Ed Corboy, a doctor-turned-lawyer in Chicago, US, was at the end of his wits. His mother, Joan Corboy, 77, was not responding to anti-diarrheal drugs after she was successfully treated with antibiotics for ulcers on her right foot. Doctors diagnosed her with the bacteria, Clostridium difficile. But the antibiotic regimen failed to kill the germs.
"She could hardly get to a commode without two people helping her," he said, adding, "I got in touch with an expert at Center for Disease Control and Prevention (CDC)." The CDC expert advised Corboy to consult with two doctors in Chicago who specialized in cases related to the bacteria. An increased dosage of the drug vencomycin finally made his mother recover from the throes of illness. He has a word of caution for everyone, who is not getting well, "If your problem persists, ask your doctor whether it is an antibiotic-resistant microbe causing it."
Antibiotic-resistant microbes are a cause of extended hospital stays and an increase in health care costs across the globe; they cost $10 billion each year in the US alone. Over 700,000 people are affected by hospital-acquired infections each year, and 75,000 died of it in 2011, the CDC said. The most potent among the microbes is the antibiotic-resistant bacteria Staphylococcus Aureus. One out of 20 patients treated in the US for this antibiotic-resistant bacteria died, according to the Agency for Healthcare Research and Quality.
This bacterium causes skin infections and respiratory diseases. It kills more Americans than AIDS, Parkinsons, emphysema and homicide put together, an Infectious Disease Society of America study found. Anti-microbial resistance not only threatens to up healthcare costs, it would also make antibiotics ineffective.
A multi-drug form of antibiotic-resistant microbe was found in 48 percent patient intensive care rooms under study over a four-month period by Dr. Keri Ann Thom, assistant professor in epidemiology at University of Maryland. "Surfaces frequently touched by patients and health-care workers are most often the source of such infections," says Ann Thom.
Frequent use of antibiotics often leads to bacteria figuring a way to develop resistance to the drugs. "They can alter normal housekeeping genes that have minimal function to counteract the functions of antibiotics," says Satish Nair, associate professor of biochemistry at the University of Illinois at Urbana-Champaign.
There is an amazing number of bacteria in any given infection, which amplifies the mutational power of the organism to create new resistance mechanisms, said Dr. Robert Palinkas, director, McKinley Health Center at the University of Illinois in Urbana-Champaign. "We move really sick people into a common building for their care, where they come in contact, either directly or indirectly, with the bacteria of other sick folks," he said of hospitals. This fosters movement of resistant bacteria from one person to another.
Many hospitals are taking steps to minimize the number of patients and healthcare providers getting infected with such microbes. "I'm afraid I don't have the number of patients who are seen with multi-drug resistant organisms, but that number is not zero," said Daniel Bronson Lowe, senior infection preventionist at Carle Foundation Hospital in Urbana-Champaign. The multi-drug resistant organisms seen most often are bacteria resistant to the antibiotic methicillin. Treatment of patients infected with such microbes depends on the severity of the infection, he said.
To start with, washing hands is an effective way to keep such infections at bay. Isolation precautions include using personal protective equipment — gloves, gowns, masks. Keeping patients in private rooms, and putting patients in rooms with special airflow, is also effective. "We also try to limit the equipment that goes into and out of isolation rooms so that there is less chance of the organisms being transported around the facility," Lowe said. The equipments used in hospitals have to be disinfected to prevent the spread of such microbes. Most disinfection products will kill multi-drug resistant organisms without any difficulty. Where doctors and staff have to be particularly careful is with the bacteria C Difficile, he said.
Though technically not a multi-drug resistant organism, this bacterium is causing a great deal of healthcare-associated mortality throughout the US. Its spores are inactivated by very few products, including bleach. When patients are first discovered having multi-drug resistant microbes their medical records are flagged. On subsequent admission they are placed on contact precautions, which include donning gown and gloves for contact with the patient and his environment. Patient room cleaning is also done. Reducing overall infections is another way to reduce transmission. "We have many ways to do that, such as preventing central line infection and catheter-associated urinary tract and ventilator-associated pneumonia and surgical site infection," Lowe said.
No specific data on the cost of antibiotic resistance exists in terms of extended hospital stay and expenditure incurred, said Dr. Arjun Srinivasan, associate director for healthcare associated infection prevention programs at the CDC.
Scientists across the globe are researching a new strategy known as "anti-virulence" to combat such microbes. "Most antibiotic-resistant microbes have a chemical, streptolysin, which is primarily responsible for causing disease. The main aim of this novel approach is to destroy the disease-causing chemical in the organism, rendering it harmless yet alive," said Abhishek Sharma, a post-doctoral researcher in the School of Chemical Sciences at the University of Illinois. Researchers hope it will be effective in reducing the dependence on drugs to kill the microbes.
Until then, however, judicious use of antibiotics is one of the best ways to prevent getting infected with antibiotic-resistant microbes. Antibiotic resistance also develops as a result of societal pressure and overuse of antibiotics in farm animals and food production, said Ann Thom.
People can prevent the development of resistance by understanding when antibiotics work: they are only effective against bacterial infections and do not work against viral infections such as influenza and common colds, she said. Only take antibiotics prescribed by a doctor, she said.