Ebola Virus Outbreak Unprecedented
An outbreak of Ebola virus is being reported in three West African countries. What makes this outbreak unprecedented is the distribution of cases throughout several towns in Guinea over hundreds of kilometers. The deadly virus is particularly lethal in that it kills nine out of ten of its victims, and at this time, there no vaccine or cure. To date, Guinean health officials have reported 122 suspected patients; 78 have died. Other cases, suspected or confirmed, have been reported in neighboring Sierra Leone and Liberia.
On March 21, 2014, the World Health Organization (WHO) confirmed eight more cases of the terrifying ebola virus in Conakry, Guinea. Of those cases, half are infected health care workers. The organization Medicins Sans Frontieres/ Doctors Without Borders (MSF), has responded to the epidemic by sending teams to Guéckédou and Macenta, two towns in south Guinea. 30 staff members are already on the ground and more doctors, nurses and sanitation specialists will be joining them in the coming days.
Here’s some background on the Ebola virus.
The Ebola virus is a highly aggressive pathogen that produces a deadly hemorrhagic fever syndrome in nonhuman primates and humans. It made its first appearance in Zaire in 1976, near the Ebola River Valley for which it is named. Ebola comes in five species with mortality rates from 50 up to 90 percent; the one currently affecting Guinea is the Zaire strain – the deadliest – which kills 90 percent of infected patients. Because an Ebola infection progresses so rapidly, there is not much chance of infected persons developing an acquired immunity to the virus.
Ebola infection tends to last 14 to 21 days. Signs of infection begin with flu-like symptoms such as fever and muscle aches, and progress to severe bleeding, rash, coagulation abnormalities, and gastrointestinal hemorrhage. Symptoms also include vomiting and diarrhea. The infected patient’s body develops exaggerated inflammatory responses and liver damage; and coagulopathy (the inability to clot blood), which produces uncontrolled internal or external bleeding. The patient eventually dies of diffuse bleeding and hypotensive shock. Transmission of ebola occurs by direct contact with the blood, tissues or body fluids infected patients. This creates a dilemma for health care workers. The patients need to be treated with dignity, and it is important to maintain family links but at the same time, there is a need to protect the family and the community from contamination.
Studying the ebola virus is extremely dangerous; it is difficult to obtain samples and the disease occurs in relatively remote areas. Paradoxically, the lack of roads where infections break out helps to contain the infection; this is in part why the present Ebola virus outbreak is unprecedented in scale. Studying the infectious virus in a laboratory setting requires a high level of biohazard containment, although more recently, scientists have learned enough about Ebola’s genetics to be able to study its genes individually, under safer conditions. MSF teams have already received 40 tons of protective equipment in Guinea to set up isolation facilities, and provide medical supplies and protective outfits for the teams to help contain the epidemic. In addition to doctors and nurses, the teams include epidemiologists, water and sanitation experts, and anthropologists.
Ebola is an unusual virus in that it can “jump species” – it can be communicated to humans from sick or dead animals such as fruit bats, monkeys, forest antelopes and gorillas. There is currently no antiviral therapy or vaccine that is effective against Ebola virus infection in humans, but it is a very active area of biological research. This means that the only way to curtail the deadly outbreak is to prevent its spread.
The MSF teams are doing what’s known as ‘contact tracing’; identifying people at risk who have had direct contact with known Ebola patients. The doctors go from village to village on foot, to trace people showing any symptoms of infection, and to bring them to places where they can be cared for. Medical care can reduce the symptoms, halt the development of the disease or reduce a patient’s suffering.
The suspected cases and deaths in Sierra Leone and Liberia that were reported to WHO were people who had traveled to regions already affected. Senegal has blocked the border with Guinea indefinitely. In response to the unprecedented outbreak of the Ebola virus, WHO has recommended that other neighboring countries step up surveillance but has not yet recommended restriction of trade or travel to Guinea, Liberia or Sierra Leone.
By Laura Prendergast