and others displaying atypical symptoms such as diarrhoea. Diagnosis is therefore difficult and swabs have to be taken for viral identification.

—Tony Cunningham, Director, Westmead Millennium Institute

Yes, it has been extensively tested in humans but only for seasonal influenza. We hope it has a high rate of efficacy for the H5N1 bird flu virus. In mice it requires a higher dose and longer treatment for bird flu than for seasonal flu. It also needs to be taken within six to 12 hours of catching the virus. People overseas with the virus have had it at too late a stage. It's important that it is available to get quickly and easily from the chemist without prescription, and at the moment it's not.

— Professor Graeme Laver, John Curtin School of Medical Research

Tamiflu is on the market as is the antiviral drug Relenza. It is available by prescription but is not yet available in pharmacies due to stockpiling by governments around the world.

The current H5N1 strain prevalent without mutation is sensitive to both Tamiflu and Relenza. The question is will the mutated pandemic human flu be sensitive? We don't know that yet. In some cases overseas we have seen resistance of H5N1 to Tamiflu but not Relenza.

— Professor Mark von Itzstein, Research Leader, Executive Director & Federation Fellow, Institute for Glycomics, Griffith University

There is very little you can do to avoid catching the virus if it did become transmissible between humans. You still have to do the shopping and get around. In the early stages of the infection it is hard to know that you have the virus. Masks may prevent you catching it, but won't prevent the spread. For instance, someone could sneeze and then remove their mask, spreading it onto their hands.

— Professor Graeme Laver, John Curtin School of Medical Research

This is extremely unlikely. Even if there were infected birds on your roof (note: there have been NO birds in Australia confirmed to have bird flu to date), there are two things that would make infection of the occupants very unlikely. Any influenza virus present in the faeces will be killed by heat and UV irradiation, so if it is a warm day or a sunny day then the virus would be killed rapidly, secondly even if it rained then the virus (if present) would be diluted very rapidly and unlikely to be at a high enough concentration to infect anybody. Also the virus would not be stable in the water for more than a few hours maximum.

— Ian Barr, Deputy Director WHO Influenza Centre

Bird flu was first discovered in Hong Kong in 1997. It was contained but has since cropped up in China and through most of southeast Asia. It is thought to have originated in wild birds.

— ABC Science Online

The influenza virus, like many viruses, can mutate relatively quickly to best fit its surrounding environment. This means different strains of the virus are constantly evolving through either "reassortment" (where genetic material is swapped between human and avian viruses during co-infection, as in the 1957 and 1968 pandemics), or the gradual process of adaptive mutation, as occurred in the 1918 pandemic.

Many of the new strains are relatively harmless and tend to be species specific. Some strains, specifically the subtypes H5 and H7, have evolved to be either very infectious or particularly harmful to birds, and more recently, in crossing to humans. In the case of H5N1, the virus has become more virulent and easier to spread in birds, as well as extending its species range to include cats and tigers. Further mutations in the viral internal genes would be required for human-to-human spread.

Unlike most other flu viral strains, H5N1 in its highly pathogenic form can survive for long periods in the environment (up to 35 days in low temperature). This means the virus can survive in bird faeces, eggs, dead animals and possibly bodies of water containing dead animals. It can be readily transferred between domestic bird flocks through the movement of live birds, contaminated clothing worn by staff, vehicles and equipment. Additionally, migratory birds are now carrying this strain rapidly to other parts of the world.

We know that right now the virus does not easily cross from birds to humans.

—Tony Cunningham, Director, Westmead Millennium Institute

We don't know what genetic mutations in the H5N1 virus would cause a disaster. So far the virus has not mutated to become transmissible between humans. What is true is that there is a new strain of influenza that is virulent in birds. It doesn't explain why this is any worse than any other virus mutation, such as HIV, or Ebola.

We do know that genetic changes do occur that make viruses more virulent. Paradoxically, it is not the aim of the virus to kill its host - if its host is too sick to move it prevents the virus from spreading.

Most viruses come from animals, for example HIV originated in monkeys. Once a virus invades a new species it usually becomes more virulent. After a while the virus adapts to become less virulent. We develop immunity, and the virus adapts so that it evades our immune system, but it also adapts to become less virulent.

Environmentally, it's important what farming practises we use, and what we do with the animals that are good hosts. For instance in China a short term plan to protect chickens by providing them with the cheap and readily available antiviral drug Amamtadine simply led to the virus becoming resistant to the drug. So it's important we don't give the drugs to chickens and still have antivirals available to treat humans.

—Professor Peter Collignon, Director of Infectious Diseases & Microbiology, Canberra Clinical School, Australian National University/University of Sydney

Yes, bird flu affects other species of birds and also mammals (eg domestic cats, tigers). It is not known how widespread the deaths from H5N1 infection are in all bird species, nor if our native species would be susceptible (and if they were to what degree they would be susceptible).

In non-poultry species there may be differences in survival rates due to natural protection in some species, such as prior exposure to similar viruses, which gives them some pre-existing immunity, or if infection occurs, it occurs with a low dose of the virus that does not cause severe disease. Whether this is the case has not yet been determined.

— Ian Barr, Deputy Director WHO Influenza Centre

Bird flu is caused by the avian influenza virus, which has many different strains. Avian influenza can affect a wide range of bird species including wild birds, however waterfowl are the natural reservoir for avian influenza viruses and the prevalence of AI viruses in other bird species is invariably much lower.

What is different about the H5N1 strain of the virus is that it causes disease in waterfowl - normally avian influenza virus infections in waterfowl do not cause clinical disease. In terms of native Australian birds, it is expected that they would be susceptible to infection, but the likely clinical effects are unclear as there have not been actual exposure.

—Peter Beers, Senior Principal Veterinary Officer, Department of Agriculture, Fisheries and Forestry

Low on most people's counts. As you correctly state, the majority of migratory birds that visit Australia are small waders, not the ducks and geese that seem to be responsible for the movement of H5N1 from China to Europe. Importantly, the H5N1 virus has not been found in the migratory birds that visit Australia (either overseas or in Australia) and secondly the commercial poultry farms in Australia have pretty good biosecurity to keep wild birds from mixing with the poultry. The risk to backyard flocks may be higher but is still low.

— Ian Barr, Deputy Director WHO Influenza Centre

Fortunately the risk for Australia is much lower than for most other countries. Waterfowl in Australia are generally nomadic within Australia rather than migratory, although they may visit neighbouring countries from time to time. Therefore they are at lesser risk of being infected through exposure to the virus overseas. In addition, wader species with a preference for coastal habitats are highly unlikely to come into contact with birds maintained at commercial poultry enterprises.

Good biosecurity is important on commercial farms including the separation of poultry from contact with wild birds and ensuring that water and feed used in the husbandry of poultry are free from contamination by wild birds. The Australian poultry industry has put in place strong biosecurity measures to reduce the chance of disease spreading from wild birds. The highly pathogenic H5N1 strain of avian influenza has not been detected in wild and domestic birds in Australia.

—Peter Beers, Senior Principal Veterinary Officer, Department of Agriculture, Fisheries and Forestry

To try to hold up at home is ridiculous. You would have to isolate yourself completely and that's impractical. It's difficult but in case of an outbreak I don't think there is a lot you can do. If you close schools, which the government has been considering as an emergency option, then emergency workers and intensive care workers have to go home and look after their kids.

Antibiotics are not necessary to control the virus, just the side effects of secondary infections. Thousands of doctors in America have been prescribing Tamiflu to people that aren't sick to stockpile, and it is absolutely the wrong thing to do. It's either not used or people misdiagnose themselves and the drug is wasted.

— Professor Graeme Laver, John Curtin School of Medical Research

There are preparedness plans formulated by governments around the world. I have always been an advocate for having a personal preparedness plan. Holding up at home may not be unreasonable, what is important however is awareness of what the media or government is indicating, avoiding danger areas, and not placing yourself at unnecessary risk. How long? How long is a piece of string? It depends on the intensity of the outbreak.

A survival kit for any potential threat should contain anything you think is necessary to survive�— a good water supply, adequate food or resources. In regards to a stockpile of drugs, it is sensible to have some drugs just in case, but some would say it is nonsense.

—Professor Mark von Itzstein, Research Leader, Executive Director & Federation Fellow, Institute for Glycomics, Griffith University.

— Ian Barr, Deputy Director WHO Influenza Centre

Poultry products are likely to be safe. A lot of infected chickens have been killed, sold and eaten with no adverse results. The reality is that if you cook chicken it kills the virus. That's not to say there isn't a risk of cross contamination. But it is obviously hard to catch the virus. Relatively few people have become infected from birds compared to the number of people dealing with infected birds. It's obviously not very transmissible at this stage.

The risk of directly contracting the virus is low, and the chance that it mutates to become transmissible between people is small, maybe a 10% chance over five years. But that's not to say the risk is zero. If this does happen, we need to have safe vaccine programs in place.

—Professor Peter Collignon, Director of Infectious Diseases & Microbiology, Canberra Clinical School, Australian National University/University of Sydney

Not to my knowledge. There is only a risk if the disease is present and if there is unhygienic handling of live birds, uncooked or incompletely cooked poultry meat. So this would localize the areas of increased risk to areas of the globe where the above situations occur.

— Trevor Ellis, Senior Research Fellow, Murdoch School of Veterinary and Biomedical Sciences