In this week’s Nature Medicine, a study brings a ray of success in researchers’ quest to fight the deadly viruses Ebola and Marburg. Testing a new approach on monkeys, scientists at the U.S. Army Medical Research Institute of Infectious Diseases saw most of the monkeys survive a normally fatal Ebola infection—and all of them who had Marburg lived.
Within an hour of infecting the primates, researchers gave them antisense phosphorodiamidate morpholino oligomers, or PMOs.
The morpholino oligomers are a new class of drugs in a family of what is known as antisense nucleotides. Antisense nucleotides are designed to bind tightly to specific areas of viral messenger RNA, blocking replication. Such compounds already are being used to treat certain types of cancer and cytomegalovirus infections, and they are being tested against HIV [Los Angeles Times].
In a medical sense, you’d be wise to steer clear of filoviruses, a group that includes the deadly Ebola, and bornaviruses, which cause neurological diseases. But in a genetic sense, it may not be possible to avoid them. A new study in PLoS pathogens shows that bits and pieces of these viruses have been floating around in the human genome, as well as those of other mammals and vertebrates, for millions of years.
It’s not that having genetic material left behind by viruses is odd—previous research had shown that viruses account for 8 percent of the human genome. But scientists thought most of that material came from retroviruses, which use their host’s DNA to replicate and leave some of their genetic material behind. What’s weird about this is that filoviruses and bornaviruses are not retroviruses—they’re RNA viruses, which don’t use the host to reproduce in the same way.
The USA Patriot Act and the Bioterrorism Preparedness Act, both enacted not long after the 9/11 attacks, contained measures to make it harder for anybody to get their hands on the kind of pathogens one might need to launch a bioterror attack. There was just one problem: The rules also slowed down and constrained our own scientists’ abilities to learn about those pathogens, according to a study out this week in the Proceedings of the National Academy of Sciences.
To be specific, lead researcher Elizabeth Casman found while there was a touch of good news—the laws didn’t appear to deter new scientists from entering the field—the major effect of those acts has been to make research on ebola virus and anthrax much more expensive, and much slower.
The researchers did find an increase in the total number of papers published. But before the laws, 17 anthrax papers appeared per million dollars of funding. With the restrictions, only three papers appeared per million dollars of funding. For ebola, the numbers dropped from 14 to six papers per million dollars. Figures for the control stayed the same [Scientific American].
The number of people infected with Ebola traced from pigs in the Philippines has reached five, but health officials say there is no cause for panic–although they do advise wary attention. The strain of the disease, Ebola Reston, is thought not to be dangerous to humans, and the first identified case, a pig handler who was infected at least six months ago, is still healthy. But experts say there remains some concern because pigs are mixing vessels for other human and animal viruses, like flu, and because it shows that pigs may also be able to transmit the lethal strains of Ebola. Far more humans are in regular contact with pigs than with apes, monkeys or bats, the other known hosts [The New York Times].
The virus was first identified in pigs in the Philippines last year, at which point two farms were closed and blood samples collected from 6,000 pigs and 50 workers. From those, four pigs and one worker tested positive, says Francisco Duque, the Philippine health secretary. In January, a new round of testing turned up four more infected men who worked on pig farms and in slaughterhouses.
Somewhere in the world within the next five years, terrorists are likely to use a biological agent like anthrax or Ebola in a major attack, a new congressional report predicts. The report acknowledges that terrorist groups still lack the needed scientific and technical ability to make weapons out of pathogens…. But it warns that gap can be easily overcome, if terrorists find scientists willing to share or sell their know-how. “The United States should be less concerned that terrorists will become biologists and far more concerned that biologists will become terrorists,” the report states [AP].
The report, which will be officially released on Wednesday by the Commission on the Prevention of Weapons of Mass Destruction and Terrorism, covers the threat of both biological and nuclear attacks. It argues that bioterrorism is a greater threat: Nuclear facilities are closely guarded, the report says, while many civilian labs contain dangerous pathogens and could more easily be breached. The number of such “high-containment” labs in the United States has tripled since 2001, yet U.S. officials have not implemented adequate safeguards to prevent deadly germs from being stolen or accidentally released, it says. “The rapid growth in the number of such labs in recent years has created new safety and security risks which must be managed,” the draft report states [Washington Post].
A warmer world will also be a sicklier place for both animals and humans, according to a new report from the Wildlife Conservation Society (WCS). Dubbed the “deadly dozen,” sicknesses such as Lyme disease, yellow fever, plague, and avian influenza, or bird flu, may skyrocket as global shifts in temperature and precipitation transform ecosystems. Babesia, cholera, Ebola, intestinal and external parasites, red tides, Rift Valley fever, sleeping sickness and tuberculosis round out the list [National Geographic News].
The report spells out how global warming is changing the ranges and habitats of animals that carry these infectious diseases, bringing the ticks that transmit Lyme disease and the mosquitoes that carry yellow fever and Rift Valley fever into contact with new human populations. “We’ve seen Lyme disease work its way up from the US into Canada, and West Nile fever as well,” said William Karesh, director of WCS’s global health programmes. “Basically what you have now are fewer frozen nights in this region, and that allows the ticks and mosquitoes that carry these diseases to survive further north” [BBC News].
Ebola has receded from the headlines since the mid- 1990s when the world briefly panicked about an African outbreak of the terrifying disease, which causes massive bleeding and kills up to 90 percent of the people it infects. Thankfully, scientists haven’t forgotten about the virus, and are still trying to unlock its secrets. In a new report, researchers say they’ve finally got a good image of the protein “spike” that the virus uses to enter healthy human cells.
Researchers also say that by revealing the protein’s shape and understanding how it works, they have exposed chinks in Ebola’s armor that could be targeted for treatment [Bloomberg]. Lead researcher Erica Ollman Saphire says the spike is almost entirely concealed: “It’s kind of like Harry Potter wrapped in an invisibility cloak. But there are three or four little sites peeking out,” she added. These may provide a target for a drug or vaccine, or perhaps an immune-based treatment for Ebola, she said [Reuters].