The Ebola virus can cause severe illness and death in people and other primates. The 2014 Ebola outbreak is the largest outbreak in history, with more than *3,600 infections and 1,800 deaths as of the end of August, according to the World Health Organization. The outbreak is the first in West Africa and the first to affect major cities.
Signs and Symptoms of the Disease from the CDC
Gates Foundation Commits $50 Million to Support Emergency Response to Ebola
Patient with exposure to Ebola has arrived safely at NIH Clinical Center
*Editor’s Note: “Nearly 1000 new cases were reported in the week ending 14 September alone — certainly an underestimate of the true burden of disease. If the present rate of increase continues — if nothing is done to intervene — somewhere between 2500 and 5000 cases will occur, each week, just four weeks from now. Affected countries could be seeing more than 10, 000 cases weekly by mid-November.” (WHO statistics)
Once Ebola virus has been transmitted from an animal host to a human, it can spread through person-to-person contact. Symptoms usually appear 2 to 21 days after exposure. Infection can cause fever, headache, body aches, weakness, stomach pain, and lack of appetite. Later symptoms include vomiting, diarrhea, rash, impaired kidney and liver function, and in some cases, internal and external bleeding (hemorrhage). There are no approved drugs for the disease, but prompt diagnosis and aggressive supportive care can improve survival.
Colorized scanning electron micrograph (25,000x magnification) of Ebola virus particles (green) attached to and budding from a cell (blue). Credit: NIAID
To better understand this outbreak, an international team led by Dr. Pardis Sabeti at the Broad Institute and Harvard University collected virus samples from 78 patients living in Sierra Leone near the origin of the 2014 outbreak. The researchers used advanced technologies to quickly and accurately analyze the viral genomes. The work was funded in part by NIH’s Common Fund and National Institute of Allergy and Infectious Diseases (NIAID). The findings were published in Science on September 12, 2014.
The researchers sequenced 99 Ebola virus genomes in total, as some people were sampled more than once. The analysis revealed more than 300 genetic differences from viruses responsible for past outbreaks. The strain responsible for this outbreak appeared to diverge as early as 2004 from one found in Central Africa, indicating movement from Central to West Africa over the span of a decade.
The team also found more than 50 mutations that arose as the outbreak spread. They estimated that the first infection from an unknown source in late 2013 was followed by exclusive human-to-human transmissions. The virus was brought into Sierra Leone by 14 people who had been in nearby Guinea to attend the funeral of a traditional healer who had treated Ebola patients.
The team released all its sequence data as it was generated to aid in relief efforts and speed global research. “By making the data immediately available to the community, we hope to accelerate response efforts,” Sabeti says.
This study highlights the need for continued “genomic surveillance” to track and try to slow the evolution of this virus as the outbreak continues. Understanding the genetics of the virus will also help in the development of new and improved drugs and vaccines.
NIH has been playing a key role in investigating potential Ebola vaccines and medications. It recently announced the launch of an early-stage trial to begin human testing of a candidate vaccine.
NIH to Launch Human Safety Study of Ebola Vaccine Candidate; Trial is First in Series of Accelerated Safety Studies of Ebola Vaccines
Initial human testing of an investigational vaccine to prevent Ebola virus disease will begin next week by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
The early-stage trial will begin initial human testing of a vaccine co-developed by NIAID and GlaxoSmithKline (GSK) and will evaluate the experimental vaccine’s safety and ability to generate an immune system response in healthy adults. Testing will take place at the NIH Clinical Center in Bethesda, Maryland.
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