For a pandemic of moderate severity, this is one of our greatest challenges: helping people to understand when they do not need to worry, and when they do need to seek urgent care.

Antimicrobial resistance is on the rise in Europe and elsewhere in the world. We are losing our first-line antimicrobials. Replacement treatments are more costly, more toxic, need much longer durations of treatment, and may require treatment in intensive care units.

Doctors and nurses, with their training and their experiences, they would be able to detect unusual patterns of disease. That's why we say it is important for every country to have a proper surveillance system. The function of the surveillance system is to detect unusual patterns of diseases.

A severe disease that transmits easily will leave very little international surge capacity as most countries will need their own staff and resources to combat the outbreak in their territories.

I am personally overseeing changes that include the establishment of a global health emergency workforce.

This change to a higher phase of alert is a signal to governments, to ministries of health and other ministries, to the pharmaceutical industry and the business community that certain actions now should be undertaken with increased urgency.

Everyone needs to remember that Ebola was not a worst-case scenario. Preparedness for the future means preparedness for a very severe disease that spreads via the airborne route or can be transmitted during the incubation period, before an infected person shows telltale signs of illness.