Against atypical bacteria that cause recurrent RTI, azithromycin works

Do atypical bacteria (in this case, Mycoplasma pneumoniae and Chlamydia pneumoniae) play a role in causing acute respiratory episodes among children with recurrent respiratory tract infections (RTIs)? And does specific antibiotic treatment of these infections ease the course of acute episodes and reduce risk of recurrence? The answers to both questions may be "Yes," according to findings of a recent investigation.

In a study conducted at an outpatient clinic in Milan, Italy, investigators assigned 352 patients between 1 and 14 years old who had an acute RTI and a history of recurrent RTIs and 208 healthy subjects to receive either azithromycin (10 mg/kg/day for three days weekly for three weeks) plus symptom-specific agents (e.g., acetaminophen) or a symptom-specific agent alone. Acute atypical bacterial infection was laboratory confirmed in 190 patients (54%) who had acute respiratory disease and a history of RTIs and in eight controls (3.8%). Acute atypical bacterial infections were significantly more common among those at least 3 years of age than among those who were younger.

After one month, acute symptoms were significantly more likely to resolve in the RTI patients who had received azithromycin together with symptom-specific agents than in those who had received only symptom-specific agents. The difference was significant only in the group of patients whose RTI were caused by atypical bacteria, however. But at six months, clinical success was significantly more common among the patients who received azithromycin in addition to symptom-specific agents whether or not their infections were associated with atypical bacteria or other pathogens. Positive outcomes were much more common among subjects with atypical bacterial infections, however (Esposito S et al: Pediatr Infect Dis J 2005;24:438).