July 30, 2015

Health workers pray before the start of their shift at an Ebola treatment center in Liberia, on Oct. 6, 2014. Daniel Berehulak was awarded the Pulitzer Prize for feature photography on April 20, 2015, for his coverage of the Ebola outbreak in West Africa for The New York Times. Credit: © Daniel Berehulak, The New York Times/Redux Pictures

The world’s largest and most deadly outbreak of the Ebola virus is not yet ended, even as coverage of the epidemic has faded from news headlines in most countries. The outbreak that began in West Africa in 2014 continues, as health care agencies struggle to contain the disease. In the first half of 2015, the World Health Organization (WHO) reported between 20 and 30 new Ebola infections each week in Guinea and Sierra Leone. Before this outbreak, such a rate of Ebola infection would have been considered a seriously dangerous outbreak. Today, it is a sign of progress. During the worst days of the West Africa outbreak, hundreds of infections were reported each week.

A public health worker sprays disinfectant on the body of a person thought to have died from Ebola virus infection during the 2014 outbreak in West Africa. AP Photo

In humans, Ebola hemorrhagic fever causes illness marked by fever, headache, diarrhea, vomiting, and massive internal bleeding. Symptoms appear within 5 to 10 days of infection. There is no known cure or vaccine for Ebola. Fatality rates for Ebola infection vary. In early outbreaks, about 80 to 90 percent of people who became infected died. Prevention efforts involve educating people about how the virus is transmitted and isolating infected individuals.

Nearly all Ebola infections in the 2014 outbreak occurred in the countries of Guinea, Liberia, and Sierra Leone. Since the outbreak was first reported in 2014,WHO officials tallied a total of 27,748 Ebola infections. The outbreak has caused 11,279 deaths, including more than 500 among health care workers. Despite the risk, American and European health care workers continue to travel to west Africa to assist in the fight against the disease.

Although the recent decline of new infections indicates health workers have gained the upper hand in the West African outbreak, the danger has not yet passed. More than 2,000 people who may have been exposed to the Ebola virus remain under watch. These patients must be monitored for 21 days for doctors to be sure they are free of infection. Health officials know that a single missed case can spark a new cluster of infections that can spread rapidly. In West Africa, where the deadly disease has strained an already poor health care system to the limit, the risk of a renewed outbreak remains great.

Other Behind the headlines articles

• Ebola Epidemic Advances in West Africa (July 28, 2014)
• Ebola Outbreak in West Africa Continues to Spread (August 1, 2014)
• U.S. Troops Deploy to West Africa To Help Contain Ebola Outbreak (September 17, 2014)

September 17, 2014

Map of Ebola virus outbreak in West Africa as of 2014. (E. Ervin, CDC/ESVP, Sept. 4, 2014)

Yesterday, speaking at Atlanta’s Center for Disease Control and Prevention (CDC), United States President Barack Obama announced that he was sending 3,000 troops to Western Africa to aid the hard-hit nations of Liberia, Sierra Leone, and Guinea in fighting an outbreak of the Ebola virus. The 2014 outbreak of the disease has been the largest in history; more than 5,000 cases have been reported in West Africa, with 2,961 people dead.

Ebola can have up to a 90 percent fatality rate in people infected with the disease. It is a hemorrhagic disease, meaning that, in addition to vomiting and diarrhea, patients often bleed uncontrollably both internally and externally (from the eyes and under the skin, for example), with fluid loss causing shock and death. Most hemorrhagic viruses have a host, often a rodent or insect, which carries the virus but does not become ill. Scientists have not yet identified the host for Ebola virus, but a species of fruit bat is strongly suspected. Ebola enters the human population via an infected animal—for example, by people preparing bushmeat infected with the disease.  The virus is then spread within the human population by contact with the blood or other bodily fluids of an infected person, body tissue, or unsterilized needles or other equipment. A shortage of hospitals, health care workers, and medical equipment have seriously hindered West African nations in stopping the spread of the disease.

The U.S. military will train up to 500 health care workers per week on how to treat people with such highly infectious diseases and set up field hospitals to treat Ebola patients. In addition, home health-care kits will be provided for hundreds of thousands of households to allow families to more safely care for patients at home.

Additional World Book articles:

• The Origin of New Diseases (a special report)
• Overpopulation and the Threat of Infectious Disease (a special report)

July 28, 2014

The worst recorded epidemic of the deadly and highly contagious Ebola virus led the West African nation of Liberia today to close most of its border crossings. Liberia is one of three nations, along with Sierra Leone and Guinea, that are being hard hit by the virus. Liberia’s President Ellen Johnson-Sirleaf also issued restrictions on public gatherings and said areas hit by the virus could be quarantined. The current outbreak of Ebola hemorrhagic fever, which began in  March in southern Guinea, has killed at least 670 people, including the Liberian doctor who was heading his country’s efforts to contain the epidemic. Yesterday, Nigeria’s Arik Air suspended all flights into Sierra Leone and Guinea after Nigerian officials confirmed the first Ebola death in Lagos, Nigeria’s capital and the most populous city in Africa. Meanwhile, medical workers in Guinea were meeting hostility and resistance from residents who blamed them for spreading the disease.

Ebola hemorrhagic fever is characterized by massive internal bleeding as well as diarrhea and vomiting. It is spread by direct contact with such bodily fluids as saliva and blood and by contact with towels and other objects cotaminated by the virus. While animals, including chimpanzees and gorillas, can transmit the virus, the natural source is unknown. There is no cure or vaccine for the disease. Symptoms appear within 5 to 10 days of infection. About 80 to 90 percent of all people who become infected die, though patients who receive treatment while in the early stages of the disease have a slightly better chance of recovery. Treatment consists mainly of rehydration to replace lost body fluids.

The current Ebola outbreak began in southern Guinea in March and has spread to Liberia and Sierra Leone. (World Book map; map data © MapQuest.com, Inc.)

As of July 20, Ebola had killed 454 people in Sierra Leone; 314 in Guinea; and 224 in Liberia, according to the World Health Organization (WHO). Forty-five cases, including 28 deaths, were reported in those three countries between July 18 and 20 alone.

Most hemorrhagic viruses have a host, often a rodent or insect, which carries the virus but does not become ill. Scientists have not yet identified the host for the Ebola virus. However, the bushmeat trade is highly suspected of spreading the virus among people. The WHO has warned people against eating raw bushmeat and avoiding contact with infected apes, bats, and monkeys.

Additional World Book article:

• Disease Detectives (a special report)
• The Origin of New Diseases (a special report)