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Biological Warfare : Biological Terrorism : Emerging Diseases

Archived News
Week ending December 31st, 2005

Scientists have cracked the genetic code of a fungus responsible for deadly infections and allergic reactions. Aspergillus fumigatus, which causes more infections than any other mould, is particularly dangerous to people with weakened immune systems.

Researchers at the Institute for Genomic Research hope their work could lead to better diagnostic tests, and treatments for fungal infections. Their international collaboration is reported in the journal Nature.

Experts believe that A. fumigatus has become an increasing threat in recent years as more people with compromised immune systems are surviving.

These include transplant patients, and people with leukaemia and Aids. The fungus also appears to trigger asthma in some people with particularly sensitive immune systems.

It is unusual because it can thrive at a wide range of temperatures, from 70C - the temperature in a compost heap - to 37C, inside the human body. By altering ambient temperatures in the lab, scientists were able to track how different genes were turned on and off as the environment warmed.

The researchers, including scientists from the UK's Wellcome Trust Sanger Institute, discovered that the genome of the fungus is made up of eight chromosomes bearing a total of almost 10,000 genes.

They found 700 genes that were either significantly different, or did not occur at all in a similar, but less infectious, fungus, Neosartorya fischeri. They also identified for the first time nine allergy-causing substances produced by the fungus...

Scientists have analysed in close detail the structure of a key protein that helps the malaria parasite infect human cells. They found the protein has a unique atomic structure which, in theory, new drugs could target directly.

Malaria kills about 2m people each year, most of them children under five. There are concerns about growing resistance to established drugs. The research, by scientists from India and France, is published by Nature.

Malaria is caused by a one-celled organism called Plasmodium, which is passed to humans through the bite of Anopheles mosquitoes. The parasite replicates inside red blood cells, which eventually burst. In order to enter these cells, it first has to bind to the cell through protein interactions which take place on the surfaces of red blood cells and the parasite.

The latest research focuses on one particular protein on the surface of Plasmodium which plays a particularly key role. The researchers obtained crystals of a part of this protein - called the Duffy-Binding Like (DBL) domain - which directly interacts with a protein on red blood cells.

Using a technique called X-ray crystallography they were able to create an atom-by-atom map of the protein, which are too small to be seen by microscopes.

Researcher Dr Amit Sharma said: "Until now we have not had a close-up view of the precise surface where the two proteins interact. "That surface is absolutely crucial in permitting the parasite to enter the cell. "If we can determine its features in atomic detail, we may be able to find weak points that could make good targets for drugs."..

In a development health experts are calling alarming, two bird flu patients in Vietnam died after developing resistance to Tamiflu, the key drug that governments are stockpiling in case of a large-scale outbreak.

The experts said the deaths were disturbing because the two girls had received early and aggressive treatment with Tamiflu and had gotten the recommended doses.

The new report suggests that the doses doctors now consider ideal may be too little. Previous reports of resistance involved people who had taken the drug in low doses; inadequate doses of medicine are known to promote resistance by allowing viruses or bacteria to mutate and make a resurgence.

Dr. Anne Moscona, a flu expert at Weill Cornell Medical College in New York City, called the deaths frightening and said they demonstrate the dangers of hoarding drugs.

"People who stockpile will naturally share or take drugs at the wrong dose, and that's really a bad idea," said Moscona, who wrote an accompanying commentary in Thursday's New England Journal of Medicine.

Since 2003, avian flu has killed about 70 people, mostly in Vietnam and Thailand, and nearly all involved close contact with infected birds. Health experts fear the virus could morph into a form that spreads easily between people. Tamiflu and another drug, Relenza, are expected to be the front-line defense if that happens, but they must be taken soon after infection to be effective...

he Amazon River basin, the world's largest rain forest, is grappling with a devastating drought that in some areas is the worst since record keeping began a century ago. It has evaporated whole lagoons and kindled forest fires, killed off fish and crops, stranded boats and the villagers who travel by them, brought disease and wreaked economic havoc.

In mid-October, the governor of Amazonas State, Eduardo Braga, decreed a "state of public calamity," which remains in effect as the drought's impact on the economy, public health and food and fuel supplies deepens. But other Brazilian states have also been severely affected, as have Amazon regions in neighboring countries like Peru, Bolivia and Colombia.

With hundreds of riverside settlements cut off from the outside world, the Brazilian Armed Forces have for three months mounted what officials describe as the biggest relief operation that they and civil defense agencies have carried out together. Nearly 2,000 tons of food and 30 tons of medicine have already been airlifted by plane and helicopter to affected communities just in Amazonas State, the region's largest.

"There have been years before in which we've had a deficit of rainfall, but we've never experienced drops in the water levels of rivers like those we have seen in 2005," said Everaldo Souza, a meteorologist at the Amazon Protection System, a Brazilian government agency in Manaus, the nine-state region's main city. "It has truly been without precedent, and it looks like it is only going to be December or January, if then, that things return to normal."

Scientists say the drought is most likely a result of the same rise in water temperatures in the tropical ..

TBA Warning an outbreak may be inevitable, the White House on Saturday conducted a test of its readiness for a feared bird flu pandemic and said federal agencies fared "quite well" without offering any details.

Cabinet secretaries, military leaders and other top officials took part in the four-hour tabletop drill, which officials said was designed to assess the level of federal preparedness for a possible outbreak of bird flu or another deadly virus.

"This is about being ready for what inevitably will come," Health and Human Services Secretary Michael Leavitt said.

But the White House refused to divulge details about the exercise and the test results, and officials said afterward that it was clear that state and local governments would have to assume a leading role.

"Quite frankly, I think we did quite well," White House homeland security adviser Fran Townsend said of the federal agencies that took part in the exercise.

The White House test came one day after a Thai boy became the 70th person to die of bird flu, which usually strikes those in close contact with infected fowl or their droppings.

Experts fear the deadly virus, known as H5N1, will mutate into a form that can easily infect and pass between people, causing a pandemic...

A pandemic caused by a mutated form of the avian-flu virus could cause a $675 billion hit to the U.S. economy, the Congressional Budget Office reported Thursday.

"A nearly $700 billion hit to the economy -- almost half of which is brought on by fear and confusion -- gives us every reason to begin preparing a prescription and implementing a course of action," Senate Majority Leader Bill Frist, a Republican from Tennessee, said in a speech unveiling the report.

A mild pandemic would cut U.S. GDP by 1.5%, the report said. A severe pandemic could infect 90 million people in the U.S. -- killing two million -- and push the economy into a recession. Under this so-called severe scenario, 30% of the work force would become ill and miss at least three weeks of work.

The report cautions: "There is a substantial amount of uncertainty associated with these scenarios because there is scant empirical evidence available to inform many of the assumptions that are needed for the calculations underlying the economic effects."

Statistics cited in the report assume that the avian flu evolves to a form that is easily transmitted from human to human. So far, most of the human cases have been transmitted from bird to human. A roughly 50% death rate from the disease has Sen. Frist and other U.S. lawmakers extremely worried.

"Just as it is difficult to forecast the severity of a pandemic, it is hard to predict its economic effects, even if the outbreak's scope and severity are known," the report said.

Sen. Frist laid out a six-point plan that he said cut the cost of such a pandemic in half. Central to his plan is a proposal that would increase what he termed the "dangerously inadequate vaccine manufacturing base." Sen. Frist proposed increasing the number of people the government suggests get annual vaccines -- thus increasing vaccine manufacturer's market base... TBA

Scientists in Newcastle claim they are closer to developing a cure for some of the world's most deadly diseases. Northumbria University researchers say the discovery could cure toxic shock syndrome, septicaemia and the flesh-eating necrotizing faciitis.

The drug-resistant diseases are caused by streptococcus bacterium, which is more common now than 10 years ago.

Scientists say they are closer to discovering why the bug, which also causes sore throats, can kill.

Dr Gary Black and a team from the university's school of applied sciences, used a technique similar to DNA testing to isolate one of the many enzymes within the bacterium, which is thought to be responsible for triggering some of the diseases.

He discovered that the enzyme has a rare triple-stranded beta-helix shape, which is similar to only four other enzymes out of the thousands tested in recent years.

Dr Black, 39, from County Durham, now hopes one of the world's leading pharmaceutical companies will take up his research and use his findings to develop revolutionary life-saving drugs.

He said: "This is a major breakthrough which has the potential to save thousands of lives ...

A 31-year-old woman in China has been diagnosed with the deadly H5N1 bird flu virus, state media reports. The farm worker from the north-eastern Liaoning province is the country's fifth confirmed case. Two female farmers from Anhui province died from the deadly strain in November. A girl in the Guangxi region has undergone emergency treatment. The H5N1 virus has killed nearly 70 people in South East Asia since the outbreak began in 2003.

The woman at the centre of China's latest case fell ill in Heishan county on 30 October, Xinhua news agency reported. She had a high fever and pneumonia-like symptoms, but she recovered following treatment at a hospital and was discharged on 29 November, it said. The China Daily newspaper has said there have been at least 30 avian outbreaks of bird flu in 11 provinces and regions this year. The case of the 10-year-old girl in Guangxi is being investigated because there have been no confirmed recent outbreaks of bird flu in the southern region.

A young boy from central Henan also caught the deadly strain but recovered.

The authorities in China have culled millions of birds, but experts are warning that the virus is entrenched in parts of the country. Beijing has said it will vaccinate all of the country's estimated 14 billion poultry, but it is feared wild birds could spread the virus...

Two reports highlight the emergence of a new, highly toxic strain of the bacterium Clostridium difficile that is resistant to fluoroquinolone antibiotics, such as Cipro (ciprofloxacin) and Levaquin (levofloxacin), and is causing geographically dispersed outbreaks.

The reports were released early by The New England Journal of Medicine to coincide with this week's report by the Centers for Disease Control and Prevention C. difficile infections in low-risk patients.

C. difficile is a microbe that can be a member of the normal bacterial colonies that live in the intestines. Problems occur, however, when neighboring bacteria are disturbed allowing an overgrowth of C. difficile, which typically results in a foul-smelling watery diarrhea. Overuse of certain antibiotics is one common cause of such disturbances.

The CDC has received an increased number of reports from health care facilities of cases of severe C. difficile-associated disease, according to one of the papers. Dr. L. Clifford McDonald, from the CDC in Atlanta, and colleagues say this suggests the emergence of an epidemic strain with increased virulence, antibiotic resistance, or both.

To test this hypothesis, the research team collected 187 C. difficile samples from outbreaks since 2001 in eight health care facilities in six states, and compared their characteristics with those of 6000 samples obtained between 1984 and 1990.

More than half of the recent samples were of one strain, termed BI/NAP1. Testing showed that this strain was particularly resistant to fluoroquinolone antibiotics.

By contrast, just 14 of the 6000 isolates obtained in the past were of this strain, the report indicates. "If this epidemic strain continues to spread and to contribute to increased...

Fruit bats may be acting as reservoirs of the killer Ebola virus, responsible for several deadly outbreaks in central Africa, research suggests. Three bat species captured during outbreaks between 2001 and 2003 in Gabon and the Republic of Congo show evidence of symptomless infection.

Writing in Nature, researchers in Gabon say this means the animals may play a key role in spreading the virus.

They say local residents should be encouraged to refrain from eating bats. The first human outbreak of Ebola was recorded in 1976, but scientists have still to pin down which species harbour the virus. If bats are among the culprits, they are more likely to pass the virus on to great apes such as gorillas and chimpanzees, which have been badly affected.

However, it is also possible that bats could infect humans directly.

Researchers from the Centre International de Recherches Medicales de Franceville trapped and tested more than 1,000 small animals in Ebola-affected areas.

They found fruit bats of three species - Hypsignathus monstrosus, Epomops franqueti and Myonycteris torquata - had either genetic sequences from the virus or evidence of an immune response to it. Traces of the virus were found in the animals' liver and spleen - two organs specifically targeted by Ebola...