Microbiology: A Systems Approach 4th Edition by Marjorie Kelly Cowan

Exercise 34

Ebola in the Congo
In 1994, Richard Preston's The Hot Zone electrified readers with gruesome descriptions of an exotic virus that caused its victims to bleed out of every orifice in a horrifying death. This book was not a work of fiction but was a factual account of outbreaks of the Ebola virus in Kenya and Sudan and its presence at an animal storage facility in Reston, Virginia. Although Ebola is a fairly rare disease, case fatality rates range from 25% to 90% and outbreaks often strike in impoverished nations with limited medical resources. Usually outbreaks are small and self-limiting, but they are deadly and quickly capture the attention of public health agencies such as the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) and news outlets alike.
Ebola first grabbed the attention of the world in 1976 with simultaneous outbreaks in Sudan and Zaire (currently the Democratic Republic of the Congo, or D.R.C.). Since then, there have been sporadic outbreaks in Sudan, Zaire/D.R.C., Gabon, Ivory Coast, Uganda, South Africa, and the Philippines. In the summer of 2012, an outbreak occurred in the D.R.C. with 15 cases and 10 deaths and in Uganda with 60 cases and 16 deaths. One case was confirmed in a man who stole a cell phone from a patient in a hospital ward where Ebola patients were quarantined. He later started showing symptoms of the disease and checked himself into the same hospital where he stole the phone.
What makes Ebola such a deadly virus
What is the reservoir of the virus
How is the virus transmitted
Ebola is an RNA virus in the Filoviridae family and is most easily recognized in electron micrographs by its long, thin, spaghetti-like shape. The virus infects the endothelial cells lining blood vessels and interferes with coagulation of the blood. The combination of damaged blood vessels and lack of coagulation leads to massive internal bleeding and shock, usually resulting in death. What makes Ebola so insidious is that its early symptoms mimic so many other tropical diseases: Fatigue, headache, muscle pain, fever, vomiting, and diarrhea are often mistaken for malaria, typhoid fever, cholera, relapsing fever, and other diseases commonly seen in this area of the world.

The reservoir of the virus is still unknown, but massive efforts have been undertaken to collect samples from live animals and corpses of infected animals during an Ebola outbreak to detect antibodies against the virus. Fruit bats are generally considered to be the host of the virus, but to date, only 3% of all fruit bat species have been sampled, making it difficult to determine the exact reservoir.
The virus is mainly transmitted through direct contact with bodily fluids or contaminated fomites such as bed linens or clothing from infected individuals. There are three main pathways for person-to-person transmission of the virus during an outbreak: between family members and caregivers of sick individuals in a home setting, through contact with dead bodies during funeral preparations, and between infected patients and the medical staff in health care settings. Of utmost importance is prevention of transmission of Ebola in the hospital setting. There have been numerous cases of health care workers contracting and dying from the virus. During an outbreak in the Democratic Republic of the Congo in 1994, the only physician at the Watsa district hospital in D.R.C. died after treating a patient. This meant that there was no physician available at that hospital from 1994 to 1996. In 2000, the medical director and 11 staff members died in Gulu, Uganda, during an outbreak.
What are some of the difficulties in controlling and treating Ebola outbreaks
In terms of "viral success," or the ability of the virus to transmit itself, Ebola is not a "successful" virus because it kills its victims so quickly. Why then is Ebola such a great concern globally
Source : 2012.www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/ebola/ebolatable.htm