1.   But the antibiotics are expensive, especially in developing countries where infections often recur, raising the need for different and better treatments.

2.   But three weeks after she began taking the anti-rejection drugs, the infection recurred.

3.   If such infections recur three or more times a year, a tonsillectomy may be needed.

4.   In most cases, the tubes fall out in six to nine months and, if an infection recurs, they would have to be replaced.