As the death toll in West Africa continues to mount, government agencies and international organizations are urging immediate action and collaboration to stop the deadliest Ebola virus outbreak in history.

The latest count of Ebola virus disease (EVD) cases in the affected West African countries of Guinea, Liberia, Nigeria, and Sierra Leone is 3,500, with more than 1,900 deaths, according to the World Health Organization (WHO). That number makes this the largest Ebola outbreak ever recorded. An unprecedented number of healthcare workers have also been infected and have died from Ebola.

In response to the worsening crisis, Dr. Tom Frieden, director of the Centers for Disease Control and Prevention (CDC), held a press conference on Sept. 2. He called for an immediate and large-scale international response to stop the outbreak from spreading further.

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Frieden, who had returned from Africa the day before, told reporters, “The bottom line is … the number of cases continues to increase and is now increasing rapidly. I’m afraid that over the next two weeks those numbers are likely to increase further and significantly. There is a window of opportunity to temp this down, but that window is closing. We need action now to scale up the response. We know how to stop Ebola. The challenge is to scale it up to the massive levels needed to stop this outbreak.”

Additional resources, healthcare and management experts, and a global, coordinated approach are urgently needed, Frieden told the press. “This is not just a problem for West Africa and for Africa. It’s a problem for the world, and the world needs to respond,” he said.

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Frieden said that in one treatment facility he visited, there were 35 beds and 63 patients. Some patients were lying on the ground.

“I didn’t see the rapid response that is needed to stop a single cluster from becoming a large outbreak. I didn’t see efficient management systems and support and transport and jeeps essential for a rapid and effective response,” Frieden said.

Doctors Without Borders has set up the largest Ebola treatment and isolation center ever created in a district in eastern Sierra Leone.

Frieden recalled meeting with a 22-year-old woman who contracted Ebola from her sister-in-law’s daughter, who came to visit from Sierre Leone.

“She learned early she had Ebola, went to a treatment unit, and she was safe. While she was in the treatment center, I asked what was the hardest thing. She said she was next to her big brother when he died horribly from Ebola. She was horrified that she couldn’t help him and was terrified she was next. That’s the reality people in these regions are dealing with,” said Frieden.

The United Nations also addressed the unprecedented outbreak at a high level briefing for Member States at its New York City headquarters this week, saying that $600 million is needed to fight Ebola. The organization urged international action to help West African countries deal with the health and economic impacts of this outbreak.

“The fear factor plays a strong role in the crisis. I encourage the Member States and businesses and individuals as well to make decisions based on scientific evidence, not on fear,” said UN Deputy Secretary-General Jan Eliasson.

The Commissioner of Health for Rivers State in Nigeria has now reported three confirmed cases of Ebola in Port Harcourt, the country’s oil hub. Nigerian health workers and epidemiologists from the WHO are monitoring more than 200 patient contacts. Of these, around 60 people are considered to have had high-risk or very high-risk exposure to the virus.

Meanwhile, the UN’s Food and Agriculture Organization warned that disruptions in food trade and marketing in Guinea, Liberia, and Sierra Leone have increased food prices and have also made it difficult to find food. Making matters worse, the forthcoming harvest season is at serious risk due to the shortage of labor.

Frieden praised Doctors Without Borders (MSF) workers for caring for patients in these incredibly difficult circumstances.

However, he warned that in the next few weeks, “We’re likely to see significant increases in cases. Already we have widespread transmission in Liberia. In Sierra Leone, we’re seeing strong signs that that will happen in the near future. We expect there will be more people in countries like Senegal and Nigeria, who come in and have the illness. As long as Ebola is spreading anywhere, all of us need to be concerned and make sure we are identifying people who could have it, and are taking prompt action so it doesn’t spread.”

The Firestone Company’s quick response to an Ebola outbreak at its rubber plantation in Liberia is proof that a prompt response can work, said Frieden. After the wife of one of its workers died of Ebola, the company set up an Ebola treatment unit and trained its staff. After tests were done by the CDC lab there, 73 contacts were placed in rooms and monitored for 21 days.

“Eleven of those contacts became ill with Ebola. They immediately put them in the isolation facility and did not have a single additional case. Their Ebola outbreak stopped,” said Frieden.

“We do know how to stop Ebola. The window of opportunity is not yet closed. We can chip away at the changes one by one and begin to get the situation under control.” — Dr. Tom Frieden, Centers for Disease Control

Frieden said he couldn’t emphasize enough, “We do know how to stop Ebola. The window of opportunity is not yet closed. We can chip away at the changes one by one and begin to get the situation under control. We can work with communities that don’t yet have Ebola in these countries, to have them well-prepared so if a single case occurs it can stop others.”

Finally, Frieden called on doctors, nurses, and healthcare management experts who have specialized skills and experience working in this kind of environment to contact aid groups like MSF, the WHO, or Save The Children.

Find Out More About the Ebola Crisis »

This week President Obama issued a statement on the crisis and sought to clear up misinformation about how the disease spreads.

“Along with our partners around the world, the United States is working with your governments to help stop this disease. And the first step in this fight is knowing the facts,” he said. “First, Ebola is not spread through the air like the flu. You cannot get it from casual contact, like sitting next to someone on a bus … Second, the most common way you can get Ebola is by touching the body fluids of someone who’s sick or has died from it, like their sweat, saliva, or blood, or through a contaminated item, like a needle.”

Workers in the European Mobile Lab Project test blood samples for Ebola.

Obama urged people who feel sick with a fever to get help right away. “With prompt treatment in a medical center, nearly half of patients can recover. And it’s why, when burying someone who died from this disease, it’s important to not directly touch their body. You can respect your traditions and honor your loved ones without risking the lives of the living,” Obama said.

He added, “You are not alone. Together, we can treat those who are sick with respect and dignity. We can save lives. And our countries can work together to improve public health, so this kind of outbreak doesn’t happen again. In this urgent work and in building a stronger and more prosperous Africa, you’ll continue to have a partner in me and in the United States of America.”

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In a separate development, aid organization SIM USA reported that Dr. Rick Sacra, a 51-year-old family physician from Massachusetts and one of its missionary doctors in Liberia, has tested positive for Ebola. Dr. Kent Brantly and Nancy Writebol were two other American workers who were infected with Ebola. They were both evacuated and treated at Emory University Hospital in Atlanta, where they recovered and were released.

Sacra was treating obstetrics patients at SIM’s ELWA hospital in Monrovia. He was not treating Ebola patients in ELWA’s Ebola isolation unit. It is not yet known how the doctor contracted the virus.

“You are not alone. Together, we can treat those who are sick with respect and dignity. We can save lives. And our countries can work together to improve public health, so this kind of outbreak doesn’t happen again.” — President Barack Obama

At onset of symptoms, the doctor immediately isolated himself and has since been transferred to the ELWA Ebola isolation unit.

“My heart was deeply saddened, but my faith was not shaken, when I learned another of our missionary doctors contracted Ebola,” said Bruce Johnson, president of SIM USA, in a statement. “We are surrounding our missionary with prayer, as well as our Liberian SIM/ELWA colleagues, who continue fighting the Ebola epidemic. We have gifted Liberian doctors, medical staff, and support staff who are carrying on the fight.”

SIM announced today that Sacra is being flown to The Nebraska Medical Center in Omaha for treatment. Sacra is expected to arrive in Omaha Friday morning and begin treatment in the hospital’s Biocontainment Patient Care Unit.

Nancy Writebol appeared this week on ABC News. Writebol said she’s thankful to be alive and getting stronger each day after surviving Ebola. She described the isolation unit where she was treated as a very lonely place when you are not able to be with the people you love. Writebol and Brantly were treated with an experimental Ebola drug called ZMapp, but Writebol said it is not certain if the drug was responsible for her survival.

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The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), has started initial human testing of a vaccine co-developed by NIAID and GlaxoSmithKline (GSK). Testing is taking place at the NIH Clinical Center in Bethesda, Maryland.

The study is the first of several phase 1 clinical trials that will examine the investigational Ebola vaccine, as well as an experimental Ebola vaccine developed by the Public Health Agency of Canada and licensed to NewLink Genetics Corp. The other trials are expected to begin this fall. These trials are conducted in healthy adults, who are not infected with Ebola, to determine if the vaccine is safe and prompts a strong immune system response.

The NIH has partnered with a British-based international consortium, which includes the Wellcome Trust, Britain’s Medical Research Council, and the UK Department for International Development. The consortium will test the new NIAID/GSK vaccine candidate on healthy volunteers in the United Kingdom and in the West African countries of Gambia and Mali (after approval from authorities).

The NIH is also supporting the Crucell biopharmaceutical company in its development of an Ebola/Marburg virus vaccine, as well as Profectus Biosciences in its development of an Ebola vaccine. The NIH and Thomas Jefferson University are also working together to develop a candidate Ebola vaccine based on the established rabies vaccine.

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Photos courtesy of European Commission Humanitarian Aid and Civil Protection/ECHO.