Strep Throat Cut When Tonsils Cut

ROCHESTER, Minn., Nov. 2 -- Children with recurrent strep throat will do better if their tonsils are removed, according to researchers here.

In a retrospective, population-based study of children with recurring Group A ?-hemolytic streptococcal infections, those who kept their tonsils were three times as likely to develop a subsequent case of strep throat as those who had tonsillectomies, found surgeon Laura Orvidas, M.D., of the Mayo Clinic.

Not only did children have fewer infections after a tonsillectomy, the time between subsequent cases was greater than for those with intact tonsils, Dr. Orvidas and colleagues reported in the Nov. 2 issue of The Laryngoscope, the journal of the American Laryngological, Rhinological, and Otological Society.

This suggests that "tonsillectomy is a useful therapy for treating children with recurrent strep throat infections," Dr. Orvidas said. The surgery "should decrease the amount of infections experienced by this subset of children and therefore diminish the number of missed school days and hopefully improve overall quality of life."

Using the database of the Rochester Epidemiology Project, Dr. Orvidas and colleagues identified children, ages four to 16, who had at least three strep throat episodes from 1994 to1998. The infections had to be at least a month apart, all within a single year.

Children who subsequently had their tonsils removed were age- and sex-matched with another child in the cohort who did not have a tonsillectomy. In all, the researchers identified 145 children who had a tonsillectomy and 145 who did not.

The index date for those in the study was the date of tonsillectomy, the researchers said, and follow-up began in both groups at that time. Analysis found:

• In the tonsillectomy group, 74 children had at least one strep infection after the index date and before they reached 16.
• Among those who did not receive a tonsillectomy, 122 experienced at least one strep infection during the follow-up.
• The median time before the first subsequent strep infection was 1.1 years for those who had a tonsillectomy, compared with 0.6 years for children whose tonsils had not been removed.
• By one year after the index date, the cumulative incidence of a strep infection was 23.1% among the children who had a tonsillectomy and 58.5% among the children with intact tonsils.

With the analysis adjusted for some possible confounding factors, children without a tonsillectomy were three times more likely to develop subsequent strep infections than those with their tonsils removed. The odds ratio was 3.1 (with a 95% confidence interval from1.9 to 4.9), which was significant at P<0.001.

The authors noted that a retrospective study cannot account for all confounding factors and cannot prove causality. As such, there may have been other unmeasured characteristics in the two groups that may have affected the study results. Dr. Orvidas said.

He also noted that "the use of the Rochester Epidemiology Project resource was unquestionably one of the strengths of the study."

The database "allowed us to access complete medical records on a geographically defined pediatric population and minimized potential referral and participation biases," she said.