Recurrent Acute Otitis Media After Completion of Antibiotic
Objective: We sought to determine whether recurrent acute otitis media (rAOM) occurring within 30 days of amoxicillin/clavulanate treatment was caused by bacterial relapse or new pathogens.
Methods: Pneumococcal conjugate vaccinated children, age 6–36 months, enrolled in a prospective, longitudinal study experiencing rAOM <1 month after completing amoxicillin/clavulanate therapy were studied. AOM episodes occurred between June 2006 and November 2012. Multilocus sequence typing was used to genotype isolates.
Results: Sixty-six children were in the study cohort; 63 otopathogens were recovered from middle ear fluid after tympanocentesis. Nontypeable Haemophilus influenzae (NTHi) accounted for 47% of initial AOMs versus 15% by Streptococcus pneumoniae (Spn), P < 0.0001. NTHi accounted for 42% of rAOM versus 24% by Spn (P value = 0.04). NTHi was the main otopathogen that caused true bacteriologic relapses (77%). β-lactamase–producing NTHi and penicillin nonsusceptible Spn were not more common in rAOM than initial AOM infections. Among 21 paired (initial and rAOM events) NTHi isolates genotyped, 13 (61.9%) were the same organism; 1 of 9 (11.1%) of paired Spn isolates was the same (P value = 0.017). rAOM occurring within a week of stopping amoxicillin/clavulanate was a different pathogen in 21% of cases, 8–14 days later in 33%, 15–21 days in 41% and 22–30 days in 57% (P = 0.04).
Conclusions: In amoxicillin/clavulanate-treated children, NTHi was the main otopathogen that caused true bacteriologic relapses. New pathogens causing rAOM versus persistence of the initial pathogen significantly increased week to week. Neither relapses nor new infections were caused more frequently by β-lactamase producing NTHi or penicillin nonsusceptible Spn.
Acute otitis media (AOM) is the most commonly diagnosed infectious disease in children associated with appropriate antibiotic prescriptions. About 30% of children develop recurrent AOM (rAOM) and are labeled otitis prone because they experience 3 AOM within 6 months or 4 episodes of AOM within 12 months. The bacteria causing rAOM have been investigated in the past. Nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae (Spn) are mainly responsible for rAOM episodes, but the relative proportion and antibiotic susceptibility varies with NTHi and antibiotic resistant strains occurring more frequently in rAOM after amoxicillin therapy.
The 2013 American Academy of Pediatrics (AAP) AOM guideline recommends amoxicillin in high dose for AOM and high dose amoxicillin/clavulanate for rAOM. A recurrence is defined according to a time interval of 30 days between completion of antibiotic therapy for an initial AOM and rAOM. One prior study by Leibovitz et al in Israel in the prepneumococcal conjugate vaccine era showed that most rAOM were caused by NTHi and were true bacteriologic relapses if they occurred within 2 weeks of initial infection. However, a recurrent episode more than 2 weeks after the initial infection was most frequently caused by a new pathogen. The purpose of this study was to determine whether rAOM that occurs in children in the United States within 30 days of initial treatment with amoxicillin/clavulanate is caused by a bacterial relapse or a new pathogen. Our study occurred during the pneumococcal conjugate vaccine era, and the use of molecular diagnostics was included to make specific organism determinations.
Abstract and Introduction
Abstract
Objective: We sought to determine whether recurrent acute otitis media (rAOM) occurring within 30 days of amoxicillin/clavulanate treatment was caused by bacterial relapse or new pathogens.
Methods: Pneumococcal conjugate vaccinated children, age 6–36 months, enrolled in a prospective, longitudinal study experiencing rAOM <1 month after completing amoxicillin/clavulanate therapy were studied. AOM episodes occurred between June 2006 and November 2012. Multilocus sequence typing was used to genotype isolates.
Results: Sixty-six children were in the study cohort; 63 otopathogens were recovered from middle ear fluid after tympanocentesis. Nontypeable Haemophilus influenzae (NTHi) accounted for 47% of initial AOMs versus 15% by Streptococcus pneumoniae (Spn), P < 0.0001. NTHi accounted for 42% of rAOM versus 24% by Spn (P value = 0.04). NTHi was the main otopathogen that caused true bacteriologic relapses (77%). β-lactamase–producing NTHi and penicillin nonsusceptible Spn were not more common in rAOM than initial AOM infections. Among 21 paired (initial and rAOM events) NTHi isolates genotyped, 13 (61.9%) were the same organism; 1 of 9 (11.1%) of paired Spn isolates was the same (P value = 0.017). rAOM occurring within a week of stopping amoxicillin/clavulanate was a different pathogen in 21% of cases, 8–14 days later in 33%, 15–21 days in 41% and 22–30 days in 57% (P = 0.04).
Conclusions: In amoxicillin/clavulanate-treated children, NTHi was the main otopathogen that caused true bacteriologic relapses. New pathogens causing rAOM versus persistence of the initial pathogen significantly increased week to week. Neither relapses nor new infections were caused more frequently by β-lactamase producing NTHi or penicillin nonsusceptible Spn.
Introduction
Acute otitis media (AOM) is the most commonly diagnosed infectious disease in children associated with appropriate antibiotic prescriptions. About 30% of children develop recurrent AOM (rAOM) and are labeled otitis prone because they experience 3 AOM within 6 months or 4 episodes of AOM within 12 months. The bacteria causing rAOM have been investigated in the past. Nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae (Spn) are mainly responsible for rAOM episodes, but the relative proportion and antibiotic susceptibility varies with NTHi and antibiotic resistant strains occurring more frequently in rAOM after amoxicillin therapy.
The 2013 American Academy of Pediatrics (AAP) AOM guideline recommends amoxicillin in high dose for AOM and high dose amoxicillin/clavulanate for rAOM. A recurrence is defined according to a time interval of 30 days between completion of antibiotic therapy for an initial AOM and rAOM. One prior study by Leibovitz et al in Israel in the prepneumococcal conjugate vaccine era showed that most rAOM were caused by NTHi and were true bacteriologic relapses if they occurred within 2 weeks of initial infection. However, a recurrent episode more than 2 weeks after the initial infection was most frequently caused by a new pathogen. The purpose of this study was to determine whether rAOM that occurs in children in the United States within 30 days of initial treatment with amoxicillin/clavulanate is caused by a bacterial relapse or a new pathogen. Our study occurred during the pneumococcal conjugate vaccine era, and the use of molecular diagnostics was included to make specific organism determinations.