This summer the largest Ebola outbreak in history gained international attention when the World Health Organization deemed it a global crisis. Although it has been contained within West Africa, the outbreak continues to spiral out-of-control and international medical leaders are now warning that time is running out to stop the spread of the virus, which threatens the possibility of becoming a pandemic.

“In Africa,” WHO said, “infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found dead or ill in the rainforest.”

According to The Scientific American, the outbreak began in December 2013 but failed to be identified until March 2014. Patient Zero is suspected to be a 2-year-old boy from southern Guinea, who infected his 3-year-old sister, mother, grandmother and a midwife before his death a few days after he had begun showing symptoms. After the midwife was taken to the nearest city of Gueckedou, the disease spread to four cities by March, when international health officials first detected the outbreak. However, the virus spread rapidly to neighboring countries Sierra Leone, Nigeria and Liberia.

“If there was a health care infrastructure in those countries of rapidly responding—identifying and isolating cases and providing adequate medical care and doing the proper contact tracing—then this epidemic might well have been put under control a long time ago,” Director of the U.S. National Institute of Allergy and Infectious Diseases, Dr. Andrew Fauci, told The Scientific American.

In late August TIME reported that Liberia had closed its borders, about a month after two American missionary workers working in the country became infected. After it was announced that the two Americans were being taken to the United States for treatment, the Peace Corps announced on July 31 that it would be evacuating all 340 of its West Africa volunteers, adding more seriousness to the situation. As reported by CNN, the infected missionaries, Dr. Kent Bradley and Nancy Writebol, were treated with the experimental drug ZMapp while still in Liberia. After they had shown signs of improvement, they were removed and flown to Emory University Hospital in Atlanta, where they were further treated. They were the first human beings to use the vaccine, and both recovered quickly and successfully. According to Huffington Post, the fourth patient to receive U.S. treatment was flown to Emory University Hospital September 9 after the third, an American doctor working in Liberia, had been taken to Nebraska last week. The availability of medical treatment in West Africa is growing increasingly worse, with WHO calling it a “dire emergency”.

“As soon as a new Ebola treatment facility is opened,” the United Nations said in a statement, “it immediately fills to overflowing with patients.”

In September the National Institute of Health began human trials of a new experimental vaccine. After a successful series of tests on chimpanzees, the vaccine has been given to three healthy human volunteers in Mali and Gambia to see if they show any signs of adverse effects. According to CNN, the first dose was a small injection into the arm, but it has yet to be confirmed whether the volunteers’ health has been determined in order to give the second injection of a higher dose. Should the vaccine prove to be effective, it will then be sent to health care workers or laboratories who are working to stop the spread, after which it might be sent to the communities with victims. NIAHD Director Fauci warned that there are no guarantees despite the promises of the trials.

“I have been fooled enough in my years of experience,” Fauci told CNN. “You really can’t predict what you will see.”

World leaders have been strongly criticized by WHO and the Centers for Disease Control and Prevention for not responding quickly enough to control the virus within its first six months and for leaving the fragile West African governments alone to handle the situation, but on September 7 The Toronto Star reported Canada’s announcement that it would be returning its Ebola laboratories to Sierra Leone. The lab was shut down in late August after three guests became infected at the hotel in which the Canadian medical team was lodging, according to The International Business Times. The Associated Press reported September 21 that more than 560 Sierra Leoneans have succumbed to Ebola, prompting the country to combat the disease by going on a 3-day lockdown starting September 19. The government was then able to assess the situation by going from household to household and taking in how many were infected and to what extent.

In a statement to CNN, Sierra Leone President Ernest Bai Koroma said, “The true picture portrays a situation that is worse than what was being reflected in reports and reveals that there are more infected persons in the community.”

The U.S. followed Canada’s decision with President Obama’s announcement on September 8 that, as reported by FOX News, the American military will be deployed to West Africa, the ultimate goal being to contain the virus within the next few months by setting up isolation units and providing medical equipment. However, on September 23 the Associated Press reported that the disease had reached Senegal. The Centers for Disease Control and Prevention has warned that the number of those infected could reach 1.4 million by mid-January if the disease is not prevented in time. International response included announcements from Great Britain and France that the countries would build centers in Sierra Leone and Guinea, and the World Bank and UNICEF have so far sent over $1 million worth of supplies to West Africa. The U.S. followed through with its promise by sending at least 1,400 troops to Liberia and announcing that it would build at least a dozen medical centers. According to The Christian Science Monitor, American troops will be sent to West Africa “in waves” to combat the disease and build hospitals. The program is expected to last six months.

“We would certainly stay there as long as required,” Pentagon Press Secretary Rear Admiral John Kirby said. “It could very well go beyond that.”

While the President assured that the disease would not reach the United States’ borders, the Associated Press confirmed that on September 30 the first patient to develop Ebola within the U.S. had been diagnosed. The patient, a Liberian citizen visiting family in Dallas, is currently being treated. PBS reported that health officials have stated that the disease should be able to be controlled. The Associated Press reported that family and friends of the patient will be closely monitored over the next three weeks, after which they will be cleared should they show no symptoms of the virus.