Ebola

Introduction

Ebola, a form of hemorrhagic fever, is one of the world’s most lethal viruses that infects primates, including humans. Endemic to Africa and the Philippines, the filovirus Ebola virus is actually a group of four subtypes that are about 40% different at the nucleotide level; this means there are four types of Ebola virus. With a high mortality rate (between 50-90%) and a highly pathogenic nature (a Biosafety level 4, AIDS is only a 2), the ability to study Ebola has proven very difficult and dangerous so not much is known about it (2).

History

As mentioned before there are four strains of Ebola. The first outbreaks of Ebola, named for the Ebola River in Zaire, occurred in 1976 in Sudan and Zaire, approximately 500 miles apart from each other (4). The strain that caused the Sudan outbreak became known as Ebola-Sudan (EBOS) and infected over 280 people, with over half dying. Just a few months later, Ebola-Zaire (EBOZ) made its debut infecting 318, killing 280. Ebola-Zaire is the most common form of Ebola and is usually the one responsible when outbreaks occur. Ebola Reston (EBOR) was identified in 1989 when infected monkeys were imported from Mindanao, Philippines to Reston, Virginia. This may also be the only airborne strain of the virus, but more testing is needed to determine this. Finally in 1994, an ethnologist in Cote d’Ivoire was infected accidentally when she was performing a necropsy on a dead chimpanzee. This fourth and final strain is known as Ebola Cote d’Ivoire (EBO-CI), no one who has gotten this strain has ever died from it.

In Nature

No one has yet to discover the exact origin where the Ebola virus is found in nature. Based on the evidence of similar viruses, Ebola is believed to be zoonotic, or animal-borne. The animal Ebola resides in is more than likely native to Africa rainforests (10). There are also several hypotheses as to what animals are the natural reservoirs; these include rats, bats, and insects. Another...