IDSA: Antibiotics over-used and of little value in suspected "strep" cases

January 12th, 2015

Trying to rein in widespread inappropriate use of antibiotics for “strep throat,” the Infectious Diseases Society of America (IDSA) has issued new guidelines on testing and treatment of Group A streptococcal (GAS) pharyngitis.

Although acute pharyngitis is a common illness – accounting for an estimated 15 million medical visits per year in the United States -- only a relatively small percentage of patients with acute pharyngitis (20%–30% of children and a smaller percentage of adults) have GAS pharyngitis, the IDSA states. Moreover, the signs and symptoms of GAS and nonstreptococcal pharyngitis overlap so broadly that accurate diagnosis on the basis of clinical grounds alone is usually impossible.

With very rare exceptions, the treatment for acute pharyngitis due to organisms other than GAS is of no proven benefit. Therefore, it is extremely important that physicians exclude the diagnosis of GAS pharyngitis to prevent inappropriate administration of antimicrobials to large numbers of patients with nonstreptococcal pharyngitis. Such therapy unnecessarily exposes patients to the expense and hazards of antimicrobial therapy, the IDSA emphasizes.

“Inappropriate antimicrobial use for upper respiratory tract infections, including acute pharyngitis, has been a major contributor to the development of antimicrobial resistance among common pathogens,” the IDSA guidelines state. “Estimated economic costs of pediatric streptococcal pharyngitis in the United States range from $224 million to $539 million per year, including indirect costs related to parental work losses.”

The guidelines note that children and adults do not need to be tested for strep throat if they have a cough, runny nose, hoarseness and mouth sores, which are strong signs of a viral throat infection. A sore throat is more likely to be caused by strep if the pain comes on suddenly, swallowing hurts and the sufferer has a fever without the above listed features, but should be confirmed through testing before antibiotics are prescribed, the guidelines note.

If strep is suspected, the guidelines recommend physicians use the rapid antigen detection test, which provides results in a few minutes. If that test is negative, a follow-up throat culture is recommended for children and adolescents, but not for adults. Results of the culture can take up to several days, but antibiotics should not be prescribed unless results are positive, the guidelines note. Because strep throat is uncommon in children three years old or younger, they don’t need to be tested, the guidelines recommend.

If a GAS infection is confirmed by testing, it should be treated with penicillin or amoxicillin – if the patient does not have an allergy – and not azithromycin or a cephalosporin. The guidelines also recommend that children who suffer from recurrent strep throat should not have their tonsils surgically removed solely to reduce the frequency of infection.