Multi-drug resistant Strep pneumo strain on the ri

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       Multi-drug resistant Strep pneumo strain on the rise in many parts of globe

  November 11, 2007 

Helen Branswell, Medical Reporter, THE CANADIAN PRESS

The Canadian Press, 2007

TORONTO - The strain of bacteria that recently sent a Toronto child to hospital with a hard-to-treat form of meningitis has become more prevalent and more drug resistant around the globe in recent years, experts say. 

And while some have questioned whether the increased threat of the Streptococcus pneumoniae serotype 19A was fuelled by the introduction of a children's vaccine to protect against pneumococcal infections, others say this bacterial bully's surge to prominence may be unrelated to vaccine use. 

Either way, infectious disease experts say 19A is a bad actor that bears watching. 

"19A can be a really, really bad bug. And it can get to be a very, very highly (drug) resistant bug," says Dr. Ron Dagan, director of the pediatric infectious disease unit of Soroka University Medical Center in Beer-Sheva, Israel. 

"It's definitely one of the six or seven most important (pneumococcal) serotypes in childhood infections. . . . It is becoming more important because of antibiotic resistance." 

"And it's a trend worldwide - it's not only in Canada and the U.S." 

The 19A serotype - one of more than 90 known strains of this type of bacteria - is not covered by the vaccine that defends children from the middle ear infections, sinusitis, pneumonia and occasionally bloodstream infections and meningitis that these common bacteria can trigger. 

The vaccine, sold under the brand name Prevnar by Wyeth Pharmaceuticals, protects against the seven strains of pneumococcus that were the leading causes of illness in children before the vaccine was introduced. Rates of infections caused by those strains have plummeted in places where the vaccine is in use. 

The disease causing potential of 19A was well known while the vaccine was being developed. But the vaccine protects against a strain known as 19F and it was thought that component might offer some defence against 19A as well. 

"We were really hoping there would be some cross-coverage of 19A and there doesn't seem to be," says Dr. Allison McGeer, an infectious diseases expert at Toronto's Mount Sinai Hospital. A new pneumococcal vaccine that would protect against 13 strains of the bacteria, including 19A, is in the final stages of clinical testing. 

The 19A strain packs two punches. It can cause severe disease and easily develops resistance to the antibiotics children are frequently given to combat ear infections and the like. 

Some variants - like the one that caused the Toronto meningitis case or others found to have caused ear infections in Rochester, N.Y. - are resistant to multiple classes of antibiotics approved for use in children, forcing doctors to turn to drugs normally reserved for adults to clear up the infections. 

Some clinicians have questioned whether the dramatic decline in illnesses caused by the Strep pneumo strains in the vaccine has created conditions which have allowed 19A to flourish. The theory is that by vanquishing the neighbourhood thugs, the vaccine has created an opening for new thugs, most notably 19A. 

Others say the jury on that is still out, noting some microbes wax and wane in undefined cycles, for reasons that aren't well understood. 

"There are clearly places in the world, for example in Israel and in Korea, where serotype 19A has increased either in the complete absence of vaccine - which is the case in Israel - or before vaccine was introduced and then has continued to increase very slowly after vaccine introduction," explains Dr. Matthew Moore, a pneumococcal expert with the national center for immunization and respiratory diseases at the U.S. Centers for Disease Control. 

In fact, Korean scientists reported at a scientific conference earlier this fall that infections caused by 19A in that country went from zero per cent in 1991-94 to eight per cent in 1995-96 - before Prevnar was brought to market. In the period from 2001-2006, 19A strains were responsible for between 20 to 26 per cent of diagnosed pneumococcal infections in Korea. 

At another conference, Dagan presented data from a study looking at Jewish and Bedouin children in southern Israel, where the vaccine is not used. The two groups of children rarely interact. 

The researchers found the percentage of pneumococcal infections caused by multi-drug resistant 19A bacteria spiked from 1999 to 2005 in the Bedouin children, but no corresponding rise was seen in the Jewish children. 

That suggests a multi-drug resistant variant of the 19A bacteria was introduced into Bedouin population, they said. 

"The point is very clear that we don't vaccinate at all and we see actually a very rapid takeover and increase of 19A otitis media in our region," Dagan says. Otitis media is the medical term for inner ear infection. 

"When you see that these more and more antibiotic resistant strains go up, you immediately understand . . . some clones or some strains that are resistant to antibiotics have been introduced into the community and are facilitated by antibiotic use." 

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July Members Profile Send Private Message Find Members Posts Add to Buddy List Valued Member Joined: May 24 2006 Status: Offline Points: 1660	Post Options Post Reply Quote July Report Post Thanks(0) Quote Reply Topic: Multi-drug resistant Strep pneumo strain on the ri Posted: November 12 2007 at 1:36pm
	Multi-drug resistant Strep pneumo strain on the rise in many parts of globe November 11, 2007 Helen Branswell, Medical Reporter, THE CANADIAN PRESS The Canadian Press, 2007 TORONTO - The strain of bacteria that recently sent a Toronto child to hospital with a hard-to-treat form of meningitis has become more prevalent and more drug resistant around the globe in recent years, experts say. And while some have questioned whether the increased threat of the Streptococcus pneumoniae serotype 19A was fuelled by the introduction of a children's vaccine to protect against pneumococcal infections, others say this bacterial bully's surge to prominence may be unrelated to vaccine use. Either way, infectious disease experts say 19A is a bad actor that bears watching. "19A can be a really, really bad bug. And it can get to be a very, very highly (drug) resistant bug," says Dr. Ron Dagan, director of the pediatric infectious disease unit of Soroka University Medical Center in Beer-Sheva, Israel. "It's definitely one of the six or seven most important (pneumococcal) serotypes in childhood infections. . . . It is becoming more important because of antibiotic resistance." "And it's a trend worldwide - it's not only in Canada and the U.S." The 19A serotype - one of more than 90 known strains of this type of bacteria - is not covered by the vaccine that defends children from the middle ear infections, sinusitis, pneumonia and occasionally bloodstream infections and meningitis that these common bacteria can trigger. The vaccine, sold under the brand name Prevnar by Wyeth Pharmaceuticals, protects against the seven strains of pneumococcus that were the leading causes of illness in children before the vaccine was introduced. Rates of infections caused by those strains have plummeted in places where the vaccine is in use. The disease causing potential of 19A was well known while the vaccine was being developed. But the vaccine protects against a strain known as 19F and it was thought that component might offer some defence against 19A as well. "We were really hoping there would be some cross-coverage of 19A and there doesn't seem to be," says Dr. Allison McGeer, an infectious diseases expert at Toronto's Mount Sinai Hospital. A new pneumococcal vaccine that would protect against 13 strains of the bacteria, including 19A, is in the final stages of clinical testing. The 19A strain packs two punches. It can cause severe disease and easily develops resistance to the antibiotics children are frequently given to combat ear infections and the like. Some variants - like the one that caused the Toronto meningitis case or others found to have caused ear infections in Rochester, N.Y. - are resistant to multiple classes of antibiotics approved for use in children, forcing doctors to turn to drugs normally reserved for adults to clear up the infections. Some clinicians have questioned whether the dramatic decline in illnesses caused by the Strep pneumo strains in the vaccine has created conditions which have allowed 19A to flourish. The theory is that by vanquishing the neighbourhood thugs, the vaccine has created an opening for new thugs, most notably 19A. Others say the jury on that is still out, noting some microbes wax and wane in undefined cycles, for reasons that aren't well understood. "There are clearly places in the world, for example in Israel and in Korea, where serotype 19A has increased either in the complete absence of vaccine - which is the case in Israel - or before vaccine was introduced and then has continued to increase very slowly after vaccine introduction," explains Dr. Matthew Moore, a pneumococcal expert with the national center for immunization and respiratory diseases at the U.S. Centers for Disease Control. In fact, Korean scientists reported at a scientific conference earlier this fall that infections caused by 19A in that country went from zero per cent in 1991-94 to eight per cent in 1995-96 - before Prevnar was brought to market. In the period from 2001-2006, 19A strains were responsible for between 20 to 26 per cent of diagnosed pneumococcal infections in Korea. At another conference, Dagan presented data from a study looking at Jewish and Bedouin children in southern Israel, where the vaccine is not used. The two groups of children rarely interact. The researchers found the percentage of pneumococcal infections caused by multi-drug resistant 19A bacteria spiked from 1999 to 2005 in the Bedouin children, but no corresponding rise was seen in the Jewish children. That suggests a multi-drug resistant variant of the 19A bacteria was introduced into Bedouin population, they said. "The point is very clear that we don't vaccinate at all and we see actually a very rapid takeover and increase of 19A otitis media in our region," Dagan says. Otitis media is the medical term for inner ear infection. "When you see that these more and more antibiotic resistant strains go up, you immediately understand . . . some clones or some strains that are resistant to antibiotics have been introduced into the community and are facilitated by antibiotic use."

July Members Profile Send Private Message Find Members Posts Add to Buddy List Valued Member Joined: May 24 2006 Status: Offline Points: 1660	Post Options Post Reply Quote July Report Post Thanks(0) Quote Reply Posted: November 12 2007 at 1:39pm
	Ontario to issue 'superbug' alert to doctors Updated Fri. Nov. 9 2007 9:20 AM ET CTV.ca News Staff Ontario's medical officer of health will be putting out an official alert to the province's doctors, notifying them about what appears to be Canada's first case of a multi-drug resistant meningitis, CTV News has learned. The alert will be issued as concern grows over the condition of a Toronto toddler being treated for meningitis caused by a new sub-strain of Streptococcus pneumoniae 19A. It's an emerging antibiotic-resistant "superbug" that has caused dozens of ear infections in Massachusetts and New York State -- prompting the U.S. Centers for Disease Control and Prevention to start tracking the new strain. Doctors suspect this super-strain is circulating in Ontario, and perhaps other parts of Canada, which is why they want to track it and alert other physicians to watch for it. The alert isn't designed to alarm, rather to inform doctors to keep an eye out for cases such as ear infections that don't clear up with the usual antibiotics. "We'll be notifying the other public health agencies in Canada and we'll be notifying them that we have this in Ontario," Dr. David Williams, Ontario's chief medical officer of health, told CTV News. The unidentified toddler has been receiving care at the Hospital for Sick Children in Toronto for more than two weeks. Doctors say it took them less than 48 hours after admission to figure out that the child had somehow picked up the newly identified strain of 19A. The child had been treated in the intensive care unit but is now in a ward room, continuing to battle the infection, hospital officials say. The child is being treated with antibiotics normally reserved for adults, after a litany of antibiotics for children proved ineffective. Hospital officials stress that the otherwise healthy child acquired the infection in the community -- not in hospital. Dr. Williams says it's still not known how the case emerged, since it appears the infected toddler had not traveled out of province before becoming ill. After trying numerous antibiotics approved for children, doctors eventually turned to the adult-approved drugs levofloxicin, vancomycin, telithromycin and rifampin, all of which appear to be effectively treating the illness. But the child is still quite ill, says SickKids official Dr. Upton Allen, and treatment is continuing. S. pneumonia is not new in Canada. It causes hundreds of chest and throat infections and ear infections each year. In rare cases, it triggers pneumonia and meningitis, illnesses that are usually easily treated with antibiotics. The 19A strain is not new either. But doctors say this new subtype of 19A can't be killed off with any of the antibiotics approved for use in children. "The big issue with this particular strain is that it's multi-drug resistant," Dr. Susan Poutanen, an infectious disease consultant at Toronto's Mount Sinai Hospital, told CTV Newsnet. "It doesn't necessarily look like it's any more aggressive than other Streptococcus pneumoniae family members, but it's certainly more resistant and difficult to treat." Dr. Michael Pichichero, a professor of microbiology, immunology and pediatrics at the University of Rochester Medical Center, was the first to identify the new 19A super-strain while he was treating children whose ear infections wouldn't clear up. In October, he published a report in the Journal of the American Medical Association, describing his experience with the superbug. He tried 18 antibiotics approved in the U.S. for children and found that the only drug that worked was levofloxacin (also called Levaquin). For one child, the cure came too late; the infection led to permanent hearing loss. Pichichero's team believes the new sub-strain was most likely created by a combination of the superbug's ability to evolve quickly and the over-prescribing of antibiotics, which has led to antibiotic resistance. 19A not covered by Prevnar The child being treated at SickKids had received all the vaccinations recommended for children, including Prevnar, which offers protection against seven strains of S. pneumoniae. Since the introduction of Prevnar in 2000, the incidence of pneumonia and meningitis caused by pneumococcus has fallen by at least 69 per cent. As well, difficult-to-treat ear infections have been reduced by 24 per cent. But Prevnar does not include the 19A strain, nor this new 19A sub-strain, and offers no protection against it. The makers of Prevnar are reportedly aware that the vaccine needs to include 19A and are reformulating their vaccine. Other vaccine makers are working on other formulations that are still being tested. But it will take two years for a new vaccine to be approved and placed on the market. In the meantime, doctors are being advised to be aware of this new drug-resistant strain of 19A, and to take action if a patient has a pneumococcal infection that isn't resolving -- such as an ear infection that defies treatment. What parents should know Infectious disease expert Dr. Neil Rau told CTV's Canada AM Thursday that, for now, he is not concerned about this new superbug, since this appears to be the first case of an extremely drug-resistant strain causing such a serious infection. But he will watching to see what develops. "The strain 19A in and of itself is a concern because it's not covered by the vaccine, and if it's really resistant to antibiotics, as this particular clone is... and if we have a lot of that around, we have a bigger concern," he said. Dr. Allen says it's important that doctors and health officials closely monitor this bug. "If one doesn't have an appropriate monitoring system... one could find that the strains that are eliminated by the (Prevnar) vaccine are basically eliminated and are quietly replaced by other strains that can cause severe disease." Dr. Poutanen says ear infections in children are quite prevalent, but it's when the symptoms persist that there is cause for concern. "Often what will happen is symptoms will go away by themselves because it was a viral infection and the body takes care of it," Putanen told Newsnet. "It's only if you're given an antibiotic prescription and you're following it properly, and if those symptoms continue to persist, that you'd have to worry you might have this particular strain." With a report by CTV medical specialist Avis Favaro and producer Elizabeth St. Philip