Ebola Outbreak in West Africa

Areas involved with current outbreak 

The WHO recently reported on the status of the ongoing Ebola outbreak in West Africa; as of July 8th there have been 888 cases with 539 deaths. Although the outbreak seems to be slowing in Guinea it is still very active in Sierra Leone and Liberia, where 44 new cases and 21 deaths were reported between July 6 and 8.

Ebola Virus Disease (EBV), also known as Ebola Hemorrhagic Fever, refers to a viral infection with several different species of a filovirus. First identified in two outbreaks in the Sudan and the Democratic Republic of the Congo in 1976, Ebola causes a severe acute illness characterized by bleeding and a mortality rate up to 90%.

Most of the Ebola outbreaks to date have occurred in small villages in West and Central Africa near tropical rain forests. The natural host of the virus is believed to be fruit bats. Animals such as chimpanzees, gorillas and monkeys can become infected with the virus after coming in contact with bats; these animals are "accidental" hosts, just like humans. Humans become infected via handling blood and body fluids from infected bats or other animals. Once someone is infected with the virus they then go on to serve as a source of transmission to other humans via their own infected blood, tissues and secretions.

The incubation period for Ebola after being infected is anywhere from 2-21 days; humans are not

infectious until they develop symptomatic illness. Ebola initially is a non-specific illness characterized by sudden fever, intense weakness, muscle pains, sore throat and headache. These symptoms are followed by vomiting, diarrhea, rash, organ dysfunction and sometimes bleeding. Once symptomatic, a person's blood and body fluids are highly infectious and serve as a source for potential human to human transmission of disease.

As noted above, Ebola is associated with mortality rates of up to 90%. There is no specific treatment or vaccine for the disease.

Distribution of different Ebola outbreaks

The ongoing, sustained outbreak of Ebola in West Africa is concerning for several key reasons. This large-scale outbreak in multiple locations is testament to just how 'small' the world has become. A disease that emerges in a rural village can spread rapidly to major cities and, theoretically, to the rest of the world. This is a great reminder that we all should be concerned with and help in the response to outbreaks such as these. Also, this outbreak highlights some of the barriers to enacting the infection control measures that would allow for its control. Specifically, it is believed some cultural burial practices have perpetuated the outbreak via exposing uninfected people to the infected blood, secretions and organs of Ebola victims.

The WHO has terrific information on Ebola available here. Some great information is also available from the CDC.