The Ebola outbreak in West Africa is an international public health emergency. As the world responds, there is a risk that American responders working on the ground may be exposed to the virus or become ill. This summer, two American health care workers infected with Ebola while working in West Africa were successfully treated at Emory University Hospital.  Their health care team used the proper infection control practices and there was no transmission of the virus to the health care team or others in the hospital and community.

Now two more American health care workers working in West Africa have become infected with Ebola virus and are being treated in the United States.

CDC has already consulted with state and local health departments on almost 100 cases where travelers had recently returned from West Africa and showed symptoms that might have been caused by Ebola. Of those cases, only eleven of were considered to be truly at risk. Specimens from all eleven patients were tested and fortunately Ebola was ruled out in all cases.

I recently travelled to West Africa to get a better understanding of how the outbreak is unfolding and to see firsthand the challenges on the ground. The current Ebola outbreak is an unprecedented crisis that will require an unprecedented international response. It is spreading with remarkable speed, and is exacting an enormous cost both in lives and in dollars.

It has been an outbreak of terrible human suffering. Sadly, there will be a great deal more suffering before this outbreak is over. But every day there are more reasons to be hopeful.
You can see four of those reasons in this photograph. They are Jaminatu Pessima, guardian of 21-month-old Isata Conteh; Isata herself; Kadi Jaward; and Sulaiman K. Saidu. Each of them had Ebola. Each of them survived.

CDC disease detective Kelsey Mirkovic, just back from West Africa, tells of working to gain the confidence of village leaders and train community health workers to spread the word about how to avoid getting – and stop spreading – Ebola.  “The community health workers are key in the effort to stop Ebola because they are working with people in their villages every day. But if they meet with resistance, it’s the village chief who can make the difference. “

An encounter in one village, resolved with the help of the chief, taught Kelsey valuable lessons in how to reach people and communicate more effectively.  A grateful chief presented Kelsey with a symbolic gift of cocoa pods and a coffee plant.  For her, the gift symbolized the important connection made and confidence gained with a trusted community leader.

Kelsey and her colleagues are fulfilling our promise to the people of West Africa, Americans, and the world that CDC is quickly ramping up its efforts to help bring the worst Ebola outbreak in history under control.

This post originally appeared in The Huffington Post.

CDC and our partners are currently fighting the biggest and most complex outbreak of Ebola virus disease ever recorded.

There are hundreds of cases in West Africa and now a new cluster of cases in Nigeria is very concerning. The spread of Ebola shows what happens if we don’t have meticulous infection control, contact tracing, and proper isolation of those with symptoms of the disease.

There are two things that are very important to understand about how Ebola spreads.

The evidence suggests that Ebola only spreads from sick people — not from people who have been exposed to the disease but haven’t yet become sick from it. The illness has an average 8-10 day incubation period, although in rare instances the incubation period may be as short as two days or as long as 21 days, which is why we recommend monitoring for 21 days after any potential exposure.

For more than four decades, Ebola virus had only been diagnosed in central or eastern Africa.

Then late this past March, the first cases of Ebola began appearing in a surprising part of the continent. The Ministry of Health in Guinea notified WHO of a rapidly evolving outbreak of Ebola virus disease. The outbreak in Guinea was the first sign the virus had made the jump across the continent.

Ebola then spread quickly to Sierra Leone and Liberia, and then to Nigeria.

As the world learned of the cases, CDC began receiving questions from American hospital labs. They were looking for guidance on how to handle testing for patients who had recently returned to the U.S. from West Africa with potential Ebola symptoms.

If U.S. hospitals were to run laboratory tests on these patients, how could they be sure their staff could safely handle materials that might contain this dangerous virus? Did they need the kind of personal protective equipment they saw CDC scientists using when they were testing for Ebola?

In order to ensure the safety of laboratory staff and other health care personnel collecting or handling specimens, we recommend they follow established OSHA bloodborne pathogens standards .