Super laws can squash superbugs
Since antibiotics began flooding the market in the late 1940s, drug-resistant bacteria has outpaced the development of stronger drugs with an ease that has turned scientists catatonic with despair. Sanchita Sharma writes.health and fitness Updated: Feb 19, 2012 00:41 IST
You would think Sweden's near permafrost weather would wipe off the mightiest of superbugs, but it doesn't. And just as adeptly they thrive in temperatures running well below 00 celsius for weeks on end, killer bacteria are side-stepping antibiotics, our most potent and only weapon against them.
Since antibiotics began flooding the market in the late 1940s, drug-resistant bacteria has outpaced the development of stronger drugs with an ease that has turned scientists catatonic with despair. After peaking in the 1960s, antibiotic development dramatically declined, with only two new drugs - Linezolid (oxazolidinone) and Daptomycin (lipopeptide) - hitting the market in 2000 and 2003.
The problem is that bacteria can evolve really fast - at times in a matter of hours - to sidestep the action of a new antibiotic. This means that unless we continue to find newer ways to target bacteria to stay a few steps ahead of bacterial evolution, we will continue to be infected with superbugs such as the New Delhi metallo-beta-lactamase, so named because of its origin being traced to the subcontinent. The NDM-1 has an enzyme which makes it resistant to all existing antibiotics, including carbapenem, is used to treat other superbugs such as methicillin-resistant Staphyloccus aureus (MRSA).
One way to stop bacterial resistance is to dramatically reduce overuse and misuse. Ninety to 95% of all infections are viral or low-acuity bacterial infections such as colds, influenza, ear infections or sinus infections that need no antibiotics. Prescription is needed in only one in 10 cases of bronchitis and sore throat. Apart from over-prescription by doctors given incentives by pharma companies to push their drugs, resistance is also caused by pills being taken without prescription to save on consultation fee, or stopping treatment mid-course.
A less known cause of rising resistance is "subtherapeutic" use, or use for anything other than illness. Much like the seizure-causing oxytocin hormone added to vegetables to make them bigger, antibiotics are widely added to livestock feed as growth promoters to increase weight and decrease illness and death in animals.
Among EU member countries, Sweden has among the lowest antibiotic consumption in livestock use, shows sales statistics from the European Medicines Agency, largely because it banned the use of antibiotic as growth promoter in 1986, said Dr Otto Cars, chair of ReAct (Action on antibiotic resistance) and Strama (Swedish strategic programme against antibiotic resistance) informed me. Since the ban, antibiotics use dropped by over 75%, and in Denmark, which introduced a similar ban two years later, use dropped by over 30,000 kg in one year.
Drug-resistant bacteria are the leading cause of nosocomial infection, better known as hospital-acquired infection that causes death due to pneumonia or infections of the urinary tract, bloodstream or other vital organs. Even countries perceived to be far more sterile than India are battling the superbug. In the US alone, superbugs cause 1.7 million infections in hospitals, causing 99,000 deaths each year, estimates the Center for Disease Control. In Europe, hospital-infection is the fourth leading cause of death.
Last month, the US banned use of the cephalosporin class of antimicrobial drugs in cattle, swine, chickens and turkeys to preserve the effectiveness of drugs for treating humans by reducing the risk of cephalosporin-resistance in bacteria.
India needs to enforce similar regulation to stop misuse or it will continue to have more superbugs named after it. As Dr Cars puts it rather neatly, the root causes of antibiotic resistance, as well as effective responses, are social, political and ecological as much as scientific and technical.
First Published: Feb 19, 2012 00:40 IST