Since the first bird flu attacks states and international private enterprises have been (sometimes) preparing for pandemic preparation plans. If such a new flu (some feared a variant of bird flu but now it seems to be a strange mix of different human and animal flus) would brake out (or in the human body and more importantly between human bodies) without any treatment available for a certain number of days, weeks or months, the number of deaths could be high in our big cities and our ever deplacing population.
The only way to prevent such from happening would be the isolation of infected cities, populations or even countries. All traffic to and within these cities or regions would come to a standstill and all public gatherings in those cities or regions would be at least a risk and at the worst case prohibited. If at the same time important personnel (going from doctors, judges, policemen, ITpeople and civil servants) would become ill or couldn't get to work public services and private enterprises would come to a standstill.
The pandemic preparation that some countries, cities and enterprises have done at a huge cost during the last years is just to prevent that. It means that people and civil services would know how to isolate certain cities or regions and how to keep the essential services working (by IT).
Some said that the chance that this would happen is near zero for the next years and that it was fear mongering and a waste of money (the same who said that the year2000 bug was hype). The security and risk people said that you have to prepare for the worst from the beginning to be able to survive every and any crisis even if it doesn't seem to be as bad. Knowing what to do and being able to do exactly what ought to be done - especially if you have tested it with an exercise - makes all the difference during a crisis. It is not during a crisis that you will develop such a plan or that you will find available consultants to set it up for you.
So when this first big possible outbreak of a new human deadly flu is taking place in Mexico some firms know they are prepared while others don't have a clue and hope it will just blow over.
The first thing you can already do is to stop all business travel to affected regions and to ask people travelling there to take all the necessary precautions and not to show up for work without a proper medical exam.
The second thing you can already do is prepare your infrastructure so that your workers can continue to work on their servers and documents even if there is no transport and some cities are quarantained. Having the necessary (even cold standby contracts) in hand gives you some more rights than the firm looking for external services and backup when the first panick reaches your country.