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Published on: February 23, 2014
Acute otitis media in infants younger than three months not vaccinated against Streptococcus pneumoniae
Patricia Sommerfleck1, María Emilia González Macchi, Silvana Pellegrini
1Otolaryngology Department, Hospital de Pediatría SAMIC Prof. Dr. Juan P. Garrahan, Combate de Pozos 1881 CABA, Argentina. p.sommerfleck@gmail.com
Insights
Acute otitis media (AOM) in infants under three months is often caused by Streptococcus pneumoniae. Early antibiotic treatment is crucial, with amoxicillin or ceftriaxone recommended for severe infections.
Area of Science:
- Pediatrics
- Infectious Diseases
- Otolaryngology
Background:
- The incidence and causative agents of acute otitis media (AOM) in neonates and infants younger than three months are not well-established.
- AOM in this vulnerable population can lead to severe systemic infections like bacteremia, sepsis, and meningitis.
Purpose of the Study:
- To investigate the clinical presentation, severe infection associations, and bacteriologic etiology of AOM in infants under three months.
- To analyze antibiotic resistance patterns of pathogens isolated from middle ear infections in this age group, specifically in unvaccinated infants.
Main Methods:
- Otomicroscopy was used to diagnose AOM in infants under three months.
- Tympanocentesis and middle ear fluid culture were performed for bacterial identification and serotyping via the Quellung technique.
Main Results:
- Streptococcus pneumoniae was the most common pathogen (50%), followed by Haemophilus influenzae (34.6%) and Streptococcus pyogenes (5.8%).
- Antibiotic resistance was observed, with 15.3% of S. pneumoniae isolates showing intermediate susceptibility to penicillin.
- Mixed infections occurred in 26.9% of cases, and 34.6% of infants had prior antibiotic treatment, with 17.3% of cultures being negative, especially in pre-treated patients.
Conclusions:
- S. pneumoniae is the predominant pathogen causing AOM in infants younger than three months.
- Empirical antibiotic therapy with amoxicillin or ceftriaxone is advised, guided by the clinical suspicion of invasive infection.
Unlabelled:
The true incidence of acute otitis media (AOM) in neonates and infants younger than three months is unknown. In this population organisms causing AOM may disseminate leading to bacteremia, sepsis, and meningitis [1].
Objectives:
To describe the clinical presentation, associated severe infections, bacteriologic etiology, and antibiotic resistance patterns of organisms isolated from the middle ear of infants younger than three months that were not vaccinated against Streptococcus pneumoniae.
Methods:
Otomicroscopy was performed in all children to confirm the suspected diagnosis of AOM. When purulent effusion retained in the middle ear was diagnosed, tympanocentesis and culture of middle-ear fluid was performed by conventional methods. Serotyping was done using the Quellung technique.
Results:
From May 2, 2009 to February 28, 2010, 52 infants met the inclusion criteria. Thirty-six were male (69.2%) and 16 were female (30.8%). From these 52 patients, 76 samples were obtained for culture. Bilateral acute suppurative otitis media was diagnosed in 24 (46.2%) infants. Of all infants, 18 (34.6%) had been treated with antibiotics before tympanocentesis. Eight patients (44.4%) had negative middle-ear fluid cultures. Sixty bacterial pathogens were isolated from the middle-ear fluid of 43 patients. Mixed infections were recorded in 14/52 patients (26.9%). Nine cultures were negative (17.3%), of which eight were from patients that had previously been treated with antibiotics. S. pneumoniae was isolated from middle-ear aspirates of 26/52 (50%) patients with acute suppurative otitis media. Twenty-two out of the 26 isolates were susceptible (84.7%) and four were intermediately susceptible to penicillin (15.3%). Streptococcus pyogenes was isolated in 3/52 (5.8%) and Haemophilus influenzae in 18/52 patients (34.6%). Five (27.8%) of these were beta-lactamase producers. Blood cultures, cerebrospinal fluid, and urine cultures were negative. Parenteral antimicrobial treatment was indicated in 29/52 (56%).
Conclusions:
S. pneumoniae is the most frequent pathogen to cause AOM in this age group. Empirical treatment with amoxicillin or ceftriaxone should be considered depending on clinical suspicion of severe invasive infection.
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