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Biological Warfare : Biological Terrorism : Emerging Diseases

More than 90,000 Americans get potentially deadly infections each year from a drug-resistant staph "superbug," the government reported Tuesday in its first overall estimate of invasive disease caused by the germ.

Methicillin-resistant Staphylococcus aureus can be carried by healthy people, living on the skin or in their noses.

Deaths tied to these infections may exceed those caused by AIDS, said one public health expert commenting on the new study. The report shows just how far one form of the staph germ has spread beyond its traditional hospital setting.

The overall incidence rate was about 32 invasive infections per 100,000 people. That's an "astounding" figure, said an editorial in Wednesday's Journal of the American Medical Association, which published the study.

Most drug-resistant staph cases are mild skin infections. But this study focused on invasive infections -- those that enter the bloodstream or destroy flesh and can turn deadly.

Researchers found that only about one-quarter involved hospitalized patients. However, more than half were in the health care system -- people who had recently had surgery or were on kidney dialysis, for example. Open wounds and exposure to medical equipment are major ways the bug spreads.

In recent years, the resistant germ has become more common in hospitals and it has been spreading through prisons, gyms and locker rooms, and in poor urban neighborhoods.

The new study offers the broadest look yet at the pervasiveness of the most severe infections caused by the bug, called methicillin-resistant Staphylococcus aureus, or MRSA. These bacteria can be carried by healthy people, living on their skin or in their noses. Video Watch Dr. Sanjay Gupta explain MRSA threat »

An invasive form of the disease is being blamed for the death Monday of a 17-year-old Virginia high school senior. Doctors said the germ had spread to his kidneys, liver, lungs and muscles around his heart.

Good hygiene is the best way to avoid infection from a potentially dangerous drug-resistant germ called methicillin-resistant Staphylococcus aureus, or MRSA.

This staph infection sometimes first appears on the skin as a red, swollen pimple or boil that may be painful or have pus. It can be spread by close skin-to skin contact or by touching surfaces contaminated with the germ.

The researchers' estimates are extrapolated from 2005 surveillance data from nine mostly urban regions considered representative of the country. There were 5,287 invasive infections reported that year in people living in those regions, which would translate to an estimated 94,360 cases nationally, the researchers said.

Most cases were life-threatening bloodstream infections. However, about 10 percent involved so-called flesh-eating disease, according to the study led by researchers at the federal Centers for Disease Control and Prevention.

There were 988 reported deaths among infected people in the study, for a rate of 6.3 per 100,000. That would translate to 18,650 deaths...

Chlamydia, the sexually transmitted infection (STI) carried by one in ten sexually-active young British adults can make men infertile by damaging the quality of their sperm, new research has shown.

While the condition, which usually passes undetected, has long been known to threaten female fertility, scientists from Spain and Mexico have now established that it presents similar risks for men.

Men with chlamydia have three times the normal number of sperm with genetic damage that can impair their ability to father children, the study found.

Antibiotic treatment can reverse the effect, and preliminary results indicate that it may dramatically enhance pregnancy rates when couples are trying for a baby. But the discovery suggests that the prevalence of the disease may be contributing to infertility across an entire generation of young adults.

Britain's national screening programme has found that 10.2 per cent of both men and women aged 18 to 25 carry the bacteria, and studies have found infection rates as high as 5 per cent among older groups with a lower risk.

The findings indicate that untreated chlamydia infections should not just concern women, who have long been warned that the condition can make them infertile, but has direct consequences for men.

This will create fresh pressure for chlamydia screening to be more effectively targeted at young men, who rarely seek testing and...

A rare tropical fungus has found its way into Washington state infecting at least four residents, two of whom have died, a health official said.

Cryptococcus gattii, invisible to the naked eye and found mostly in trees and soil, has infected at least four residents this year, two of them fatally, county health officer Greg Stern said.

The fungus first appeared in British Columbia six years ago and is believed to have crossed the border into Washington's Whatcom County.

"I'm concerned about the emergence of a new disease, but it still is relatively rare and that part is reassuring," Stern said. "Even on Vancouver Island and the B.C. mainland, where the assumption would be fairly significant exposure to the spores, very few people get sick."

Scientists haven't found a way to reduce the risk of getting the disease, he noted.

Cryptococcus gattii is sometimes resistant to medication that is used to treat a more common, related fungus, Cryptococcus neoformans, which typically infects people whose immune systems are impaired.

Courtney Blomeen, 16, of Blaine, the county's fourth known case this year, first thought she had a severely strained shoulder muscle and a chest cold last month, but a computer imaging scan revealed otherwise.

"I couldn't breathe, it scared me so much," her father, Greg Blomeen, told The Bellingham Herald. "Her left lung had completely blocked off. There were marble-sized nodules that were showing bright white. It was so bad that the one lung was at collapse."

The next day the teenager and her parents had to stay in a special room at Children's Hospital in Seattle until doctors confirmed that the lung problem was not contagious.

Back at her mother's house in Blaine, she still finds breathing difficult at times and expects to be on anti-fungal medication for about a year but is glad to be getting better.

"There's not much air space in there," she said. "Other than that, it's not that bad. I can walk now."

When Cryptococcus gattii infections usually begin in the lungs but can also spread to the brain and develop into deadly meningitis.

The fungus was believed to be largely confined to the tropics until 2001, when it was first diagnosed on Vancouver Island. Since then it has been found in dogs, cats, horses and porpoises, as well as humans, and has been blamed for the death of eight people in British Columbia.

Spores of the fungus have been found on trees and in soil, air and water throughout eastern Vancouver Island, mainland areas around Vancouver and more recently on a fence post just south of the border, health officials said.

No parks or other areas in British Columbia have been closed to the public because of the fungus....

The young American Army medic would not stop bleeding.

He had been put on a powerful regimen of antibiotics by doctors aboard the hospital ship Comfort in the Persian Gulf. But something was wrong.

He was in shock and bleeding from small pricks where nurses had placed intravenous lines. Red, swollen tissue from an active bacterial infection was expanding around his abdominal wound. His immune system was in overdrive.

How odd, thought Dr. Kyle Petersen, an infectious disease specialist. He knew of one injured Iraqi man with similar symptoms and a few days later encountered an Iraqi teenager with gunshot wounds in the same condition.

Within a few days, blood tests confirmed that the medic and the two wounded Iraqis were infected with an unusual bacterium, Acinetobacter baumannii.

This particular strain had a deadly twist. It was resistant to a dozen antibiotics. The medic survived, but by the time Petersen connected the dots, the two Iraqi patients were dead.

It was April 2003, early in the Iraq war - and 41/2 years later, scientists still are struggling to understand the medical mystery.

The three cases aboard the Comfort were the first of a stubborn outbreak that has spread to at least five other American military hospitals, including Walter Reed Army Medical Center in Washington and the Army's Landstuhl Regional Medical Center in Germany.

Hundreds of patients - the military says it has not tabulated how many - have been infected with the bacterium in their bloodstream, cerebrospinal fluid, bones or lungs. Many of them were troops wounded in Iraq or Afghanistan; others have been civilians infected after stays in military hospitals.

At least 27 people have died in military hospitals with Acinetobacter infections since 2003, although doctors are uncertain how many of the deaths actually were caused by the bacteria.

The rise in infections has been dramatic. In 2001 and 2002, Acinetobacter infections made up about 2 percent of admissions at the specialized burn unit at Brooke Army Medical Center in Texas. In 2003, the rate jumped to 6 percent, and then to 12 percent by 2005. Other military hospitals have reported similar levels.

In the early days of the war, there were so many infections in an intensive care unit on the Comfort that a nurse posted a sign: "Acinetobacter Alley." In two months, the bacterium was found in 44 of the 211 patients wounded in battle....

Craig Venter, the controversial DNA researcher involved in the race to decipher the human genetic code, has built a synthetic chromosome out of laboratory chemicals and is poised to announce the creation of the first new artificial life form on Earth.

The announcement, which is expected within weeks and could come as early as Monday at the annual meeting of his scientific institute in San Diego, California, will herald a giant leap forward in the development of designer genomes. It is certain to provoke heated debate about the ethics of creating new species and could unlock the door to new energy sources and techniques to combat global warming.

Mr Venter told the Guardian he thought this landmark would be "a very important philosophical step in the history of our species. We are going from reading our genetic code to the ability to write it. That gives us the hypothetical ability to do things never contemplated before".

The Guardian can reveal that a team of 20 top scientists assembled by Mr Venter, led by the Nobel laureate Hamilton Smith, has already constructed a synthetic chromosome, a feat of virtuoso bio-engineering never previously achieved. Using lab-made chemicals, they have painstakingly stitched together a chromosome that is 381 genes long and contains 580,000 base pairs of genetic code.

The DNA sequence is based on the bacterium Mycoplasma genitalium which the team pared down to the bare essentials needed to support life, removing a fifth of its genetic make-up. The wholly synthetically reconstructed chromosome, which the team have christened Mycoplasma laboratorium, has been watermarked with inks for easy recognition.

It is then transplanted into a living bacterial cell and in the final stage of the process it is expected to take control of the cell and in effect become a new life form. The team of scientists has already successfully transplanted the genome of one type of bacterium into the cell of another, effectively changing the cell's species. Mr Venter said he was "100% confident" the same technique would work for the artificially created chromosome.

The new life form will depend for its ability to replicate itself and metabolise on the molecular machinery of the cell into which it has been injected, and in that sense it will not be a wholly synthetic life form. However, its DNA will be artificial, and it is the DNA that controls the cell and is credited with being the building block of life...