February 20, 2009
We spoke to Dr. Helene Boucher, director of the Infectious Diseases Fellowship Program at Tufts Medical Center and lead author for the Infectious Diseases Society of America report on gram-negative bacteria. Here are some notes:
CNN: Give us an overview.
Dr. Helene Boucher: The big reason that we wrote report at this time is to make a point and try to get some interest in a big problem that we're facing: infections due to gram-negative organisms. MRSA, which most everyone knows about now, is gram-positive. We know about MRSA, but there has been an increase in infections caused by gram-negative bacteria, and they are resistant to many, or sometimes all, drugs. Another point: There has been a decrease in investment in antibiotics to treat these infections, for which we have limited or no treatment options. There is no antibiotic drug in Phase II or beyond, in patients.
CNN: Where is this cropping up? Mostly in hospitals?
Boucher: We see these infections a lot in hospital settings. Acinetobacter is seen in servicemen, Iraq war vets. Vets often have wound infections. There is difficulty with treating them, deformities that they leave. Some people at risk: ICU patients; very young or old patients; people with a lot of other health problems who are already immunocompromised. Some patients who have had a transplant, a burn or some other thing happen to them. We also worry about infection control problems. We saw this in Brooklyn. A lot of infections spread.
CNN: How does this spread in hospitals? Same way as with MRSA?
Boucher: All infections are thus far in hospitals. Most commonly, it spreads from not washing hands when going between patients. We really emphasize hand hygiene. Sometimes doctors call for private rooms for patients who are infected.
CNN: Do you fear that this will become another MRSA? Or worse?
Boucher: It has borne out in Brooklyn, infection gone from rehab centers to nursing homes to hospitals. Patients move around faster: They go to rehab, go home, go to the dialysis center, etc. That's a lot to worry about, where these bugs tend to be moving. The concern is, this could be as bad as, if not worse than, MRSA. At least with MRSA, we have some drugs to treat it.
CNN: What would it take for this to become more like MRSA, to spread into the community?
Boucher: That's a hard question. It takes a bug being strong enough over time. It takes some change that makes it more transmissible. It takes a breakdown in infection control: not washing hands, not paying attention, etc. This bug gets a little "better" over time. With MRSA, it took football players who took whirlpools in same tub, sharing the same towels. Men having sex with men. If you put people factors and bug factors together, then you see the spread. It depends on how "fit" the bug is, how able it is to grow and replicate when gets resistant to antibiotics.
A lot of people are trying to understand this. Some people -- John Bartlett at Johns Hopkins is one scientist -- have predicted a linear increase over time in these infections. We can predict that in several years, we will get a lot worse off. We can't predict whether or when it would end up being something we see in healthy adults, kids, etc.
One thing we have seen is a number of urinary tract infections in women caused by one of these bad bugs; the key is that the women have never been in the hospital, not gotten antibiotics.
CNN: Why haven't we heard about this much until now?
Boucher: Depends on whom you ask: We infectious disease experts have been talking about it. War victims have gotten some press, but this is not a sexy story. The is not always a community interest, unless there's a famous patient/victim, like the Brazilian model.
CNN: The "double membrane" makes it harder to fight these infections; why? Why are they so tough to fight?
Boucher: There are difficult challenges to developing drugs for gram-negative infections. These infections produce a lot of toxins that make people sick fast. Basically, these gram-negative infections make enzymes that chew up antibiotics. Some make enzymes that chew up penicillin or chew up other antibiotics. So you don't have to get an antibiotic that fights one enzyme but multiple enzymes.
Now, these gram-negatives have become resistant to carbapenems; these are the "smartest" antibiotics. It's not likely we're going to find one drug that overcomes every enzyme; it will be more likely a variety of approaches and drugs.
CNN: Are antibiotic drugs hard to get into a clinical study?
Boucher: It's definitely harder than getting drugs for diabetes or obesity, something you take your whole life. Also, there are regulatory hurdles for people trying to make antibiotics. We're trying to make paths more clear for developing new antibiotics. We hope that encourages investment back in this area.
[The National Institutes of Health] this week signaled interest in sponsoring some studies in this area. The NIH hasn't traditionally been into antibiotic development, so that's promising. Government agencies and industry are banding together to get this done. I see that as good news.
CNN: Is this a big public health problem now or on the horizon?
Boucher: This is a public health problem now. The problem is here and now. Doctors have had people in their hospital succumb to these infections. Maybe there is one, and sometimes no, option for treatment.
CNN: Bottom line?
Boucher: We at IDSA advocate a three-pronged strategy for fighting these gram negative infections:
1) Infection control: prevent people from getting an infection in first place.
2) Prudent use of antibiotics: not overusing antibiotics.
3) Developing new antibiotics: generating interest at NIH, CDC, private industry. Get all key stakeholders more involved with developing effective antibiotics to stem infections.