Science Current Events | Science News | Brightsurf.com
 

Researchers warn of 'fever from the forest'

June 14, 2011
Dengue virus circulating between monkeys and mosquitoes could emerge to cause human outbreaks

GALVESTON, Texas - More than a thousand years ago, somewhere in Southeast Asia, a fateful meeting occurred between a mosquito-borne virus that infected mainly monkeys and a large, susceptible group of humans.

The result: the world's first outbreak of dengue fever.

Today, dengue virus - which can produce high fever, excruciating joint pain and even death - has spread throughout tropical Asia, Africa and South America, and in 2008 it re-appeared in the Florida Keys. It could be even more widespread along the U.S. Gulf Coast but there is no surveillance in place to detect it.

Annually dengue strikes about 100 million people and causes an estimated 50,000 deaths, thriving in the urban environments infested by Aedes aegypti, the mosquito species primarily responsible for human dengue transmission.

Meanwhile, the virus' forest-dwelling counterpart - known as "sylvatic dengue" - continues to flourish in Southeast Asia and West Africa, cycling between non-human primates and the mosquitoes that feed on them. Since the 1970s, sylvatic dengue has received very little scientific attention - a situation that badly needs to be remedied, according to the authors of "Fever from the forest: Prospects for the continued emergence of sylvatic dengue virus and its impact on public health," an article published online June 13 in Nature Reviews Microbiology.

"This virus continues to circulate in the forests, and now economic and ecological pressures are driving more and more people into the forests in Africa and Southeast Asia," said University of Texas Medical Branch at Galveston assistant professor Nikos Vasilakis, lead author of the paper. "In the last 10 years we've seen a number of outbreaks of disease with real public health impact caused by what we call zoonotic viruses, viruses that start out in wild animals but can also be transmitted to humans - look at SARS, Nipah and Hendra, for example. Sylvatic dengue could be capable of a similar emergence - or rather, re-emergence, since we know previous dengue spillovers into urban and near-urban settings have occurred."

Dengue virus may also be capable of movement from the widespread urban cycles into primates and forest mosquitoes of Latin America, which would establish a new reservoir for human infections in the New World.

In the paper, Vasilakis and his collaborators identify two factors that make a dengue re-emergence a "clear and present danger": rapid human population growth near and in tropical forests, and the fact that little or no genetic change would be needed for sylvatic dengue to adapt to human hosts and urban mosquitoes.

"Experiments show that there is little or no adaptive barrier to the emergence of sylvatic dengue into human populations," Vasilakis said. "In other words, the virus can emerge from its current environment at any time, without further adaptation."

The article also presents additional reasons for boosting research into sylvatic dengue, among them the possibility that its behavior in nonhuman primate animal models might offer critical new perspectives on the pathology of human dengue. (Most monkeys tested so far show no clinical signs of the disease, limiting their usefulness as experimental models.) Another significant issue is the possibility that vaccines against human dengue, which could be licensed in as little as five years, might push the virus to the brink of eradication in the urban, human transmission cycle, leaving an ecological opening that could be filled by sylvatic dengue.

"We see a precedent for this with yellow fever, where we have a very good vaccine - urban yellow fever has been nearly eliminated in some regions - but we don't have good vector control programs, and especially in South America we now have outbreaks fueled by sylvatic yellow fever," Vasilakis said. "If we eradicate human dengue and then stop vaccinating, as we often do after the disease disappears, we could see a re-emergence of dengue from a sylvatic source."

With the exception of a research program in Malaysia that ended in 1975, fieldwork on sylvatic dengue has been minimal, according to Vasilakis. In the article, he and his fellow authors call for new surveillance programs to monitor mosquitoes, non-human primates and humans in areas where sylvatic dengue is endemic, as well as the development of new diagnostic tools that will enable researchers to more easily accomplish those studies. (One such surveillance effort is now underway in Senegal, funded by the National Institutes of Health and led by UTMB professor Scott Weaver, the paper's senior author.)

"Of all the viruses with the potential to shift from animals into humans, the most likely to do so are those that, like sylvatic dengue, are carried by the non-human primates and/or bats," Vasilakis said. "For our own good, we need to know as much as we can about this virus."

###

Other authors of the paper include Jane Cardosa of the Universiti Sarawak Malaysia, Kathryn Hanley of New Mexico State University and Edward Holmes of Pennsylvania State University. The National Institutes of Health supported this work.

ABOUT UTMB Health: Established in 1891, Texas' first academic health center comprises four health sciences schools, three institutes for advanced study, a research enterprise that includes one of only two national laboratories dedicated to the safe study of infectious threats to human health, and a health system offering a full range of primary and specialized medical services throughout Galveston County and the Texas Gulf Coast region. UTMB Health is a component of the University of Texas System and a member of the Texas Medical Center.

University of Texas Medical Branch at Galveston


Related Dengue Fever Current Events and Dengue Fever News Articles


Scientists identify important mechanism involved in production of mosquito eggs
Diseases transmitted by mosquitoes have contributed to the death and suffering of millions throughout human history, earning the mosquito the title as the world's most dangerous animal.

Researchers from Mainz and Würzburg propose better substances for treating the dengue virus
Researchers from Johannes Gutenberg University Mainz (JGU) and the Julius Maximilian University of Würzburg are proposing potential new active substances for treating the dengue virus. Just like Ebola, dengue fever is also caused by a virus for which there is currently no cure and no vaccine and can be fatal.

El Niño stunts children's growth in Peru
Extreme weather events, such as El Niño, can have long-lasting effects on health, according to research published in the open access journal Climate Change Responses.

Genetic tweak gave yellow fever mosquitoes a nose for human odor
One of the world's deadliest mosquitoes sustains its taste for human blood thanks in part to a genetic tweak that makes it more sensitive to human odor, according to new research.

QUT helps China to better predict dengue fever outbreaks
Queensland University of Technology (QUT) researchers have found the habit of Googling for an online diagnosis before visiting the doctor can be a powerful predictor of infectious diseases outbreaks.

Malaria from monkeys now dominant cause of human malaria hospitalizations in Malaysia
The majority of malaria hospitalizations in Malaysia are now caused by a dangerous and potentially deadly monkey-borne parasite once rarely seen in humans, and deforestation is the potential culprit in a growing number of infections that could allow this virulent malaria strain to jump from macaque monkeys to human hosts.

Global infection outbreaks, unique diseases rising since 1980
Enterovirus. Tuberculosis. Cholera. Measles. Various strains of the flu and hepatitis.

Ebola Highlights Disparity of Disease Burden in Developed vs. Developing Countries
A study recently published in the Journal of the American Academy of Dermatology shows that for Ebola, measles, syphilis and many other conditions with skin manifestations the mortality rates are hundreds of times higher in developing countries than they are in developed countries. The case of Ebola, the paper writes, "Highlights the importance of monitoring disease burden in the developing world even when the burden is low."

New study finds nearly 6 million more dengue cases in India than official annual tally
The annual number of dengue fever cases in India is 282 times higher than officially reported, and the disease inflicts an economic burden on the country of at least US$1.11 billion each year in medical and other expenses.

New defence mechanism against viruses discovered
Researchers have discovered that a known quality control mechanism in human, animal and plant cells is active against viruses. They think it might represent one of the oldest defence mechanisms against viruses in evolutionary history.
More Dengue Fever Current Events and Dengue Fever News Articles

Dealing with Dengue, the Complete Guide: Dengue Disease Prevention and Treatment: A Guide to Healthy Dengue Fever Symptom Treatment and Cures

Dealing with Dengue, the Complete Guide: Dengue Disease Prevention and Treatment: A Guide to Healthy Dengue Fever Symptom Treatment and Cures


The complete Dengue fever guide: informative, authoritative, tightly-written chapters on every aspect of Dengue infection:
What not to Do...
What is Dengue?
Diagnosing Dengue
Treatment
Folk Remedies
Children & Dengue
Pregnancy & Dengue
Severe Dengue
Painkillers & Your Liver
Recovery & TCM
Doctors & Drugs
Immunity
Lab Tests
Somebody Stop Me!
Call Me Aedes
99% Prevention
Insecticides & Repellents
Traps, Nets, Coils & More
Case Studies
Transmission
Vaccines, Bacteria & GMOs
Regular Mosquito Bites
Your Community
Blogs, Links, Downloads
Myths & Rumors
Videos
Dengue for MDs

The Dengue mosquito depends on human society (and...

Surviving Dengue Fever: A Personal Day-by-Day Account of the Symptoms, Treatments and Aftereffects

Surviving Dengue Fever: A Personal Day-by-Day Account of the Symptoms, Treatments and Aftereffects


Surviving Dengue Fever is a factual personal account of what it is like to suffer from this unpleasant tropical disease. Far from being a mild flu-like virus, as some sources suggest, this mosquito-borne disease causes unpleasant symptoms and long-lasting after-effects that last for months. In more serious cases, Dengue Fever can be fatal.

The frustrating lack of available detailed information motivated the author to keep a diary of the symptoms, along with the best treatments found to alleviate the fever, rash, painful joints and peeling skin that accompany dengue fever. Written in simple layman's terms, Surviving Dengue Fever offers an in-depth insight into what to expect if you are unfortunate enough to be contract dengue fever. It answers many questions that sufferers and...

Dengue and Dengue Hemorrhagic Fever

Dengue and Dengue Hemorrhagic Fever
by Duane J. Gubler (Editor), Eng Eong Ooi (Editor), Subhash Vasudevan (Editor), Jeremy Farrar (Editor)


Continued geographic expansion of dengue viruses and their mosquito vectors has seen the magnitude and frequency of epidemic dengue/dengue hemorrhagic fever (DF/DHF) increase dramatically. Recent exciting research on dengue has resulted in major advances in our understanding of all aspects of the biology of these viruses, and this updated second edition brings together leading research and clinical scientists to review dengue virus biology, epidemiology, entomology, therapeutics, vaccinology and clinical management.

Dengue Fever and Other Hemorrhagic Viruses (Deadly Diseases and Epidemics)

Dengue Fever and Other Hemorrhagic Viruses (Deadly Diseases and Epidemics)
by Tritha, Ph.D. Chakraborty (Author)


Dengue fever is an infectious disease found around the world that is caused by four closely related, but distinct, types of viruses commonly transmitted by Aedes aegypti mosquitoes. Triggering excessive bleeding, dengue fever, dengue hemorrhagic fever, and dengue hemorrhagic shock can be fatal. "Dengue Fever and Other Hemorrhagic Viruses" explores the biology of the dengue virus and similar viruses such as Ebola, Marburg virus, and Lassa fever, as well as their symptoms, where they are commonly found, how they are transmitted, and the efforts to treat and eradicate them.Chapters include: Ins and Outs of Dengue; Hemorrhagic Fevers; Vectors - Bugs That Carry Disease; The Immune System: Our Line of Defense; and, Vaccination - Waking Up the Army in Us.

An American Plague: The True and Terrifying Story of the Yellow Fever Epidemic of 1793 (Newbery Honor Book)

An American Plague: The True and Terrifying Story of the Yellow Fever Epidemic of 1793 (Newbery Honor Book)
by Jim Murphy (Author)


1793, Philadelphia. The nation's capital and the largest city in North America is devastated by an apparently incurable disease, cause unknown . . . In a powerful, dramatic narrative, critically acclaimed author Jim Murphy describes the illness known as yellow fever and the toll it took on the city's residents, relating the epidemic to the major social and political events of the day and to 18th-century medical beliefs and practices. Drawing on first-hand accounts, Murphy spotlights the heroic role of Philadelphia's free blacks in combating the disease, and the Constitutional crisis that President Washington faced when he was forced to leave the city--and all his papers--while escaping the deadly contagion. The search for the fever's causes and cure, not found for more than a century...

Dengue Fever Natural Remedies - A Comprehensive Guide to Identifying and Treating Dengue Fever at Home

Dengue Fever Natural Remedies - A Comprehensive Guide to Identifying and Treating Dengue Fever at Home
by Green Initiative


Early Detection, Cure and Prevention: A Comprehensive Guide to Identifying and Treating Dengue Fever at Home

INTRODUCTION
CHAPTER I. Understanding Dengue Fever
A. What Is Dengue Fever
B. Classifications, Signs, and Symptoms
C. The Four Strains
D. Transmission
E. How The Dengue Virus Attacks The Immune System
CHAPTER II. The Treatment Methods
A. What To Do When Threat Arises
B. Rehydration
C. Tawa-tawa Leaves
D. Sweet Potato Tops
E. Quail Eggs
F. Pork Liver
G. Papaya Leaves
H. Vitamin C
I. Warnings and Precautions
CHAPTER III. Preventive Measures
A. Clean
B. Wear insect repellent lotions
C. Fumigation
EPILOGUE

Sanitation Worker New York City Speed-Study Guide!

Sanitation Worker New York City Speed-Study Guide!
by Angelo Tropea (Author)


New SPEED-STUDY GUIDE to help you prepare for the February 2015 NYC Sanitation Worker exam!

Seven reasons why you should study with this book:

1. This book was prepared by Angelo Tropea, bestselling author of exam preparation books. He has more than 30 years experience in preparing candidates for exams.

2. The book covers in detail the following 7 types of questions and excludes material not relevant to this specific test, such as general test-taking discussions about civil service and long discussions about benefits which do not help you attain a higher score.
   1. Written Comprehension
   2. Written Expression
   3. Problem Sensitivity
   4. Deductive Reasoning
   5. Spatial Orientation
   6. Visualization
   7. Arithmetic...

Understanding Pathophysiology, 5e (Huether, Understanding Pathophysiology)

Understanding Pathophysiology, 5e (Huether, Understanding Pathophysiology)
by Sue E. Huether RN PhD (Author), Kathryn L. McCance RN PhD (Author)


Learn the essential concepts of pathophysiology and stay up to date on treatments, manifestations, and mechanisms of disease with Understanding Pathophysiology, 5th Edition. Filled with vibrant illustrations and complemented by online resources that bring pathophysiology concepts to life, this easy-to-read text delivers the latest, most accurate information on the disease process across the lifespan, giving you the fundamental knowledge you need to move forward in your nursing education. Consistent presentation helps you better distinguish pathophysiology, clinical manifestations, and evaluation and treatment for each disease.More than 1,000 high-quality illustrations vividly depict clinical manifestations and cellular mechanisms underlying diseases.Lifespan coverage details age-specific...

CURRENT Medical Diagnosis and Treatment 2015

CURRENT Medical Diagnosis and Treatment 2015
by Maxine Papadakis (Author), Stephen J. McPhee (Author), Michael W. Rabow (Author)


To deliver the best care to your patients, turn to the #1 annually updated guide in internal medicine and clinical practice. The 2015 Edition is packed with important NEW information! For more than 70 years, professors, students, and clinicians have trusted LANGE for high-quality, current, concise medical information in a convenient, affordable, portable format. Whether for coursework, clerkships, USMLE prep, specialty board review, or patient care, there's a LANGE book that guarantees success. NEW TO THIS EDITION: Latest 2014 American Heart Association/American College of Cardiology guidelines for anticoagulation in atrial fibrillation, and indications for interventions in valvular heart disease Update on the epidemic of opioid-based prescription drug abuse, misuse and overdose, and new...

Global Health 101 (Essential Public Health)

Global Health 101 (Essential Public Health)
by Richard Skolnik (Author)


Global Health 101, Second Edition (formerly titled Essentials of Global Health) is a clear, concise, and user-friendly introduction to the most critical issues in global health. It illustrates key themes with an extensive set of case studies, examples, and the latest evidence. While the book offers a global perspective, particular attention is given to the health-development link, to developing countries, and to the health needs of poor and disadvantaged people. Global Health 101 builds on the success of an introductory global health course taught by the author at the George Washington School of Public Health and Health Services and is ideally suited for the the Association of American Colleges and Universities recommended course by the same name. The text is accompanied by a wealth of...

© 2015 BrightSurf.com