What’s the difference between viruses and bacteria?
Bacteria: Single-celled microscopic organisms that are everywhere. They’re small enough for 1,000 in a line to fit across a pen cap; smaller than a human cell. The average person has 10 times more bacteria in and on their body than they have cells. Those bacteria are mostly beneficial, helping us digest food and fight other, potentially harmful microbes. A small subset of bacteria cause disease. Some can be tough to eliminate because they’ve evolved the ability to survive for years in a dormant state. The E. coli bacteria lives for about a day outside the body, but bacteria like C. difficile and Staphylococcus aureus can live for weeks or months by forming spores, and then reactivating in the right temperature and humidity.
Viruses are up to 1,000 times smaller than bacteria, and they aren’t really living organisms. They’re packets of genetic material that latch onto living cells and then use the cell’s internal machinery to make copies of themselves. Influenza, hepatitis, herpes, chicken pox, HIV and warts are all caused by viruses. They don’t usually live more than a few hours outside their host. The flu is an exception – it’s been shown to live a couple of days on plastic and metal. Regardless, antibiotics won’t do anything to stop viruses, and they may even hurt, by eliminating the flora that keep other microbes in check.
What is CRE? – CRE doesn’t represent one germ; it’s an acronym that refers to the antibiotic resistant strains of a group of gut-based bacteria, Enterobacteriaceae. They can become killers if they acquire a dangerous snippet of genetic code that disables the last-resort group of antibiotics called carbapenems. The drugs imipenem, meropenem, Invanz and Azactam are carbapenems. Hospitals usually restrict their use, saving them for only serious infections.
Who is at risk?
Patients in extended-stay hospitals, intensive care units and nursing homes as well as hospitalized diabetics. The more time spent in hospitals on antimicrobial drugs, the greater the risk.
People who need invasive devices. These devices — medication ports, urinary catheters and machines that help patients breathe — all can introduce germs into the body. Bed sores and other open wounds can also allow the germs to enter the bloodstream.
Patients on ventilators – breathing machines – at long-term acute care hospitals are at increased risk of acquiring CRE by a factor of seven. The odds of becoming colonized or infected with CRE while hospitalized increase by 4 percent per day on antimicrobial drugs.
How dangerous is CRE? – The danger depends on whether the patient is colonized or infected. If a patient is colonized, he has about a one in 10 chance of suffering infection. If infected, his chances depend on where his infection is and how healthy he was before he got sick. Sepsis, a bloodstream infection, is the most dangerous form of CRE infection. Sepsis has a mortality rate of 15 to 20 percent in the best of cases. If that sepsis is caused by CRE, the mortality rate jumps to around 50 percent. Urinary tract infections with CRE have a lower mortality rate than blood infections. Infection with CRE increases the risk of death from all causes.
Why is this happening? – Blame natural selection. Every time antibiotics are used, resistant bacteria survive. Over the course of decades, old antibiotics lose effectiveness and new ones must be found. Bacteria are constantly adapting to threats all around them, both natural and man-made. Antimicrobial drugs are just one more threat they face.
During the past 70 years, scientists have done a good job of staying one step ahead, continually discovering new classes of drugs to kill the bacteria. But it appears the end of that era may be upon us. The pipeline of potential new antibiotics is nearly empty, even as the germs are gaining. Economics are part of the problem. Regulatory changes have increased the costs of bringing drugs to market. A new antibiotic costs about $1 billion to develop. Drug companies typically lose money on them, because their use is limited. But there’s also evidence that scientists may have already found all the types of antibiotics that exist in nature.
When did CRE emerge, and is there still time to act?
In 2001, a study looking at antimicrobial resistance in hospital ICUs discovered the earliest sample of a CRE germ, in a North Carolina lab. It was from an old sample taken from a patient in 1996. It was next found concentrated in parts of New York and New Jersey. Today, it’s in nearly every state, and in many countries across the globe, including Israel, France, Greece, Turkey, India and Pakistan.
What’s being done to try to contain it?
Although the CDC wants carbapenem resistance to become a reportable condition – meaning every infected patient should be reported to state health officials — the CDC lacks the power to do anything more than suggest. Starting this month, Florida is requiring laboratories report multi-drug resistant germs. Once the reports start arriving, they’ll have a much better handle on the extent of the threat.
The CDC is encouraging states to create regional collaboratives, to get hospitals and nursing homes in areas at risk to work together to inform each other about multi-drug resistant outbreaks. But when Palm Beach County and Broward hospitals were asked to form such a collaborative, they declined, saying they were already overburdened with data requests.
Best practices from the CDC
1. Rigorous hand-washing
2. Contact precautions, such as using gowns and gloves, for every encounter with patients who test positive. Pre-emptive precautions are recommended for patients transferred from high-risk settings like long-term acute-care hospitals.
3. Isolation of infected patients, with separate staff.
4. Education of all health personnel about CRE.
5. Minimal use of invasive devises like ports and catheters. Disposable devices for infected patients.
6. Screening of current and prior roommates of CRE-positive patients.
7. Notification of a patient’s CRE status if they’re being transferred.
8. Screening of high-risk patients for CRE on admission and periodically during their stay.
9. Bathing of patients in targeted wards daily with 2 percent clorhexidine, an antiseptic.
10. Minimal use of antimicrobial drugs and antibiotics.
11. Improved cleaning around high-touch areas of hospital rooms.