Etiology of Acute Otitis Media and Characterization of Pneumococcal Isolates After Introduction of 13-Valent Pneumococcal Conjugate Vaccine in Japanese Children

Health-economic burden attributable to novel serotypes in candidate 24- and 31-valent pneumococcal conjugate vaccines

INTRODUCTION

Next-generation pneumococcal vaccines currently in clinical trials include 24- and 31-valent pneumococcal conjugate vaccines (PCV24, PCV31), which aim to prevent upper-respiratory carriage and disease involving the targeted serotypes. We aimed to estimate the comprehensive health-economic burden associated with acute respiratory infections (ARIs) and invasive pneumococcal disease (IPD) attributable to PCV24- and PCV31-additional (non-PCV20) serotypes in the United States.

MATERIAL AND METHODS

We multiplied all-cause incidence rate estimates for acute otitis media (AOM), sinusitis, and non-bacteremic pneumonia by estimates of the proportions of each of these conditions attributable to pneumococci and the proportions of pneumococcal infections involving PCV24- and PCV31-additional serotypes. We estimated serotype-specific IPD incidence rates using US Active Bacterial Core surveillance data. We accounted for direct medical and non-medical costs associated with each condition to estimate resulting health-economic burden. Non-medical costs included missed work and lost quality-adjusted life years due to death and disability.

RESULTS

The health-economic burden of PCV24-additional serotypes totaled $1.3 ($1.1-1.7) billion annually in medical and non-medical costs, comprised of $0.9 ($0.7-1.2) billion due to ARIs and $0.4 ($0.3-0.5) billion due to IPD. For PCV31-additional serotypes, medical and non-medical costs totaled $7.5 ($6.6-8.6) billion annually, with $5.5 ($4.7-6.6) billion due to ARIs and $1.9 ($1.8-2.1) billion due to IPD. The largest single driver of costs was non-bacteremic pneumonia, particularly in adults aged 50-64 and ≥65 years.

CONCLUSIONS

Additional serotypes in PCV24 and PCV31, especially those included in PCV31, account for substantial health-economic burden in the United States.

A rapid simultaneous antigen detection of Haemophilus influenzae and Streptococcus pneumoniae for predicting the prognosis of acute otitis media

BACKGROUND

Rapid identification of causative bacteria in treatment of acute otitis media (AOM) is of paramount importance for appropriate antibiotic use.

MATERIALS AND METHODS

This prospective observational study was conducted in 15 hospitals and clinics in Japan between 2018 and 2020. A new rapid antigen test kit (AOS-116), which simultaneously detects antigens for Streptococcus pneumoniae (Sp) and Haemophilus influenzae (Hi), was applied for middle ear fluids (MEFs) and nasopharyngeal secretions (NPSs) in patients with moderate to severe AOM. We investigated relationship between the results of rapid test, severity at initial visit, and clinical course.

RESULTS

Regarding performance accuracy based on culture results, AOS-116 showed 1) high (>80%) sensitivity, specificity, and negative predictive value (NPV) in MEFs for both antigens, 2) high sensitivity, specificity, and positive predictive value (PPV) in NPSs for Hi antigen, and 3) high specificity, and PPV in NPSs for Sp antigen. Regarding predictive value of nasopharyngeal culture and antigen detection for causative middle ear pathogens, similar results were observed between AOS-116 and culture, which was characterized with high sensitivity and NPV for both pathogens. MEFs/NPSs positive for Hi antigen were significantly associated with eardrum findings, and severity. MEFs/NPSs positive for pneumococcal antigen were significantly associated with severity of otalgia, fever, and otorrhea. Among patients with prior antimicrobial treatment, improvement tended to be slower in cases positive for Hi than in cases negative.

CONCLUSION

The rapid antigen detection test is useful as a decision-making tool for prescribing antimicrobial agents and may play an important role in promoting appropriate antimicrobial use.

Otitis Media Prevalence in Children Below 18 Years of Age of India and the Associated Risk Factors: A Systematic Review and Meta-Analysis

Ear ailments in children are a major public health problem in India. This systematic review and meta-analysis aim to quantitatively pool the epidemiologic evidence on the prevalence of all forms of otitis media in children of India. In this review PRISMA guidelines (preferred reporting items for systematic reviews and meta-analysis) were followed. We did extensive literature search in PubMed, Embase, Cinahl and Web of Science to identify relevant community based cross sectional studies that investigated the prevalence of otitis media in children of India. We used STATA version 16.0 software to perform meta-analysis. Six studies reporting the prevalence of otitis media in children were included in the final analysis. Based on the results of the random-effects sub-group meta-analysis model, the pooled estimated prevalence of Chronic suppurative otitis media in children of India was 3.78% (95% CI 2.72-4.84), Otitis media with effusion was found to be 2.68% (95% CI 1.80, 3.55) and Acute suppurative otitis media to be 0.55 (95% CI 0.32, 0.78). This review suggests substantial otitis media related disease burden in children of India. But due to lack of epidemiological studies, the actual disease burden remains concealed. It is imperative to promote more epidemiological studies that will aid policy makers in recommendation of preventive, diagnostic and treatment strategies for this disease.

Risk factors and pathogen characteristics associated with unfavorable outcomes among adults with pneumococcal meningitis in Japan, 2006 to 2016

PURPOSE

In this study, we aimed to clarify the risk factors associated with unfavorable outcomes in adults with pneumococcal meningitis (PnM).

METHODS

Surveillance was conducted between 2006 and 2016. Adults with PnM (n = 268) were followed up for outcomes within 28 days after admission using the Glasgow Outcome Scale (GOS). After classifying the patients into the unfavorable (GOS1-4) and favorable (GOS5) outcome groups, i) the underlying diseases, ii) biomarkers at admission, and iii) serotype, genotype, and antimicrobial susceptibility for all isolates were compared between both groups.

RESULTS

Overall, 58.6% of patients with PnM survived,15.3% died, and 26.1% had sequelae. The number of living days in the GOS1 group was highly heterogeneous. Motor dysfunction, disturbance of consciousness, and hearing loss were the commonest sequelae. Of the underlying diseases identified in 68.9% of the PnM patients, liver and kidney diseases were significantly associated with unfavorable outcomes. Of the biomarkers, creatinine and blood urea nitrogen, followed by platelet and C-reactive protein had the most significant associations with unfavorable outcomes. There was a significant difference in the high protein concentrations in the cerebrospinal fluid between the groups. Serotypes 23F, 6C, 4, 23A, 22F, 10A, and 12F were associated with unfavorable outcomes. These serotypes were not penicillin-resistant isolates possessing three abnormal pbp genes (pbp1a, 2x, and 2b), except for 23F. The expected coverage rate of the pneumococcal conjugate vaccine (PCV) was 50.7% for PCV15 and 72.4% for PCV20.

CONCLUSIONS

In the introduction of PCV for adults, the risk factors for underlying diseases should be prioritized over age, and serotypes with unfavorable outcomes should be considered.

Cost-effectiveness analysis of pediatric immunization program with 15-valent pneumococcal conjugate vaccine in Japan

BACKGROUND

The 15-valent pneumococcal conjugate vaccine (PCV15 or V114) has recently been approved for pediatric vaccination against pneumococcal diseases (PDs) in Japan. The study aims to evaluate the cost-effectiveness of pediatric vaccination with V114 versus 13-valent PCV (PCV13) in Japan.

METHODS

The study used a decision analytical Markov model to estimate the cost and effectiveness outcomes for a birth cohort in Japan over a 10-year time horizon. The model tracked the occurrences of acute PD events, including invasive PD (IPD), non-bacteremic pneumococcal pneumonia (NBPP) and pneumococcal acute otitis media (AOM) and the long-term impact of post-meningitis sequalae. Vaccine effectiveness was estimated based on literature and assumptions, and accounted for indirect effects and vaccine waning. The base case took the societal perspective, including both direct and indirect costs, while a healthcare payer perspective was modeled in a scenario analysis. Additional scenario analyses and sensitivity analyses were conducted.

RESULTS

In the base case, V114 was associated with an incremental gain of 24 quality-adjusted life years and a reduction of ¥365,610,955 in total costs compared to PCV13. It was expected to reduce the number of pneumococcal AOM, NBPP, and IPD cases by 1,832, 1,333 and 25, respectively. All scenario analyses and most sensitivity analyses showed that V114 was a dominant strategy compared to PCV13.

CONCLUSIONS

Pediatric vaccination with V114 is expected to lead to cost savings and more health benefits compared to PCV13 in Japan from both societal and healthcare payer perspectives. The findings are robust under plausible assumptions and inputs.

Haemophilus influenzae drug resistance in France from 2017 to 2021: consideration for treatment of otitis media

OBJECTIVES

Haemophilus influenzae is a prevalent agent of respiratory infections, including acute otitis media (AOM), that lead to high antibiotic prescription and may contribute to the development of bacterial resistance to antibiotics. The objective of this work was to describe and analyse antibiotic resistance of H. influenzae from 2017 to 2021 in France.

METHODS

We characterized H. influenzae isolates transmitted to the French national reference centre for H. influenzae between 2017 and 2021. We included all the 608 non-invasive respiratory isolates. Resistance rates to the main antibiotics were described. The relationship between resistance rate, age, and sex of patients and germ serotype was investigated.

RESULTS

Isolates were mainly from alveolar lavage (29.3%), expectoration (22.9%), or sputum (15%). Resistance to amoxicillin (61.4%), amoxicillin/clavulanic acid (47.4%), and cefotaxime (39.3%) was high and correlated with the presence of β-lactamase and/or modifications of the ftsI gene encoding penicillin-binding protein 3. Resistance to sulfamethoxazole/trimethoprim (33.2%) was more moderate. There were no significant differences according to serotype, age, or gender.

CONCLUSIONS

The benefit/risk balance of first choice use of amoxicillin and even of amoxicillin/clavulanic acid in AOM is questionable in view of the significant resistance to H. influenzae. The use of sulfamethoxazole/trimethoprim could be an alternative but may still need further evaluation.

Diversity of amino acid substitutions of penicillin-binding proteins in penicillin-non-susceptible and non-vaccine type Streptococcus pneumoniae

PURPOSE

In Japan, the introduction of pneumococcal conjugate vaccine (PCV) in children has decreased vaccine-type (VT) pneumococcal infections caused by penicillin (PEN)-non-susceptible Streptococcus pneumoniae. PEN-non-susceptible strains have gradually emerged among non-vaccine types (NVT). In this study, we aim to investigate the pbp gene mutations and the characteristics of PEN-binding proteins (PBPs) that mediate PEN resistance in NVT strains.

MATERIALS AND METHODS

Pneumococcal 41 strains of NVT isolated from patients with invasive pneumococcal infection were randomly selected. Nucleotide sequences for pbp genes encoding PBP1A, PBP2X, and PBP2B were analyzed, and amino acid (AA) substitutions that contribute to β-lactam resistance were identified. In addition, the three-dimensional (3D) structure of abnormal PBPs in the resistant strain was compared with that of a reference R6 strain via homology modeling.

RESULTS

In PEN-non-susceptible NVT strains, Thr to Ala or Ser substitutions in the conserved AA motif (STMK) were important in PBP1A and PBP2X. In PBP2B, substitutions from Thr to Ala, adjacent to the SSN motif, and from Glu to Gly were essential. The 3D structure modeling indicated that AA substitutions are characterized by accumulation around the enzymatic active pocket in PBPs. Many AA substitutions detected throughout the PBP domains were not associated with resistance, except for AA substitutions in or adjacent to AA motifs. Clonal complexes and sequence types showed that almost all NVT cases originated in other countries and spread to Japan via repeat mutations.

CONCLUSIONS

NVT with diverse AA substitutions increased gradually with pressure from both antimicrobial agents and vaccines.

Investigation on the virulence of non-encapsulated Streptococcus pneumoniae using liquid agar pneumonia model

INTRODUCTION

Since the introduction of pneumococcal conjugate vaccine, there have been warnings of an increase in infections caused by non-vaccine type of Streptococcus pneumoniae strains. Among them, nonencapsulated Streptococcus pneumoniae (NESp) has been reported to cause invasive infections, especially in children and the elderly. Due to low virulence, however, basic experimental reports on invasive infections are limited.

METHODS

We applied a liquid-agar method to establish a mouse model of invasive NESp infection. Mice were intratracheally administered a bacterial suspension including agar. With this technique, we investigated the pathogenicity of NESp and the effect of Pneumococcal surface protein K (PspK), a specific surface protein antigen of NESp. NESp wild-type strain (MNZ11) and NESp pspK-deleted mutant strain (MNZ1131) were used in this study. The survival rate, number of bacteria, cytokine/chemokine levels in the bronchoalveolar lavage fluid, and histology of the lung tissue were evaluated.

RESULTS

Mice that were intratracheally administered MNZ11 developed lethal pneumonia with bacteremia within 48 h. Conversely, MNZ1131 showed predominantly low lethality without significant pro-inflammatory cytokine production. NESp was found to cause severe pneumonia and bacteremia upon reaching the lower respiratory tract, and PspK was a critical factor of NESp for developing invasive infections.

CONCLUSIONS

The current study demonstrated the ability of NESp to develop invasive diseases, especially in connection with PspK by use of a mouse pneumonia model.

Estimating population-based incidence of community-acquired pneumonia and acute otitis media in children and adults in Ontario and British Columbia using health administrative data, 2005-2018: a Canadian Immunisation Research Network (CIRN) study

BACKGROUND

There is a paucity of data on the burden of the full spectrum of community-acquired pneumonia (CAP) and acute otitis media (AOM) from outpatient and inpatient settings across the age spectrum.

METHODS

We conducted a population-based retrospective study in Ontario and British Columbia (BC), Canada, to estimate the incidence rate of CAP and AOM in children and adults over a 14-year period using health administrative databases. CAP and AOM cases were identified from outpatient physician consultation and hospitalisation data in both provinces, and from emergency department visit data in Ontario.

RESULTS

During 2005-2018, Ontario had 3 607 124 CAP, 172 290 bacterial CAP, 7814 pneumococcal pneumonia, and 8 026 971 AOM cases. The incidence rate of CAP declined from 3077/100 000 in 2005 to 2604/100 000 in 2010 before increasing to 2843/100 000 in 2018; bacterial CAP incidence rate also declined from 178/100 000 in 2005 to 112/100 000 in 2010 before increasing to 149/100 000 in 2018. The incidence rate of AOM decreased from 4192/100 000 in 2005 to 3178/100 000 in 2018. BC had 970 455 CAP, 317 913 bacterial CAP, 35 287 pneumococcal pneumonia and 2 022 871 AOM cases. The incidence rate of CAP in BC decreased from 2214/100 000 in 2005 to 1964/100 000 in 2010 before increasing to 2176/100 000 in 2018; bacterial CAP incidence rate increased from 442/100 000 in 2005 to 981/100 000 in 2018. The incidence rate of AOM decreased from 3684/100 000 in 2005 to 2398/100 000 in 2018. The incidence rate of bacterial CAP increased with age in older adults (≥65 years) with the highest burden in the oldest cohort aged ≥85 years both before and after 13-valent pneumococcal conjugate vaccine (PCV13) programme in both provinces. Hospitalised pneumococcal pneumonia decreased slightly but non-hospitalised pneumococcal pneumonia increased in BC during PCV13 period. No consistent direct benefit of PCV13 on CAP was observed in the paediatric population.

CONCLUSIONS

There is a substantial burden of CAP and AOM in Ontario and BC. Indirect benefits from childhood PCV vaccination and polysaccharide vaccination of older adults have not substantially decreased the burden of pneumococcal pneumonia in older adults.

The broader impacts of otitis media and sequelae for informing economic evaluations of pneumococcal conjugate vaccines

INTRODUCTION

Otitis media (OM) is a common childhood infection. Pneumococcal conjugate vaccines (PCVs) prevent OM episodes, thereby reducing short- and long-term clinical, economic, humanistic, and societal consequences. Most economic evaluations of PCVs focus on direct health gains and cost savings from prevented acute episodes but do not fully account for the broader societal impacts of OM prevention.

AREAS COVERED

This review explores the broader burden of OM on children, caregivers, and society to better inform future economic evaluations of PCVs.

EXPERT OPINION

OM causes a substantial burden to society through long-term sequelae, productivity losses, reduced quality of life for children and caregivers, and contribution to antimicrobial resistance from inappropriate antibiotic use. The effect of PCVs on acute OM has been recognized globally, yet the broader impact has not been consistently quantified, studied, or communicated. Economic evaluations of PCVs must evolve to include broader effects for patients, caregivers, and society from OM prevention. Future PCVs with broader coverage may further reduce OM incidence and antimicrobial resistance, but optimal uptake will depend on increasing the recognition and use of novel frameworks that include broader benefits. Communicating the full value of PCVs to decision makers may result in wider access and positive societal returns.

Two decades of otitis media in northern Israel: Changing trends in the offending bacteria and antibiotic susceptibility

OBJECTIVE

Bacteriology and antibiotic resistance trends changed considerably following introduction of the pneumococcal conjugate vaccines (PCV) 7 and 13, with differences between geographic regions. The objective of this study was to evaluate changes in acute otitis media (AOM) bacteriology and antibiotic susceptibility from the pre-vaccination period (2002-2008) to after the introduction of PCV13 (2010-2019) in northern Israel.

METHODS

Data were collected from 3277 middle ear fluid (MEF) cultures and 4822 common AOM-generating pathogens of children aged <5 years with otitis media, taken during 2002-2019. Age of the child, bacteriology, and antibiotic resistance were compared between 2002 and 2008, the pre-vaccination period when no vaccination was available and 2010-2019 when PCV13 was introduced.

RESULTS

The mean age of the children in the pre-vaccination and the vaccination periods was 18.7 ± 13.7 and 15.7 ± 12.5 months, respectively (p < 0.001); the mean age of those with group A streptococcus (GAS) positive cultures was older, p < 0.001.The prevalence of Streptococcus pneumoniae (S. pneumoniae) decreased between those periods, from 47% to 25.8%, p < 0.001, Haemophilus influenzae (H. influenza) increased from 38.4% to 47.1%, p < 0.001, GAS increased from 12.9% to 23.8%, p < 0.001, and Moraxella catarrhalis (M. cat) increased but not statistically significant from 1.7% to 3.1%. The yearly number of positive MEF cultures decreased from 395.1 to 205.6, p < 0.001. The antibiotic sensitivity rate of almost all antibiotics increased between the two study periods.

CONCLUSION

The most common MEF bacteria in northern Israel today is H. influenzae. Comparing the pre-vaccination to the vaccination period, the incidence of S. pneumonia-positive cultures decreased while GAS and H. influenza cultures increased. The age of children with positive cultures increased, and the antibiotic sensitivity rate increased. Key This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Novel Antimicrobial Treatment Strategy Based on Drug Delivery Systems for Acute Otitis Media

Despite tremendous success of pneumococcal conjugated vaccine and antimicrobial treatment by amoxicillin, acute otitis media (AOM) still remains as a great medical concern. Failure of antimicrobial treatment includes several factors. The middle ear cavity is surrounded by bone tissue, which makes it difficult to maintain sufficient concentration of antibiotics. Tympanic membrane of AOM patients thickens and actually becomes a barrier for topical therapy. This review discusses novel antimicrobial treatment strategies based on drug delivery systems (DDS) for AOM. To deliver drugs enough to kill the pathogenic bacteria without systemic side effects, the development of new antimicrobial treatment strategy applying innovative drug DDS has been expected. The sustained-release DDS can achieve sufficient time for antimicrobial concentrations to exceed minimum inhibitory concentration (MIC) for time-dependent antibiotics as well as enough maximum concentration for dose-dependent antibiotics to eradicate causative pathogens in the middle ear. The development of trans-tympanic membranes of DDS, such as hydrogels with chemical permeation enhancers (CPEs), is another attractive strategy. Phage is a promising strategy for developing DDS-based therapies. The DDS formulations enable antimicrobial treatment of AOM by a single dose and thus, an attractive future antimicrobial treatment for AOM.

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.

Improvement in the appropriate antimicrobial usage for treating pediatric acute otitis media in Japan: A descriptive study using nation-wide electronic medical record data

OBJECTIVES

We investigated changes in prescriptions for antimicrobial agents to treat children with acute otitis media (AOM).

METHODS

A descriptive study using an electronic medical record database. Of 199,896 patients enrolled between 2001 and 2019, a total of 10,797 were aged <16 years and had AOM as their first and primary disease (overall pediatric AOM cohort). In addition, 4786 patients with AOM without other comorbidities (pediatric AOM cohort) were included.

RESULTS

In the overall pediatric AOM cohort, the age distribution ranged from 11% to 23% for those younger than 2 years and from 66% to 77% for those younger than 6 years, with no change over time. In the pediatric AOM cohort, the antimicrobial prescription rate was 91% in 2001 but declined to 40% by 2019. Antimicrobial use increased from 0% to 75% for penicillins, whereas use of cephalosporins decreased from 84% to 10%. The prescription rate for acetaminophen alone increased from 33% to 58%. There were no differences in the incidence of adverse reactions among the prescribed antimicrobials.

CONCLUSIONS

Due to education efforts and promotion of the proper use of antimicrobials through means such as the Clinical practice guidelines for the diagnosis and management of acute otitis media in children (2006) and the Manual of Antimicrobial Stewardship (2016), a change in the use of antimicrobials occurred, leading to a trend to more proper use of these agents.

A single nucleotide polymorphism in an IgA1 protease gene determines Streptococcus pneumoniae adaptation to the middle ear during otitis media

Factors facilitating the chronicity of otitis media (OM) in children are, to date, not fully understood. An understanding of molecular factors aiding bacterial persistence within the middle ear during OM could reveal pathways required for disease. This study performed a detailed analysis of Streptococcus pneumoniae populations isolated from the nasopharynx and middle ear of one OM case. Isolates were assessed for growth in vitro and infection in a mouse intranasal challenge model. Whole genome sequencing was performed to compare the nasopharyngeal and middle ear isolates. The middle ear isolate displayed a reduced rate of growth and enhanced potential to transit to the middle ear in a murine model. The middle ear population possessed a single nucleotide polymorphism (SNP) in the IgA1 protease gene igA, predicted to render its product non-functional. Allelic exchange mutagenesis of the igA alleles from the genetic variant middle ear and nasopharyngeal isolates was able to reverse the niche-adaptation phenotype in the murine model. These results indicate the potential role of a SNP in the gene encoding the IgA1 protease, in determining S. pneumoniae adaptation to the middle ear during chronic OM. In contrast, a functional IgA1 protease was associated with increased colonisation of the nasopharynx.

Drastic reduction in pneumococcal meningitis in children owing to the introduction of pneumococcal conjugate vaccines: Longitudinal analysis from 2002 to 2016 in Japan

INTRODUCTION

The characteristics of pneumococcal isolates and their associations with outcomes in pediatric meningitis are unclear. This study aimed to clarify serotypes and resistance genotypes of Streptococcus pneumoniae from children with meningitis and evaluate the patient prognoses and backgrounds.

METHODS

Large-scale surveillance was conducted from 2002 to 2016 through periods I-V. Serotypes and penicillin (PEN) resistance genotypes were analyzed for pneumococcal isolates (n = 459) and cerebrospinal fluid (CSF) samples (n = 25). Furthermore, underlying diseases (n = 251), prognoses (n = 202), and laboratory data were evaluated.

RESULTS

The number of meningitis cases decreased drastically after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7) to -53.6% and after switching to PCV13 to -70.2%. In particular, this reduction was apparent at ≤3 years of age. The proportion of the PCV7 serotype decreased sharply from 70.1% before introduction to 2.6% during period V; however, the non-vaccine type increased from 17.5% to 87.2%. The PEN resistance rate (gPRSP) was decreased from approximately 49% to 12.2% during period V. Among cases revealed prognosis, sequelae and mortality rates were 16.3% and 5.4%, respectively. The rate of the patients with underlying diseases was 26.3% and relatively high in ≥6 years. Laboratory data associated with a poor prognosis were low white blood cell count (<12.7 × 10³/μL), low platelet count (<28.1 × 10⁴/μL), low CSF-glucose (<36 mg/dL), and high CSF-protein (≥142 mg/dL).

CONCLUSIONS

Changes in serotype prevalence warrant continuous monitoring to observe future trends of pneumococcal meningitis, and further developments in multivalent conjugate vaccines are required.

Molecular epidemiological characterization in mucoid-type Streptococcus pneumoniae isolates obtained from invasive pneumococcal disease patients in Japan

INTRODUCTION

Streptococcus pneumoniae with a mucoid-type capsule is associated with invasive pneumococcal diseases (IPDs). Despite the introduction of pneumococcal vaccines, IPDs caused by mucoid-type isolates are still prevalent. The present study aimed to characterize mucoid-type S. pneumoniae isolated from IPD patients throughout Japan in 2017 (post-vaccination era).

METHODS

A total of 225 mucoid-type isolates were collected. The serotype, antimicrobial susceptibility, and multilocus sequence type of these isolates were determined.

RESULTS

The prevalence of IPDs caused by mucoid-type isolates was high in adults, especially in the elderly (≥65 years of age), and prognosis in these patients was significantly poor. Of the mucoid-type isolates, the predominant serotype was serotype 3 (84.4%), and the remaining were serotypes 37 (15.1%) and 8 (0.4%). Antimicrobial susceptibility showed that most mucoid isolates exhibited the penicillin-intermediate resistant S. pneumoniae genotype (gPISP). However, the serotype 3 isolate exhibited the penicillin-resistant S. pneumoniae genotype (gPRSP). This gPRSP isolate was classified into ST166, which is related to serotypes 9 V and 11 strains. Sequence analysis of the capsule-coding regions and its flanking regions indicated that recombination occurred upstream and downstream of the capsule-coding region, suggesting that gPRSP (serotype 9 V/ST166) obtaining the type-3 capsule gene cluster resulted in the emergence of gPRSP (serotype 3/ST166).

CONCLUSIONS

Our findings indicated that IPDs caused by mucoid-type S. pneumoniae are still a serious concern and mucoid-type S. pneumoniae with novel phenotype could emerge via capsular switching in response to environmental changes such as introduction of vaccines and improper use of antimicrobial agents.

Children in Coronaviruses' Wonderland: What Clinicians Need to Know

Human coronaviruses (HCoVs) commonly cause mild upper-respiratory tract illnesses but can lead to more severe and diffusive diseases. A variety of signs and symptoms may be present, and infections can range in severity from the common cold and sore throat to more serious laryngeal or tracheal infections, bronchitis, and pneumonia. Among the seven coronaviruses that affect humans (SARS)-CoV, the Middle East respiratory syndrome (MERS)-CoV, and the most recent coronavirus disease 2019 (COVID-19) represent potential life-threatening diseases worldwide. In adults, they may cause severe pneumonia that evolves in respiratory distress syndrome and multiorgan failure with a high mortality rate. Children appear to be less susceptible to develop severe clinical disease and present usually with mild and aspecific symptoms similar to other respiratory infections typical of childhood. However, some children, such as infants, adolescents, or those with underlying diseases may be more at-risk categories and require greater caution from clinicians. Available data on pediatric coronavirus infections are rare and scattered in the literature. The purpose of this review is to provide to clinicians a complete and updated panel useful to recognize and characterize the broad spectrum of clinical manifestations of coronavirus infections in the pediatric age.

Recent trends in pediatric bacterial meningitis in Japan, 2016-2018 - S. agalactiae has been the most common pathogen

BACKGROUND

Haemophilus influenzae type b (Hib) vaccine and pneumococcal conjugated vaccine (PCV) have been widely used since 2010 in Japan. The overall incidence of bacterial meningitis decreased thereafter. Streptococcus agalactiae has become the main organism.

OBJECTIVES

The purpose of the present study was to investigate the incidence rate per 1000 admissions of bacterial meningitis and the change in causative organisms in subsequent years.

METHODS

A cross-sectional, multicenter, non-interventional retrospective study regarding pediatric bacterial meningitis was conducted in Japan in 2019. We analyzed the epidemiological and clinical data for 2016-2018, and compared the information obtained in our previous nationwide survey database. We also investigated the risk factors for disease outcome.

RESULTS

In the 2016-2018 surveys, 197 patients from 153 hospitals from all prefectures were evaluated. S. agalactiae (0-3 months, 39%), Streptococcus pneumoniae (2-112 months, 20%), and E. coli (0-136 months, 13%) were the main organisms. The total number of patients hospitalized with bacterial meningitis per 1000 admissions decreased from 1.00 to 1.68 in 2000-2010 to 0.38 in 2013-2015, bu remained stable thereafter (0.35-0.40 in 2016-2018). Only one case with Neisseria meningitidis was reported. Nine cases with death were reported, including four cases with S. agalactiae. Risk factors for death and sequelae were consciousness disturbance, duration of convulsion, low CSF glucose levels, and disuse of dexamethasone (p < 0.05).

CONCLUSIONS

The incidence in pediatric bacterial meningitis remained low, and S. agalactiae remains the most common cause of bacterial meningitis in Japan since 2012. S. pneumoniae is the most common cause after 3 months of age.

The prevalence and antimicrobial susceptibility of Streptococcus pneumoniae isolated from patients at Jikei University Hospitals after the implementation of the pneumococcal vaccination program in Japan

Studies have shown that pneumococcal vaccination reduces the incidence of Streptococcus pneumoniae infections but does not change the prevalence of S. pneumoniae nasopharyngeal colonization. To comprehensively and longitudinally assess the epidemiology of S. pneumoniae after the introduction of pneumococcal vaccination, we monitored the prevalence and antimicrobial susceptibility of S. pneumoniae, irrespective of its serotypes or pathogenicity, by analyzing specimens collected from a large number of patients at Jikei University Hospitals from 2009 to 2017. A total of 5763 S. pneumoniae isolates were identified out of 375,435 specimens from various sources of patients in different age groups. The prevalence of S. pneumoniae isolated only from patients <5 years old was significantly reduced with the widespread use of pneumococcal vaccines, although this reduction differed by areas where patients resided. The incidence of pneumococcal infections, including bacteremia and otitis media, clearly decreased among patients <5 years old after the introduction of pneumococcal vaccination, while the prevalence of S. pneumoniae isolated from blood specimens of patients 15-64 years old increased, suggesting the involvement of non-vaccine serotypes in the incidence of invasive pneumococcal infections. The antimicrobial susceptibility of S. pneumoniae improved after the introduction of pneumococcal vaccination. Our results show that pneumococcal vaccination has a suppressive effect on the prevalence of S. pneumoniae and the incidence of pneumococcal infections, at least for children <5 years old, in association with an improvement in the antimicrobial susceptibility of S. pneumoniae. However, further measures will be needed to control invasive pneumococcal infections caused by non-vaccine serotypes.

Epidemiology of hospitalised paediatric community-acquired pneumonia and bacterial pneumonia following the introduction of 13-valent pneumococcal conjugate vaccine in the national immunisation programme in Japan

Studies on community-acquired pneumonia (CAP) and pneumococcal pneumonia (PP) related to the 13-valent pneumococcal conjugate vaccine (PCV13) introduction in Asia are scarce. This study aimed to investigate the epidemiological and microbiological determinants of hospitalised CAP and PP after PCV13 was introduced in Japan. This observational hospital-based surveillance study included children aged ⩽15 years, admitted to hospitals in and around Chiba City, Japan. Participants had bacterial pneumonia based on a positive blood or sputum culture for bacterial pathogens. Serotype and antibiotic-susceptibility testing of Streptococcus pneumoniae and Haemophilus influenzae isolates from patients with bacterial pneumonia were assessed. The CAP hospitalisation rate per 1000 child-years was 17.7, 14.3 and 9.7 in children aged <5 years and 1.18, 2.64 and 0.69 in children aged 5-15 years in 2008, 2012 and 2018, respectively. There was a 45% and 41% reduction in CAP hospitalisation rates, between the pre-PCV7 and PCV13 periods, respectively. Significant reductions occurred in the proportion of CAP due to PP and PCV13 serotypes. Conversely, no change occurred in the proportion of CAP caused by H. influenzae. The incidence of hospitalised CAP in children aged ⩽15 years was significantly reduced after the introduction of PCV13 in Japan. Continuous surveillance is necessary to detect emerging PP serotypes.

Epidemiological and molecular characterization of Streptococcus pneumoniae carriage strains in pre-school children in Arkhangelsk, northern European Russia, prior to the introduction of conjugate pneumococcal vaccines

BACKGROUND

The 13-valent Pneumococcal Conjugate Vaccine (PCV-13) was introduced in the National Immunization Programme (NIP) schedule in Russia in March 2014. Previously, the 7-valent Pneumococcal Conjugate Vaccine (PCV-7) was marketed in Russia in 2009 but has never been offered for mass vaccination. A carriage study was performed among children in Arkhangelsk in 2006. The objective was to determine the prevalence of carriage, serotype distribution, antimicrobial susceptibility and the molecular structure of Streptococcus pneumoniae strains before marketing and introduction of PCV-13.

METHODS

A cross-sectional study was conducted on a cluster-randomized sample of children and a self-administrated questionnaire for parents/guardians.  Nasopharyngeal samples were collected from 438 children younger than 7 years attending nurseries and kindergartens in the Arkhangelsk region, Russia. Detailed demographic data, as well as information about the child's health, traveling, exposure to antimicrobials within the last 3 months and anthropometric measurements were collected for all study subjects. Variables extracted from the questionnaire were analysed using statistic regression models to estimate the risk of carriage. All pneumococcal  isolates were examined with susceptibility testing, serotyping and multilocus sequence typing.

RESULTS

The overall prevalence of asymptomatic carriage was high and peaking at 36 months with a rate of 57%. PCV-13 covered 67.3% of the detected strains. High rates of non-susceptibility to penicillin, macrolides and multidrug resistance were associated with specific vaccine serotypes, pandemic clones, and local sequence types. Nine percent of isolates represented three globally disseminated disease-associated pandemic clones; penicillin- and macrolide-resistant clones Norway^NT-42 and Poland^6B-20, as well as penicillin- and macrolide-susceptible clone Netherlands³-31. A high level of antimicrobial consumption was noted by the study. According to the parent's reports, 89.5% of the children used at least one antimicrobial regime since birth. None of the hypothesised predictors of S. pneumoniae carriage were statistically significant in univariable and multivariable logistic models.

CONCLUSIONS

The study identified a high coverage of the PCV-13-vaccine, but serotype replacement and expansion of globally disseminated disease-associated clones with non-vaccine serotypes may be expected. Further surveillance of antimicrobial resistance and serotype distribution is therefore required.

Panel 7 - Pathogenesis of otitis media - a review of the literature between 2015 and 2019

OBJECTIVE

To perform a comprehensive review of the literature from July 2015 to June 2019 on the pathogenesis of otitis media. Bacteria, viruses and the role of the microbiome as well as the host response are discussed. Directions for future research are also suggested.

DATA SOURCES

PubMed database of the National Library of Medicine.

REVIEW METHODS

PubMed was searched for any papers pertaining to OM pathogenesis between July 2015 and June 2019. If in English, abstracts were assessed individually for their relevance and included in the report. Members of the panel drafted the report based on these searches and on new data presented at the 20th International Symposium on Recent Advances in Otitis Media.

CONCLUSIONS

The main themes that arose in OM pathogenesis were around the need for symptomatic viral infections to develop disease. Different populations potentially having different mechanisms of pathogenesis. Novel bacterial otopathogens are emerging and need to be monitored. Animal models need to continue to be developed and used to understand disease pathogenesis.

IMPLICATIONS FOR PRACTICE

The findings in the pathogenesis panel have several implications for both research and clinical practice. The most urgent areas appear to be to continue monitoring the emergence of novel otopathogens, and the need to develop prevention and preventative therapies that do not rely on antibiotics and protect against the development of the initial OM episode.

Panel 8: Vaccines and immunology

OBJECTIVE

To review and highlight significant advances made towards vaccine development and understanding of the immunology of otitis media (OM) since the 19th International Symposium on Recent Advances in Otitis Media (ISOM) in 2015, as well as identify future research directions and knowledge gaps.

DATA SOURCES

PubMed database, National Library of Medicine.

REVIEW METHODS

Key topics were assigned to each panel member for detailed review. Draft reviews were collated, circulated, and thoroughly discussed when the panel met at the 20th ISOM in June 2019. The final manuscript was prepared with input from all panel members.

CONCLUSIONS

Since 2015 there have been a number of studies assessing the impact of licensed pneumococcal vaccines on OM. While these studies have confirmed that these vaccines are effective in preventing carriage and/or disease caused by vaccine serotypes, OM caused by non-vaccine serotype pneumococci and other otopathogens remains a significant health care burden globally. Development of multi-species vaccines is challenging but essential to reducing the global burden of OM. Influenza vaccination has been shown to prevent acute OM, and with novel vaccines against nontypeable Haemophilus influenzae (NTHi), Moraxella catarrhalis and Respiratory Syncytial Virus (RSV) in clinical trials, the potential to significantly prevent OM is within reach. Research into alternative vaccine delivery strategies has demonstrated the power of maternal and mucosal vaccination for OM prevention. Future OM vaccine trials must include molecular diagnostics of middle ear effusion, for detection of viruses and bacteria that are persisting in biofilms and to enable accurate assessment of vaccine impact on OM etiology. Understanding population differences in natural and vaccine-induced immune responses to otopathogens is also important for development of the most effective OM vaccines. Improved understanding of the interaction between otopathogens will also advance development of effective therapies and encourage the assessment of the indirect benefits of vaccination.

IMPLICATIONS FOR PRACTICE

While NTHi and M. catarrhalis are the predominant otopathogens, funding opportunities to drive vaccine development for these species are limited due to a focus on prevention of childhood mortality rather than morbidity. Delivery of a comprehensive report on the high financial and social costs of OM, including the potential for OM vaccines to reduce antibiotic use and subsequent development of antimicrobial resistance (AMR), would likely assist in engaging stakeholders to recognize the value of prevention of OM and increase support for efforts on OM vaccine development. Vaccine trials with OM prevention as a clinical end-point are challenging, however a focus on developing assays that measure functional correlates of protection would facilitate OM vaccine development.

A Cross-Reactive Protein Vaccine Combined with PCV-13 Prevents Streptococcus pneumoniae- and Haemophilus influenzae-Mediated Acute Otitis Media

Acute otitis media is one of the most common childhood infections worldwide. Currently licensed vaccines against the common otopathogen Streptococcus pneumoniae target the bacterial capsular polysaccharide and confer no protection against nonencapsulated strains or capsular types outside vaccine coverage. Mucosal infections such as acute otitis media remain prevalent, even those caused by vaccine-covered serotypes. Here, we report that a protein-based vaccine, a fusion construct of epitopes of CbpA to pneumolysin toxoid, confers effective protection against pneumococcal acute otitis media for non-PCV-13 serotypes and enhances protection for PCV-13 serotypes when coadministered with PCV-13. Having cross-reactive epitopes, the fusion protein also induces potent antibody responses against nontypeable Haemophilus influenzae and S. pneumoniae, engendering protection against acute otitis media caused by emerging unencapsulated otopathogens. These data suggest that augmenting capsule-based vaccination with conserved, cross-reactive protein-based vaccines broadens and enhances protection against acute otitis media.

Antibiotic Resistance Profiles of Haemophilus influenzae Isolates from Children in 2016: A Multicenter Study in China

BACKGROUND AND OBJECTIVE

Haemophilus influenzae (HI) is a common cause of community-acquired pneumonia in children. In many countries, HI strains are increasingly resistant to ampicillin and other commonly prescribed antibiotics, posing a challenge for effective clinical treatment. This study was undertaken to determine the antibiotic resistance profiles of HI isolates from Chinese children and to provide guidelines for clinical treatment.

METHODS

Our Infectious Disease Surveillance of Pediatrics (ISPED) collaboration group includes six children's hospitals in different regions of China. The same protocols and guidelines were used by all collaborators for the culture and identification of HI. The Kirby-Bauer method was used to test antibiotic susceptibility, and a cefinase disc was used to detect β-lactamase activity.

RESULTS

We isolated 2073 HI strains in 2016: 83.9% from the respiratory tract, 11.1% from vaginal secretions, and 0.5% from blood. Patients with respiratory isolates were significantly younger than nonrespiratory patients (P < 0.001). Of all 2073 strains, 50.3% were positive for β-lactamase and 58.1% were resistant to ampicillin; 9.3% were β-lactamase-negative and ampicillin-resistant. The resistance rates of the HI isolates to trimethoprim-sulfamethoxazole, azithromycin, cefuroxime, ampicillin-sulbactam, cefotaxime, and meropenem were 71.1%, 32.0%, 31.2%, 17.6%, 5.9%, and 0.2%, respectively.

CONCLUSIONS

More than half of the HI strains isolated from Chinese children were resistant to ampicillin, primarily due to the production of β-lactamase. Cefotaxime and other third-generation cephalosporins could be the first choice for the treatment of ampicillin-resistant HI infections.

Impact of the introduction of a 13-valent pneumococcal vaccine on pneumococcal serotypes in non-invasive isolates from 2007 to 2016 at a teaching hospital in Japan

PURPOSE

To prevent severe invasive pneumococcal infection, pneumococcal conjugate vaccines (PCVs) were introduced in Japan in 2010, and in 2013 a pneumococcal 13-valent conjugate vaccine (PCV13) was included in the routine vaccination schedule for infants. In this study, we analysed the antimicrobial susceptibilities and capsular types of pneumococci isolated from non-invasive patient sites from 2007 to 2016 to assess the impact of the introduction of PCV13.

METHODOLOGY

A total of 618 pneumococcal isolates collected at a teaching hospital from 2007 to 2016 were used. These isolates were characterized by capsular typing, multilocus sequence typing and antimicrobial susceptibility testing.

RESULTS

Capsular typing indicated that, after the introduction of the PCV, the proportion of PCV13 serotypes decreased (P<0.01), while non-PCV13 serotypes became diverse. In particular, increases in 22 F, 15A and 23A were noted among non-PCV13 serotypes. Regarding antimicrobial susceptibility, the non-susceptibility rate to penicillin of pneumococci that showed higher minimum inhibitory concentrations (MICs) than the susceptibility breakpoint decreased, and pneumococci tended to become susceptible. However, all type 23A pneumococci and 77.8  % of type 15A pneumococci showed the reverse trend, with low susceptibility to penicillin. Furthermore, all 15A and 23A isolates had macrolide resistance genes.

CONCLUSION

These data suggest that PCVs can prevent infections caused by PCV serotypes. However, since non-PCV13-type pneumococci, in particular 15A and 23A, which have acquired multidrug resistance, have already emerged over time, the development of a novel vaccine targeting a broader spectrum of pneumococci is warranted.

Genetic characteristics and antibiotic resistance of Haemophilus influenzae isolates from pediatric patients with acute otitis media after introduction of 13-valent pneumococcal conjugate vaccine in Japan

Acute otitis media (AOM) occurs commonly in pediatric populations. We examined resistance genotype, antibiotic susceptibility, quinolone (QL) resistance, and multilocus sequence type (MLST) among Haemophilus influenzae isolates causing AOM following introduction of pneumococcal conjugate vaccines in Japan. The AOM surveillance group included 69 participating otolaryngologists. Causative pathogens isolated from middle ear fluid (MEF) samples collected from 582 children with AOM were identified using both bacterial culture and real-time PCR. H. influenzae isolates among these pathogens were characterized by capsular type, resistance genotype, antibiotic susceptibility, QL resistance, and MLST. In 2016, H. influenzae was identified in 319 samples (54.8%), among which 72.4% (n = 231) tested positive by both culture and PCR; remaining H. influenzae cases were only PCR-positive. This proportion of H. influenzae positivity has increased significantly from 41.2% in 2006 (p < 0.001). Among culture-positive strains, genotypic β-lactamase-nonproducing ampicillin (AMP)-resistant (gBLNAR) strains were frequent (63.2%), with β-lactamase-nonproducing AMP-susceptible (gBLNAS) strains accounting for only 24.2%. Susceptibilities of gBLNAR to oral antimicrobials were best for tosufloxacin, followed by cefditoren and tebipenem; MIC₉₀s were 0.031 μg/mL, 0.5 μg/mL, and 1 μg/mL, respectively. In 7 gBLNAR isolates (3.0%), QL susceptibility was low, owing to amino acid substitutions in GyrA and/or ParC. Sequence types identified numbered 107, including 28 that were new. Prevention of further increases in resistance to antimicrobial agents will require antibiotic selection based on characterization of causative pathogens in clinical practice.

Emergence of Haemophilus influenzae with low susceptibility to quinolones and persistence in tosufloxacin treatment

BACKGROUND

The use of non-β-lactam agents has increased in Japan due to the prevalence of β-lactam-resistant pathogens. This study aimed to clarify the recent trend of antimicrobial susceptibility and molecular epidemiological features in Haemophilus influenzae.

METHODS

Fifty-seven Haemophilus influenzae isolated from a Japanese teaching hospital in 2017 were characterised, and the data were compared with those of a previous study. The MICs were determined using the broth dilution method. Genetic backgrounds were compared by multilocus sequence typing. The bactericidal activity of tosufloxacin at, or near, the therapeutic Cmax was determined in vitro, with susceptible isolates and quinolone low-susceptible isolates by time-kill assay.

RESULTS

The results of the susceptibility tests showed that >90% of isolates were susceptible to cephalosporins and carbapenems, whereas ampicillin-susceptible and clarithromycin-susceptible isolates decreased. Regarding quinolones, low-susceptible isolates were noted in 2017, although all isolates were judged as susceptible. All low-susceptible isolates had an amino acid substitution in GyrA, and two isolates had an additional substitution in ParC. These isolates had different genetic backgrounds. Furthermore, the time-kill kinetic assay using the Cmax of tosufloxacin indicated that the low-susceptible isolates could persist for at least 8hours.

CONCLUSIONS

This study revealed that Haemophilus influenzae has demonstrated multidrug low-susceptibility in recent years. The low-susceptible isolates had genetic diversity, meaning that resistance occurred independently.

Association Between Pneumococcal Surface Protein A Family and Genetic/Antimicrobial Resistance Traits of Non-Invasive Pneumococcal Isolates from Adults in Northern Japan

Pneumococcal isolates from adult patients in northern Japan in 2016 were subjected to molecular investigation related to pneumococcal surface protein A (PspA) and drug resistance determinants. Of the 51 isolates, serotype 3/ST180 was the most prevalent (17.6%), followed by 35B (ST2755/ST558) (11.8%) and 15A (ST63/ST7874/ST13068/ST13785) (9.8%). Coverage of serotypes by 13-valent conjugate vaccine and 23-valent polysaccharide vaccine was 27.5% and 49%, respectively. All the isolates expressed PspA family 1 or 2 (51% and 49%, respectively). Each serotype was associated with either of the PspA families (e.g., serotype 3, PspA family 1; serotypes 35B and 15A, PspA family 2). Multidrug resistance (MDR) was found in 84.3% of the isolates. Minimum of one altered penicillin-binding protein gene was detected in 82.4% of isolates, indicating 25.5% non-susceptibility to penicillin. Serotypes 15A and 35B were predominant and demonstrated MDR. An isolate of serotype 15A/ST13785 (single-locus variant of ST242) was resistant to fluoroquinolones associated with double mutation in the quinolone resistance-determining regions of gyrA and parC. The present study indicates the spread of MDR pneumococci represented by isolates of serotypes 3, 15A, and 35B, and prevalence of both PspA family 1 and 2 in isolates obtained from adult patients.

Influenza vaccination and prevention of antimicrobial resistance

INTRODUCTION

Abuse and misuse of available antimicrobial drugs have increased antimicrobial resistance (AMR), with relevant adverse health and economic impacts. Several factors suggest that the influenza vaccine is a possible effective measure to control AMR through a significant reduction in antibiotic consumption. In this paper, aspects related will be discussed.

AREAS COVERED

Although the effectiveness of influenza immunization can significantly vary according to the study design, the circulating influenza viruses, the type of vaccine, the age of the enrolled subjects, the outcome measured and the season of the study, all experts agree that the influenza vaccine can significantly reduce the risk of contracting influenza in subjects of any age. Consequently, influenza vaccination may reduce the number of bacterial superimposed infections that can complicate influenza and require antibiotic prescriptions

EXPERT COMMENTARY

Several indirect and direct observations seem to indicate that influenza vaccines can play an important role in reducing influenza-related antibiotic prescriptions. This finding can lead to at least two undeniable advantages, reductions in drug expenditure and limitations of the risk of favoring AMR development. However, only when universal vaccination is accepted and implemented will the true advantages of the influenza vaccine in reducing AMR development be completely known and exploited.