It is well known that AIDS takes numerous lives every year. What is less well known is that drugresistant bacterial infections are becoming a similarly serious problem. A shocking new study has found that the number of deaths due to drugresistant Staphylococcus infections may soon exceed those caused by AIDS in the United States.
Staphylococcus bacteria are responsible for more than 90,000 infections and nearly 19,000 deaths annually in America, although it remains unclear if the bug is the direct cause of death in every case. A high-school student in Virginia, for example, died due to complications after an infection took over his heart, liver, and other organs. In its invasive form, the bug enters the bloodstream
or becomes a flesh-eating disease with often deadly results. The incidence rate is approximately 32 invasive cases per 100,000 people— astounding, according to an editorial in the Journal of the American Medical Association.
More than half of these cases involved patients within a health-care setting. Transmission is often through the hands of health-care workers, as healthy people can carry the bacteria without experiencing any symptoms. Bacteria typically colonize the nose and skin of a patient and are transmitted to a nurse or doctor when that patient is examined. If proper sanitary measures are not taken between patient visits, the healthcare worker will carry the bacteria and possibly transmit it to the next patient. Open wounds and a weakened immune system leave patients more susceptible to contracting an infection. In addition, many cases were discovered in low-income urban areas, prisons, school gyms, and locker rooms.
The new study investigates the pervasiveness of these potentially invasive bacteria, called methicillin-resistant Staphylococcus aureus, or MRSA. After surveying nine urban areas considered representative of the American population, the study found that bloodstream infections accounted for the majority of probable deadly cases. Flesh-eating disease was also a contributor in 10 per cent of cases.
The case fatality rate (number of deaths per number of infections) was 6.3 per 100,000 people, or 18,650 deaths in 2005. If every one of these deaths could be directly attributed to MRSA, then this death rate would exceed the 17,011 Americans killed by AIDS in 2005.
Treatment is still possible, although penicillin or penicillin derivatives are ineffective because the bacteria have developed resistance to these drugs. Antibiotics that were designed to kill the bacteria are no longer effective, as MRSA has evolved over many generations to become immune. In this case, medicines that are normally prescribed when no other treatment is successful, such as the antibiotic vancomycin, are utilized. It may only be a temporary measure, though, as researchers believe it is only a matter of time before MRSA develops resistance to these alternative drugs as well.
Ideally, exercising preventative measures will reduce the use of antibiotics so that when infection does occur a treatment will still be available. It seems inevitable that MRSA will eventually develop resistance to all treatments and that an effective vaccine is needed. Dr. Buddy Creech, a specialist in infectious disease at Vanderbilt University, emphasizes the need for a vaccine as “the holy grail of staphylococcal research.”
