When infected with the Ebola virus, within two to 21 days people start to show symptoms that are similar to other tropical diseases or to influenza: fever and sweating, weakness, headache, body aches and pains, then vomiting and diarrhea. Five to seven days after the first symptoms start, about half of all Ebola patients develop internal bleeding. Ebola is assumingly contracted through human contact with animals, especially via the consumption of bush meat like apes and bats. However, little is known about how the virus changes or adapts to humans. Once it is settled within human bodies, the virus is easily spread through blood and other bodily fluids.
The latest outbreak in West Africa is the largest Ebola epidemic so far. As of March 2016, this outbreak had resulted in almost 29,000 cases and over 11,300 deaths. The most affected countries included Guinea, Liberia and Sierra Leone, and the worst hit areas remain under heightened surveillance. The first victim of this epidemic died in late December 2013 in Guinea. The World Health Organization (WHO) reported a major outbreak for the region in March 2014. Five months later, it declared the outbreak an international public health emergency. The West African outbreak involves the Zaire Ebola virus, the deadliest of all Ebola virus strains. By the end of 2014, further related Ebola cases had been reported in Nigeria, Senegal, Mali, and even Spain, the United States, and the United Kingdom.
The impact of this outbreak was felt both socially and economically. It was estimated that as of February 2015, the outbreak had resulted in 780 hours of learning lost due to school closures in Sierra Leone. Economically, the outbreak was calculated to cost Sierra Leone a decrease of 286.8 million U.S. dollars in GDP. It was estimated that in all of West Africa this loss could equal some 4.4 billion dollars in GDP in 2015.