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result(s) for
"Leach, Amanda"
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Chronic suppurative otitis media
by
Bhutta, Mahmood F
,
Leach, Amanda J
,
Brennan-Jones, Christopher G
in
Adult
,
Anti-Bacterial Agents - therapeutic use
,
Antibiotics
2024
Chronic suppurative otitis media (CSOM) is a leading global cause of potentially preventable hearing loss in children and adults, associated with socioeconomic deprivation. There is an absence of consensus on the definition of CSOM, which complicates efforts for prevention, treatment, and monitoring. CSOM occurs when perforation of the tympanic membrane is associated with severe or persistent inflammation in the middle ear, leading to hearing loss and recurrent or persistent ear discharge (otorrhoea). Cholesteatoma, caused by the inward growth of the squamous epithelium of the tympanic membrane into the middle ear, can also occur. The optimal treatment of discharge in CSOM is topical antibiotics. In resource-limited settings where topical antibiotics might not be available, topical antiseptics are an alternative. For persistent disease, surgery to repair the tympanic membrane or remove cholesteatoma might offer long-term resolution of otorrhoea and potential improvement to hearing. Recent developments in self-fitted air-conduction and bone-conduction hearing aids offer promise as new options for rehabilitation.
Journal Article
Nirsevimab for Prevention of RSV in Healthy Late-Preterm and Term Infants
by
Ren, Pin
,
Hammitt, Laura L
,
Wählby Hamrén, Ulrika
in
Antibodies, Monoclonal, Humanized - administration & dosage
,
Antibodies, Monoclonal, Humanized - adverse effects
,
Antibodies, Monoclonal, Humanized - therapeutic use
2022
Nirsevimab is a monoclonal antibody to the RSV fusion protein that has an extended half-life. In this clinical trial, a single dose of nirsevimab resulted in a significantly lower incidence of medically attended RSV-associated lower respiratory tract infection than that with placebo.
Journal Article
Standard method for detecting upper respiratory carriage of Streptococcus pneumoniae: Updated recommendations from the World Health Organization Pneumococcal Carriage Working Group
by
Turner, Paul
,
Sá-Leão, Raquel
,
Satzke, Catherine
in
Allergy and Immunology
,
Bacteriological Techniques - standards
,
Carriage
2013
•We present updated recommendations from a World Health Organization working group.•These are a core set of standard methods for pneumococcal carriage studies.•Methods for the collection, transport and storage of nasopharyngeal samples are outlined.•Methods for identification and serotyping of pneumococci are described.•The epidemiological rationale for pneumococcal carriage studies is described.
In 2003 the World Health Organization (WHO) convened a working group and published a set of standard methods for studies measuring nasopharyngeal carriage of Streptococcus pneumoniae (the pneumococcus). The working group recently reconvened under the auspices of the WHO and updated the consensus standard methods. These methods describe the collection, transport and storage of nasopharyngeal samples, as well as provide recommendations for the identification and serotyping of pneumococci using culture and non-culture based approaches. We outline the consensus position of the working group, the evidence supporting this position, areas worthy of future research, and the epidemiological role of carriage studies. Adherence to these methods will reduce variability in the conduct of pneumococcal carriage studies undertaken in the context of pneumococcal vaccine trials, implementation studies, and epidemiology studies more generally so variability in methodology does not confound the interpretation of study findings.
Journal Article
Acute otitis media symptoms and symptom scales in research with Aboriginal and Torres Strait Islander children
by
Abbott, Penelope
,
Walsh, Robyn
,
Hu, Wendy C. Y.
in
Analysis
,
Antibiotics
,
Australian Aboriginal and Torres Strait Islander Peoples
2023
Aboriginal and Torres Strait Islander children experience a high burden of otitis media. We collected data on symptoms associated with acute otitis media (AOM) in a clinical trial involving children receiving primary care at urban Aboriginal Medical Services. Two scales were employed to monitor symptoms over time: the AOM-Severity of Symptoms scale (AOM-SOS) and the AOM-Faces Scale (AOM-FS). This study took place at a mid-point of the un-blinded trial.
We examined symptoms at enrolment and day 7, and compared the scales for trends, and bivariate correlation (Spearman's rho) over 14 days. Responsiveness of the scales to clinical change was determined by Friedman's test of trend in two subgroups stratified by day 7 AOM status. We interviewed parents/carers and research officers regarding their experience of the scales and analysed data thematically.
Data derived from 224 children (18 months to 16 years; median 3.6 years). Common symptoms associated with AOM at baseline were runny nose (40%), cough (38%) and irritability (36%). More than one third had no or minimal symptoms at baseline according to AOM-SOS (1-2/10) and AOM-FS scores (1-2/7). The scales performed similarly, and were moderately correlated, at all study points. Although scores decreased from day 0 to 14, trends and mean scores were the same whether AOM was persistent or resolved at day 7. Users preferred the simplicity of the AOM-FS but encountered challenges when interpreting it.
We found minimally symptomatic AOM was common among Aboriginal and Torres Strait Islander children in urban settings. The AOM-SOS and AOM-FS functioned similarly. However, it is likely the scales measured concurrent symptoms related to upper respiratory tract infections, given they did not differentiate children with persistent or resolved AOM based on stringent diagnostic criteria. This appears to limit the research and clinical value of the scales in monitoring AOM treatment among Aboriginal and Torres Strait Islander children.
Journal Article
Molecular and phenotypic characteristics of RSV infections in infants during two nirsevimab randomized clinical trials
by
Mankad, Vaishali S.
,
Sparklin, Benjamin
,
Ahani, Bahar
in
13/1
,
631/250/2152/2153/1291
,
692/308/3187
2023
Nirsevimab is a monoclonal antibody that binds to the respiratory syncytial virus (RSV) fusion protein. During the Phase 2b (NCT02878330) and MELODY (NCT03979313) clinical trials, infants received one dose of nirsevimab or placebo before their first RSV season. In this pre-specified analysis, isolates from RSV infections were subtyped, sequenced and analyzed for nirsevimab binding site substitutions; subsequently, recombinant RSVs were engineered for microneutralization susceptibility testing. Here we show that the frequency of infections caused by subtypes A and B is similar across and within the two trials. In addition, RSV A had one and RSV B had 10 fusion protein substitutions occurring at >5% frequency. Notably, RSV B binding site substitutions were rare, except for the highly prevalent I206M:Q209R, which increases nirsevimab susceptibility; RSV B isolates from two participants had binding site substitutions that reduce nirsevimab susceptibility. Overall, >99% of isolates from the Phase 2b and MELODY trials retained susceptibility to nirsevimab.
Nirsevimab binds the respiratory syncytial virus (RSV) fusion protein and has been tested for RSV prevention in clinical trials. Here, the authors analyse RSV from infections and show that binding site substitutions are rare and that over 99% of isolates remain susceptible to nirsevimab.
Journal Article
What does microbiology have to do with the Hearing for Learning Initiative (HfLI)?
2022
Where would we be without microbiology in tackling the high prevalence of otitis media (OM; middle ear infection) and disabling hearing loss that disadvantage Australian First Nations children living in remote communities? Understanding the microbiology of OM in this population has been critical in directing innovative clinical trials research and developing appropriate evidence-based practice guidelines. While these processes are critical to reducing disadvantage associated with OM and disabling hearing loss, a remaining seemingly insurmountable gap has remained, threatening progress in improving the lives of children with ear and hearing problems. That gap is created by the crisis in primary health care workforce in remote communities. Short stay health professionals and fly-in fly-out specialist services are under-resourced to manage the complex needs of the community, including prevention and treatment of otitis media and hearing loss rehabilitation. Hence the rationale for the Hearing for Learning Initiative – a workforce enhancement model to improve sustainability, cultural appropriateness, and effectiveness of evidence-based ear and hearing health care for young children in remote settings. This paper summarises the role of microbiology in the pathway to the Hearing for Learning Initiative.
Journal Article
Epidemiology of nasopharyngeal carriage of respiratory bacterial pathogens in children and adults: cross-sectional surveys in a population with high rates of pneumococcal disease
by
Morris, Peter S
,
Leach, Amanda J
,
Fisher, Janelle
in
Adolescent
,
Adult
,
Australia - epidemiology
2010
Background
To determine the prevalence of carriage of respiratory bacterial pathogens, and the risk factors for and serotype distribution of pneumococcal carriage in an Australian Aboriginal population.
Methods
Surveys of nasopharyngeal carriage of
Streptococcus pneumoniae
, non-typeable
Haemophilus influenzae
, and
Moraxella catarrhalis
were conducted among adults (≥16 years) and children (2 to 15 years) in four rural communities in 2002 and 2004. Infant seven-valent pneumococcal conjugate vaccine (7PCV) with booster 23-valent pneumococcal polysaccharide vaccine was introduced in 2001. Standard microbiological methods were used.
Results
At the time of the 2002 survey, 94% of eligible children had received catch-up pneumococcal vaccination. 324 adults (538 examinations) and 218 children (350 examinations) were enrolled. Pneumococcal carriage prevalence was 26% (95% CI, 22-30) among adults and 67% (95% CI, 62-72) among children. Carriage of non-typeable
H. influenzae
among adults and children was 23% (95% CI, 19-27) and 57% (95% CI, 52-63) respectively and for
M. catarrhalis
, 17% (95% CI, 14-21) and 74% (95% CI, 69-78) respectively. Adult pneumococcal carriage was associated with increasing age (p = 0.0005 test of trend), concurrent carriage of non-typeable
H. influenzae
(Odds ratio [OR] 6.74; 95% CI, 4.06-11.2) or
M. catarrhalis
(OR 3.27; 95% CI, 1.97-5.45), male sex (OR 2.21; 95% CI, 1.31-3.73), rhinorrhoea (OR 1.66; 95% CI, 1.05-2.64), and frequent exposure to outside fires (OR 6.89; 95% CI, 1.87-25.4). Among children, pneumococcal carriage was associated with decreasing age (p < 0.0001 test of trend), and carriage of non-typeable
H. influenzae
(OR 9.34; 95% CI, 4.71-18.5) or
M. catarrhalis
(OR 2.67; 95% CI, 1.34-5.33). Excluding an outbreak of serotype 1 in children, the percentages of serotypes included in 7, 10, and 13PCV were 23%, 23%, and 29% (adults) and 22%, 24%, and 40% (2-15 years). Dominance of serotype 16F, and persistent 19F and 6B carriage three years after initiation of 7PCV is noteworthy.
Conclusions
Population-based carriage of
S. pneumoniae
, non-typeable
H. influenzae
, and
M. catarrhalis
was high in this Australian Aboriginal population. Reducing smoke exposure may reduce pneumococcal carriage. The indirect effects of 10 or 13PCV, above those of 7PCV, among adults in this population may be limited.
Journal Article
Molecular Surveillance of True Nontypeable Haemophilus influenzae: An Evaluation of PCR Screening Assays
2012
Unambiguous identification of nontypeable Haemophilus influenzae (NTHi) is not possible by conventional microbiology. Molecular characterisation of phenotypically defined NTHi isolates suggests that up to 40% are Haemophilus haemolyticus (Hh); however, the genetic similarity of NTHi and Hh limits the power of simple molecular techniques such as PCR for species discrimination.
Here we assess the ability of previously published and novel PCR-based assays to identify true NTHi. Sixty phenotypic NTHi isolates, classified by a dual 16S rRNA gene PCR algorithm as NTHi (n = 22), Hh (n = 27) or equivocal (n = 11), were further characterised by sequencing of the 16S rRNA and recA genes then interrogated by PCR-based assays targeting the omp P2, omp P6, lgtC, hpd, 16S rRNA, fucK and iga genes. The sequencing data and PCR results were used to define NTHi for this study. Two hpd real time PCR assays (hpd#1 and hpd#3) and the conventional iga PCR assay were equally efficient at differentiating study-defined NTHi from Hh, each with a receiver operator characteristic curve area of 0.90 [0.83; 0.98]. The hpd#1 and hpd#3 assays were completely specific against a panel of common respiratory bacteria, unlike the iga PCR, and the hpd#3 assay was able to detect below 10 copies per reaction.
Our data suggest an evolutionary continuum between NTHi and Hh and therefore no single gene target could completely differentiate NTHi from Hh. The hpd#3 real time PCR assay proved to be the superior method for discrimination of NTHi from closely related Haemophilus species with the added potential for quantification of H. influenzae directly from specimens. We suggest the hpd#3 assay would be suitable for routine NTHi surveillance and to assess the impact of antibiotics and vaccines, on H. influenzae carriage rates, carriage density, and disease.
Journal Article
High Nasopharyngeal Carriage of Non-Vaccine Serotypes in Western Australian Aboriginal People Following 10 Years of Pneumococcal Conjugate Vaccination
by
Stemberger, Natalie A.
,
Richmond, Peter C.
,
Leach, Amanda J.
in
Adolescent
,
Adult
,
Age Distribution
2013
Invasive pneumococcal disease (IPD) continues to occur at high rates among Australian Aboriginal people. The seven-valent pneumococcal conjugate vaccine (7vPCV) was given in a 2-4-6-month schedule from 2001, with a 23-valent pneumococcal polysaccharide vaccine (23vPPV) booster at 18 months, and replaced with 13vPCV in July 2011. Since carriage surveillance can supplement IPD surveillance, we have monitored pneumococcal carriage in western Australia (WA) since 2008 to assess the impact of the 10-year 7vPCV program.
We collected 1,500 nasopharyngeal specimens from Aboriginal people living in varied regions of WA from August 2008 until June 2011. Specimens were cultured on selective media. Pneumococcal isolates were serotyped by the quellung reaction.
Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were carried by 71.9%, 63.2% and 63.3% respectively of children <5 years of age, and 34.6%, 22.4% and 27.2% of people ≥5 years. Of 43 pneumococcal serotypes identified, the most common were 19A, 16F and 6C in children <5 years, and 15B, 34 and 22F in older people. 7vPCV serotypes accounted for 14.5% of all serotypeable isolates, 13vPCV for 32.4% and 23vPPV for 49.9%, with little variation across all age groups. Serotypes 1 and 12F were rarely identified, despite causing recent IPD outbreaks in WA. Complete penicillin resistance (MIC ≥2µg/ml) was found in 1.6% of serotype 19A (5.2%), 19F (4.9%) and 16F (3.2%) isolates and reduced penicillin susceptibility (MIC ≥0.125µg/ml) in 24.9% of isolates, particularly 19F (92.7%), 19A (41.3%), 16F (29.0%). Multi-resistance to cotrimoxazole, tetracycline and erythromycin was found in 83.0% of 23F isolates. Among non-serotypeable isolates 76.0% had reduced susceptibility and 4.0% showed complete resistance to penicillin.
Ten years after introduction of 7vPCV for Aboriginal Australian children, 7vPCV serotypes account for a small proportion of carried pneumococci. A large proportion of circulating serotypes are not covered by any currently licensed vaccine.
Journal Article
Comprehensive Summary of Safety Data on Nirsevimab in Infants and Children from All Pivotal Randomized Clinical Trials
by
Alexandre Kiazand
,
Amanda Leach
,
Manish Shroff
in
Anaphylaxis
,
Antibodies, Monoclonal, Humanized - administration & dosage
,
Antibodies, Monoclonal, Humanized - adverse effects
2024
Background: Nirsevimab is approved in the US for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants during their first RSV season and in children aged ≤24 months who remain vulnerable to severe RSV disease through their second RSV season. We summarize a pre-specified analysis of nirsevimab safety data from three randomized controlled trials: Phase 2b (NCT02878330; healthy infants born ≥29 to <35 weeks’ gestational age [wGA]); Phase 3 MELODY (NCT03979313; healthy infants born ≥35 wGA); and Phase 2/3 MEDLEY (NCT03959488; infants with congenital heart disease [CHD] and/or chronic lung disease of prematurity [CLD] or born ≤35 wGA). Methods: Participants (randomized 2:1) received a single intramuscular dose of nirsevimab or comparator (placebo, Phase 2b/MELODY; 5× once-monthly palivizumab, MEDLEY) before their first RSV season (recipients < 5 kg, nirsevimab 50 mg; ≥5 kg, nirsevimab 100 mg). In MEDLEY, children with CHD/CLD continued to a second RSV season: first-season nirsevimab recipients received nirsevimab 200 mg; first-season palivizumab recipients were re-randomized 1:1 to receive nirsevimab 200 mg or 5× once-monthly palivizumab. Results: The incidence, severity, and nature of AEs were similar across treatments (nirsevimab, n = 3184; placebo, n = 1284; palivizumab, n = 304). Most AEs were mild to moderate in severity, with ≥98% unrelated to treatment. AEs of special interest occurred infrequently (<1%): no anaphylaxis or thrombocytopenia were treatment-related, and no immune complex disease was reported. Deaths (incidence < 1.0%) were all unrelated to treatment. Conclusions: A single dose per season of nirsevimab for the prevention of RSV disease had a favorable safety profile, irrespective of wGA or comorbidities.
Journal Article