In an op-ed article, “What We’re Afraid to Say About Ebola,” published in the New York Times Sept. 11, Dr. Michael T. Osterholm, the McKnight Presidential Endowed Chair in Public Health and director of the Center for Infectious Disease Research and Policy at the University of Minnesota, wrote the Ebola scenario “virologists are loath to discuss openly but are definitely considering in private: that an Ebola virus could mutate to become transmissible through the air. You can now get Ebola only through direct contact with bodily fluids. But viruses like Ebola are notoriously sloppy in replicating, meaning the virus entering one person may be genetically different from the virus entering the next. The current Ebola virus’s hyper-evolution is unprecedented; there has been more human-to-human transmission in the past four months than most likely occurred in the last 500 to 1,000 years. Each new infection represents trillions of throws of the genetic dice.
“If certain mutations occurred, it would mean that just breathing would put one at risk of contracting Ebola. Infections could spread quickly to every part of the globe, as the H1N1 influenza virus did in 2009, after its birth in Mexico.”
In fact, there has already been some antigenic drift in the current novel Ebola-Zaire (EBO-Z) subclade from viral samples sequenced in Sierra Leone in June and sequences from Guinea in March three months earlier.
Osterholm is also an international expert on American preparedness for an influenza pandemic, and from 2001 to 2005, served as a special advisor to then–U.S. Health and Human Services Secretary Tommy G. Thompson on issues related to bio-terrorism and public health preparedness.
Ebola virus causes severe viral hemorrhagic fever with a high fatality rate estimated at about 70 per cent on average. Five Ebola virus species within the genus Ebolavirus are known, including four that cause Ebola virus disease (EVD) in humans: Zaire, Bundibugyo, Sudan and Taï Forest, while Reston. the fifth species, has only caused disease in non-human primates. The current outbreak in West Africa, plus a handful of travel-related additional cases in Madrid in Spain and in the United States in Dallas and New York City, is Ebola Zaire, the deadliest form of the disease in previous outbreaks with case fatality rates of 90 per cent reported.
With more than 10,000 reported cases and more than 5,000 people dead (for what is widely believed to be a vastly under-reported case fatality rate of about 50 per cent), the 2013-14 outbreak in Guinea, Liberia, Sierra Leone, Mali, Nigeria and Senegal in West Africa, caused by Ebola virus (Zaire ebolavirus species), is the 20th, largest and most complex outbreak of EVD in its 38-year history, with more cases and deaths in this outbreak than all others combined, since the disease was first discovered in 1976 during two simultaneous outbreaks, one in Nzara in Sudan, and the other in Yambuku in the Democratic Republic of Congo, which was then called Zaire, where a Belgian Roman Catholic nun at a small mission hospital was infected. The latter occurred in a village near the Ebola River in what was then northern Zaire, from which the disease and species both takes their names. When those first cases were reported in the mid-1970s they were from remote villages in Central Africa, near tropical rainforests. The World Health Organization (WHO) said earlier this month the Ebola outbreak is now over in both Nigeria and Senegal, although the disease is threatening the Ivory Coast, which shares a 716-kilometre international border with Liberia in the southwest; a 610-kilometre border with Guinea to the northwest; and a 532-kilometre border with Mali to the north and northwest.
It began last December with an index case in Meliandou, in southeastern Guinea, not far from the borders with both Liberia and Sierra Leone.
Two decades ago, scientists at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), based at Fort Detrick, Maryland, exposed monkeys to airborne Ebola, which “caused a rapidly fatal disease” in four to five days, they concluded in their 10-page August 1995 article, “Lethal Experimental Infections of Rhesus Monkeys by Aerosolized Ebola Virus,” published in the International Journal of Experimental Pathology.
The researchers hypothesized Ebola can spread through air but likely hasn’t in Africa because the equatorial region is generally too warm, with temperatures rarely dropping below 18.3°C or 65°F.
In 2012, Canadian researchers here in Manitoba, led by Gary Kobinger, head of Special Pathogens and Vector Design and Immunotherapy at the Special Pathogens Program of the Biosafety Level-Four (BSL-4) National Microbiology Laboratory of the Public Health Agency of Canada on Arlington Street in Winnipeg, along with researchers from the National Centre for Foreign Animal Disease in Winnipeg and the University of Manitoba in Winnipeg, observed transmission of Ebola from pigs, which can remain largely healthy and carry Ebola with only minor ill effects, including heavier breathing and mild fever, to monkeys where the disease was fatal, indicating the Ebola virus may spread between species through the air, although the researchers could not say for certain that is how the transmission actually occurred. Their research was published in Scientific Reports 2 on Nov. 15, 2012.
The Biosafety Level-Four (BSL-4) National Microbiology Laboratory in Winnipeg is where some of the world’s deadliest pathogens – such as Ebola, Marburg, Lassa and Crimean-Congo hemorrhagic fever viruses and Nipah Virus Encephalitis – are studied.
In December 1989, not far away from USAMRIID, in a strip mall in Isaac Newton Square in suburban Reston, Virginia, army scientists from nearby Fort Detrick, Maryland were called in when monkeys from the Philippines, kept by Hazelton Research Products for shipment to other U.S. laboratories, began to die in their cages, one by one, after contracting what is now known as Reston ebolavirus species, the only known form of Ebola that causes disease only in in non-human primates. While the Reston Ebola species can infect humans no one got sick in Virginia 25 years ago and no serious illness or death in humans have been reported to date as a result of human exposure to the the Reston Ebola species. The Reston episode would become a key part of author Richard Preston’s electrifying 1994 non-fiction thriller, The Hot Zone: A Terrifying True Story, an earlier version of which had appeared in The New Yorker magazine on Oct. 26, 1992 as “Crisis in the Hot Zone.”
The Atlanta-based Centers for Disease Control and Prevention (CDC) says in its “Review of Human-to-Human Transmission of Ebola Virus” summary of published information on the current science that “airborne transmission of Ebola virus has been hypothesized but not demonstrated in humans. While Ebola virus can be spread through airborne particles under experimental conditions in animals, this type of spread has not been documented during human EVD outbreaks in settings such as hospitals or households.”
Referring to the USAMRIID experiment that provided the data for the 10-page August 1995 article, “Lethal Experimental Infections of Rhesus Monkeys by Aerosolized Ebola Virus,” published in the International Journal of Experimental Pathology, CDC says, “In the laboratory setting, non-human primates with their heads placed in closed hoods have been exposed to and infected by nebulized aerosols of Ebola virus.”
You can also follow me on Twitter at: https://twitter.com/jwbarker22
soundingsjohnbarker 