What is Ebola Virus?
The Ebola virus disease is a disease of humans and other primates caused by the Ebola virus. Signs and symptoms such fever, sore throat, muscle pain, and headaches typically start between two days and three weeks after contracting the virus.
How Ebola Virus is transmitted?
It is thought that fruit bats of the Pteropodidae family are natural Ebola virus hosts. Ebola then spreads through human-to-human transmission via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids.
People remain infectious as long as their blood and body fluids, including semen and breast milk, contain the virus. Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness.
What are the symptoms of Ebola Virus Diseases?
The incubation period, that is, the time interval from infection with the virus to the onset of symptoms is 2 to 21 days. Humans are not infectious until they develop symptoms. First symptoms are the sudden onset of fever, fatigue, muscle pain, headache and sore throat. This is followed by vomiting, diarrhea, rash, symptoms of impaired kidney and liver function, and in some cases, both internal and external bleeding (e.g. oozing from the gums, blood in the stools).
How Ebola Virus is diagnosed?
It can be difficult to distinguish EVD from other infectious diseases such as malaria, typhoid fever and meningitis. Confirmation that symptoms are caused by Ebola virus infection are made using the following investigations:
• antibody-capture enzyme-linked immunosorbent assay (ELISA)
• antigen-capture detection tests
• serum neutralization test
• reverse transcriptase polymerase chain reaction (RT-PCR) assay
• electron microscopy
• Virus isolation by cell culture.
What are the treatment and vaccines for Ebola Virus?
Supportive care-rehydration with oral or intravenous fluids- and treatment of specific symptoms, improve survival. There is as yet no proven treatment available for EVD. However, a range of potential treatments including blood products, immune therapies and drug therapies are currently being evaluated. No licensed vaccines are available yet, but 2 potential vaccines are undergoing human safety testing.
Timeline of the spread of the Ebola virus
The World Health Organization said there has been 7,588 reported deaths. We take a look back at the timeline of events which led to the current health epidemic:
• 1976
Ebola was first discovered in Yambuku, Zaire in 1976. It was spread through the use of contaminated syringes to dispense malaria medication, as well as other drugs, at the Yambuku Mission Hospital, located in the village. The virus that lay quietly inside them would quickly develop into full blown hemorrhagic fever, with a 90% mortality rate. Epidemiologists and doctors from all over came to Zaire to help with the epidemic and to learn more about the mysterious new disease. But as mysteriously as it arrived, Ebola soon died out and faded in people’s minds.
• 1979
Occurred in Nzara, Maridi. Recurrent outbreak at the same site as the 1976 Sudan epidemic.
• 1994
Occurred in Mékouka and other gold-mining camps deep in the rain forest. Initially thought to be yellow fever; identified as Ebola hemorrhagic fever in 1995.
• 1995
Occured in Kikwit and surrounding area. Traced to index case-patient who worked in a forest adjoining the city. The epidemic spread through families and hospitals.
• 1996
Occured in Mayibout area. A chimpanzee found dead in the forest was eaten by people hunting for food. Nineteen people who were involved in the butchery of the animal became ill; other cases occurred in family members.
• 2000
Occurred in Gulu, Masindi, and Mbarara districts of Uganda. The three most important risks associated with Ebola virus infection were attending funerals of Ebola hemorrhagic fever case-patients, having contact with case-patients in one’s family, and providing medical care to Ebola case-patients without using adequate personal protective measures.
• 2002
Outbreak occurred in the districts of Mbomo and Kéllé in Cuvette Ouest Department.
• 2004
Outbreak occurred in Yambio County of southern Sudan. This outbreak was concurrent with an outbreak of measles in the same area, and several suspected EHF cases were later reclassified as measles cases
• 2007
Outbreak occurred in Kasai Occidental Province. The outbreak was declared over by November 20. Last confirmed case on October 4 and last death on October 10.
• 2012
Outbreak occurred in DRC’s Province Orientale. Laboratory support was provided through CDC and the Public Health Agency of Canada (PHAC)’s field laboratory in Isiro, and through the CDC/UVRI lab in Uganda. The outbreak in DRC has no epidemiologic link to the near contemporaneous Ebola outbreak in the Kibaale district of Uganda.
• December 2013
An unidentified fever claims the lives of a handful of people in Guinea, it is later confirmed they died of Ebola
• March 2014
A major Ebola outbreak in Guinea is reported by the World Health Organization and Liberia identifies its first case. In the following months the virus spreads to neighboring Sierra Leone
• July 20, 2014
Patrick Sawyer, a Liberian government employee, sparks fears that the virus could cross borders when he travels to Lagos, Nigeria, where he dies of Ebola
• August 8, 2014
An “international health emergency” is declared by the World Health Organization just four days before the death toll exceeds 1,000.
• October 6, 2014
Spanish nurse Teresa Romero becomes the first person known to have caught the disease outside the outbreak zone in West Africa
• October 17, 2014
David Cameron says Britain is “leading the way” in its efforts to tackle the outbreak, committing “well over £100 million, 750 troops, training 800 members of health staff, providing 700 beds” to the region.
• November 22
The first NHS volunteers, including GPs, nurses, psychiatrists and emergency medicine consultants, leave for Sierra Leone to join the fight against Ebola.
• December 24
The WHO says there have been 19,497 reported cases of Ebola, with 7,588 reported deaths.
References:
http://www.who.int/mediacentre/factsheets/fs103/en/
http://emedicine.medscape.com/article/216288-overview
http://bigpictureeducation.com/evolution-ebola
http://theconversation.com/genetic-evolution-how-the-ebola-virus-changes-and-adapts-31525