Posts Tagged: dengue
His foe? The day-biting, tiger-striped mosquito, Aedes aegypti. It transmits a virus that causes dengue, sometimes called "break-bone fever."
It's the world’s worst insect-transmitted virus.
And it's on the rise.
"Spread by mosquitoes, it can make you feel as if your bones are broken and leave you exhausted for months," writes Zimmer, who teaches Yale University students how to write about science and the environment. "In more serious cases, people suffer uncontrollable bleeding and sometimes die. Dengue is expanding its range, and is even making incursions into the United States. Scott and I talk about what scientists know and don't know yet about dengue, and what the best strategy will be to drive the virus down."
When Scott leaves his mosquito research laboratory at UC Davis, he’s likely heading for his field stations in Peru, Thailand or Mexico to try to stop that killer mosquito from transmitting dengue.
Scott’s goal: to save lives through research, surveillance and implementation of disease prevention strategies.
“I study the patterns of human infection with dengue virus, doing detailed studies of mosquito populations and disease in humans in order to predict which prevention strategies work the best,” said Scott, who assesses risks, develops computer models and implements disease prevention strategies.
The culprit: Aedes aegypti, or the yellow-fever mosquito, that transmits dengue virus to people.
The disease: Dengue, caused by any one of four serotypes or closely related viruses known as DEN-1, DEN-2, DEN-3, or DEN-4. Nicknamed “break-bone fever,” classic dengue is characterized by high fever, headaches, muscle and joint pain, nausea, vomiting and a rash.
At risk: Some 2.5 to 3 billion people, primarily in tropical and sub-tropical countries around the world.
The prevalence: Some 50 to 100 million annual cases of debilitating dengue fever. The most severe form of the disease, dengue haemorrhagic fever (DHF), strikes half a million a year, according to the Centers for Disease Control and Prevention. An estimated 5 percent with DHF die.
There’s no vaccine. There’s no cure. The only way to prevent this disease is to kill the mosquito vector.
Scott directs the state-funded UC Mosquito Research Laboratory, based in Briggs Hall on the UC Davis campus. His team includes UC Davis associate professor and medical entomologist Anthony “Anton” Cornel, based at the Kearney Agricultural Center, Parlier; researcher Amy Morrison who lives in Iquitos, Peru and has directed their research there since 1999; program manager Leslie Sandburg; postdoctoral and graduate students; and a long list of collaborators at his field sites in Mexico, Peru and Thailand.
Listen to the podcast and learn how Thomas Scott (who at 6-foot, 6 inches tall, towers over his tiny foe) is battling this killer.
(Editor's note: Professor Scott will be teaching a winter course on medical entomology at UC Davis, discussing such diseases as malaria, dengue, West Nile virus, lyme disease, yellow fever, and river blindness.)
UC Davis medical entomologist Thomas Scott is mentioned in "The War on Dengue Fever," a news article published Nov. 3, 2008 in the New York Times.
Scott is a leading expert on dengue fever, a mosquito-borne disease transmitted by Aeges egypti.
Reporter Thomas Fuller began his story:
BANGKOK — There was little that doctors could do for a 3-year-old boy brought to Bangkok’s main children’s hospital two weeks ago with dengue fever. Like thousands before him, he had reached the most dangerous phase of the disease, dengue shock syndrome, and he died of internal bleeding and organ failure three days after being admitted.
The U.S. Army maintains a medical research laboratory in Bangkok, where military scientists study tropical diseases. One of their goals: to develop a vaccine for dengue.
Here's where Scott comes in:
"The mosquito can breed in something as small as a soda bottle, but its ideal breeding conditions are large containers common in many parts of Southeast Asia to store drinking water," Fuller wrote. "(Unlike other mosquitoes, Aedes aegypti prefers clean water, according to Thomas W. Scott, a professor at the University of California, Davis, who is a leading expert on the species.)"
We wrote about researcher Scott's work in July: On the Trail of Dengue: A Disease with No Vaccine, No Cure.
Scott's goal is to save lives through research, surveillance and implementation of disease prevention strategies. He maintains field stations in Peru, Mexico and Thailand.
He's studying "the patterns of human infection with dengue virus, doing detailed studies of mosquito populations and disease in humans in order to predict which prevention strategies work the best."
Basically, Scott assesses risks, develops computer models and implements disease prevention strategies.
The culprit: Aedes egypti, or the yellow-fever mosquito, that transmits dengue virus to people.
The disease: Dengue, caused by any one of four serotypes or closely related viruses known as DEN-1, DEN-2, DEN-3, or DEN-4. Nicknamed “break bone fever,” classic dengue is characterized by high fever, headaches, muscle and joint pain, nausea, vomiting and a rash.
The prevalence: Some 50 to 100 million annual cases of debilitating dengue fever. The most severe form of the disease, dengue haemorrhagic fever (DHF), strikes half a million a year, according to the Centers for Disease Control and Prevention (CDC). An estimated 5 percent with DHF die.
The CDC says dengue outbreaks occur in most tropical urban areas of the world where the Aedes egypti lives.
In the United States, dengue is rare. Occasionally travelers to infected areas return with the disease.
Now the Armed Forces Research Institute of Medical Sciences, Bangkok, is attempting to develop a vaccine for dengue. As New York Times reporter Thomas Fuller wrote, quoting Col. James Boles, the laboratory commander: "There's no dengue in Kansas. No malaria, either. That's why we are here."
And that's why medical entomologists like Thomas Scott are here, too.
Medical entomologist Thomas Scott
In the lab
What's medical entomolology?
Anyone who's an entomologist or who works in entomology is asked that question periodically. Medical, they know. Entomology? Often not. But medical entomology?
Well, it's the study of relationships among arthorpods, microbial pathogens and human health, according to medical entomologist Thomas Scott, professor of entomology at UC Davis.
Scott teaches courses on medical entomology. His next one: the 2009 winter quarter, Jan. 5 through March 16.
Worldwide, Scott says, arthropod-borne diseases have devastating effects on human health; they are a leading cause of human morbidity and mortality.
In his course, he explains the basic biology of medically important arthropods and the pathogens they transmit. The diseases include malaria, dengue fever, yellow fever, West Nile virus, Lyme disease and River Blindness.
Scott, a noted mosquito-borne disease expert and newly elected fellow of the prestigious American Association for the Advancement of Science (for "distinguished contributions to the biology and ecology of mosquitoes and his leadership in developing strategic concepts for preventing dengue fever and other mosquito-borne diseases”) does research from his mosquito research laboratory at UC Davis and at field stations in Peru, Thailand and Mexico.
In January, Scott hosted the 42nd annual U.S.-Japan Parasitic Disease Conference on the UC Davis campus. Some 100 scientists from throughout the world participated in the three-day conference "to develop a cross-cutting perspective on what the priorities should be for the future research on arthropod vectors of disease," he explained.
With new and emerging diseases, increasing national and international travel, settlement in endemic areas, and the proliferation of commerce, we can expect disease from vector-borne pathogens to increase, Scott says.
It's obvious what we need less of (diseases) and what we need more of (medical entomologists).
Thomas Scott in Kenya
Mosquito that tranmits dengue