The Ebola outbreak in Western Africa that started last year at this time has killed more than 10,000 people, according to the World Health Organization. Unlike previous outbreaks of the hemorrhagic disease, this one was not stamped out quickly. International health agencies and organizations and the governments of the countries affected now say that they did not act fast enough to respond to the emergency.
The countries that have been hardest hit are Guinea, Liberia, and Sierra Leone, but deaths have also occurred in Mali, Nigeria, the Unites States, and Spain. The outbreak started in Guinea in March 2014. It was difficult to control because national borders in West Africa are easy to cross.
Liberia, the country that was hardest hit in the epidemic, has not had a new Ebola patient since March 5. If 42 days pass from then without a new case, the country will officially be declared free of Ebola. The 42=day period is twice the 21 days that is thought to be the longest time between exposure to Ebola and the appearance of the first symptoms.
However, new cases of Ebola continue to be reported in Guinea and Sierra Leone. Many deaths in those countries occur outside of the hospital system because people are hiding or are scared to get medical help. Western medical workers are still being attacked in both countries, making it difficult to track the spread of the disease.
This outbreak, the largest outbreak of Ebola by far, has speeded up the development of both vaccines and treatments for the virus. Two vaccines are in clinical trials. Both are intended to be used on someone who has been exposed to the virus, but who has not yet developed symptoms.
The World Health Organization hopes to have stockpiles of a vaccine against Ebola available if and when another outbreak occurs.