What is the history of Ebola hemorrhagic fever?

Ebola hemorrhagic fever was first noted in Zaire (currently, the Democratic Republic of the Congo or DRC) in 1976. The original outbreak was in a village near the Ebola River after which the disease was named. During that time, the virus was identified in person-to-person contact transmission. Of the 318 patients diagnosed with Ebola, 88% died. Since that time, there have been multiple outbreaks of Ebola virus, and five strains have been identified; four of the strains are responsible for the high death rates. The four Ebola strains are termed as follows: Zaire, Sudan, Tai Forest, and Bundibugyo virus, with Zaire being the most lethal strain. A fifth strain termed Reston has been found in the Philippines. The strain infects primates, pigs, and humans and causes few if any symptoms and no deaths in humans. Most outbreaks of the more lethal strains of Ebola have occurred in Africa and mainly in small- or medium-sized towns. Once recognized, African officials have isolated the area until the outbreak ceased. However, in this new outbreak that began in Africa in March 2014, some of the infected patients have reached larger city centers and have been hospitalized. Unfortunately, many people may have been exposed to the virus in the city, thus causing more infections (and deaths). This outbreak in Africa has now spread to Guinea's capital and has been detected in the neighboring countries of Liberia and Sierra Leone. About 122 infected people have been diagnosed and 78 have died as of Apr. 1, 2014. The infecting Ebola virus detected this outbreak is the Zaire strain, the most pathogenic strain of Ebola. Health agencies are terming this outbreak as an "unprecedented epidemic."