A few years ago I wrote several books for Enslow Publishers in New Jersey for a series called Diseases and People. I covered meningitis, arthritis, hemophilia…and Ebola. My most recent book for Enslow, Disease-Hunting Scientist, also talks about Ebola, and some of the scientists who travel to the sites of outbreaks to help with containment efforts.
Ask someone on the street to name a particularly deadly disease, and there’s a good chance he’ll say “Ebola.” Yet of the diseases I wrote about, the biggest killer by far is meningitis, the bacterial form of which kills some 170,000 people every year, according to the World Health Organization. (And if you want even bigger killers, in sub-Saharan Africa alone tuberculosis kills some 5,000 people a day, and yearly in that region malaria kills 700,000 and simple diarrhea 900,000.)
Ebola has captured the public imagination, however, because unlike most diseases, it’s gotten a foothold in pop culture, through books like Richard Preston’s 1994 best-seller The Hot Zone and the 1995 movie Outbreak.
I admit it also captured my imagination as I wrote my own book, not least because Ebola (which, by the way, is named after a river near Yambuku, Democratic Republic of the Congo, site of the first recognized outbreak), begins with fever, weakness, muscle pain, headache and sore throat—in other words, “flu-like symptoms.” Which I experienced while I was writing the book, since I was, after all, writing in Saskatchewan in the winter. Oh, sure, I knew intellectually I didn’t have Ebola, but still…
The symptoms get a lot worse than that, of course. Eventually, vomiting, diarrhea and rash develop, the kidneys and liver may stop functioning, and, in fatal cases, uncontrollable internal and external bleeding begins, resulting in the vomiting of blood and bleeding from the eyes, ears, nose and other orifices. And the most deadly of three different strains of Ebola, Ebola-Zaire, is fatal in up to 90 percent of cases.
(Fortunately, human-to-human transmission is via direct contact with blood or other bodily secretions, or contact with contaminated objects: no airborne transmission of Ebola has been documented in humans, which makes breaking the chain of transmission relatively easy with proper isolation and sterilization procedures.)
Ebola is frightening not only because it’s an awful way to die, but because there has been no effective treatment. But that may be changing, and a B.C. biotech firm is involved.
In a proof-of-concept study just published in the medical journal The Lancet, scientists report that they used tiny particles of genetic material to interfere in the replication process of the Ebola virus, and by doing so successfully prevented monkeys exposed to that virus from dying of hemorrhagic fever.
The scientists used particles called small interfering RNAs (siRNAs) to target a protein essential for Ebola virus replication. The process is similar to a natural mechanism used by all cells to silence genes.
Three rhesus macaques were given anti-Ebola-Zaire siRNAs intravenously half an hour after they were exposed to the virus, and again on days one, three and five. A second group of four macaques was given the treatment after half an hour and then for six consecutive days. The technique used to deliver the siRNAs is called SNALP (for “stable nucleic acid-lipid particles”), and was developed by Tekmira Pharmaceuticals Corporation of Vancouver.
Two of the three animals in the first group survived, and all four of the second group survived. The treatment itself seemed to produce no complications.
The results were so encouraging that lead author Dr. Thomas W. Geisbert of the Boston University School of Medicine says the work “justifies the immediate development of Ebola SNALP as a countermeasure to treat Ebola-infected patients.”
Of course there’s further research to be done: further studies in monkeys are needed to figure out dosing, toxicology and other issues before the treatment can be licensed for human use.
Still, it’s wonderful to think there may actually be hope for an effective treatment for Ebola at last…and what’s even more exciting is the fact that this approach to treating Ebola could also be used to combat other deadly viral diseases.
Even if it does make my books obsolete.