Just back from a week in the Ebola hot zone, Centers for Disease Control and Prevention (CDC) Director Dr. Tom Frieden had a dire assessment of the situation on the ground there.

“The bottom line is that despite tremendous efforts from the U.S. government, CDC, from within countries, the number of cases continues to increase and is now increasing rapidly,” Freiden told a press conference at the CDC today.

The virus is moving faster than anyone anticipated and that’s why we need to move now, he said.

During his trip, Freiden visited the three countries hardest hit by the Ebola epidemic – Liberia, Sierra Leone and Guinea. In Liberia, Frieden donned the familiar yellow suits, face masks and goggles healthcare workers in Africa wear and visited a ward where Ebola patients are being treated.

“There is a window of opportunity to tamp this down”, Frieden said, “but that window is closing…we need action now to scale up the response.”

The World Health Organization (WHO) today said that the “magnitude of the Ebola outbreak has been vastly underestimated.” According to the latest WHO figures, 3,069 people have come down with Ebola. Of them, 1,552 have died— a fatality rate greater than 50 percent. Dr. Frieden told Fox News that unless urgent action is taken to contain the epidemic, it may be impossible to stop. There are not enough hospitals, wards, clinics, doctors or nurses to take care of the numbers of people who are coming down with Ebola, he said.

The world, Frieden said, needs to come together to open more wards and clinics and train health care workers or Ebola could continue to spread to other countries. The West African nation of Senegal yesterday declared a first-priority health emergency after a 21-year-old student who traveled to Senegal from Guinea showed symptoms of Ebola. His brother had died from the disease days earlier. The Democratic Republic of Congo is investigating 24 cases of Ebola hemmorhagic fever, though those cases are believed to be caused by a different strain than the virus that is devastating West Africa.

Frieden says every nation of the world should be worried.

“It’s not just in the interest of these countries to get it under control. For every day that this continues to spread in West Africa, the likelihood of someone getting infected and becoming sick elsewhere increases,” he told reporters.

The CDC is dispatching a team to Senegal in an attempt to prevent any further spread of the disease there.

But Frieden issued an ominous prediction for what might happen if the world doesn’t come together to fight the disease. Rather than the sporadic outbreaks of Ebola that have come and gone since the virus was first described in Congo in 1976, Ebola may become endemic— that is, there will always be a certain level of infection in some African nations, marked by more frequent outbreaks than in the past.

It’s certainly possible to feel hopeless,” Frieden said today. “But it’s not hopeless. We do know how to stop Ebola. The window of opportunity is not yet closed. We can turn this around.”

Frieden also warned that the virus may threaten the economies of African nations struggling to dig themselves out of third-world poverty. The more it spreads on the continent, the greater the risk becomes that a traveler will touch down in an American city— infected with Ebola.