Retrospective database analysis for clinical diagnoses commonly associated with pneumococcal diseases in the Malaysian healthcare system over a 3-year period (2013-2015).

BACKGROUND: Pneumococcal disease caused by Streptococcus pneumoniae is an important cause of morbidity and mortality across all ages, particularly in younger children and older adults. Here, we describe pneumococcal disease hospitalizations at Ministry of Health (MoH) facilities in Malaysia between 2013 and 2015. METHODS: This was a retrospective databases analysis. Tabular data from the Malaysian Health Data Warehouse (MyHDW) were used to identify microbiologically confirmed, pneumococcal disease hospitalizations and deaths during hospitalization, using hospital-assigned ICD-10 codes (i.e., classified as meningitis, pneumonia, or non-meningitis non-pneumonia). Case counts, mortality counts, and case fatality rates were reported by patient age group and by Malaysian geographic region. RESULTS: A total of 683 pneumococcal disease hospitalizations were identified from the analysis: 53 pneumococcal meningitis hospitalizations (5 deaths and 48 discharges), 413 pneumococcal pneumonia hospitalizations (24 deaths and 389 discharges), and 205 non-meningitis non-pneumonia pneumococcal disease hospitalizations (58 deaths and 147 discharges). Most hospitalizations occurred in children aged < 2 years. Crude mortality was highest among children aged < 2 years (for all three disease categories), among adults aged ≥ 65 years (for pneumococcal pneumonia), or among adults aged 65-85 years (for non-meningitis non-pneumonia pneumococcal disease). The case fatality rate, all ages included, was 5.8% for pneumococcal pneumonia, 9.1% for pneumococcal meningitis, and 28.3% for non-meningitis non-pneumonia pneumococcal disease. CONCLUSIONS: Our study is the first to document pneumococcal disease hospitalizations and deaths during hospitalization in Malaysia. Although this database analysis likely underestimated case counts, and the true disease burden could be even greater, the study demonstrates a substantial burden of pneumococcal disease. Public health measures, including vaccination, would significantly contribute to the prevention of hospitalizations and deaths associated with pneumococcal disease in Malaysia.

Sensory unpleasantness of very-high frequency sound and audible ultrasound.

Audible very-high frequency sound (VHFS) and ultrasound (US) have been rated more unpleasant than lower frequency sounds when presented to listeners at similar sensation levels (SLs). In this study, 17 participants rated the sensory unpleasantness of 14-, 16-, and 18-kHz tones and a 1-kHz reference tone. Tones were presented at equal subjective loudness levels for each individual, corresponding to levels of 10, 20, and 30 dB SL measured at 1 kHz. Participants were categorized as either "symptomatic" or "asymptomatic" based on self-reported previous symptoms that they attributed to exposure to VHFS/US. In both groups, subjective loudness increased more rapidly with sound pressure level for VHFS/US than for the 1-kHz reference tone, which is consistent with a reduced dynamic range at the higher frequencies. For loudness-matched tones, participants rated VHFS/US as more unpleasant than that for the 1-kHz reference. These results suggest that increased sensory unpleasantness and reduced dynamic range at high frequencies should be considered when designing or deploying equipment which emits VHFS/US that could be audible to exposed people.

The burden of Clostridioides difficile infections in South-East Asia and the Western Pacific: A narrative review.

BACKGROUND: Clostridioides difficile (formerly Clostridium difficile) is well-documented in Europe and North America to be a common cause of healthcare-associated gastrointestinal tract infections. In contrast, C difficile infection (CDI) is infrequently reported in literature from Asia, which may reflect a lack of clinician awareness. We conducted a narrative review to better understand CDI burden in Asia. METHODS: We searched the PubMed database for English language articles related to C difficile, Asia, epidemiology, and molecular characteristics (eg, ribotype, antimicrobial resistance). RESULTS: Fifty-eight articles that met eligibility criteria were included. C difficile prevalence ranged from 7.1% to 45.1 % of hospitalized patients with diarrhea, and toxigenic strains among all C difficile in these patients ranged from 68.2% to 91.9 % in China and from 39.0% to 60.0 % outside of China. Widespread C difficile ribotypes were RT017, RT014/020, RT012, and RT002. Recurrence in patients with CDI ranged from 3.0% to 17.2 %. Patients with CDI typically had prior antimicrobial use recently. High rates of resistance to ciprofloxacin, clindamycin, and erythromycin were frequently reported. CONCLUSION: The regional CDI burden in Asia is still incompletely documented, seemingly due to low awareness and limited laboratory testing. Despite this apparent under recognition, the current CDI burden highlights the need for broader surveillance and for application of preventative measures against CDI in Asia.

Vaccine-Preventable Disease Incidence Based on Clinically, Radiologically, and Etiologically Confirmed Outcomes: Systematic Literature Review and Re-analysis of Pneumococcal Conjugate Vaccine Efficacy Trials.

BACKGROUND: Vaccine regulatory decision making is based on vaccine efficacy against etiologically confirmed outcomes, which may underestimate the preventable disease burden. To quantify this underestimation, we compared vaccine-preventable disease incidence (VPDI) of clinically defined outcomes with radiologically/etiologically confirmed outcomes. METHODS: We performed a systematic review of efficacy trials for several vaccines (1997-2019) and report results for pneumococcal conjugate vaccines. Data were extracted for outcomes within a clinical syndrome, organized from most sensitive to most specific. VPDI was determined for each outcome, and VPDI ratios were calculated, with a clinically defined outcome (numerator) and a radiologically/etiologically confirmed outcome (denominator). RESULTS: Among 9 studies, we calculated 27 VPDI ratios; 24 had a value >1. Among children, VPDI ratios for clinically defined versus vaccine serotype otitis media were 0.6 (95% CI not calculable), 2.1 (1.5-3.0), and 3.7 (1.0-10.2); the VPDI ratios comparing clinically defined with radiologically confirmed pneumonia ranged from not calculable to 2.7 (1.2-10.4); the VPDI ratio comparing clinically suspected invasive pneumococcal disease (IPD) with laboratory-confirmed IPD was 3.8 (95% CI not calculable). Among adults, the ratio comparing clinically defined with radiologically confirmed pneumonia was 1.9 (-6.0 to 9.1) and with vaccine serotype-confirmed pneumonia was 2.9 (.5-7.8). CONCLUSIONS: While there is substantial uncertainty around individual point estimates, there is a consistent trend in VPDI ratios, most commonly showing under-ascertainment of 1.5- to 4-fold, indicating that use of clinically defined outcomes is likely to provide a more accurate estimate of a pneumococcal conjugate vaccine's public health value.

Systematic Review and Meta-analysis of Lyme Disease Data and Seropositivity for Borrelia burgdorferi, China, 2005‒2020.

Since its initial identification in 1986, Lyme disease has been clinically diagnosed in 29 provinces in China; however, national incidence data are lacking. To summarize Lyme disease seropositivity data among persons across China, we conducted a systematic literature review of Chinese- and English-language journal articles published during 2005‒2020. According to 72 estimates that measured IgG by using a diagnostic enzyme-linked assay (EIA) alone, the seropositivity point prevalence with a fixed-effects model was 9.1%. A more conservative 2-tier testing approach of EIA plus a confirmatory Western immunoblot (16 estimates) yielded seropositivity 1.8%. Seropositivity by EIA for high-risk exposure populations was 10.0% and for low-risk exposure populations was 4.5%; seropositivity was highest in the northeastern and western provinces. Our analysis confirms Lyme disease prevalence, measured by seropositivity, in many Chinese provinces and populations at risk. This information can be used to focus prevention measures in provinces where seropositivity is high.

Mental Health Outcomes of Unaccompanied Refugee Minors: a Rapid Review of Recent Research.

PURPOSE: To examine mental health outcomes of unaccompanied refugee minors during global policy shift. Additionally, to consider mental health service delivery and placement type for this group. METHODS: A rapid systematic search of research published since 2018 which related to mental health outcomes of unaccompanied refugee minors. Data extracted, risk of bias assessed and outcomes reviewed qualitatively. RESEARCH FINDINGS: We found 181 papers, of which 14 met inclusion criteria. This review found consistently high levels of PTSD and PTSS among URMs in various contexts. Exposure to trauma, being unaccompanied (compared to accompanied), being female and being older are associated with poor outcomes. Depression and anxiety were consistently high among URMs and associated with discrimination, limited language attainment and daily hassles. High rates of mental illness and symptoms among unaccompanied refugee minors were consistent across national and settlement contexts but the quality of the evidence is variable with significant heterogeneity of assessment. We relate persistence of poor mental health outcomes with problems accessing mental health services and discuss the role of key post-migration factors influencing outcomes-in particular placement type and the use of detention centres.

Sensitivity to Haptic Sound-Localization Cues at Different Body Locations.

Cochlear implants (CIs) recover hearing in severely to profoundly hearing-impaired people by electrically stimulating the cochlea. While they are extremely effective, spatial hearing is typically severely limited. Recent studies have shown that haptic stimulation can supplement the electrical CI signal (electro-haptic stimulation) and substantially improve sound localization. In haptic sound-localization studies, the signal is extracted from the audio received by behind-the-ear devices and delivered to each wrist. Localization is achieved using tactile intensity differences (TIDs) across the wrists, which match sound intensity differences across the ears (a key sound localization cue). The current study established sensitivity to across-limb TIDs at three candidate locations for a wearable haptic device, namely: the lower tricep and the palmar and dorsal wrist. At all locations, TID sensitivity was similar to the sensitivity to across-ear intensity differences for normal-hearing listeners. This suggests that greater haptic sound-localization accuracy than previously shown can be achieved. The dynamic range was also measured and far exceeded that available through electrical CI stimulation for all of the locations, suggesting that haptic stimulation could provide additional sound-intensity information. These results indicate that an effective haptic aid could be deployed for any of the candidate locations, and could offer a low-cost, non-invasive means of improving outcomes for hearing-impaired listeners.

Public exposure to ultrasound and very high-frequency sound in air.

Recent work showing the presence of a new generation of ultrasound (US) sources in public places has reopened the debate about whether there are adverse effects of US on humans, and has identified weaknesses in standards and exposure guidelines. Systems that rely on very high-frequency sound (VHFS) and US include public-address voice-alarm (PAVA) systems (whose operational status is often monitored using tones at ∼20 kHz) and pest deterrents. In this study, sound pressure levels (SPLs) produced by 16 sources that were either publically available or installed in busy public spaces were measured. These sources were identified through a citizen science project, wherein members of the public were asked to provide smartphone recordings of VHFS/US sources. With measurements made in realistic listening positions, pest deterrents were found that produced levels of up to 100 dB SPL at ∼20 kHz, and a hand dryer was found to produce 84 dB SPL at 40 kHz. PAVA systems were found to emit lower levels of up to 76 dB SPL at ∼20 kHz. Pest deterrents measured breach recommended safe listening limits for public exposure for people who are nearby even for relatively short periods.

Effects of very high-frequency sound and ultrasound on humans. Part II: A double-blind randomized provocation study of inaudible 20-kHz ultrasound.

Some people have reported symptoms such as nausea, dizziness, and headaches that they attribute to ultrasound (US) emitted by devices in public places. The primary aim of the present study was to investigate whether inaudible US can provoke adverse symptoms compared to a sham presentation, under double-blind conditions. A second aim was to investigate whether the expectation of US being present could provoke adverse symptoms (a nocebo response). The US stimulus was a 20 kHz tone presented continuously for 20 min set to at least 15 dB below the participants' detection threshold, giving a typical sound pressure level (SPL) of 84 dB. No evidence that US provoked symptoms was found, but there was evidence of small nocebo effects. A case study on an individual with high self-reported sensitivity to US gave similar results. The present study did not reproduce the severe symptoms reported previously by some members of the public; this may be due to the SPL or duration of the stimulus, or strength of the nocebo stimulus. These findings cannot be used to predict outcomes from exposures to sounds that are audible to the individual in question, or to sounds with higher SPLs, longer durations, or different frequency content.

Effects of very high-frequency sound and ultrasound on humans. Part I: Adverse symptoms after exposure to audible very-high frequency sound.

Various adverse symptoms resulting from exposure to very high-frequency sound (VHFS) and ultrasound (US) have previously been reported. This study aimed to establish whether these symptoms are experienced under controlled laboratory conditions and are specific to VHFS/US. To do this, participants were exposed to VHFS/US (at frequencies between 13.5 and 20 kHz and sound pressure levels between 82 and 92 dB) and to a 1 kHz reference stimulus, both at 25 dB above their hearing threshold. The VHFS/US and reference stimuli were presented 4 times, each time for 3 min, during which participants performed a sustained attention task, rated their symptom severity, and had their galvanic skin response (GSR) measured to assess their level of anxiety. Prior to exposure, participants were assigned either to a symptomatic or an asymptomatic group, based on their prior history of symptoms that they attributed to VHFS/US. In both groups, overall discomfort ratings were higher in the VHFS/US condition than the reference condition. In the symptomatic group only, difficulty concentrating and annoyance were also rated higher in the VHFS/US than the reference condition. No difference between the two stimulus conditions was seen in performance on the attention task or on average GSRs for either group.

Measurements of ultrasonic deterrents and an acoustically branded hairdryer: Ambiguities in guideline compliance.

Acoustic radiation from three commercial pest deterrents and two hair dryers were measured in an anechoic chamber. The deterrents were chosen because the frequency range at which they emit the most energy is either in the very high-frequency sound band (11.2-17.8 kHz) or the ultrasound band (greater than 17.8 kHz). These are sources that may be heard by a subset of the general population, with the young typically having better high frequency sensitivity. A hairdryer reported to increase the frequency of the motor noise above the audible hearing range was compared with a standard hairdryer. The outputs of the deterrents are compared against six international regulations and guidelines for audible and ultrasound exposure. Multiple ambiguities in the application of these guidelines are discussed. These ambiguities could lead to a device being considered as in compliance despite unconventionally high levels. Even if a device measured here meets a guideline, actual exposures can exceed those taken here and may therefore breach guidelines if the listener is closer to the device or reflections increase the exposure level.

Individual differences in regional cortical volumes across the life span are associated with regional optical measures of arterial elasticity.

Aging is often accompanied by changes in brain anatomy and cerebrovascular health. However, the specific relationship between declines in regional cortical volumes and loss of cerebral arterial elasticity is less clear, as only global or very localized estimates of cerebrovascular health have been available. Here we employed a novel tomographic optical method (pulse-DOT) to derive local estimates of cerebral arterial elasticity and compared regional volumetric estimates (obtained with FreeSurfer) with optical arterial elasticity estimates from the same regions in 47 healthy adults (aged 18-75). Between-subject analyses revealed a global correlation between cortical volume and cortical arterial elasticity, which was a significant mediator of the association between age and cortical volume. Crucially, a novel within-subject analysis highlighted the spatial association between regional variability in cortical volumes and arterial elasticity in the same regions. This association strengthened with age. Gains in the predictability of cortical volumes from arterial elasticity data were obtained by sharpening the resolution up to individual cortical regions. These results indicate that some of the variance of sub-clinical age-related brain atrophy is associated with differences in the status of cerebral arteries, and can help explain the unique patterns of brain atrophy found within each individual.

Improved tactile speech perception and noise robustness using audio-to-tactile sensory substitution with amplitude envelope expansion.

Recent advances in haptic technology could allow haptic hearing aids, which convert audio to tactile stimulation, to become viable for supporting people with hearing loss. A tactile vocoder strategy for audio-to-tactile conversion, which exploits these advances, has recently shown significant promise. In this strategy, the amplitude envelope is extracted from several audio frequency bands and used to modulate the amplitude of a set of vibro-tactile tones. The vocoder strategy allows good consonant discrimination, but vowel discrimination is poor and the strategy is susceptible to background noise. In the current study, we assessed whether multi-band amplitude envelope expansion can effectively enhance critical vowel features, such as formants, and improve speech extraction from noise. In 32 participants with normal touch perception, tactile-only phoneme discrimination with and without envelope expansion was assessed both in quiet and in background noise. Envelope expansion improved performance in quiet by 10.3% for vowels and by 5.9% for consonants. In noise, envelope expansion improved overall phoneme discrimination by 9.6%, with no difference in benefit between consonants and vowels. The tactile vocoder with envelope expansion can be deployed in real-time on a compact device and could substantially improve clinical outcomes for a new generation of haptic hearing aids.

Improved tactile speech perception using audio-to-tactile sensory substitution with formant frequency focusing.

Haptic hearing aids, which provide speech information through tactile stimulation, could substantially improve outcomes for both cochlear implant users and for those unable to access cochlear implants. Recent advances in wide-band haptic actuator technology have made new audio-to-tactile conversion strategies viable for wearable devices. One such strategy filters the audio into eight frequency bands, which are evenly distributed across the speech frequency range. The amplitude envelopes from the eight bands modulate the amplitudes of eight low-frequency tones, which are delivered through vibration to a single site on the wrist. This tactile vocoder strategy effectively transfers some phonemic information, but vowels and obstruent consonants are poorly portrayed. In 20 participants with normal touch perception, we tested (1) whether focusing the audio filters of the tactile vocoder more densely around the first and second formant frequencies improved tactile vowel discrimination, and (2) whether focusing filters at mid-to-high frequencies improved obstruent consonant discrimination. The obstruent-focused approach was found to be ineffective. However, the formant-focused approach improved vowel discrimination by 8%, without changing overall consonant discrimination. The formant-focused tactile vocoder strategy, which can readily be implemented in real time on a compact device, could substantially improve speech perception for haptic hearing aid users.

Adult indication 13-valent pneumococcal conjugate vaccine clinical development overview: formulation, safety, immunogenicity (dosing and sequence), coadministration, and efficacy.

INTRODUCTION: There was no 13-valent pneumococcal conjugate vaccine (PCV13) adult antibody concentration threshold regulatory criterion for licensure - unlike the pediatric indication; consequently, for the adult indication, PCV13 serotype-specific opsonophagocytic activity (OPA) geometric mean titer (GMT) values were immunobridged to the 23-valent plain polysaccharide vaccine (PPV23) to infer efficacy against invasive pneumococcal disease (IPD). Subsequently, a double-blind, randomized, controlled PCV13 efficacy trial (CAPiTA) was performed in community-living, older adults to confirm efficacy against vaccine-serotype IPD (VT-IPD) and establish efficacy against vaccine-serotype pneumococcal community-acquired pneumonia (VT-CAP). AREAS COVERED: This article summarizes 31 publications from the PCV13 adult indication clinical development trials and other PCV13 clinical studies, organized by formulation, reactogenicity and safety, immunogenicity, coadministration, and clinical efficacy. EXPERT OPINION: PCV13 had a favorable safety profile with an OPA response generally greater than PPV23 irrespective of age and of previous pneumococcal vaccination. PCV13 primed for enhanced immune responses with subsequent PCV13 or PPV23 dosing. Conversely, PPV23 was shown to blunt the response to subsequent PCV13. CAPiTA demonstrated PCV13 efficacy for at least five years against both VT-IPD and VT-CAP. The PCV13 clinical development program provided fundamental insights into this vaccine's adult-specific immune responses and confirmed the advantages of conjugate over plain polysaccharide technology.

Serotype distribution of invasive pneumococcal disease from countries of the WHO Africa, Americas, Eastern Mediterranean, South-East Asia, and Western Pacific regions: a systematic literature review from 2010 to 2021.

Background: Most publications on invasive pneumococcal disease (IPD) serotype distribution are from about 20 countries (Australia, Canada, China, European Union members, Japan, New Zealand, South Korea, and USA). Here, we reviewed the literature among underrepresented countries in the Americas (AMRO), Africa (AFRO), Eastern Mediterranean (EMRO), South-East Asia (SEARO), and Western Pacific (WPRO) WHO regions. Methods: We performed a systematic review of the most recent IPD serotype surveillance publications (from 01/01/2010 to 31/12/2021, Medline/Embase) in those WHO regions. Selection criteria were delineated by contemporality, within-country geographical scope, and number of samples. Reported serotype distributions for each country were stratified by age group, pneumococcal conjugate vaccine (PCV) serotype category (considering undifferentiated serotypes), and PCV program period (pre-PCV, intermediate, or PCVhv [higher valency PCV formulation]). Pre-PCV period pooled data estimated PCV serotype category distribution by age group across WHO regions, while for the PCVhv period, country-level dataset tables were prepared. Results: Of 2,793 publications screened, 107 were included (58 pediatric, 11 adult, 37 all ages, and one comprising every age group). One-third of eligible countries (51/135) published serotype distribution, ranging from 30 to 43% by WHO region. Considering number of samples per WHO region, a few countries prevailed: AMRO (Brazil), AFRO (South Africa, Malawi, and Burkina Faso), and WPRO (Taiwan). In the pre-PCV period, PCV13 formulation serotypes predominated: ranging from 74 to 85% in children and 58-86% in adults in the different WHO regions. The PCVhv period represented half of the most recent IPD surveillance by countries (26/51). Undifferentiated serotypes represented >20% of IPD from most countries (34/51). Conclusion: Ubiquity of undifferentiated serotypes among the publications could constrain estimates of PCV program impact and of serotype coverage for newer PCVhv formulations; consequently, we recommend that countries favor techniques that identify serotypes specifically and, rather than reporting PCV formulation serotype distributions, provide serotype results individually. Systematic review registration: The protocol has been prospectively registered at PROSPERO, identifier: CRD42021278501. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=278501.

Improved tactile speech robustness to background noise with a dual-path recurrent neural network noise-reduction method.

Many people with hearing loss struggle to understand speech in noisy environments, making noise robustness critical for hearing-assistive devices. Recently developed haptic hearing aids, which convert audio to vibration, can improve speech-in-noise performance for cochlear implant (CI) users and assist those unable to access hearing-assistive devices. They are typically body-worn rather than head-mounted, allowing additional space for batteries and microprocessors, and so can deploy more sophisticated noise-reduction techniques. The current study assessed whether a real-time-feasible dual-path recurrent neural network (DPRNN) can improve tactile speech-in-noise performance. Audio was converted to vibration on the wrist using a vocoder method, either with or without noise reduction. Performance was tested for speech in a multi-talker noise (recorded at a party) with a 2.5-dB signal-to-noise ratio. An objective assessment showed the DPRNN improved the scale-invariant signal-to-distortion ratio by 8.6 dB and substantially outperformed traditional noise-reduction (log-MMSE). A behavioural assessment in 16 participants showed the DPRNN improved tactile-only sentence identification in noise by 8.2%. This suggests that advanced techniques like the DPRNN could substantially improve outcomes with haptic hearing aids. Low-cost haptic devices could soon be an important supplement to hearing-assistive devices such as CIs or offer an alternative for people who cannot access CI technology.

Nasopharyngeal carriage of Streptococcus pneumoniae among children aged 30 days to <60 months in Beijing and Shenzhen, China (2018-2021) during pneumococcal conjugate vaccine introduction and the coronavirus disease (COVID-19) pandemic.

Objectives: To describe the carriage rate, serotype distribution, and antimicrobial susceptibility patterns of Streptococcus pneumoniae (S. pneumoniae) nasopharyngeal (NP) isolates among healthy children aged 30 days to <60 months in the cities of Beijing and Shenzhen during 2018-2021. Methods: A NP swab sample was collected among four annual cohorts of healthy children at routine well-child visits. S. pneumoniae was identified by culture, optochin sensitivity and bile solubility, serotypes determined by latex agglutination and Quellung, and antimicrobial susceptibility testing performed using E-test strips. Results: S. pneumoniae NP carriage was 13.1% (645/4,911), with the highest S. pneumoniae carriage prevalence (15.3%) observed in 25 to <60 months. The carriage prevalence was 15.1% in children 13-24 months, 13.2% in children 7-12 months, and 8.2% in children 30 days to 6 months (P < 0.01). Living with siblings [20.0% vs. 9.4%: OR: 2.42 (95% CI: 2.05-2.87)] or attending day-care [31.8% vs. 11.3%: OR: 3.67 (95% CI: 2.94-4.57)] increased the risk (P < 0.01). During the period (January 2020-April 2021) of strict non-pharmaceutical interventions to prevent and control the COVID-19 pandemic, the proportion of children with S. pneumoniae colonization declined from 16.0% (94/587) to 5.8% (108/1,848) in Beijing while increasing from 14.5% (64/443) to 18.6% (379/2,033) in Shenzhen. Among S. pneumoniae isolates, 36.7% (237/645) belonged to 13-valent pneumococcal conjugate vaccine (PCV13) serotypes, 64.3% (408/645) were non-PCV13 serotypes, including 20.8% (134/645) non-serotypeable S. pneumoniae (NST). A total of 158/644 isolates (24.5%) were MDR. For the PCV13 isolates, MDR was detected in 36.3% (86/237) of isolates; in comparison, 17.6% (72/407) of non-PCV13 serotypes, including NST, were MDR (P < 0.01). S. pneumoniae NP carriage was detected in 10.7% of children with previous pneumococcal vaccination (PCV7 or PCV13 only) compared with 14.9% in children without previous pneumococcal vaccination. Conclusions: The highest S. pneumoniae carriage prevalence were found in the oldest age group (25 to <60 months) and in children living with siblings or attending day-care. Vaccination with PCV7 or PCV13 was associated with lower PCV13-serotype colonization. In Beijing, S. pneumoniae carriage significantly declined during the COVID-19 pandemic.

Is overshoot caused by an efferent reduction in cochlear gain?

Under certain conditions, detection of a masked tone is improved by a preceding sound ("precursor"). This phenomenon is referred to as the "temporal effect" or "overshoot". A prevalent model of overshoot, referred to as the "gain reduction model", posits that overshoot is caused by efferent reduction in cochlear gain mediated by the medial olivocochlear (MOC) bundle. The model predicts that reduction in cochlear gain will reduce masking when masking is suppressive or when masking is excitatory and the signal-to-masker ratio is high. This study was aimed at testing the validity of these predictions. It consisted of two experiments. The first experiment investigated the relative contributions of suppressive versus excitatory masking to overshoot. The signal was a short 4-kHz tone pip, and the masker and precursor were limited to contain energy either only within (-on-frequency) or only outside (off-frequency) the cochlear filter around the signal frequency. The on-frequency masker would be expected to cause mainly excitatory masking, whereas masking by the off-frequency masker would be expected to be mainly suppressive. Only the off-frequency masker and precursor yielded -significant overshoot. This suggests that measurable overshoot requires suppressive masking. The second experiment sought to quantify the effect of a precursor on cochlear -suppression more directly by measuring the amount of suppression caused by a 4.75-kHz suppressor on a lower-frequency (4-kHz) suppressee with and without a precursor present. Suppression was measured using a forward-masking paradigm. While we found large suppression and large overshoot, we found no reduction in suppression by the precursor. This is contrary to the gain reduction model. Taken together, our results indicate that measurable overshoot requires off-frequency masking and that off-frequency overshoot must be caused by a mechanism other than MOC-mediated reduction in cochlear suppression.

Improving speech perception for hearing-impaired listeners using audio-to-tactile sensory substitution with multiple frequency channels.

Cochlear implants (CIs) have revolutionised treatment of hearing loss, but large populations globally cannot access them either because of disorders that prevent implantation or because they are expensive and require specialist surgery. Recent technology developments mean that haptic aids, which transmit speech through vibration, could offer a viable low-cost, non-invasive alternative. One important development is that compact haptic actuators can now deliver intense stimulation across multiple frequencies. We explored whether these multiple frequency channels can transfer spectral information to improve tactile phoneme discrimination. To convert audio to vibration, the speech amplitude envelope was extracted from one or more audio frequency bands and used to amplitude modulate one or more vibro-tactile tones delivered to a single-site on the wrist. In 26 participants with normal touch sensitivity, tactile-only phoneme discrimination was assessed with one, four, or eight frequency bands. Compared to one frequency band, performance improved by 5.9% with four frequency bands and by 8.4% with eight frequency bands. The multi-band signal-processing approach can be implemented in real-time on a compact device, and the vibro-tactile tones can be reproduced by the latest compact, low-powered actuators. This approach could therefore readily be implemented in a low-cost haptic hearing aid to deliver real-world benefits.