Epidemiology of Otitis Media With Otorrhea Among Bangladeshi Children: Baseline Study for Future Assessment of Pneumococcal Conjugate Vaccine Impact

Systematic Literature Review of the Epidemiological Characteristics of Pneumococcal Disease Caused by the Additional Serotypes Covered by the 20-Valent Pneumococcal Conjugate Vaccine

Higher valency pneumococcal conjugate vaccines (PCV15 and PCV20) have been developed to address the disease burden of current non-vaccine serotypes. This review describes the epidemiological characteristics of serotypes beyond PCV13 (serotypes 8, 10A, 11A, 12F, 15B/C, 22F, and 33F; PCV20nonPCV13 serotypes). Peer-reviewed studies published between 1 January 2010 (the year PCV13 became available) and 18 August 2020 were systematically reviewed (PROSPERO number: CRD42021212875). Data describing serotype-specific outcomes on disease proportions, incidence, severity, and antimicrobial non-susceptibility were summarized for individual and aggregate PCV20nonPCV13 serotypes by age group and by type and duration of pediatric PCV immunization program. Of 1168 studies, 127 (11%) were included in the analysis. PCV20nonPCV13 serotypes accounted for 28% of invasive pneumococcal disease (IPD), although the most frequent serotypes differed between children (10A, 15B/C) and adults (8, 12F, 22F). In children, serotype 15B/C tended to be more frequently associated with pneumococcal meningitis and acute otitis media; in adults, serotype 8 was more frequently associated with pneumonia and serotype 12F with meningitis. Serotypes 10A and 15B/C in children and 11A and 15B/C in adults were often associated with severe IPD. Serotype 15B/C was also among the most frequently identified penicillin/macrolide non-susceptible PCV20nonPCV13 serotypes. These results could inform decision making about higher valency PCV choice and use.

Acute otitis media pneumococcal disease burden and nasopharyngeal colonization in children due to serotypes included and not included in current and new pneumococcal conjugate vaccines

INTRODUCTION

Despite the introduction of effective pneumococcal conjugate vaccines (PCV), Streptococcus pneumoniae remains a major cause of acute otitis media (AOM) worldwide. New, higher valency vaccines that offer broader serotype coverage have been recently developed and others are in development. However, given the capsular serotypes expressed by pneumococci causing AOM, it is unclear to what extent differing or higher valency PCVs will provide additional protection.

AREAS COVERED

We conducted a systematic literature search of the MEDLINE database to identify articles published from January 2016 to September 2021 in 4 low and middle income and 10 high-income countries. We searched PubMed with terms: (Streptococcus pneumoniae) OR pneumococcal AND serotype AND (conjugate vaccine). We evaluated serotype distribution and the actual or projected coverage of pneumococcal serotypes by PCV10 (GlaxoSmithKline), PCV13 (Pfizer), PCV10SII (Serum Institute of India) PCV15 (Merck) and PCV20 (Pfizer).

EXPERT OPINION

Our review highlights the important epidemiological differences in serotype distribution and coverage by existing and higher valency vaccines to protect against AOM in children. These data provide support for further evaluation of serotype-independent vaccines for optimal control of pneumococcal AOM disease worldwide.

Increase in Haemophilus influenzae Detection in 13-Valent Pneumococcal Conjugate Vaccine Immunized Children With Acute Otitis Media

NTHi was the predominant pathogen in ear cultures from severe acute otitis media (AOM) episodes in PCV-13 vaccinated children, more commonly in girls. NTHi-AOM episodes were associated with more myringotomies due to a higher treatment failure incidence. The low rate of β-lactamase NTHi isolates in middle ear fluid cultures from PCV-13 vaccinated children presenting with AOM strengthens to still use amoxicillin as the first-line antibiotics.

Isolation and Identification of Pathogenic Bacteria Causing Otitis Media in Misan Governorate

This study examined 150 ear swab samples from patients with otitis media who consulted at Al-Sadr Teaching Hospital from January to April 2021 in Misan, Iraq. The participants were aged 14–50 years, among which the infection rate was highest in participants aged 14–22 years and lowest in those aged 40–50 years. Subsequently, bacterial isolates were identified based on their morphology in various culture media and using biochemical tests. Six bacterial species were identified, namely Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae, Klebsiella pneumoniae, and Staphylococcus epidermidis. Staphylococcus aureus had the highest infection rate (30%), whereas Staphylococcus epidermidis had the lowest infection rate (8.55%). When the sensitivity of each isolate to antibiotics was determined, Escherichia coli was the most sensitive to trimethoprim (TMP), whereas Pseudomonas aeruginosa was the most resistant to 75% of the tested antibiotics.

Comparison of Culture, Antigen Test, and Polymerase Chain Reaction for Pneumococcal Detection in Cerebrospinal Fluid of Children

Background

Sensitivity of culture for the detection of Streptococcus pneumoniae is limited by prior antibiotic exposure. Immunochromatographic test (ICT) is highly sensitive and specific for pneumococcal antigen detection in the cerebrospinal fluid (CSF) of meningitis cases. We determined the specificity and sensitivity of culture, ICT, and polymerase chain reaction (PCR) and the effect of antibiotic exposure on their performance.

Methods

CSF specimens from suspected meningitis cases admitted to Dhaka Shishu Hospital, Bangladesh, were tested using culture, ICT and PCR. Additionally, 165 specimens collected from 69 pneumococcal cases after antibiotic treatment were tested.

Results

Of 1883 specimens tested, culture detected 9, quantitative PCR (qPCR) detected 184, and ICT detected 207 pneumococcal cases (including all culture and qPCR positives). In comparison to ICT, sensitivity of culture was 4.4% and of qPCR was 90.6%; both were 100% specific. After antibiotic exposure, culture sensitivity plummeted rapidly; conventional PCR and qPCR sensitivity disappeared after day 6 and 20, respectively. ICT detected pneumococcal antigen for >10 weeks.

Conclusions

While culture provides the most information about bacterial characteristics, in high antibiotic exposure settings, ICT exhibits maximum sensitivity. We recommend culture and ICT as mainstay for pneumococcal diagnosis and surveillance; qPCR can generate additional molecular data where possible.

Prevalence and Antimicrobial Resistance of Bacteria in Children With Acute Otitis Media and Ear Discharge: A Systematic Review

BACKGROUND

Of children with acute otitis media (AOM), 15%-20% present with acute onset ear discharge due to a spontaneous perforation of the tympanic membrane (AOMd). This review aims to quantify the prevalence and antimicrobial resistance (AMR) status of bacteria in children with AOMd in the pneumococcal conjugate vaccine (PCV) era.

METHODS

Systematic searches were performed in PubMed, EMBASE and Cochrane Library from inception to June 7, 2019. Two reviewers extracted relevant data and assessed risk of bias independently. All English studies reporting any prevalence and/or AMR data of bacterial middle ear isolates from children with AOMd were included. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal checklist.

RESULTS

Of 4088 unique records retrieved, 19 studies (10,560 children) were included. Overall quality was judged good. Streptococcus pneumoniae (median 26.1%, range 9.1%-47.9%), Haemophilus influenzae (median 18.8%, range 3.9%-55.3%), Staphylococcus aureus (median 12.3%, range 2.3%-34.9%) and Streptococcus pyogenes (median 11.8%, range 1.0%-30.9%) were the most prevalent bacteria. In 76.0% (median, range 48.7%-100.0%, 19 studies, 1,429 children) any bacterium was identified. AMR data were sparse and mainly limited to S. pneumoniae. We found no evidence of a clear shift in the prevalence of bacteria and AMR over time.

CONCLUSIONS

In children with AOMd, S. pneumoniae and H. influenzae are the 2 predominant bacteria, followed by S. aureus and S. pyogenes in the post-PCV era. AMR data are sparse and no clearly change over time was observed. Ongoing surveillance of the microbiology profile in children with AOMd is warranted to guide antibiotic selection and to assess the impact of children's PCV status.

Impact of Streptococcus salivarius K12 on Nasopharyngeal and Saliva Microbiome: A Randomized Controlled Trial

BACKGROUND

Probiotic lactobacilli have been ineffective in preventing acute otitis media. In contrast to lactobacilli, alpha-hemolytic streptococci belong to the core microbiome of nasopharynx.

METHODS

We investigated the effects of Streptococcus salivarius K12 probiotic on the saliva and nasopharyngeal microbiome in 121 children attending daycare. Children were randomly allocated to receive oral K12 product for 1 month or no treatment. We obtained saliva and nasopharyngeal samples at study entry, at 1 and 2 months. The next-generation sequencing of the bacterial 16S gene was performed.

RESULTS

After the intervention, the diversity of saliva or nasopharyngeal microbiome did not differ between groups. The proportion of children with any otopathogen did not differ between the groups. At 1 month, the abundance of otopathogens in nasopharynx was lower in K12 group compared with that in control children (34% vs. 55%, P = 0.037). When we compared each otopathogen separately, Moraxella was the only group lower in the treatment group. We could not verify the reduction of Moraxella when an alternative Human Oral Microbiome Database taxonomy database was used. In children receiving K12 product, the mean abundance of S. salivarius was greater in saliva after the intervention (0.9% vs. 2.0%, P = 0.009).

CONCLUSIONS

The use of S. salivarius K12 probiotic appeared to be safe because it did not disrupt the normal microbiome in young children. Even though a short-term colonization of S. salivarius was observed in the saliva, the impact of S. salivarius K12 probiotic on the otopathogens in nasopharyngeal microbiome remained uncertain.

Bacterial causes of otitis media with spontaneous perforation of the tympanic membrane in the era of 13 valent pneumococcal conjugate vaccine

After pneumococcal conjugate vaccine (PCV) implementation, the number of acute otitis media (AOM) episodes has decreased, but AOM still remains among the most common diagnoses in childhood. From 2% to 17% of cases of AOM feature spontaneous perforation of the tympanic membrane (SPTM). The aim of this study was to describe the bacteriological causes of SPTM 5 to 8 years years after PCV13 implementation, in 2010. From 2015 to 2018, children with SPTM were prospectively enrolled by 41 pediatricians. Middle ear fluid was obtained by sampling spontaneous discharge. Among the 470 children with SPTM (median age 20.8 months), no otopathogen was isolated for 251 (53.4% [95% CI 48.8%;58.0%]): 47.1% of infants and toddlers, 68.3% older children (p<0.001). Among children with isolated bacterial otopathogens (n = 219), non-typable Haemophilus influenzae (NTHi) was the most frequent otopathogen isolated (n = 106, 48.4% [95% CI 41.6%;55.2%]), followed by Streptoccocus pyogenes (group A streptococcus [GAS]) (n = 76, 34.7% [95% CI 28.4%;41.4%]) and Streptococcus pneumoniae (Sp) (n = 61, 27.9% [95% Ci 22.0%;34.3%]). NTHi was frequently isolated in infants and toddlers (53.1%), whereas the main otopathogen in older children was GAS (52.3%). In cases of co-infection with at least two otopathogens (16.9%, n = 37/219), NTHi was frequently involved (78.4%, n = 29/37). When Sp was isolated, PCV13 serotypes accounted for 32.1% of cases, with serotype 3 the main serotype (16.1%). Among Sp strains, 29.5% were penicillin-intermediate and among NTHi strains, 16.0% were β-lactamase-producers. More than 5 years after PCV13 implementation, the leading bacterial species recovered from AOM with SPTM was NTHi for infants and toddlers and GAS for older children. In both age groups, Sp was the third most frequent pathogen and vaccine serotypes still played an important role. No resistant Sp strains were isolated, and the frequency of β-lactamase-producing NTHi did not exceed 16%.