Etiology Of Acute Otitis Media Research Articles

Bacterial and viral etiology of acute otitis media

Bacterial and viral etiology of acute otitis media

Natural Development of Antibodies to Pneumococcal Capsular Polysaccharides Depends on the Serotype: Association with Pneumococcal Carriage and Acute Otitis Media in Young Children

To study the natural development of antibodies to pneumococcal capsular polysaccharides of types 1, 6B, 11A, 14, 19F, and 23F and its association with pneumococcal carriage and acute otitis media (AOM), 329 children were followed-up prospectively during their first 2 years of life. Nasopharyngeal carriage was determined by cultures of nasopharyngeal swab samples, and etiology of AOM was determined by cultures of middle ear fluid. Antibodies were measured in serum samples collected at 6, 12, 18, and 24 months by EIA. Antibodies increased modestly but significantly with age. Contact with serotypes 11A and 14 was associated with increased antibody concentration as early as age 6 months. Children with contact with serotypes 6B, 19F, and 23F had antibody levels similar to those in children without contact. Antibodies increased modestly, even in children without known contact with Streptococcus pneumoniae and in children with contact with heterologous serotypes. Antibody concentrations were equal after carriage or AOM.

Bacterial and viral etiology of acute otitis media in Chilean children.

Acute otitis media (AOM) is a main cause for antimicrobial prescription in Latin America. Pathogen diversity in different geographic regions underscores the need for updated knowledge on AOM microbiology. To prospectively determine the role of bacteria and viruses in Chilean children with AOM. Between July, 1998, and June, 1999, children >3 months with a presumptive diagnosis of AOM were referred to the study ear, nose and throat physician. Middle ear fluid and nasopharyngeal aspirates were obtained from children with confirmed AOM and processed for common bacteria, Mycoplasma pneumoniae, Chlamydia pneumoniae and viruses. Antimicrobial susceptibility patterns and serotypes of Streptococcus pneumoniae strains were determined. An ear, nose and throat physician confirmed diagnoses for 222 (42%) of 529 children referred with diagnosis of AOM, and 170 children met eligibility criteria for the study. One or more pathogens were detected in 140 of 170 (82%) children. Predominant bacteria were S. pneumoniae (37%), Haemophilus influenzae (24%) and Streptococcus pyogenes (13%). M. catarrhalis was detected in 2 children, C. pneumoniae was found in 1 and M. pneumoniae was not detected. Viruses were detected in 22 children (13%) from nasopharyngeal aspirates, and in 6 of them the same virus was detected in middle ear fluid. Penicillin-resistant (intermediate and high) S. pneumoniae represented 40% of isolates and 10% of H. influenzae were beta-lactamase producers. All 10 penicillin-resistant S. pneumoniae strains were resistant to cefuroxime. Eighteen S. pneumoniae serotypes were detected and 19F was associated with high level penicillin resistance. This study can impact local management of AOM, and it should encourage continuous surveillance of AOM microbiology in Chile and other developing countries.

Acute otitis media: bacteriology and bacterial resistance in 205 pediatric patients

Acute otitis media (AOM) is one of the most frequent diagnoses in children below the age of 2 years. Treatment is usually based on information included in the literature concerning bacteriology. The purpose of this work was to define the most frequent germs in the etiology of AOM within our community, in order to optimize therapeutics for this pathology. Cultures in middle ear secretions obtained through tympanocentesis were performed to this end, ensuring careful sample taking and processing. The results obtained are similar to those published in previous papers for which Streptococcus pneumoniae and Haemophilus influenzae proved to be the predominant germs. However, there are certain discrepancies concerning the incidence of Moraxella catarrhalis and this has a direct impact on the total percent of resistant strains, thus modifying therapeutic approaches for treatment of AOM. The antibiotic sensitivity profiles of the most frequent etiologic agents were studied in accordance with the principles established by the ‘National Committee for Clinical Laboratory Standards’ (NCCLS).

Interleukin 8 in middle ear fluid during acute otitis media: correlation with aetiology and bacterial eradication

OBJECTIVESTo study the concentration of interleukin 8 (IL-8) in the middle ear fluid of children with acute otitis media and the association between IL-8 concentrations, aetiology of acute otitis media,...

Role of surgery for otitis media in the era of resistant bacteria

Otitis media is currently the most common diagnosis made by clinicians, and its prevalence has an impact on managed health care. With the emergence of bacterial pathogens resistant to many antimicrobial agents, an urgent need exists to reassess the indications for surgical management of this more prevalent disease. In an effort to determine the causative bacterial etiology of acute otitis media, which may be resistant to commonly prescribed antimicrobial agents, tympanocentesis is indicated today more than ever, especially when patients fail to improve or worsen while receiving antibiotics (i.e. treatment failures). In an effort to reduce the use of antimicrobial agents, prophylactic administration of these drugs for prevention of recurrent otitis media should only be prescribed on an individualized basis, with myringotomy and tympanostomy tube insertion being a more reasonable alternative. Adenoidectomy should be also considered when moderate to severe nasal obstruction is present or when repeat tympanostomy tube placement is needed. Likewise when chronic otitis media with effusion is unresponsive to a trial of antimicrobial therapy, tympanostomy tube insertion, adenoidectomy or both procedures should be considered, as opposed to re-treating with a variety of antibiotics. The role of these surgical procedures has become more important today in this era of antibiotic-resistant bacteria. Also in our cost-conscious environment, it is uncertain which method of management is more expensive, surgery or prolonged medical management.

Acute otitis media in children with bronchiolitis.

We investigated the prevalence and the etiology of acute otitis media (AOM) in children with bronchiolitis to determine whether AOM in such children is due entirely or mainly to respiratory syncytial virus (RSV), in which case routine antimicrobial treatment would not be appropriate. The study group consisted of children aged 2 to 24 months with bronchiolitis. In patients with AOM at entry, nasal washings for RSV enzyme-linked immunosorbent assay were obtained, and Gram-stained smear, bacterial culture, and reverse transcriptase polymerase chain reaction to detect the presence of RSV were performed on middle-ear aspirates. Patients without AOM were reevaluated at 48 to 72 hours, 8 to 10 days, and 18 to 22 days. Forty-two children with bronchiolitis were enrolled. Sixty-two percent had AOM at entry or developed AOM within 10 days. An additional 24% had or eventually developed otitis media with effusion. Only 14% remained free of both AOM and otitis media with effusion throughout the 3-week observation period. All patients with AOM had 1 or more bacterial pathogens isolated from one or both middle-ear aspirates. Of 33 middle-ear aspirates, Streptococcus pneumoniae was isolated in 15, Haemophilus influenzae in 8, Moraxella catarrhalis in 8, and Staphylococcus aureus in 2. Two middle-ear aspirates yielded 2 pathogens each; 2 aspirates had no growth. RSV was identified in 17 (71%) of 24 patients with AOM. Bacterial AOM is a complication in most children with bronchiolitis. Accordingly, in patients with bronchiolitis and associated AOM, antimicrobial treatment is indicated.

Microbial etiologies of acute otitis media

The bacterial etiology of acute otitis media (AOM) in children is well known; Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis account for up to 80% of the cases. Negative cultures are obtained from 15 to 34% of the middle ear effusions obtained from patients with AOM and could represent non-viable bacterial organisms, Chlamydia, Mycoplasma, anaerobes and, perhaps, new and unknown organisms. Viruses are rarely involved as a cause of AOM but upper respiratory tract infections by respiratory syncitial virus, adenovirus, enterovirus, influenza virus and rhinovirus usually precede AOM episodes. Other organisms isolated from middle ear effusions are identified as coagulase-negative staphylococci, α-haemolytic streptococci and diphtheroids and could be responsible for AOM; thus these organisms should not always be disregarded and considered as contaminants.

Etiology of acute otitis media in human immunodeficiency virus-infected children

Acute otitis media (AOM) is one of the most common infections that are implicated as significant contributors to morbidity in HIV-infected children. To establish the optimal antibiotic therapy tympanocentesis is indicated as the first line diagnostic procedure, because unusual pathogens may play a role in advanced stages of deficient humoral or cellular immunity. The microbiology of 60 episodes of AOM diagnosed in 21 symptomatic HIV-infected children (ages 9 months to 12 years) was compared with that of 121 episodes of AOM occurring in 113 immunocompetent HIV-negative children (ages 6 months to 12 years) in the last 5 years. The prevalence of the three most common pathogens (Streptococcus pneumoniae, Haemophilus influenzae and group A beta-hemolytic Streptococcus) was similar in HIV-infected and in normal children (56.5% vs. 54.9% of the ears). Staphylococcus aureus was significantly more frequent in AOM diagnosed in severely immunosuppressed stages. A significantly lower proportion of middle ear effusions obtained in HIV-infected children yielded no bacteria compared with normal children. Beta-lactamase production among isolates of H. influenzae was a rare phenomenon, both in HIV-infected and in normal children. No penicillin-resistant S. pneumoniae was found. In HIV-infected children with absent or moderate immunosuppression empiric antibiotic therapy should be based on the recommendations given for immunocompetent children of the same geographic area. In severe immunosuppressed stages, given the possible role of Staph. aureus, extended spectrum antibiotics should be considered.

Therapeutic Considerations for Management of Otitis Media, Sinusitis, and Tonsillopharyngitis

The etiology of acute otitis media and sinusitis has evolved over the past decade. Streptococcus pneumoniae is the causative pathogen less often now than in the past in many parts of the United States, and two gram-negative bacteria, Haemophilus influenzae and Moraxella catarrhalis, are increasingly important. Both of these organisms often produce beta-lactamase and, therefore, may resist eradication by amoxicillin. Increasingly, the clinical situation emerges whereby an alternative antimicrobial is sought to improve therapeutic efficacy. The choices include trimethoprim-sulfamethoxazole, cefaclor, cefuroxime axetil, amoxicillin-clavulanate, cefixime, cefprozil, loracarbef, cefpodoxime proxetil, clarithromycin, and azithromycin. Selecting among these alternatives requires a knowledge of their antimicrobial spectrum, side effect profile, dosing frequency, and cost. The etiology of pharyngitis has also become a topic of renewed research. Penicillin treatment failure occurs in 10-30% of group A beta-hemolytic streptococcal (GABHS) throat infections. A possible role for other pharyngeal microflora to protect GABHS from eradication through elaboration of beta-lactamase in the tonsillopharyngeal milieux is an intriguing hypothesis. As a consequence, alternative antibiotics that are able to resist beta-lactamase action are receiving attention as rational therapeutic choices in GABHS treatment.

Identification of respiratory virus antigens in middle ear fluids of children with acute otitis media.

Antigens of respiratory viruses were tested by immunoassay of the middle ear fluids and nasopharyngeal secretions of 137 children with acute otitis media. The following were found: (1) an epidemic of infection with respiratory syncytial virus (RSV) caused a significant increase in the occurrence of acute otitis media. (2) Fifteen percent of the children had RSV antigens in middle ear fluid, and in 7% RSV was the sole pathogen found. Adenovirus antigens were found in the middle ear fluid of 3% of the children. (3) Bacteriologic findings in otitis media related and unrelated to viral (RSV) infection were similar. These findings indicate that some episodes of otitis media are associated with viral infection and that the disease may be solely due to viral infection. Thus, at least during an epidemic of respiratory virus infections, treatment failures--e.g., fever and earache unresponsive to antimicrobial therapy--may be due to a viral etiology of acute otitis media.

VIRUSES IN ACUTE OTITIS MEDIA

There is epidemiologic evidence that otitis media is associated with viral respiratory infections but minimal information exists to prove such an etiology. We have tested antigens of respiratory viruses by immunoassay in the middle ear fluid and nasopharyngeal secretions of 137 children with acute otitis media (Sarkkinen et al, submitted). We found that 1) an epidemic of respiratory syncytial virus (RSV) infection caused a significant increase in the occurrence of acute otitis media, 2) 15% of the children had RSV in the middle ear fluid and in 7% RSV was the sole pathogen found. In addition, an adenovirus was found in middle ear fluid of 3% of the children, 3) bacteriological findings in otitis media related and unrelated to virus (RSV) infection were similar. These findings confirm and extend the results obtained earlier in this laboratory and indicate that otitis media is associated with virus infection and that in the early stages of infection the disease may be due solely to virus infection. Thus, at least during respiratory virus epidemic, treatment failures e.g. fever and earache unresponsive to antimicrobial therapy, may be due to a viral etiology of acute otitis media.

Emergence of beta-lactamase-producing strains of Branhamella catarrhalis as important agents of acute otitis media.

We performed a prospective study to monitor changes in the bacterial etiology of acute otitis media. Branhamella catarrhalis was isolated from middle ear exudates of 3 of 47 children (6.4%) studied between September 1979 and September 1980 and from 26 of 98 children (26.5%) studied between October 1980 and February 1982 (P = 0.0055). Twenty of 26 B. catarrhalis strains (76.9%) were found to be resistant to ampicillin and to produce beta-lactamase. In contrast only 2 of 26 strains of Haemophilus influenzae (7.7%) isolated from the same group of patients were resistant to ampicillin. We could not detect changes in culture methods, in demographic features, in patterns of medical care or in prior middle ear disease or antimicrobial drug usage, which might explain this striking increase in the relative importance of resistant strains of B. catarrhalis.

The role of respiratory syncytial virus and other viral pathogens in acute otitis media

We utilized recently developed enzyme immunoassay techniques to examine the role of selected viruses in the etiology of acute otitis media. Viral pathogens were found in middle ear fluids obtained from 13 (24%) of 53 children with acute otitis media; respiratory syncytial virus accounted for ten of the 13 viral agents identified. In addition, respiratory syncytial viral antigen was found in nasopharyngeal washings obtained from 15 of the 53 children. Seven of these children had RSV identified as the sole middle ear pathogen, whereas six children had otitis caused by Streptococcus pneumoniae as either the sole middle ear pathogen or in combination with RSV. Similarly, all three children with respiratory infections caused by influenza virus had ear infections caused by bacterial pathogens, either alone or in combination with influenza virus. These findings suggest that, in patients with viral respiratory infection, coexisting acute otitis media may be associated with the recovery of either viruses or bacteria from the middle ear exudates.

A longitudinal study of respiratory viruses and bacteria in the etiology of acute otitis media with effusion.

We analyzed data from a 14-year longitudinal study of respiratory infections in young children to determine the relative importance of viral respiratory infection and nasopharyngeal colonization with Streptococcus pneumoniae and Haemophilus influenzae as factors influencing the occurrence of acute otitis media with effusion. The incidence of this disorder was increased in children with viral respiratory infections (average relative risk, 3.2; P less than 0.0001). Infection with respiratory syncytial virus, influenza virus (type A or B), and adenovirus conferred a greater risk of otitis media than did infection with parainfluenza virus, enterovirus, or rhinovirus. Colonization of the nasopharynx with Str. pneumoniae or H. influenzae had a lesser effect on the incidence of the disease (average relative risk; 1.5; P less than 0.01). Infections with the viruses more closely associated with acute otitis media (respiratory syncytial virus, adenovirus, and influenza A or B) were correlated with an increased risk of recurrent disease. Prevention of selected otitis-associated viral infections should reduce the incidence of this disease.

The aetiology of acute otitis media in children. Occurrence of bacteria, L forms of bacteria and mycoplasma in the middle ear exudate. Relationship between bacterial findings in the middle ear exudate, nasopharynx and throat.

AbstractFrom 75 children with primary acute otitis media middle ear exudate was collected by needle aspiration through the tympanic membrane and investigated with respect to the presence of bacteria, bacterial L forms and mycoplasmas. In 60 cases (80%) bacteria were found by cultivation. Diplococcus pneumoniae was isolated in 50.7%, Haemophilus influenzae in 14.7%, group A streptococci in 5.3% and Neisseria catarrhalis in 9.3%. From 2 cases D. pneumoniae was isolated only on media designed for the isolation of L forms. In 5 of the 15 cases with negative culture findings, evidence for a bacterial infection was obtained by microscopic examination of the exudate. Mycoplasma was not demonstrated in any of the exudates. The bacterial findings from the throat were of little value in assessing the aetiology of otitis media. On the other hand, the bacterium isolated from the middle ear exudate was isolated from the nasopharynx in all but one case. The bacterium that was isolated from the middle ear exudate was re...