By Chris Adams

The world has 7.7 billion people, and in any given year 220 million of them are the grips of an emergency – 35 million of those in acute emergencies. From epidemics to floods to the ravages of war, the toll never ends.

It’s up to officials at the World Health Organization to do the triage necessary to know which of those calamites may benefit from WHO resources.

In a session with National Press Foundation fellows, WHO’s senior emergency coordinator for health emergency response, Dr. Jorge Castilla, described how those decisions are made.

“Not all emergences are the same, and to we need to approach them differently based on what they are,” said Castilla (bio, Twitter). From experience as a general physician in a Colombian rural hospital, to project coordinator of a primary health care project in Sudan, to a range of emergency actions in other global hot spots, Castilla has been responding to people in peril for more than 30 years.

Given global needs, WHO has to be deliberate in where and how it marshals its resources. It has a system to look for signals worldwide – everything from reports of a disease outbreak to a natural disaster – and it receives 7,500 of those each month. About 450 of those get follow-up attention, and 30 of those are verified as a legitimate concern. Ten are then subject to a formal risk assessment – and possible intervention.

But there are only so many resources to go around.

Some events are monitored but no WHO response is required. But then are three levels of WHO response: Grade 1 is a limited response, Grade 2 is a moderate response with some WHO inputs and staff, and Grade 3 means “major/maximal WHO response.”