MedicineWorld.Org
Your gateway to the world of medicine
Home
News
Cancer News
About Us
Cancer
Health Professionals
Patients and public
Contact Us
Disclaimer

Medicineworld.org: Archives of infectious disease blog


Go Back to the main infectious disease blog

Subscribe To Health Blog RSS Feed  RSS content feed What is RSS feed?

Archives Of Infectious Disease Blog From Medicineworld.Org


April 4, 2006, 10:55 PM CT

US Tuberculosis Cases At An All-time Low

US Tuberculosis Cases At An All-time Low
The latest national surveillance data show that tuberculosis (TB) rates reached an all-time low in the United States in 2005, but progress to eliminate TB is slowing.1 Furthermore, the increasing occurrence of drug-resistant TB, including extensively drug-resistant cases, presents significant challenges to therapy and control of the disease both in the United States and abroad.

TB Rate Declines Nationwide

A total of 14,093 TB cases were published in the United States in 2005, down from 14,516 cases in 2004. The 2005 national TB case rate - 4.8 cases per 100,000 persons - was the lowest since reporting began in 1953. However, the decline of 3.8 percent in the national TB case rate from 2004 to 2005 was one of the smallest declines in more than a decade.

Increase in Multi-Drug Resistant TB Presents Serious Challenges

At the same time, persons with multi-drug-resistant (MDR) TB - TB that is resistant to at least two first-line therapies (isoniazid and rifampin) -- increased 13.3 percent in the United States from 2003 to 2004, the most recent years for which those data are available. This was the largest single-year increase in MDR TB since 1993.

MDR TB, which is difficult and costly to treat, and can be fatal, now accounts for 1.2 percent of all TB cases for which drug-susceptibility data are available. Closely following MDR TB trends in the coming years will be critical in determining whether the 2005 increase represents a nationwide trend, and in understanding the implications of resistance for TB therapy and control.........

Posted by: Mark      Permalink         Source


April 4, 2006, 0:09 AM CT

Supercomputer Maps One Million Atoms of a Complete Virus

Supercomputer Maps One Million Atoms of a Complete Virus
For the first time, researchers have visualized the changing atomic structure of a virus by calculating how each of the virus' one million atoms interacted with each other every femtosecond--or one-millionth-of-a-billionth of a second. A better understanding of viral structures and mechanisms may one day allow researchers to design improved strategies to combat viral infections in plants, animals and even humans.

Led by Klaus Schulten at the University of Illinois at Urbana-Champaign, the team tapped the high-performance power of the National Center for Supercomputing Applications (NCSA) processors to accomplish the task. Still, it took about 100 days to generate just 50 nanoseconds of virus activity. Schulten says it would have taken the average desktop computer 35 years to come up with the results.

The simulation revealed key physical properties of satellite tobacco mosaic virus, a very simple, plant-infecting virus. Ultimately, scientists will generate longer simulations from bigger biological entities, but to do so, they need the next generation of supercomputers, the so-called "petascale high-performance computing systems." The National Science Foundation (NSF) is currently devising a national strategy for petascale computing to give scientists and engineers the resources needed to tackle their most computationally intensive research problems.........

Posted by: Scott      Permalink         Source


April 3, 2006, 11:37 PM CT

Avian Flu Modeled On Supercomputer

Avian Flu Modeled On Supercomputer
Using supercomputers to respond to a potential national health emergency, researchers have developed a simulation model that makes stark predictions about the possible future course of an avian influenza pandemic, given today's environment of world-wide connectivity. The research, by a team of researchers from Los Alamos National Laboratory in New Mexico, the University of Washington and the Fred Hutchinson Cancer Research Center in Seattle, is presented in the Proceedings of the National Academy of Science online the week of April 3-7, and in the print issue of April 11.

The large-scale, stochastic simulation model examines the nationwide spread of a pandemic influenza virus strain, such as an evolved avian H5N1 virus, should it become transmissible human-to-human. The simulation rolls out a city- and census-tract-level picture of the spread of infection through a synthetic population of 281 million people over the course of 180 days, and examines the impact of interventions, from antiviral treatment to school closures and travel restrictions, as the vaccine industry struggles to catch up with the evolving virus.

"Based on the present work. we think that a large stockpile of avian influenza-based vaccine containing potential pandemic influenza antigens, coupled with the capacity to rapidly make a better-matched vaccine based on human strains, would be the best strategy to mitigate pandemic influenza," say the authors, Timothy Germann, Kai Kadau, Ira Longini and Catherine Macken.........

Posted by: Mark      Permalink         Source


April 2, 2006, 8:39 PM CT

Juice improves health, No increase Obesity Risk

Juice improves health, No increase Obesity Risk
As per a recent analysis of government data, children who drank 100 percent juice had healthier overall diets than non-juice consumers and consumed more total fruits, fiber and key nutrients such as vitamin C, potassium, magnesium and folate. The juice consumers also had significantly lower intakes of total fat, saturated fat and sodium.

As per the researchers, the group of 100 percent juice consumers also had equal or lower bodyweights and body mass indexes (BMI) than the non-juice consumers, adding to the scientific evidence which shows that 100 percent juices play a role in a healthful diet and are not associated with overweight. The research is being presented this week at the Experimental Biology 2006 meeting.

Using well-established data from the government's National Health and Nutrition Examination Survey (NHANES), researcher Victor Fulgoni, Ph.D., examined the impact of 100 percent juice in children's diets on bodyweight and BMI among more than 7,500 children ages 2-18. This analysis of the most recent NHANES database (1999-2002), combined with growth chart data from the Centers for Disease Control and Promotion (CDC), found that juice consumers had significantly lower z-scores for body mass index for their age than non-juice consumers (body mass index is a relative measure taking into consideration body weight and body size and z-scores represent the distance from the mean or average of the total population studied). While there were no differences specifically in BMI between the juice consumers and non-juice consumers for children aged 2-11, there were differences in children aged 12-18 years -- the juice consumers had significantly lower BMIs than those who drank no juice at all.........

Posted by: Mark      Permalink         Source


March 30, 2006, 5:04 PM CT

Quantum Dot Method To Identify Bacteria

Quantum Dot Method To Identify Bacteria Caption: This fluorescence micrograph shows phage-quantum dot complexes (bright spots) bound to E. coli cells (cylindrical shapes). The NCI/NIST method of tagging cells with quantum dots can be used to identify bacteria much faster than conventional methods. The fluorescence signal is strong and stable for hours, enabling scientists to count the number of phage viruses bound to a cell.

Credit: NCI/NIST
A rapid method for detecting and identifying very small numbers of diverse bacteria, from anthrax to E. coli, has been developed by researchers from the National Cancer Institute (NCI) and National Institute of Standards and Technology (NIST). Described in the March 28 issue of Proceedings of the National Academy of Sciences,* the work could lead to the development of handheld devices for accelerated identification of biological weapons and antibiotic-resistant or virulent strains of bacteria--situations where speed is essential.

Traditional ways of identifying infectious bacteria and their possible therapys can be time consuming and laborious, requiring the isolation and growth of the bacteria over a number of hours or even days. The new method speeds up the process by using fast-replicating viruses (called bacteriophages or phages) that infect specific bacteria of interest and are genetically engineered to bind to "quantum dots." Quantum dots are nanoscale semiconductor particles that give off stronger and more intense signals than conventional fluorescent tags and also are more stable when exposed to light. The method detects and identifies 10, or fewer, target bacterial cells per milliliter of sample in only about an hour.

The phages were genetically engineered to produce a specific protein on their surface. When these phages infect bacteria and reproduce, the bacteria burst and release a number of phage progeny attached to biotin (vitamin H), which is present in all living cells. The biotin-capped phages selectively attract specially treated quantum dots, which absorb light efficiently over a wide frequency range and re-emit it in a single color that depends on particle size. The resulting phage-quantum dot complexes can be detected and counted using microscopy, spectroscopy or flow cytometry, and the results used to identify the bacteria. The new method could be extended to identify multiple bacterial strains simultaneously by pairing different phages with quantum dots that have different emission colors.........

Posted by: Mark      Permalink         Source


March 30, 2006, 7:19 AM CT

Improving Dengue Vaccinations

An innovative new study explains, for the first time, the failure of prior attempts to vaccinate against the four known Dengue viruses, and it suggests a very simple solution - injecting the four vaccines simultaneously at different locations on the body.

A mosquito-born disease, Dengue kills tens of thousands of people per year and sickens 100 million more. Typically known as "bone-break disease," dengue is characterized by excruciating pain and was "the most important mosquito-borne viral disease affecting humans" in 2005 as per the U.S. Centers for Disease Control.

The study, from bioengineers and physicists at Rice University, appears in the March 24 issue of the journal Vaccine. The study suggests that the multi-site vaccination strategy, termed polytopic vaccination, may be effective against other diseases as well, including HIV and cancer.

Dengue infection occurs from one of four closely related viruses. Prior exposure to one of the four - either by previous infection or by vaccination - makes people significantly more likely to develop a potentially lethal hemorrhagic infection if they are later infected by one of the other three viruses.

"This is a classic case of something called 'original antigenic sin,' which happens when our immune system becomes overly reliant upon memory when recognizing diseases similar to those that it has seen before," said lead researcher Michael Deem, the John W. Cox Professor in Biochemical and Genetic Engineering and professor of physics and astronomy. "With diseases like HIV, influenza and Dengue, our acquired immune system's tendency to go-with-what-it-knows can leave us more vulnerable to infection from a mutant strain or a related virus. The immune system may respond less favorably in these cases than if it had never been exposed to the disease in the first place."........

Posted by: Mark      Permalink         Source


March 29, 2006, 10:55 PM CT

Tiny water purification packet may save lives

Tiny water purification packet may save lives
Chemists have developed a powerful household water purification system that puts the cleansing power of an industrial water therapy plant into a container the size of a ketchup packet. The scientists have shown that the tiny packet, which acts as a chemical filter, can be added to highly contaminated water to dramatically reduce pathogen-induced diarrhea - the top killer of children in much of the developing world.

The packets also show promise for boosting water safety during emergencies and natural disasters, such as earthquakes, floods and hurricanes, where water purity is suddenly compromised, the scientists say. The lifesaving packets, whose use is being expanded globally, was described today at the 231st national meeting of the American Chemical Society.

Worldwide, approximately 1.5 million children under age five die each year from simple diarrhea acquired from pathogens found in drinking water, as per public health experts. That translates to about 4,000 children dying each day as a result of contaminated water.

"It's like a 9-11 catastrophe happening everyday worldwide, but this is a tragedy that can be prevented," says Greg Allgood, Ph.D., director of Procter & Gamble's Children's Safe Drinking Water program, which manufactures the packets. The company has been developing the packets since 1995 in collaboration with the U.S. Centers for Disease Control and Prevention (CDC).........

Posted by: Janet      Permalink         Source


March 21, 2006, 8:55 PM CT

Warming May Increase Malaria Risk

Warming May Increase Malaria Risk
Could global warming be contributing to the resurgence of malaria in the East African Highlands?.

A widely-cited study published a few years ago said no, but new research by an international team that includes University of Michigan theoretical ecologist Mercedes Pascual finds that, while other factors such as drug and pesticide resistance, changing land use patterns and human migration also may play roles, climate change cannot be ruled out.

"Our results do not mean that temperature is the only or the main factor driving the increase in malaria, but that it is one of a number of factors that should be considered," Pascual said. The new study is slated would be published online this week in the Proceedings of the National Academy of Sciences.

After being nearly or completely eradicated in a number of parts of the world, malaria still affects hundreds of millions of people worldwide and has been on the rise in some highland regions and desert fringes. Because the life cycle of the mosquito that transmits malaria and the microorganism that causes the disease are extremely sensitive to changes in temperature, some researchers have speculated that rising average temperatures may be making conditions more favorable for mosquitoes and pathogen development, leading in turn to the surge in malaria cases.........

Posted by: Mark      Permalink


March 19, 2006, 8:05 PM CT

Scientist Highlights Bugs' Benefits

Scientist Highlights Bugs' Benefits
Bacteria are bad. Mothers and doctors, not to mention the cleaning product industry, repeatedly warn of their dangers. But a Stanford University School of Medicine microbiologist is raising the intriguing idea that persistent bacterial and viral infections have benefits.

Stanley Falkow, PhD, the Robert W. and Vivian K. Cahill Professor in Cancer Research, is publishing his thoughts on this topic in an essay in the Feb. 24 issue of the journal Cell, in which he asks, "Is persistent bacterial infection good for your health?" The essay is based on a talk he was invited to give at Cambridge University in November.

Falkow points out that the medical community and those who fund medical research focus on curing disease. He wonders if this single-mindedness might distract scientists from appreciating the beneficial contributions of micro-organisms to the body.

"Organisms that cause disease are commonly considered in the context of harm and epidemics and so on," said Falkow. "But the fact is that a great number of organisms that infect humans come in and set up housekeeping as it were. There are no clinical symptoms of anything wrong and people take the organisms with them to their graves".

It's not that the organisms in question - such as the bacteria that cause pneumonia or meningitis - are innocuous, he said. It's just that most of the individuals do not get disease from being infected.........

Posted by: Mark      Permalink         Source


March 18, 2006, 10:45 AM CT

Mutations In Avian Flu Virus May Cause Human Infection

Mutations In Avian Flu Virus May Cause Human Infection
The H5N1 avian influenza virus, usually known as "bird flu," is a highly contagious and deadly disease in poultry. So far, its spread to humans has been limited, with 177 documented severe infections, and nearly 100 deaths in Indonesia, Vietnam, Thailand, Cambodia, China, Iraq, and Turkey as of March 14, 2006, as per the World Health Organization (www.who.int).

"With continued outbreaks of the H5N1 virus in poultry and wild birds, further human cases are likely," said Ian Wilson, a Scripps Research professor of molecular biology and head of the laboratory that conducted the recent study. "The potential for the emergence of a human-adapted H5 virus, either by re-assortment or mutation, is a clear threat to public health worldwide."

Of the H5N1 strains isolated to date, the scientists looked at A/Vietnam/1203/2004 (Viet04), one of the most pathogenic H5N1 viruses studied so far. The virus was originally isolated from a 10-year-old Vietnamese boy who died from the infection in 2004. The hemagglutinin (HA) structure from the Viet04 virus was found to be closely correlation to the 1918 virus HA, which caused some 50 million deaths worldwide.

Using a recently developed microarray technology-hundreds of microscopic assay sites on a single small surface-the study showed that relatively small mutations can result in switching the binding site preference of the avian virus from receptors in the intestinal tract of birds to the respiratory tract of humans. These mutations, the study noted, were already "known in [some human influenza] viruses to increase binding for these receptors."........

Posted by: Mark      Permalink         Source



Older Blog Entries   1   2   3   4   5   6   7   8  

Did you know?
Scientists at Baylor College of Medicine in Houston have found a genetic marker that may identify individuals at greater risk for life-threatening infection from the West Nile virus. Results of the study are reported in the Nov. 15 print edition of Journal of Infectious Diseases.

Medicineworld.org: Archives of infectious disease blog

SARS Main| SARS Abroad| SARS and Goverment| SARS Information in different languages| Media about SARS| Physicians resources for SARS| Reference information for SARS| Updates on SARS|

Copyright statement
The contents of this web page are protected. Legal action may follow for reproduction of materials without permission.