they are the enemy that infectious disease doctors dreaded for so long ' bacteria clever enough to outwit the drugs that saved millions of lives in the 20th century. Once, these rogue germs thrived only in hospitals, where they found easy targets ' critically ill patients with ravaged immune systems.
But then, with little warning, staph bacteria capable of evading penicillin and other front-line antibiotics started appearing on the skin of otherwise healthy children and adults.That was five years ago, and it was novel ' and frightening. Today, it has become common 'and even more frightening.
Across the United States, patients are turning up in emergency rooms and clinics with mysterious bumps easily mistaken for pimples or spider bites. Left untreated, or treated with antibiotics that won't do any good, the bump can sprout into a boil and from there the germs can migrate to the bloodstream, multiplying, and spawning life-threatening complications. 'Right now I'm awash in this stuff,' said Dr Gregory Harrington, a public-health authority in Battle Creek, Michigan, who treats four or five cases a week of infections caused by particularly vicious strains of bacteria. This is a disease outbreak cloaked in mystery. In different places, the bacteria strike different clusters of victims: in one city, it's professional football players; in another, it's prisoners; in a third, it's men who have sex with men. And contrary to what specialists initially believed, the bacteria aren't simply renegade germs that broke free from hospital wards. Instead, genetic testing has revealed that these are distinctly different strains, origin uncertain.
Maybe they changed their genetic clothing because of overexposure to drugs: when antibiotics are used too widely or when patients don't take all their pills, only the most susceptible germs get zapped, leaving the hardier, drug-resistant strains to flourish. Or maybe they pilfered genetic material from unrelated germs, giving them the ability to circumvent antibiotics. 'There is a lot we're still learning here,' said Dr Daniel B. Jernigan, a top disease tracker at the US Centers for Disease Control and Prevention. 'Are we concerned about it' Absolutely.' It's not just the germs they're worried about ' because at the same time the bacteria are getting smarter, the weapons to battle them are getting weaker.
In most cases, the dangerous staph can be thwarted with later-generation, costlier medications. But the fear is that the bacteria will ultimately evade even those drugs ' at a time when the pipeline of new antibiotics has slowed to a trickle. A study this year found that of 506 drugs coming close to market, only five were antibiotics. In the past six years, only two truly novel antibiotics have made it into medicine cabinets, including one, daptomycin, developed by Lexington biotech company Cubist Pharmaceuticals.
'There simply aren't enough new drugs in the pharmaceutical pipeline to keep pace with drug-resistant bacterial infections, so-called 'superbugs,' Dr John G. Bartlett, a leader of the Infectious Diseases Society of America, told two US Senate committees this month ' part of a campaign by specialists to spotlight the lack of new antibiotics. It is a problem born of both economics and science. Development of new antibiotics is challenging and expensive, and even if a drug does make it into pharmacies, it has far less earning potential than blockbuster drugs used daily to tame cholesterol or blood pressure ' in part because specialists will want to use new antibiotics sparingly to maintain their effectiveness.
'If you're going to restrict the use of the drug, how can the company achieve a successful return on investment' said Alan Goldhammer, associate vice-president for regulatory affairs for PhRMA, the leading pharmaceutical industry trade group. With little prospect of new drugs coming to the rescue, doctors are examining individual cases to understand how the bacterial infections start and how they can be stopped. They're looking for links. Football, it turns out, is one.
| Tough bugs: The bacteria have undergone genetic changes
Investigating an outbreak on a professional team, a CDC epidemiologist used the sort of play chart that's typically the preserve of coaches to show that players on the front line are most susceptible to infection. That's probably because linemen have so much crushing contact, resulting in scrapes and cuts that become entry points for bacteria. Young athletes also transfer the bacteria by sharing locker room razors.
For Nicholas Johnson,the first hint that something was wrong arrived one fall afternoon last year when he returned from football practice at his suburban Houston middle school. After tackling an eighth-grader, Nicholas wandered home complaining of a banged-up shoulder. A trip to the paediatrician a couple of days later showed he had a sprain. But, by the next day, his temperature had raged to 104.60 C and his chest ached. In the emergency room at Texas Children's Hospital, he was given a painkiller and a commonly prescribed antibiotic. 'I thought after a couple of days on the antibiotics, he would feel better,' said his mother, Janet. But, three days after the first trip to the ER, he was back ' and worse than before.
The doctors had dreadful news: An infection had taken root in Nicholas's blood, lungs and bones. They didn't know what it was ' or how to stop it, even as his blood pressure plummetted and doctors tethered him to a breathing machine. 'Our paediatrician came in and told us she didn't think he was going to make it,' Janet Johnson said. 'She kept saying, 'I'm sorry. I'm so sorry.' Following a desperate hunch, the doctors tested his blood for bacteria. They found methicillin-resistant Staphylococcus aureus, or MRSA. After intravenous doses of later-generation antibiotics ' drugs still effective against most MRSA strains ' the 12-year-old recovered. But it took more than five weeks in the hospital and a $425,000 charge to his family's health insurer. Cases like Nicholas' reportedly are showing up all over the country, particularly in the West and Sunbelt.
In northern California, patients stricken with the infection in San Francisco between 2000 and 2002 carried a different genetic variant of MRSA than patients treated at Stanford University's hospital 30 miles to the south. And they had distinctly different risk factors: the San Francisco patients were likely to have HIV or hepatitis, to have taken drugs intravenously, or to be homeless. The Stanford patients were more likely to have lived in nursing homes.
Nicholas, now 13 and back playing football, has a straightforward solution: 'Just stay clean.' 'I wash my hands a lot,' he said. 'And after practice, I take a shower. I didn't do that before.' (NYTNS)