Mike the Mad Biologist

Guidelines for Treating Strep Throat

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.

Comments

  1. #1 catswym
    October 23, 2006

    who are these doctors who prescribe antibiotics without a strep culture? cuz i’ve never met one, and i’ve had upwards of 10 strep infections in my short 26 years.

    i’ve actually never even had a doctor who would allow me to have the script until the test had come back positive for strep, which i actually think is a pain in the ass.

    and as for the recommendation of waiting nine days before antibiotics: um, yeah right. strep makes your throat hurt like a bastard–that is ridiculous.

  2. #2 csrster
    October 24, 2006

    I thought they could do a while-u-wait swab test for strep?

  3. #3 Dan R.
    October 24, 2006

    I’ve very rarely seen a primary care physician get a throat culture — I’ve seen two responses:

    Sore throat = antibiotics (usually older ones, but this is now fairly rare).

    Sore throat = Strep A Antigen Screen (25 min swab) = gargle if neg, abx if pos. If treatment doesn’t work, culture and refer to ENT.

    I’m more interested in how the antigen screening is being used and perhaps overused than the “culture” everything. No one cultures much in my experience unless they expect zebras or resistance.

  4. #4 Chris Lawson
    October 28, 2006

    It’s interesting to read this from an Australian perspective where we really don’t get too concerned about strep throats. As the evidence shows, most throat infections are viral, most get better within 3-4 days whether you treat with antibiotics or not, and even a positive throat swab or antigen test doesn’t prove that the infective agent is streptococcus. Apart from Aboriginal communities, the rate of rheumatic disease is virtually zero here. Meanwhile, all that antibiotic prescribing for minimal benefit is creating resistance like crazy. To answer catswym — 9 days of throat pain may be unpleasant, but being in hospital with an MRSA eating away at a surgical wound is much, much worse.

    The big difference, I think, in Australia is that the federal health department got wise after about 15 years of unsuccessfully promoting conservative treatment among doctors. They finally realised that the main reason doctors prescribed antibiotics was because of patient expectation — so they expanded the education campaigns to include the public. I have noticed a major decline in the number of patients insisting on antibiotics over the last 10 years, and that makes it a lot easier to treat the disease symptomatically. I know from my own audits that I prescribe antibiotics for a small minority of URTIs — and those almost always have some complicating factor such as COPD or clinically evident tonsillitis, or have been unwell for over a week.

    There are obviously considerable cultural differences between the Australian and US medical systems. For instance, in Australia, throat swabs are almost never ordered. The last time I swabbed someone’s throat was years ago, and I never see throat swab results coming back from my colleagues. I suspect that if the US wants to get its antibiotic prescribing rate down, then the Surgeon-General needs to educate the public as well as the medical profession.

  5. #5 mirc
    March 18, 2009

    thanksss

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