Ebola is the virus Ebolavirus (EBOV), a viral genus, and the disease Ebola hemorrhagic fever (EHF), a viral hemorrhagic fever (VHF). The virus is named after the Ebola River Valley in the Democratic Republic of the Congo (formerly Zaire), which is near the site of the first recognized outbreak in 1976 at a mission hospital run by Flemish nuns.
It has remained largely obscure until 1989 when several widely publicized outbreaks occurred among monkeys in the United States. The virus interferes with the interior cells lining the surface of blood vessels and with blood clotting. As the blood vessel walls become damaged and destroyed, the platelets are unable to clot and patients fall into to hypovolemic shock. Ebola is transmitted through bodily fluids, while conjunctiva exposure may also lead to transmission. There are five recognized species within the Ebolavirus genus, which have a number of specific strains.
The Zaire virus is the type species, which is also the first discovered and the most lethal. Ebola hemorrhagic fever is potentially lethal and encompasses a range of symptoms including fever, vomiting, diarrhoea, generalized pain or malaise, and sometimes internal and external bleeding. The span of time from onset of symptoms to death is usually between 2 and 21 days. By the second week of infection, patients will either defervesce (the fever will lessen) or undergo systemic multi-organ failure.
Mortality rates are typically high, with the human case-fatality rate ranging from 50 to 89%, depending on the species or viral strain. The cause of death is usually due to hypovolemic shock or organ failure. Unfortunately there is no standard treatment for Ebola hemorrhagic fever. Vaccines have successfully protected non-human primates; however, the six months needed to complete immunization made it impractical in an epidemic. In 2003 a vaccine using an adenoviral vector carrying the Ebola spike protein was tested on crab-eating macaques.
The monkeys were challenged with the virus twenty-eight days later, and remained resistant. Outbreaks of Ebola, with the exception of Reston Ebolavirus, have mainly been restricted to Africa. * The Zaire virus, formerly named Zaire Ebolavirus, has the highest case-fatality rate, up to 90% in some epidemics, with an average case fatality rate of approximately 83% over 27 years. The first outbreak took place on 26 August 1976 in Yambuku. * The Sudan Ebolavirus was the second species of Ebola emerging simultaneously with the Zaire virus. It was believed to have originated amongst cotton factory workers in Nzara, Sudan.
The most recent outbreak occurred in May 2004 in Yambio County, Sudan. The average fatality rates for SEBOV were 54% in 1976, 68% in 1979, and 53% in 2000 and 2001. * The Reston Ebolavirus was discovered during an outbreak of Simian hemorrhagic fever virus (SHFV) in crab-eating macaques from Hazleton Laboratories (now Covance) in 1989. Since the initial outbreak in Reston, Virginia, it has emerged in Siena Italy, Texas, and among pigs in the Philippines. Despite its status as a Level-4 organism, it is non-pathogenic to humans although hazardous in monkeys.
The Ivory Coast Ebolavirus also referred to as Tai Ebolavirus, was first discovered among chimpanzees from the Tai Forest in Cote d’Ivoire, Africa, on 1 November 1994. * On November 24, 2007, the Uganda Ministry of Health confirmed an outbreak of Ebolavirus in the Bundibugyo District. A study conducted by WHO and Uganda Ministry of Health scientists determined there were 116 confirmed and probable cases of the Bundibugyo Ebolavirus, and that the outbreak had a mortality rate of 34% (39 deaths). Plants, arthropods, and birds have been considered as possible reservoirs; however, bats are considered the most likely candidate.
Bats were known to reside in the cotton factory in which the index cases for the 1976 and 1979 outbreaks were employed, and they have also been implicated in Marburg infections in 1975 and 1980. The stated evidence above proves the contention of this essay is correct, the contention being; historically Ebola has had a serious impact on human health and hygiene and still does due to the fact of no cure being discovered, but because of improvements in scientific and medical knowledge it is now a controllable problem.