08 November 2007

Rumors of the blog's death are only slightly exaggerated

Yes, I vanished. Yes, I had a good reason: For the past few months, I've been neck-deep and sinking into a massive project for the infectious-disease website CIDRAP News, examining the search for a vaccine against pandemic influenza. Very short version of the many conclusions: Let's hope the pandemic takes a long time to arrive, because we are nowhere near ready, and the obstacles are both formidable and largely of our own making.

The entire project ran to seven installments. Read the first installment here. At the bottom, you'll find links to the other installments, and to the more-than-100 cite bibliography. The series has been well-received in the flu-blog world:
Plus, a Very Important National Magazine has been in touch to, umm, suggest that it gave them some ideas.

Meanwhile, while I was away, there was a ton of news on the MRSA front. We'll be taking a look at some recent developments in the next few days.

12 June 2007

Yes, it is everywhere

Via the journal Emerging Infectious Diseases, a report from a multi-country European team that surveyed CA-MRSA isolates from around the world to determine their ability to produce Panton-Valentine leukocidin, the potent toxin blamed for CA-MRSA's unique ability to cause eruptions on healthy-appearing skin.

Deep-seated infections due to PVL-positive S. aureus can be extremely severe. For example, necrotizing pneumonia carries a mortality rate close to 75%.

Research published in 2003 found that some clones of CA-MRSA were "continent-specific," confined to some extent to particular locations or countries. That appears no longer to be the case.

The ST1 clone USA400 is now detected in Europe and Asia. Some PVL-positive clones, such as ST1 and ST30, can now be considered pandemic, as they are detected in America, Europe, and Asia. Second, on a given continent, PVL-positive CA-MRSA have spread from country to country. For instance, in Europe, PVL-positive CA-MRSA were recently detected in Slovenia, Romania, and Croatia. Third, new PVL-positive CA-MRSA clones are emerging in strains with different genetic backgrounds. While most of the clones described in 2003 by Vandenesch et al. (4) had an agr3 background, the newly described clones are agr1 or agr2. Fourth, PVL-positive CA-MRSA, which were initially susceptible to most antistaphylococcal antimicrobial agents, have acquired new antimicrobial resistance determinants, to gentamicin and ofloxacin, for instance.
The isolates were gathered between 1999 and 2005 and sent to the French National Reference Center for Staphylococci, where the work for this paper was conducted. Yes, 2005. That gap between the obtaining of the isolates adn this analysis underlines one more time the critical need for comprehensive national and global suveillance to track MRSA's movement and evolution. If we don't know where it is, or how it is changing, how can we begin to talk about control?

Link to the full-text paper here.

29 May 2007

7-fold increase CA-MRSA in parts of Chicago

Via the Archives of Internal Medicine, a new study from Cook County Hospital and Rush University Medical Center in Chicago. Betwen 2000 and 2005, the incidence of CA-MRSA at the hospital and its neighborhood clinics increased 6.84 times. Notably, meth-sensitive staph (MSSA) did not decrease - this was a true addition, not a substitution of one strain for another. And 79% of the strains identified were USA300. Important clues to the rapid spread of the bug: Those infected were more likely to have been incarcerated more than once (carrying the bug from the known epicenters of jails and prisons back out into the community) or to live in public housing (possibly because of overcrowding as Chicago demolishes its old-style projects and moves the people who live there into its remaining public housing). The paper raises but can't answer the question of a synergy between those factors: People coming out of jail may be returning to households in public housing creating a bridge between a known epicenter and a population whose living conditions put them at greater risk.

Find the paper here.

10 May 2007

Got (wallaby) milk?

Researchers in Melbourne, Australia report finding a broad-spectrum antimicrobial compound in the milk of the Tammar wallaby, which lives on islands off Australia's south and west coasts. Like other young, wallabies are born with an undeveloped immune system yet seem notably resistant to infection; the compound, AGG01, may be why.
Using advanced computer systems, researchers at the state of Victoria's Department of Primary Industries in Melbourne, Australia, found more than 30 potential bug-fighting compounds in the milk of the Tammar Wallaby (Macropus eugenii). One compound, known as AGG01, was particularly potent said lead researcher and animal geneticist, Ben Cocks.

Some experiments showed small amounts of a synthetic form of the drug were able to kill all bacteria in 30 minutes. "We found in lab tests that AGG01 is very effective against multidrug-resistant gram negative bacteria, including those that are most difficult to treat," he said.
Next research step: Designing a wallaby-milking machine.

Full text: Anti-superbug weapon developed from wallaby milk

(Hat tip to Boing Boing.)

MRSA pneumonia deaths in children - on the rise?

On Wednesday afternoon, the Centers for Disease Control and Prevention pushed out an official Health Advisory (an electronic communication to state and local health departments) asking them to report any children in their area who have died from MRSA pneumonia. Deaths seem to be on the rise. Money quote:
Only one influenza and S. aureus co-infection was identified in 2004-2005, and 3 were identified in 2005-2006. Of the 16 children reported with S. aureus so far in 2006-2007, 11children had methicillin-resistant (MRSA) isolated from a sterile site (9) or sputum (2), and 5 had methicillin-susceptible S.aureus isolated from a sterile site (3) or sputum (2). ... Children with influenza and S. aureus co-infections were reported to be in good health before illness onset but progressed rapidly to severe illness. Influenza strains isolated from these children have not been different from common strains circulating in the community and the MRSA strains have been typical of those associated with MRSA skin infection outbreaks in the United States.
The possibility always exists that surveillance has changed - in other words, that more cases are being found because doctors are authorities are looking harder for them. Still, the rise is troubling.

Here's the full text: Influenza-Associated Pediatric Mortality and the Increase of Staphylococcus aureus co-infection

First post!

Hi all - I'm Maryn McKenna, independent health journalist, author, journalism teacher, now working on a new book about drug-resistant staph. I'm interested in hearing from researchers, victims and disease geeks; all tips, thoughts, leads and personal stories are welcome. For more about me, check my website in the blogroll, along with other important sites about public health and disease. Let's get started.