biomedcentral | Abstract - Response to the current ebolavirus outbreak based on traditional control measures
has so far been insufficient to prevent the virus from spreading rapidly. This has
led to urgent discussions on the use of experimental therapies and vaccines untested
in humans and existing in limited quantities, raising political, strategic, technical
and ethical questions.
Ebolavirus outbreaks and disease - The ongoing outbreak in West Africa of ebolavirus hemorrhagic fever (EHF) [1], lately also referred to as Ebola virus disease (EVD), has led to a surge in public
interest and concern regarding this virus, which was first discovered in 1976 during
simultaneous outbreaks in Zaire (now the Democratic Republic of the Congo) and Sudan
[2]. Humans initially contract the virus either through contact with the infected reservoir,
which is thought to be fruit bats, or by hunting and butchering of infected wildlife,
particularly great apes. Since their discovery, ebolaviruses have caused frequent
outbreaks almost exclusively in Central Africa. However, the recent emergence of Zaire ebolavirus in West Africa, resulting in what is the largest outbreak to date (Figure 1), with 4,390 cases and 2,226 deaths as of 7 September 2014, shows that ebolaviruses
are more widely distributed than previously thought. While EHF is commonly associated
with high case fatality rates (up to 90% for Zaire ebolavirus, approximately 50% for Sudan ebolavirus, and approximately 35% for Bundibugyo ebolavirus), the pathogenicity of Taï Forest ebolavirus, which was discovered in the mid-1990s in Ivory Coast, is unknown because only a
single case has been reported, and Reston ebolavirus, which is found in the Philippines, is considered apathogenic for humans. Outbreaks
are usually driven by human-to-human transmission as a result of direct contact with
live or deceased patients and their body fluids, mainly during patient management
and care, and participation in traditional local burial practices. Basic hygiene measures
and barrier nursing techniques are usually sufficient to disrupt ebolavirus transmission
and spread in the community. Nevertheless, because of its high case fatality rate
and the absence of licensed vaccines or treatments, this virus is considered of the
highest biosafety concern, restricting work on infectious virus to a few maximum containment
laboratories worldwide. Despite the restricted and highly regulated handling of the
pathogen, there have been considerable scientific achievements over the past years;
however, many challenges remain in the public health sector in relation to identifying
and managing cases and interrupting virus spread.
