September 14, 2010
Superbug Found In 3 U.S. States, Global Response Needed
A new "superbug" from India that is resistant to every known antibiotic has sickened people in three states as it continues to spread throughout the globe, health officials said Monday.
The bacteria now poses a worldwide threat, warned experts attending the 50th annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), the world's largest gathering of infectious disease specialists.
"There is an urgent need, first, to put in place an international surveillance system over the coming months and, second, to test all the patients admitted to any given health system" wherever possible, said Patrice Nordmann of Bicetre Hospital in France.
"For the moment, we don't know how fast this phenomenon is spreading... it could take months or years, but what is certain is that it will spread," Nordmann told the AFP from the ICAAC conference in Boston, where 12,000 specialists were in attendance from September 12-14.
Measures have already been approved in France, and are being negotiated in Japan, Singapore and China, said Nordmann, a microbiology professor at South-Paris Medical School and head of Bicetre's department of bacteriology and virology.
"It's a bit like a time bomb," he warned, urging health authorities to track the new superbug, which contains the gene "“ known as NDM-1 (New Delhi metallo-beta-lactamase 1) "“ believed responsible for the antibiotic resistance.
The bacteria and its variants appear to have originated in India, but were first detected in Britain in 2007.
A citizen of Belgium who had been hospitalized in Pakistan following an auto accident was the first known death related to an NDM-1 infection, the AFP reported.
The U.S. cases, along with two others in Canada, all involve people who had recently received medical care in India.
Last month, an article published in a British medical journal described scores of cases involving Britons who received medical procedures in India.
However, the total number of deaths from the infection is unknown since there is no central tracking of such cases.
So far, NDM-1 has primarily been found in bacteria that cause digestive or urinary infections.
Scientists have long feared an infectious-disease nightmare such as this "” a highly adaptable gene that incorporates itself into many types of common germs and confers widespread drug resistance.
"It's a great concern," because antibiotic resistance has been increasing, and few new antibiotics are in development, said Dr. M. Lindsay Grayson, director of infectious diseases at the University of Melbourne.
"It's just a matter of time" until the gene is transmitted more broadly person-to-person, he told The Associated Press (AP).
This year, the U.S. cases occurred in people from California, Massachusetts and Illinois, said Brandi Limbago, a lab chief with the U.S. Centers for Disease Control and Prevention (CDC).
Three types of bacteria were involved in the cases, and three different mechanisms allowed the gene become part of them.
"We want physicians to look for it," particularly in patients who have recently traveled to Pakistan or India, she added.
Limbago advises people not to add to the problem of drug resistance by pressuring doctors for antibiotics if they say they are not needed. Instead, use the ones that are prescribed properly, and try to avoid infections by thorough hand washing.
The gene is carried by bacteria that can spread hand-to-mouth, making good hygiene a critical component of preventing infections.
It's also why health officials are so concerned about where the threat is coming from, said Nordmann.
With 1.3 billion people, India is an overpopulated nation that overuses antibiotics and has widespread diarrheal disease. Many of its citizens are without clean water.
"The ingredients are there" for widespread transmission, Nordmann told AP.
"It's going to spread by plane all over the world."
The U.S. patients were not related. The case in California involved a woman who sought hospital care following a car accident in India. The Illinois case involved a man with pre-existing medical conditions and a urinary catheter. He is believed to have contracted an infection with the gene while traveling in India. The Massachusetts case involved a woman from India who had surgery and chemotherapy there before traveling to the United States.
According to lab tests, in all three cases the germs were not killed by the types of antibiotics typically used to treat drug-resistant infections, including "the last-resort class of antibiotics that physicians go to," Limbago said.
Although she did not know how the three patients were treated, all survived.
Physicians have tried treating some cases with combinations of antibiotics, hoping the approach would be more effective than individual antibiotics alone.
Some doctors have even turned to using polymyxins "” antibiotics used half a century ago that were unpopular because they can result in kidney damage.
The two Canadian cases, one in Alberta and one in British Columbia, were treated with a combination of antibiotics, said Dr. Johann Pitout of the University of Calgary in Alberta, Canada.
Both patients had medical emergencies while traveling in India, and developed urinary infections involving bacteria once they returned home to Canada, Pitout told AP.
The CDC advises any hospitals that find NDM-1 cases to medically isolate the patient, check the patient's close contacts for possible infection and look for possible additional infections in the hospital.
Any case "should raise an alarm," said Limbago.
Image Caption: Klebsiella pneumoniae, the bacterium in which NDM-1 was first identified. Credit: CDC
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