Mostrando entradas con la etiqueta Mosquitoes. Mostrar todas las entradas
Mostrando entradas con la etiqueta Mosquitoes. Mostrar todas las entradas

domingo, 21 de diciembre de 2014

nsf.gov - National Science Foundation - Ebola, Dengue fever, Lyme disease: The growing economic cost of infectious diseases.- Enfermedad de Ebola, la fiebre del dengue, de Lyme: El creciente costo económico de las enfermedades infecciosas

Hola amigos: A VUELO DE UN QUINDE EL BLOG., la Fundación Nacional de Ciencias de Los Estados Unidos de América nos informa, que cada año aparecen cinco (5) nuevas enfermedades de la misma mortandad como el Ébola, e incide que hay que establecer nuevas estrategias para recibirlas y combatirlas..
NSF. nos dice: "...Surgimiento de los brotes de enfermedades pandémicas como el Ébola amenazan cada vez más las economías globales de salud y públicos mundiales, tal como lo dicen los científicos. Podemos esperar cinco nuevos tales enfermedades cada año, en el futuro............Y esperan que se propaguen. La fiebre del dengue enfermedad tropical, por ejemplo, ha hecho su camino a Florida y Texas, al parecer para quedarse....
NSF . añade : ".....Pero la respuesta mundial a las enfermedades infecciosas a menudo es demasiado tarde para evitar efectos importantes sobre la salud y el crecimiento económico, los investigadores creen.....Según la Organización Mundial de la Salud (OMS), el número de personas infectadas con el Ébola ha superado 17.000, con más de 6.000 muertes. El Banco Mundial estima ahora que el costo financiero de dos años de Ébola puede llegar a $ 32.6 mil millones y obligar a algunas economías de África Occidental a gastar ingentes cantidades del escaso dinero; que ya sufren en una recesión profunda............"
Five new such diseases expected each year; strategies to reduce climate change adaptable to infectious diseases
health worker with biohazard gear on
Stopping Ebola in its tracks calls for rapid control measures; long-term, is there a better way?
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December 16, 2014
The following is part 13 in a series on the NSF-NIH-USDA Ecology and Evolution of Infectious Disease (EEID) Program. See parts: one, two, three, four, five, six, seven, eight, nine, 10, 11, and 12.
Emerging pandemic disease outbreaks such as Ebola increasingly threaten global public health and world economies, scientists say. We can expect five new such diseases each year, into the future.
And expect them to spread. The tropical disease dengue fever, for example, has made its way to Florida and Texas, seemingly to stay.
But the global response to infectious diseases is often too late to prevent major effects on health and economic growth, researchers believe.
According to the World Health Organization (WHO), the number of people infected with Ebola has surpassed 17,000, with more than 6,000 deaths. The World Bank now estimates that the two-year financial cost of Ebola may reach $32.6 billion and force some already suffering West African economies into a deep recession.
 
Growing economic cost of global disease outbreaks
 
Scientists at EcoHealth Alliance in New York and other organizations studied the economic cost of such global disease outbreaks.
Economists, disease ecologists and others collaborated on an in-depth economic analysis of strategies to address pandemic threats in a proactive way--rather than a reactive response to a crisis. The results are published in this week's issue of the journal Proceedings of the National Academy of Sciences (PNAS).
"Our research shows that new approaches to reducing emerging pandemic threats at the source would be more cost-effective than trying to mobilize a global response after a disease has emerged," says Peter Daszak, senior author of the paper and president of EcoHealth Alliance.
The researchers used economic modeling to analyze two strategies for a pandemic response: Current business-as-usual approaches that rely on global surveillance to identify new diseases in people, and new "mitigation" strategies to reduce the underlying drivers of emerging diseases and lower the risk of their emergence.
"Our economic modeling demonstrates that the new approach to dealing with disease emergence is the right strategy in the long-term," says Jamie Pike, an economist at EcoHealth Alliance and first author of the paper.
The results indicate that the strategy for pandemics needs to be coordinated on a global scale to be effective in reducing risk. And that mitigation strategies will be far more cost-effective in the long-term.
The results follow those reported in a September, 2014, paper in the journal EcoHealth, in which Daszak, Charles Perrings of Arizona State University, A. Marm Kilpatrick of the University of California at Santa Cruz, and colleagues show that economic epidemiology has the potential to improve predictions of the course of infectious diseases, and to support new approaches to management of such diseases.
 
Environmental change causing increase in number of new diseases
 
Ebola. West Nile virus. Lyme disease. All are infectious diseases spreading in animals, and in humans. Is our interaction with the environment somehow responsible for the increase in incidence of these diseases?
With 60 percent of all human diseases and 75 percent of all emerging infectious diseases involving animal-to-human transmission, the underlying factors that contribute to disease outbreaks are mostly related to environmental changes to global ecosystems, the scientists found. Deforestation and illegal wildlife trade are two culprits.
Large-scale environmental events alter the risks of emergence of viral, parasitic and bacterial diseases in humans and animals.
"Virtually all the world's terrestrial and aquatic communities have undergone dramatic changes in biodiversity due primarily to habitat transformations such as deforestation and agricultural intensification, invasions of exotic species, chemical contamination, and climate change events," says Sam Scheiner, National Science Foundation (NSF) program director for the joint NSF-NIH-USDA Ecology and Evolution of Infectious Diseases (EEID) Program, which funded the research.
 
Ebola epidemic highlights need to address infectious disease threats
 
"The current Ebola epidemic highlights the need to anticipate possible health threats from these changes," says Scheiner. "This study shows that the long-term economic benefits outweigh the short-term costs, not to mention the human benefits of preventing the next pandemic."
Rapid changes to the environment are resulting in a continuous year-by-year increase in the number of new diseases emerging, the researchers found.
"With continued pressure causing diseases to rise, we need to analyze the ecological and economic foundations of the risk, and identify economically effective strategies to reduce it," says David Finnoff, an economist at the University of Wyoming and co-author of the PNAS paper.
The paper highlights WHO International Health Regulations goals, and points out that the global capacity to achieve such targets needs to be addressed to deal with the continuous rise in the rate of new diseases.
 
Five new diseases each year into the future
 
"We show that we can expect more than five new emerging diseases each year into the future," says Daszak.
"With this continuous rise in the pandemic threat, and our increasing global connectivity, we are at a critical moment in history to act."
-- 
Cheryl Dybas, NSF (703) 292-7734
  cdybas@nsf.gov
Related Programs Ecology of infectious diseases
Related WebsitesNSF Special Report: Ecology and Evolution of Infectious Diseases: http://www.nsf.gov/news/special_reports/ecoinf/
NSF EEID Discovery Article Series:
http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=133281&org=NSF
NSF Grant: Risks of Animal and Plant Infectious Diseases through Trade (RAPID Trade): http://www.nsf.gov/awardsearch/showAward?AWD_ID=1414374&HistoricalAwards=false
NSF News: Racing ahead of disease outbreaks: $12 million in new research grants: http://nsf.gov/news/news_summ.jsp?cntn_id=132570
NSF News: Outbreak: Ecology and Evolution of Infectious Disease grants support research on disease transmission:
http://www.nsf.gov/news/news_summ.jsp?cntn_id=129280
NSF News: Controlling the Spread of Diseases Among Humans, Other Animals and the Environment:
 http://www.nsf.gov/news/news_summ.jsp?cntn_id=125496
Scientist Peter Daszak surrounded by roosters and hens at a farm in China.
Scientist Peter Daszak studies infectious disease transmission at a chicken farm in China.
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illustration showing animals, insects, trees and houses.
Our interaction with the environment is likely responsible for increasing infectious diseases.
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Mosquito on skin
Mosquitoes transmit the virus that causes the often-deadly disease dengue fever.
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maps showing north and south americas and counries at risk of dengue fever
Dengue fever is on-the-march across the Western Hemisphere, appearing in new regions.
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close up image of a tick
Where ticks are, Lyme disease may follow. Lyme is now rampant in many northeastern U.S. states.
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The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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sábado, 19 de octubre de 2013

nsf.gov : National Science Foundation : Outbreak: Ecology and Evolution of Infectious Disease grants support research on disease transmission

Awards fund studies of how diseases spread among humans, other animals and the environment
A Tasmanian devil
EEID scientists will research an infectious cancer decimating Tasmanian devil populations.
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September 30, 2013
facial disease; infection with antibiotic-resistant staphylococcus; foot-and-mouth disease; malaria: Is our interaction with the environment somehow responsible for the increased incidence of these diseases?
The joint National Science Foundation (NSF) and National Institutes of Health (NIH) Ecology and Evolution of Infectious Diseases (EEID) program is providing answers.
The EEID program supports efforts to understand the ecological and biological mechanisms behind human-induced environmental changes and the emergence and transmission of infectious diseases.
NSF and NIH--in collaboration with the U.S. Department of Agriculture National Institute of Food and Agriculture (NIFA) and the U.K.'s Biotechnology and Biological Sciences Research Council (BBSRC)--have awarded more than $16 million in new EEID grants.
"Our understanding of the ecology and evolution of pathogens comes from knitting together information from many different sources," says Sam Scheiner, NSF EEID program director. At NSF, EEID is funded by the Directorates for Biological Sciences, Geosciences, and Social, Economic & Behavioral Sciences.
"They include diseases of humans, frogs, honeybees and plants," says Scheiner. "Each system provides a different piece of the puzzle that helps us protect human health, the health of our agricultural systems and that of our natural world."
Projects funded through the EEID program allow scientists to study how large-scale environmental events--such as habitat destruction, invasions of non-native species and pollution--alter the risks of emergence of viral, parasitic and bacterial diseases in humans and other animals.
"This year's EEID projects bring together multiple scientific fields to address how human and natural processes influence infectious diseases in humans and other animals, including diseases that affect wildlife and agriculture, as well as those of significant public health concern in the developing world," says Christine Jessup, EEID program director at NIH's Fogarty Center.
"Findings from EEID-supported research are improving public health interventions and management decisions."
Researchers supported by the EEID program are advancing basic theory related to infectious diseases, and improving understanding of how pathogens spread through populations at a time of increasing environmental change.
The benefits of research on the ecology and evolution of infectious diseases include development of theories about how diseases are transmitted, improved understanding of unintended health effects of development projects, increased capacity to forecast disease outbreaks, and knowledge of how infectious diseases emerge and reemerge.
"Animal and plant diseases cause significant losses in food production around the globe and pose risks to human health," says Sonny Ramaswamy, NIFA director.
"As NIFA and the scientific community work toward solutions that ensure our food security, research on the evolution and spread of infectious diseases will help us understand how best to prevent, predict and respond to these threats."
This year's EEID awardees will conduct research on such topics as the emergence of Tasmanian devil facial tumor disease, honeybees and their parasites, the evolution and spread of virulent infectious diseases, the macroecology of infectious disease, and the persistence of foot-and-mouth disease.
"Tackling the infectious diseases that threaten the health of humans and livestock is a critical need, especially in the face of a growing global human population expected to reach 9 billion by 2050," says Douglas Kell, BBSRC chief executive.
"We face many challenges related to food security and health. These EEID projects will combine international expertise to help us find solutions."
Closeup of a bee on a flower
The largest cause of honeybee declines is the Varroa mite, subject of an EEID award.
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Closeup of a mosquitoe on skin
Mosquitoes: the vector for the malaria parasite Plasmodium falciparum.
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Cape buffalo in the field
Cape buffalo in Africa act as a host for the contagious foot-and-mouth disease virus.
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A frog in water
Amphibian pathogens, such as a fungus infecting frogs, are the focus of an EEID award.
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Pigs grazing on a field
Do livestock practices contribute to the emergence of antibiotic-resistant bacteria?
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EEID 2013 Grants
Additional Collaborators: Hamish McCallum, Griffith University; Menna Jones, University of Tasmania; Elizabeth Murchison, Wellcome Trust Sanger Institute; Paul Hohenlohe, University of Idaho
Patrick Stephens, University of Georgia, RCN Proposal: Macroecology of infectious disease
Additional Collaborators: Robert Poulin, University of Otago; Sonia Altizer, University of Georgia; Katherine Smith, Brown University; Alonso Aguirre, Smithsonian-Mason School of Conservation
Additional Collaborators: Jacqueline A. MacDonald, Rachel T. Noble, Marc L. Serre, Steven B. Wing, University of North Carolina at Chapel Hill
Additional Collaborators: Kelli Hoover, Penn State University; Michael Stout, Louisiana State University AgCenter; Vanja Dukic, University of Colorado
Additional Collaborators: Andrew R. Blaustein, Oregon State University, Jason T. Hoverman, Perdue University, Pieter T. Johnson, University of Colorado, Jason R. Rohr, University of South Florida
Additional Collaborators: Berry J. Brosi, Emory University; Keith Delaplane, University of Georgia
Wayne K. Potts, University of Utah, The evolution and spread of virulent infectious disease
Additional Collaborators: Frederick R. Adler, University of Utah; Henry D. Hunt, Michigan State University
Additional Collaborators: Jan Medlock, Oregon State University
Additional Collaborators: Laura E. Jones, Cornell University
-NSF-
Media Contacts Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Related WebsitesNSF Special Report: The Ecology and Evolution of Infectious Diseases:
 http://www.nsf.gov/news/special_reports/ecoinf/index.jsp
NSF Discovery Article Series: Ecology and Evolution of Infectious Diseases:
 http://www.nsf.gov/news/news_summ.jsp?cntn_id=117857
NSF News and Photo Gallery: Precautions for Tick-Borne Disease Extend "Beyond Lyme":
 http://www.nsf.gov/news/news_summ.jsp?cntn_id=124286
NSF News: Infectious diseases and climate change intersect with no simple answers:
 http://www.nsf.gov/news/news_summ.jsp?cntn_id=128617
NSF News: Interplay of Ecology, Infectious Disease, Wildlife and Human Health Featured at Annual Conference: http://www.nsf.gov/news/news_summ.jsp?cntn_id=128411
The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget was $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 50,000 competitive requests for funding, and makes about 11,500 new funding awards. NSF also awards about $593 million in professional and service contracts yearly.
Useful NSF Web Sites:
NSF Home Page:
 http://www.nsf.gov
NSF News:
 http://www.nsf.gov/news/
For the News Media:
 http://www.nsf.gov/news/newsroom.jsp
Science and Engineering Statistics:
 
The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui

domingo, 3 de marzo de 2013

nsf.gov - Discovery - "Defective" Virus Leads to Epidemic of Dengue Fever

Virus may have led to widespread disease in Myanmar in 2001.-

 close up of a mosquito on skin

Mosquitoes transmit the virus that causes the often-deadly disease dengue fever.
Credit: Wikimedia Commons
Download the high-resolution JPG version of the image. (1.2 MB)
 Pagoda in Myanmar surrounded by buildings

Pagoda in Myanmar, site of a 2001-2002 epidemic of dengue fever.
Credit: Ruian Ke
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 Map showing where dengue has occurred in the Eastern Hemisphere.

Map showing where dengue has occurred in the Eastern Hemisphere.
Credit: CDC
Download the high-resolution JPG version of the image. (81 KB)
 Bare back of a man showing rash seen in people with dengue fever.
The typical rash seen in people with dengue fever.
Credit: Wikimedia Commons
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 map of western hemisphere showing countries with dengue fever cases

Dengue is also on-the-march across the Western Hemisphere.
Credit: CDC
Download the high-resolution JPG version of the image. (67 KB)
 Worker men in the southern U.S. in the 1920s dig a drainage ditch to control mosquitoes.

Workers in the southern U.S. in the 1920s dig a drainage ditch to control mosquitoes.
Credit: Wikimedia Commons
Download the high-resolution JPG version of the image. (82 KB)

The following is part four in a series on the NSF-NIH Ecology and Evolution of Infectious Diseases (EEID) Program. For part one, please see: Cool Cat in a Hot Zone. For part two: Snails in the Waters, Disease in the Villages. For part three: Underwater Whodunit: What's Killing Florida's Elkhorn Coral?.
It's 2001 in Myanmar (formerly known as Burma), a country in Southeast Asia. Almost 200 people have died, and more than 15,000 are ill--all having contracted dengue fever.
Dengue is a disease transmitted by mosquitoes and caused by four types of dengue virus. Infection may not result in symptoms, or may cause mild, flu-like illness--or hemorrhagic fever.
Dengue virus infects some 50-100 million people annually in Southeast Asia, South America and parts of the United States.
In 1998, a pandemic of dengue resulted in 1.2 million cases of dengue hemorrhagic fever in 56 countries.
In Myanmar, dengue is endemic. The disease has occurred there in three- to five-year cycles since the first recorded outbreak in 1970. Each one has been more deadly.
What caused the widespread infection in Myanmar in 2001, a disease that resulted from one type of dengue virus, DENV-1? For more than a decade, researchers have been working to solve the puzzle.
All viruses not created equal
Could the DENV-1 in Myanmar have been different in some way, perhaps "defective"?
Defective viruses result from genetic mutations or deletions that eliminate essential functions. They're generated in viruses with high mutation rates, but were believed to be unimportant.
But it now appears that defective viruses may be able to play a critical role in the spread of disease.
In a paper published this week in the journal PLoS Pathogens, scientists funded by the National Science Foundation (NSF) report a significant link between one such defective virus and the high rate of transmission of DENV-1 in Myanmar in 2001.
"The idea has always been that defective viruses are either meaningless or detrimental," says James Lloyd-Smith, an ecologist and evolutionary biologist at University of California, Los Angeles.
"We've found the opposite--that the defective virus is actually helping the normal, functional virus. It's bizarre and hard to believe, but the data are the data."
"We've shown that the defective virus not only goes with the normal virus, but increases the transmission of that virus," says scientist Ruian Ke, also of UCLA.
While defective viruses can't complete their life cycle on their own, if they're able to get into the same cell with a non-defective virus, they can "hitch-hike" with the non-defective one and propagate.
Deadly outbreak of DENV-1
The research team--James Lloyd-Smith; Ruian Ke; John Aaskov, a virologist at Queensland University of Technology in Brisbane, Australia; and Edward Holmes, a biologist at the University of Sydney--found that the presence of a defective DENV-1 virus may have led to a spike in dengue fever cases in Myanmar during 2001-2002.
"The causes of epidemics are much more complicated than we thought," says Sam Scheiner, NSF program director for the joint NSF-National Institutes of Health Ecology and Evolution of Infectious Diseases (EEID) Program. At NSF, EEID is funded by the Directorates for Biological Sciences and Geosciences.
In addition to EEID, the research was supported by NSF's Advancing Theory in Biology Program.
"Pathogens can depend on the presence of other microbial species or, as in this case, other varieties of the same species," says Scheiner. "Understanding these interactions is critical for predicting when the next epidemic might occur--and how to prevent it."
In the study, Ke designed a mathematical model to learn how the defective DENV-1 virus interacted with the normal virus.
Aaskov and Holmes collected genetic sequences from the defective viruses from 15 people sampled over an 18-month period in Myanmar. All were infected with DENV-1 virus; nine were also infected with the defective version.
Ke discovered that the lineage of defective viruses emerged between June 1998 and February 2001; it spread through the population until at least 2002.
The following year, the lineage appeared in the South Pacific island of New Caledonia, carried there by a mosquito or a person.
The scientists analyzed the genetic sequences of the defective and normal viruses to estimate how long the defective virus had been transmitting in the human population.
"We can see from the gene sequence of the defective version that it's the same lineage, and is a continued propagation of the virus," says Lloyd-Smith.
"From 2001 to 2002, it went from being quite rare to being in all nine people we sampled that year," says Lloyd-Smith. "Everyone sampled who was getting dengue fever was getting the defective version along with the functional virus.
"It rose from being rare to being very common in just one year."
Most surprisingly, say the scientists, the combination of the defective virus with the normal virus was "more fit" than the normal dengue virus alone.
"What we've shown is that this defective virus, which everyone had thought was useless or even detrimental to the fitness of the functional virus, actually appears to have made it better able to spread," Lloyd-Smith says.
Ke calculated that the defective virus makes it at least 10 percent more transmissible. "It was spreading better with its defective cousin tagging along than on its own," says Lloyd-Smith.
It takes two (viruses) to tango
The functional virus and defective virus travel in unison. The two transmit together in an unbroken chain.
"That's not just a matter of getting into the same human or the same mosquito--they need to get into the same cell inside that human or mosquito in order to share their genes, and for the defective version to continue hitchhiking," says Lloyd-Smith.
"We're gaining insights into the cellular biology of how dengue is infecting hosts. It must be the case that frequently there are multiple infections of single cells."
The defective virus appeared one to three years before the major epidemics in 2001 and 2002.
"One could imagine that if you build an understanding of this mechanism, you could measure it, see it coming and potentially get ahead of it," says Lloyd-Smith.
Defective viruses: disease transmitters beyond dengue?
Might defective viruses play a role in the transmission of the flu, measles and other diseases?
"There are a few signs that this phenomenon may be happening in other viruses," Lloyd-Smith says.
"We may be cracking open the book on the possible interactions between normal, functional viruses and the defective ones that people thought were just dead-ends.
"These supposedly meaningless viruses may be having a positive effect--positive for the virus, not for us.
"There's great variation from year to year in dengue epidemics in various locations, but we don't understand why. This is a possible mechanism."
Why would a defective virus increase transmission of a disease?
Lloyd-Smith offers two hypotheses.
One is that the presence of the defective virus with the functional virus in the same cell makes the functional virus replicate better within the cell by an unknown mechanism.
"It might give the virus flexibility in how it expresses its genes, and may make it more fit and better able to reproduce under some circumstances," Lloyd-Smith says.
A second idea is that the defective virus may be interfering with the disease-causing virus, making the disease less intense.
People then have a milder infection, and because they don't feel as sick, they're more likely to go out of their homes and spread the disease.
In conducting the research, Lloyd-Smith and Ke combined genetic sequence analyses with sophisticated mathematical models and bioinformatics.
"We were able to show that this defective virus transmitted in an unbroken chain across this population in Myanmar for a year-and-a-half," Lloyd-Smith says.
"Without gene sequencing, we wouldn't have been able to establish that."
The biologists hope their work will help turn the tide of the next deadly outbreak of dengue in Myanmar--and in other tropical countries around the globe.
--  Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Related Websites
NSF Special Report: Ecology and Evolution of Infectious Diseases: 
http://newsroom.ucla.edu/portal/ucla/defective-virus-surprisingly-243742.aspx
U.S. Centers for Disease Control and Prevention: Dengue:
The National Science Foundation (NSF) 
 Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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