I am concerned about avian flu. I am concerned about what an avian flu outbreak could mean for the United States and the world. I am -- I have thought through the scenarios of what an avian flu outbreak could mean. I tried to get a better handle on what the decision-making process would be by reading Mr. Barry's book on the influenza outbreak in 1918. I would recommend it.

The policy decisions for a President in dealing with an avian flu outbreak are difficult. One example: If we had an outbreak somewhere in the United States, do we not then quarantine that part of the country, and how do you then enforce a quarantine? When -- it's one thing to shut down airplanes; it's another thing to prevent people from coming in to get exposed to the avian flu. And who best to be able to effect a quarantine? One option is the use of a military that's able to plan and move.  (White House)

At the moment bird flu only seems to be transmitted from birds to humans or as between humans in very, very close contact. But the worry is that this could change. If it does there might easily be a flu pandemic with an agent which seems to kill 50% of the people who contract it.

Governments and individuals are making plans for bird flu. Shutting down public schools, closing theatres, creating quarantine areas will all slow the spread of any outbreak. The use of Tamiflu to treat people who contract the disease (although supplies are limited after recent spikes in demand, a situation the White House needs to get a better handle on); and, of course, a crash program to create a vaccine once the specific mutation of the H5N1 virus is identified, are all in train.

To a degree the response is going to depend on the ease of transmission of the agent. Gloves and a mask may be enough and will limit the need for quarantine. Or limit the duration of the quarantine. At the moment we do not have sufficient information to really assess what the threat level is or will be.

The other question is the duration of the outbreak. This will be controlled by a) how fast a vaccine can be developed, b) the lethality of the agent. SARS was lethal enough that it burnt itself out (at the cost of dozens of lives) fairly quickly. However an agent which was deadly in, say, 20% of the cases would last a long time but would create -- we hope -- a class of survivors who would be immune. As people caught the flu and most survived, the economic disruption would be reduced but still horrific.

The vaccine question is more difficult. We don't know if the agent will mutate around broad spectrum anti-virals -- there seems some evidence that it already has. We do know that the time from isolation of the agent to the production of a specific vaccine seems irreducibly fixed at six months and that full production may take another few months after that.

There are plenty of places on the web to get more information about the potential pandemic. Future Pundit considers the potential economic effects and infrastructure responses, a Flu Wiki has been set up to bring together information

Meanwhile a number of things can be done to prepare for the point  bird flu mutates to a virus which can spread easily between people. The President has a grasp of the issue:

Obviously, the best way to deal with a pandemic is to isolate it and keep it isolated in the region in which it begins. As you know, there's been a lot of reporting of different flocks that have fallen ill with the H5N1 virus. And we've also got some cases of the virus being transmitted to person, and we're watching very carefully. (White House)

At the moment there are limited restrictions on the health of people traveling to the US, the EU and many other nations. In the United States there are quarantine stations and people exhibiting symptoms of any of the following diseases, Cholera and Suspected Cholera, Diphtheria, Infectious Tuberculosis, Plague, Suspected Smallpox, Yellow Fever, Suspected Viral Hemorrhagic Fevers, such as Lassa, Marburg, Ebola, Congo-Crimean, and others not yet isolated or named may be apprehended, detained, or medically examined. Adding avian flu to the list would be a first step.

A more aggressive, forward, preemptive policy may be impossible politically; but the real means of quarantine would be to require individuals traveling from areas of the world where avian flu is present to be kept in isolation for a week or two upon arrival so as to ensure they are symptom free. Ideally that needs to start now. If that is seen as too restrictive, then at least limiting the ports of entry for people from Viet Nam and Indonesia to those centers with quarantine stations would improve the odds of containment.

Once there is hard evidence of human to human transmission, serious thought and planning needs to be given to immediately prohibiting travel to uninfected countries from infected ones. There are very few absolute reasons individuals need to travel and an early and complete travel ban might provide a critical few months of safety.

Obviously a period of quarantine or an outright ban on travel from certain nations would be a huge inconvenience. However, compared to a full blown outbreak of a lethal flu in the US with the quarantine and restrictions needed to prevent the potential deaths of millions of people, this would seem trivial in retrospect.

Plans for effective quarantine within the US need to be drawn up, discussed and agreed upon. The President is absolutely correct when he asks how a quarantine of a particular part of the United States could be enforced. To prevent a repeat of the difficulties Katrina underscored, the planning needs to be done now at the federal, state and local level. If there is to be military involvement that needs to be discussed and agreed upon in advance and the military planners need to be working with civil authorities.

Critically, with the right planning, an effective quarantine strategy, a little luck on the vaccine front and rapid reaction to a human to human mutation, an outbreak need not become a pandemic killing millions and crippling the economy.

Jay Currie is a TCS contributing writer.