July 23, 2013 — Disabling a protein in Ebola virus cells can stop the virus from replicating and infecting the host, according to researchers from the Icahn School of Medicine at Mount Sinai. The data are published in July in the journal Cell Host and Microbe.
Ebola viruses cause severe disease in humans because they can deactivate the innate immune system. Christopher Basler, PhD, Associate Professor of Microbiology at Mount Sinai and his team have studied how Ebola viruses evade the immune system, and discovered that a viral protein called VP35 is critical to deactivating the immune system. They found that when VP35 interacts with an important cellular protein called PACT, it blocks PACT from activating the immune system, allowing the virus to spread.
"Ebola viruses are extremely lethal, and are a great threat to human health as a bioweapon," said Dr. Basler. "Currently, there is no approved vaccine or treatment. Our findings will hopefully pave the way for future antiviral treatments."
With the help of collaborators at the University of Texas with access to special high containment facilities, Dr. Basler and his team infected healthy cells with Ebola virus cells that had mutated versions of VP35. The mutations disabled VP35's ability to interact with PACT, therefore allowing it to activate the immune system and prevent the virus from replicating. Next, the researchers overexpressed PACT in healthy cells, and infected them with Ebola virus cells. They found that overexpressing PACT also inhibited viral replication.
Armed with this discovery, Dr. Basler and his team hope to develop drugs that disrupt the interaction of VP35 with PACT, or drugs that overexpress PACT.
The work was supported in part by National Institutes of Health grants AI059536 and AI093786 .
Infectious Disease Could Become More Common In a Warmer World - Especially for Plants and Animals
Fri, 02 Aug 2013, 12:00 AM
The venerable Science magazine has a special issue out today on climate change. Some of the content is free, and it’s well worth checking out. That includes an article on one of the most important and perplexing areas in global warming research: the possible connection between a changing climate and a growing threat from infectious disease.
It’s been known for awhile that warming temperatures could help certain diseases. Malaria, which kills about 650,000 people a year, thrives in the hot and humid areas where the Anopheles mosquito can live. As the climate warms, the territory where the mosquito and the malaria parasite will be able to live will likely expand, putting more people at risk. Already dengue fever, another mosquito-borne tropical disease, has reestablished itself in the Florida Keys, where it was wiped out decades ago. Tropical diseases will loom that much larger in a warmer world, as host-parasite cycles accelerate. In the Arctic, which is warming faster than any other region on the planet, higher temperatures are allowing parasites like the lungworm, which afflicts muskoxen, to develop faster and be transmitted over longer periods.
But as the Science study—by American and Canadian researchers—points out, the connection between climate change and disease is actually a lot more complicated than that. It’s true that warmer temperatures may be helping dengue fever to return to the Florida Keys, but the disease was initially vanquished in the 20th century not because the climate was cooler, but because public health officials systematically controlled mosquito populations, cutting off the spread of the dengue virus. Both Singapore and Burma are tropical countries well within the malaria belt, but rich, urban Singapore has largely eliminated malaria, while the disease is still common in impoverished, rural Burma. (I should know—I contracted a mild case of malaria while reporting along the Thai-Burmese border in 2005.) Healthcare infrastructure and wealth—or lack it—have a lot more to do with the spread of infectious disease than climate change does, and that will continue to be the case even as the globe warms.
Still, the study points out that climate change will be a major factor in the spread of infectious disease in the future—and the impact is likely to be even greater in wildlife and agricultural systems, which aren’t likely to be able to react as quickly as human beings can. In the Caribbean, where I was just on a reporting trip, warmer water temperatures have stressed vulnerable corals, which then leaves them less able to fight off infections by pathogenic fungi and bacteria. Whole species of coral in the Caribbean have been lost thanks to the rapid spread of disease—and since corals are the framework builders of the marine ecosystems, other species can quickly follow them into oblivion.
As coauthor Richard Ostfeld of the Cary Institute of Ecosystem Studies in New York put it in a statement:
Biodiversity loss is a well-established consequence of climate change. In a number of infectious disease systems, such as Lyme disease and West Nile virus, biodiversity loss is tied to greater pathogen transmission and increased human risk. Moving forward, we need models that are sensitive to both direct and indirect effects of climate change on infectious disease.
Climate change is likely to impact infectious disease just as it will impact other areas of life. Human beings—especially relatively rich ones—will muddle through, adapting to a warmer, more parasite-ridden world. Plants and animals, though, won’t be able to adapt as fast, or perhaps at all. Good thing we don’t need them. Right?
Read more: http://science.time.com/2013/08/02/infectious-disease-could-be-more-common-in-a-warmer-world-especially-for-plants-and-animals/#ixzz2aquTO16F
A Patient in Minnesota Has Lassa Hemorrhagic Fever.
Sun, 06 Apr 2014, 12:00 AM
News from the Minnesota Department of Public Health and the Centers for Disease Control and Prevention: A Minnesota traveler returning from Africa has been hospitalized with what the CDC confirms to be Lassa fever, a viral hemorrhagic fever that is often lumped together with Ebola hemorrhagic fever, though they are caused by different organisms. Read more at: http://www.wired.com/2014/04/minnesota-lassa/
9 APRIL 2014 | LONDON, UNITED KINGDOM - WHO has issued its first guidance for the treatment of hepatitis C, a chronic infection that affects an estimated 130 million to 150 million people and results in 350 000 to 500 000 deaths a year.
The publication of the "WHO Guidelines for the screening, care and treatment of persons with hepatitis C infection" coincides with the availability of more effective and safer oral hepatitis medicines, along with the promise of even more new medicines in the next few years.
Read more at: http://www.who.int/mediacentre/news/releases/2014/hepatitis-guidelines/en/