The NY Times recently had a very good article about strep throat, which is caused by group A streptococci (which, if I’m not mistaken are near and dear to fellow ScienceBlogling Tara). Sore throats are one of the leading causes of the overprescribing of antibiotics (it’s been estimated that 20% of all antibiotic prescriptions are incorrectly prescribed to treat viral infections, including sore throats), which leads to the evolution of antibiotic resistant bacteria:
Symptoms of a strep throat and a sore throat caused by a virus can overlap (children may experience stuffy noses, coughs and sneezing with a strep infection as well as with a cold), further complicating a doctor’s decision on whether to treat the illness or to let nature take its course. Nationally, 70 percent of children with sore throats who are seen by a physician are treated with antibiotics, though at most 30 percent have strep infections. And as many as half who are treated with antibiotics because a throat culture was positive for strep are healthy carriers and actually have a cold or some other viral infection, says Dr. Edward L. Kaplan, a pediatrician at the University of Minnesota in Minneapolis and an expert on streptococcal illness.
Antibiotic treatment is best reserved for illnesses in which it is likely to be effective. Overuse of antibiotics can give rise to dangerous antibiotic-resistant bacteria. Antibiotics can wipe out friendly bacteria in the gut, and they sometimes cause life-threatening allergic reactions.
Given the confusing nature of these infections, there are two possible treatment strategies:
Dr. Bisno explained that the examining physician has two options. The preferred course of treatment, as described in the 2002 practice guidelines of the Infectious Diseases Society of America, is to wait for the results of the throat culture before starting antibiotic therapy. The physician can write a prescription for antibiotics but suggest that it not be filled unless the throat culture is positive.
The second option, considered less than ideal, is to start antibiotic therapy right away and then stop it if the throat culture is negative, which almost always means the throat infection is caused by a virus, Dr. Bisno said. But, he added, this course of action is reasonable if, in spite of a negative result on the rapid test, “the child is really sick” with symptoms that suggest a strep infection.
An advantage of this option is that if the infection is indeed strep, 24 hours on an antibiotic renders the patient noncontagious, allowing a return to school or work after just a day’s absence.
With or without treatment, Dr. Bisno said, strep infections are limited, and most people are better within three or four days. Furthermore, he said, it is safe to wait several days — and perhaps as many as nine days — before starting antibiotic therapy without compromising the chances of preventing rheumatic fever.
In addition, the decision to treat or not to treat can be simplified, Dr. Bisno said, if children with sore throats have symptoms of a cold — “no fever, no red throat, a runny nose and a cough.” Such children, he said, “shouldn’t be tested at all for strep” and should not be given antibiotics.
The good news is that some cheap and rapid diagnostics are being developed to determine if an infection is bacterial or viral. This will help preserve the power of antibiotics.