GENEVA -- Some two dozen disease experts meet every morning at nine in an underground room at the World Health Organization headquarters here to scrutinize the latest reports of infectious disease.

The 18 outbreaks being tracked on a recent morning in the bunker, hub of the WHO's alert and response operations, ranged from polio in Indonesia and avian flu in Vietnam to anthrax in Guinea-Bissau and the Marburg virus in Angola.

But what got everyone's attention was an email received over the previous weekend from the Ministry of Health in the Republic of Congo. A band of elephant hunters in the country's northern rain forests, along with several people with whom they were in contact, had died from an acute form of hemorrhagic fever. The team in the WHO bunker feared the worst: a re-emergence of Ebola, the deadly virus that killed scores of people in the same area two years ago.

With a giant electronic map of the African nation projected on a screen in front of him, one WHO official fretted that the Congolese government hadn't yet provided virus samples for labs to confirm the disease. Another suggested that if the outbreak worsened, an isolation unit in use in Angola for the Marburg outbreak -- including specially trained staff, protective clothing, generators and other gear -- could be moved to the Congo.

Known officially as the Strategic Health Operations Center, the WHO bunker is home to a high-tech effort to track and respond to infectious-disease outbreaks around the world. Officials here organize lab tests, purchase and ship medical supplies and coordinate the activities of local health authorities. In addition to the electronic maps, the room has four large plasma TV screens, computers and a satellite-video system that can simultaneously link 180 people, including the WHO's--8 country and regional offices, with scores of health ministries and labs world-wide.

The WHO bunker, which the United Nations agency opened last December, is part of a push to better track epidemics, no matter how far-flung. Not only are infectious diseases on the rise, but a surge in international travel means a local outbreak can quickly become a global contagion.

One early challenge came in April with four polio cases in Yemen, the first polio outbreak there in nearly a decade. Each new case represents a setback for the WHO's ambitious goal of eliminating polio by year-end. The bunker team monitors the outbreak at most morning meetings and stays in touch with local health authorities. With the WHO's help, Yemen has embarked on a massive immunization campaign using six million doses of a new polio vaccine.

"Every single case of polio means that there are hundreds" of additional people who are infected but who don't suffer paralysis, which the polio virus can cause, said Lee Jong-wook, WHO director-general, during a recent tour of the bunker. In Yemen alone, he said, "we'll have to spend tens of millions of dollars to clean it up." Since the Yemen outbreak, new cases of polio have been reported in Indonesia, fueling the agency's concerns.

For mild outbreaks, the WHO typically offers technical help or medical supplies to local health authorities. In more serious cases, it sends an emergency team. So far this year, the agency has dispatched one team a week -- four times the 2004 rate.

Dr. Lee decided to establish the bunker as a permanent feature of the WHO after agency workers spearheading the fight against SARS in 2003 set up a makeshift crisis center. The new one, built in an old underground movie theater for $8 million, opened officially after the Indian Ocean tsunami in December, which provided the facility's first test.

Last month, the agency adopted global health procedures requiring its 192 member countries to inform it of any worrisome disease outbreaks. And the bunker is getting a $2 million technology upgrade so that the agency can provide real-time data on epidemics to health ministries world-wide.

Before the bunker was established, WHO officials got their information from a less-centralized system of email, faxes and one-to-one phone calls with field workers and laboratories -- a process that could take days. The new set-up makes use of email, satellite phone links and even video images. "We can verify things in an average of one day," said Mike Ryan, who runs the bunker and is the director of WHO's alert and response operations. "In the past, it took five or six days."

Yet serious limitations remain. The data the bunker team gets from impoverished, hard-to-reach areas isn't always timely or reliable. In Angola, for example, the first cases of Marburg may have occurred as early as fall last year; rumors of the disease surfaced across the border, in Congo, in January this year. The regional WHO office didn't officially hear about the first cases until March, when the outbreak was well under way. As of May 26, 335 of the 399 infected people had died.

"It's a step back for us. The system isn't perfect," said Dr. Ryan. He blamed Angola's health infrastructure, wrecked by three decades of civil war. Marburg was new in the region, and local authorities weren't prepared to deal with it.

The bunker team now has email links and holds regular conference calls with colleagues in Angola. On one such call last month, several field teams dialed in, one using a mobile "field communications box," which holds a laptop computer, a Wi-Fi hookup for use as a local walkie-talkie, three satellite phones and a digital video camera.

In Geneva, Dr. Ryan and his colleagues pondered whether to redeploy key members of the Angolan team to the Congo, scene of the possible Ebola outbreak. A disease related to Marburg, Ebola also causes fatal hemorrhagic fevers. On a static-filled phone link, a WHO expert in the field in Angola indicated that the battle with Marburg was far from over.

"We have four new deaths," she said, and pleaded with her Geneva colleagues to send an expert on "social mobilization," the process in which experts fan out into local municipalities to search house by house for new cases and properly handle victims' bodies. A big challenge was to trace every person who had been in contact with a Marburg patient and isolate them, to prevent further infections.

WHO officials in Geneva said they had two infection-control specialists on standby, and that an expert on social mobilization would arrive in Angola within days. But the agency was running out of money to finance the Angolan team and was considering whether to pull out. "We have to decide soon," said Dr. Ryan. "We've got so much else going on." (The isolation unit stayed in Angola: The Congo cases were confirmed as Ebola, but the government responded swiftly, and the isolation unit wasn't needed.)

The bunker has been put to other uses. After the Marburg outbreak, WHO officials used it to speak simultaneously to officials from 26 European governments, in an effort to dissuade them from imposing travel restrictions to Angola. (The WHO is reluctant to see such drastic measures imposed unless the international threat is high.) Later, the room was used for a 39-hour-long simulation game, in which an accident at a nuclear plant in Romania sparks an emergency, requiring WHO participants to organize a speedy medical response.

Later that evening, Dr. Ryan's boss, Guenael Rodier, who leads the WHO team for communicable diseases, used the bunker's video system to show slides and address a U.S. Senate subcommittee. After explaining the bunker's high-tech capabilities, Mr. Rodier said that more than 30 new infectious diseases have emerged over the past 25 years. "This global interconnectedness is not a luxury," he warned. "It is essential."