The current Ebola outbreak is by far the largest since this hemorrhagic fever was identified in 1976. Previous outbreaks involved dozens or hundreds of infected people (click here for CDC chronology). Estimates of the current outbreak are 2,473 infections and 1350 deaths thus far. Outbreaks begin by transmission through close contact with infected animals, then rapidly spread through human communities via direct contact with bodily fluids of infected people, or through contact with items contaminated with such fluids. Once infected, case fatality is as high as 90% (click here for WHO fact sheet). There are currently no vaccines, treatments, or cures. Traditionally, outbreaks have been controlled largely by infection control measures (masks, gloves, etc.) and quarantine, and supportive care such as hydration of the infected patient.
Experimental Treatments: A promising drug called ZMAPP was given at Emory University to two missionaries who were infected with Ebola. Both have gotten better. The drug was also given to a Spanish priest who died soon thereafter, though the timing of drug delivery may have played a part in the drug’s efficacy in this case. As of this week, it appears to be helping three Liberian health care workers. The drug is manufactured by Mapp Biopharmaceutical Inc. It is not FDA approved at present, nor can this monoclonal antibody be produced quickly in large quantities. Other drugs are in development but have yet to show as much promise as ZMAPP. Ebola is a rare disease and affects poor countries almost exclusively, so limited funding is provided mostly by government agencies (see $28 million consortium led by Scripps and funded by NIH, and the recent $10.8 million initiative announced by Wellcome Trust and the United Kingdom’s Department of International Development.) I generally distrust .com coverage of anything related to medicine (and so should you), but this recent CNN piece on ZMAPP seems reasonable, if you would like more information.
Cause of the Current Outbreak: NIH announced this morning that researchers funded by NIH have used advanced genomic analysis to determine the single point of infection from an animal that led to the current outbreak, and that since that initial infection the spread has been solely human to human. Importantly, through their genetic analysis, the researchers can see how the virus has mutated since December to outsmart human immune systems. As we know, viruses are little more than tiny pieces of DNA that can mutate with diabolical speed to outsmart the comparatively slow human immune response. By understanding how infection occurs, how disease is spread, and how viruses are mutating to defy immune attack, these researchers have taken a giant step toward improved treatments and a cure. The team was led by Pardis Sabeti, MD, PhD (who not surprisingly won a highly prestigious NIH Director’s New Innovator award in 2009.)
Experimental Vaccines: Next week, NIAID will begin the first of several phase I clinical trials of an Ebola vaccine produced in collaboration with GlaxoSmithKline (for details, click here). They will also test an Ebola vaccine developed by the Public Health Agency of Canada and licensed to NewLink Genetics Corp. NIH will partner with a British-based international consortium to test volunteers in the UK, and in the West African countries of Gambia (with approval of local authorities) and Mali. The CDC is in discussion with Nigerian officials about testing vaccines there.