Boat noise impedes vocalizations of wild plainfin midshipman fish.

Marine noise is recognised as a growing threat that can induce maladaptive behavioural changes in many aquatic animals, including fishes. The plainfin midshipman is a soniferous fish with a prolonged breeding period, during which males produce tonal hums that attract females, and grunts and growls during agonistic interactions. In this study, we used acoustic recordings to assess the effects of boat noise on the presence, peak frequencies, and durations of plainfin midshipman calls in the wild. We found that all three call types were less likely to occur, and the peak frequencies of hums and grunts increased in the presence of boat noise. We also show that loud and quiet boat noise affected plainfin midshipman vocalizations similarly. As anthropogenic noise is likely to increase in the ocean, it will be important to understand how such noise can affect communication systems, and consequently population health and resiliency.

'We did everything by phone': a qualitative study of mothers' experience of smartphone-aided screening of cerebral palsy in Kathmandu, Nepal.

BACKGROUND: International guidelines recommend early intervention to all children at risk of cerebral palsy, but targeted screening programs are often lacking in low- and middle-income settings with the highest burden of disease. Smartphone applications have the potential to improve access to early diagnostics by empowering parents to film their children at home followed by centralized evaluation of videos with General Movements Assessment. We explored mothers' perceptions about participating in a smartphone aided cerebral palsy screening program in Kathmandu, Nepal. METHODS: This is an explorative qualitative study that used focus group discussions (n = 2) and individual interviews (n = 4) with mothers of term-born infants surviving birth asphyxia or neonatal seizures. Parents used the NeuroMotion™ smartphone app to film their children at home and the videos were analysed using Precthl's General Movements Assessment. Sekhon et al.'s framework on the acceptability of health care interventions guided the design of the group discussions and interviews, and the deductive qualitative content analysis. RESULTS: Mothers were interested in engaging with the programme and expressed hope it would benefit their children. Most felt using the app was intuitive. They were, however, unclear about the way the analysis was performed. Support from the research team was often needed to overcome an initial lack of self-confidence in using the technology, and to reduce anxiety related to the follow-up. The intervention was overall perceived as recommendable but should be supplemented by a face-to-face consultation. CONCLUSION: Smartphone aided remote screening of cerebral palsy is acceptable in a lower middle-income population but requires additional technical support.

Exploring gestational age, and birth weight assessment in Thatta district, Sindh, Pakistan: Healthcare providers' knowledge, practices, perceived barriers, and the potential of a mobile app for identifying preterm and low birth weight.

INTRODUCTION: Reliable methods for identifying prematurity and low birth weight (LBW) are crucial to ending preventable deaths in newborns. This study explored healthcare providers' (HCPs) knowledge, practice, perceived barriers in assessing gestational age and birth weight and their referral methods for preterm and LBW infants. The study additionally assessed the potential of using a mobile app for the identification and referral decision of preterm and LBW. METHODS: This qualitative descriptive study was conducted in Thatta District, Sindh, Pakistan. Participants, including doctors, nurses, lady health visitors, and midwives, were purposefully selected from a district headquarter hospital, and private providers in the catchment area of Global Network's Maternal and Newborn Health Registry (MNHR). Interviews were conducted using an interview guide after obtaining written informed consent. Audio recordings of the interviews were transcribed and analyzed using NVIVO® software with an inductive approach. RESULTS: The HCPs had extensive knowledge about antenatal and postnatal methods for assessing gestational age. They expressed a preference for antenatal ultrasound due to the perceived accuracy, though accept practical barriers including workload, machine malfunctions, and cost. Postnatal assessment using the Ballard score was only undertaken sparingly due to insufficient training and subjectivity. All HCPs preferred electronic weighing scales for birth weight Barriers encountered included weighing scale calibration and battery issues. There was variation in the definition of prematurity and LBW, leading to delays in referral. Limited resources, inadequate education, and negative parent past experiences were barriers to referral. Foot length measurements were not currently being used. While mobile apps are felt to have potential, unreliable electricity supply and internet connectivity are barriers. CONCLUSION: The HCPs in this study were knowledgeable in terms of potential tools, but acknowledged the logistical and parental barriers to implementation.

Saving ambulance resources: a service evaluation of the identification of non-viable out-of-hospital cardiac arrest in London by advanced paramedic practitioners in critical care.

Background: Advanced paramedic practitioners in critical care (APPCCs) are advanced clinical practitioners focused on the delivery of pre-hospital critical care. While working in an ambulance control room setting, APPCCs seek to identify emergency calls appropriate for operational APPCCs to attend. These would include out-of-hospital cardiac arrest (OHCA). Through interrogation of incoming emergency calls they are also able to identify OHCA calls where resuscitation may be futile. In these cases, and within a governance framework, they stand down multiple ambulance responders, leaving only the closest responding resource to attend, thereby 'saving resources' that can be re-directed to other waiting emergency calls. It is believed that this is the first initiative of this nature in the United Kingdom. Methods: A three-year retrospective service evaluation of data was undertaken. The aim was to quantify the number of 'saved resources', including both double crewed ambulances (DCAs) and solo (single-person) responders, and furthermore to equate those savings into potential hours saved, using average known job cycle times (JCTs). Additionally, safety was assessed by searching all mandated incident reports for occasions where, despite cancellation of resources by an APPCC, resuscitation was commenced by the first response to scene. Results: A total of 13,356 ambulance resources were saved. Of these, 6593 (49.4%) were DCAs and 6763 (50.6%) were solo responders. Using the average JCT for deceased patients of 104.8 minutes, the total time saving equated to 23,328.48 hours of work or 1944.04 12-hour shifts. When considering DCAs alone, the average JCT for obviously deceased patients was 110.9 minutes. This equates to 12,186.1 hours of work or 1015.5 12-hour shifts. A total of 15 incident reports were identified. All had been investigated, revealing appropriate decision making in cancelling ambulance resources. No patient harm was identified. Conclusion: APPCCs working within a governance framework safely saved a significant number of ambulance resources over a three-year period. Perceived benefits include 'freeing up' DCA and solo responders, allowing them to be redirected to other emergency calls, leading to potential improvement in response times for patients waiting for an ambulance resource.

NeuroMotion smartphone application for remote General Movements Assessment: a feasibility study in Nepal.

OBJECTIVES: To evaluate the feasibility of using the NeuroMotion smartphone application for remote General Movements Assessment for screening infants for cerebral palsy in Kathmandu, Nepal. METHOD: Thirty-one term-born infants at risk of cerebral palsy due to birth asphyxia or neonatal seizures were recruited for the follow-up at Paropakar Maternity and Women's Hospital, 1 October 2021 to 7 January 2022. Parents filmed their children at home using the application at 3 months' age and the videos were assessed for technical quality using a standardised form and for fidgety movements by Prechtl's General Movements Assessment. The usability of the application was evaluated through a parental survey. RESULTS: Twenty families sent in altogether 46 videos out of which 35 had approved technical quality. Sixteen children had at least one video with approved technical quality. Three infants lacked fidgety movements. The level of agreement between assessors was acceptable (Krippendorf alpha 0.781). Parental answers to the usability survey were in general positive. INTERPRETATION: Engaging parents in screening of cerebral palsy with the help of a smartphone-aided remote General Movements Assessment is possible in the urban area of a South Asian lower middle-income country.

Predictors of neurocognition outcomes in children and young people with primary brain tumor presenting to tertiary care hospitals of Karachi, Pakistan: a prospective cohort study.

INTRODUCTION: Primary brain tumors are a common cause of morbidity and mortality in children and young people (CYP) globally. Impaired neurocognitive function is a potential severe consequence in primary brain tumor (PBT) survivors. There are no in-depth studies from low- and middle-income countries (LMICs) to inform management and follow-up. The research questions of this study were as follows: Are the sociodemographic factors (lower age of CYP, female gender, low socioeconomic status, low parental education), disease-related factors (high grade of tumor, presence of seizures, presence of hydrocephalous), and treatment-related factors (adjuvant therapy, no surgical intervention, post-treatment seizures, placement of shunts) associated with decline in neurcognition outcomes 12 months post-treatment in CYP with PBTs? METHODS: A prospective cohort study was conducted from November 2020 to July 2023 at the Aga Khan University Hospital and Jinnah Postgraduate Medical Centre, tertiary care hospitals in Karachi, Pakistan. All CYP aged 5 to 21 years with a newly diagnosed PBTs were eligible. The neurocognition assessment was undertaken by a psychologist at two points, i.e., pre-treatment and at 12 months post-treatment using validated tools. The verbal intelligence was assessed by Slosson Intelligence tool, revised 3rd edition (SIT-R3), perceptual reasoning by Raven's Progressive Matrices (RPM), and the Processing Speed Index by Wechsler Intelligence Scale (WISC V) and Wechsler Adult Intelligence Scale (WAIS-IV). The data were analyzed by STATA version 12 software. Generalized estimating equation (GEE) was used to determine the factors associated with the mean change in 12 months post-treatment verbal and non-verbal neurocognition scores. Unadjusted and adjusted beta coefficients with their 95% confidence intervals were reported. RESULTS: A total of 48 CYPs with PBTs were enrolled, 23 (48%) of them were lost to follow-up and 10 (21%) died. The remaining 25 (52%) were reassessed 12 months after treatment. On multivariable analysis, a significant decline in verbal intelligence scores at 12 months was predicted by post-treatment seizures beta = - 20.8 (95% CI, - 38.2, - 3.4), mothers having no formal educational status and lower household monthly income. Similarly, a significant decline in perceptual reasoning scores was also predicted by post-treatment seizures beta = - 10.7 (95% CI, - 20.6, - 0.8), mothers having no formal education and having lower household monthly income. Worsening of processing speed scores at 12 months post-treatment were predicted by tumor histology, post-treatment seizures beta = - 33.9 (95% CI, - 47.7, - 20.0), lower educational status of the mother, and having lower household monthly. However, an improvement was seen in processing speed scores after surgical tumor resection. CONCLUSION: In this novel study, the post-treatment mean change in verbal and non-verbal neurocognition scores was associated with sociodemographic, tumor, and treatment factors. These findings may have potential implications for targeted early psychological screening of higher risk CYP with PBTs. Identification of these predictors may serve as a foundation for developing more cost-effective treatment thereby alleviating the burden of neurocognitive morbidity. However to establish generalizability, future research should prioritize larger-scale, multicountry studies. (Trial registration: ClinicalTrials.gov Identifier: NCT05709522).

Socio-demographic characteristics of children and young people with primary brain tumours: comparison between a public and private sector tertiary hospital in Karachi, Pakistan.

Primary brain tumours (PBTs) are the commonest solid tumours in children and young people (CYP). A study was conducted at a private and a public sector hospital in Karachi, Pakistan, to determine the socio-demographic and tumour-related characteristics of CYP with PBTs between those presenting to the public and private hospitals. A total of 49 patients were included. The commonest PBT was pilocytic astrocytoma (29%). There were no differences in tumour-related characteristics between the two groups. However, parents of CYP with PBTs presenting to the public sector hospital were significantly less educated and had lower household incomes. No significant differences in age, gender, educational status, and ethnicity of CYP with PBTs were observed. Since CYP with PBTs presenting at the public sector hospital were from significantly lower socioeconomic backgrounds and their parents were less educated, it suggests socio-economic disparities in PBT care for CYPs in Karachi, Pakistan.

Diagnostic accuracy of foot length measurement for identification of preterm newborn in rural Sindh, Pakistan.

INTRODUCTION: Assessing gestational age accurately is crucial for saving preterm newborns. In low and middle-income countries, such as Pakistan, where access to antenatal ultrasonography (A-USG) is limited, alternative methods are needed. This study evaluated the diagnostic accuracy of foot length (FL) measurement for identifying preterm newborns in rural Pakistan using A-USG as the reference standard. METHODS: A test validation study was conducted between January and June 2023 in rural Sindh, Pakistan, within the catchment area of the Global Network for Maternal Newborn Health Registry, Thatta. Singleton newborns whose mothers had an A-USG before 20 weeks of gestation were enrolled. A research assistant measured FL three times using a rigid transparent plastic ruler within 48 hours of birth and the average FL was reported. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) and likelihood ratios were calculated. The optimal FL cut-off for the identification of preterm newborns was determined using the Youden Index. RESULTS: A total of 336 newborns were included in the final analysis, of whom 75 (22.3%) were born before 37 weeks of gestation. The median gestational age of the newborns was 38.2 weeks, and the median FL was 7.9 cm. The area under the curve was 97.6%. The optimal FL cut-off for identifying preterm newborns was considered as ≤7.6 cm with a sensitivity of 90.8%, specificity of 96.0%, PPV of 86.7% and NPV of 97.3%. A lower cut-off of ≤7.5 cm had a sensitivity of 95.4%, specificity of 84.0%, PPV of 63.1% and NPV of 98.5%. CONCLUSION: In conclusion, this study highlights the utility of FL measurement for identifying preterm newborns in rural settings where A-USG is unavailable before 20 weeks of gestation. Optimal cut-offs of ≤7.6 and ≤7.5 cm provide a simple, cost-effective and reliable tool for clinicians and frontline healthcare providers in rural areas, respectively. TRIAL REGISTRATION NUMBER: NCT05515211.

Construction and validation of ShaMaq developmental screening tool.

INTRODUCTION: The diagnosis of developmental delay and early intervention ameliorates long-term sequelae. There is a need for an appropriate, regionally adapted and reliable developmental screening tool to be used in low and middle-income countries with scarce resources. AIM: The aim of this research is to construct and validate a screening tool for identifying developmental delay in Pakistani children. METHOD: ShaMaq developmental screening tool (SDST) was developed consisting of five proformas to be administered at different age groups: 6-8 weeks (Group 1), 6-10 months (Group 2), 18-24 months (Group 3), 3-3.5 years (Group 4), and 4.5-5.5 years (Group 5). On an average, Groups 1-3 took 10-15 min, whereas Groups 4 and 5 took 20-25 min. We sampled children between the ages of 6 weeks to 5.5 years and tested them all within their designated age groups. Internal consistency was assessed by Cronbach's alpha. Interobserver testing was done for reliability and concurrent validity was undertaken by using the senior consultant developmental paediatrician's final diagnosis as the gold standard. RESULTS: Out of 550 healthy children, 8-19% in the five groups were found to have some form of developmental delay using SDST. Approximately 50% of the families were in the low-to-moderate income bracket, and nearly 93% lived in a joint family system. Internal consistency of items in the five groups ranged from 0.784 to 0.940, whereas both interobserver reliability and concurrent validity ranged from 0.737 to 1.0. SDST showed 94.4% sensitivity and 92.9% specificity. CONCLUSION: SDST is an effective tool for identifying delay in healthy children with good internal consistency, reliability, and validity.

Identifying the barriers faced by obstetricians and registrars in screening or enquiry of intimate partner violence in pregnancy: A systematic review of the primary evidence.

INTRODUCTION: Intimate partner violence (IPV) disproportionally affects women compared to men. The impact of IPV is amplified during pregnancy. Screening or enquiry in the antenatal outpatient setting regarding IPV has been fraught with barriers that prevent recognition and the ability to intervene. AIMS: The aim of this systematic review was to determine the barriers that face obstetricians/gynaecologists regarding enquiry of IPV in antenatal outpatient settings. The secondary objective was to determine facilitators. METHODS: Primary evidence was searched using Ovid MEDLINE, Ovid Maternity and Infant Care, PubMed and Proquest from 1993 to May 2023. The included studies comprised empirical studies published in English language targeting a population of doctors providing antenatal outpatient care. The review was PROSPERO-registered (CRD42020188994). Independent screening and review was performed by two authors. The findings were analysed thematically. RESULTS: Nine studies addressing barriers and two studies addressing facilitators were included: three focus-group or semi-structured interviews, six surveys and two randomised controlled trials. Barriers for providers centred at the system level (time, training), provider level (personal beliefs, cultural bias, experience) and provider-perceived patient level (fear of offending, patient readiness to disclose). Increased experience and the use of validated tools were strong facilitators. CONCLUSION: Barriers to screening reflect multi-level obstruction to the identification of women exposed to IPV. Although the antenatal outpatient clinic setting addresses a particular population vulnerable to IPV, the barriers for obstetricians are not unique. The use of validated cueing tools provides an evidence-based method to facilitate enquiry of IPV among antenatal women, assisting in identification by clinicians. Together with education and human resources, such aids build capacity in women and obstetric providers.

Expression Atlas update: insights from sequencing data at both bulk and single cell level.

Expression Atlas (www.ebi.ac.uk/gxa) and its newest counterpart the Single Cell Expression Atlas (www.ebi.ac.uk/gxa/sc) are EMBL-EBI's knowledgebases for gene and protein expression and localisation in bulk and at single cell level. These resources aim to allow users to investigate their expression in normal tissue (baseline) or in response to perturbations such as disease or changes to genotype (differential) across multiple species. Users are invited to search for genes or metadata terms across species or biological conditions in a standardised consistent interface. Alongside these data, new features in Single Cell Expression Atlas allow users to query metadata through our new cell type wheel search. At the experiment level data can be explored through two types of dimensionality reduction plots, t-distributed Stochastic Neighbor Embedding (tSNE) and Uniform Manifold Approximation and Projection (UMAP), overlaid with either clustering or metadata information to assist users' understanding. Data are also visualised as marker gene heatmaps identifying genes that help confer cluster identity. For some data, additional visualisations are available as interactive cell level anatomograms and cell type gene expression heatmaps.

Socio-demographic and antenatal risk factors of brain tumor in children and young people: A matched case-control study from Karachi, Pakistan.

Background: Brain tumors are a common cause of morbidity, disability, cognitive deterioration and mortality in children, even after treatment. Little is know about the specific causes. The study aimed to assess potential socio-demographic and antenatal factors in primary brain tumor (PBTs) in children and young people (CYP) in Karachi, Pakistan. Designs and methods: A single center hospital based matched case control study in Karachi, Pakistan. Cases were defined as CYP aged between 5 and 21 years with any histological type and grade of primary brain tumor of any histology, stage or grade. Data were collected from parents of 244 patients at the selected center between 2017 and 2021 via telephonic interview. Controls were 5-21 years old CYP admitted with non-oncological diagnoses matched on age and sex. Matched Odds Ratios for predictors of brain tumor in children were derived. Those of statistical significance were included in a multivariable logistic regression model. Results: In the adjusted model, lower paternal education (matched adjusted odds ratio (maOR) 2.46; 95% CI 1.09-5.55), higher household monthly income (maOR 3.4; 95% CI 1.1-10.2), antenatal paternal use of addictive substances (maOR 19.5; 95% CI 2.1-179.8), and antenatal maternal use of analgesics during pregnancy (maOR 3.0; 95% CI 1.2-7.9) were all independently predictive of brain tumors. Conclusion: This matched case-control study found novel associations between maternal use of analgesics, paternal use of addictive substances, higher household income, and lower paternal education and Primary Brain Tumors in Children and Young People. Longitudinal multicenter studies will be required to test these associations prospectively.

Interfacial rheology insights: particle texture and Pickering foam stability.

Interfacial rheology studies were conducted to establish a connection between the rheological characteristics of particle-laden interfaces and the stability of Pickering foams. The behavior of foams stabilized with fumed and spherical colloidal silica particles was investigated, focusing on foam properties such as bubble microstructure and liquid content. Compared to a sodium dodecyl sulfate-stabilized foam, Pickering foams exhibited a notable reduction in bubble coarsening. Drop shape tensiometry measurements on particle-coated interfaces indicated that the Gibbs stability criterion was satisfied for both particle types at various surface coverages, supporting the observed arrested bubble coarsening in particle-stabilized foams. However, although the overall foam height was similar for both particle types, foams stabilized with fumed silica particles demonstrated a higher resistance to liquid drainage. This difference was attributed to the higher yield strain of interfacial networks formed by fumed silica particles, as compared to those formed by spherical colloidal particles at similar surface pressures. Our findings highlight that while both particles can generate long-lasting foams, the resulting Pickering foams may exhibit variations in microstructure, liquid content, and resistance to destabilization mechanisms, stemming from the respective interfacial rheological properties in each case.

Psychosocial factors influencing quality of life in patients with primary brain tumors in Pakistan: an analytical cross-sectional study.

OBJECTIVE: Despite quality of life (QoL) being recognized as an important outcome in neuro-oncology, there is a lack of research from Pakistan where sociocultural differences may influence QoL. This study aimed to measure the QoL in patients with primary brain tumors (PBTs) and assess its association with mental health outcomes and social support. RESULTS: Our study included a total of 250 patients, with a median age of 42 years (range 33-54 years). The commonest brain tumors were glioma (46.8%) and meningioma (21.2). The mean global QoL of the sample was 75.73 ± 14.9. The majority of patients had high social support (97.6%) and were not depressed (90%) or anxious (91.6%). On multivariable linear regression, global QoL was inversely associated with no or low income (beta coefficients: -8.75 to -11.84), having hypertension (-5.53), currently using a urine catheter (-13.55), having low social support (-28.16) suffering from mild (-15.31) or symptomatic (-23.84) depression, or mild anxiety (-13.22).

Incidence and outcomes of intrapartum-related neonatal encephalopathy in low-income and middle-income countries: a systematic review and meta-analysis.

AIM: To examine the incidence of intrapartum-related neonatal encephalopathy, and neonatal mortality and neurodevelopmental outcomes associated with it in low-income and middle-income countries. METHODS: Reports were included when neonatal encephalopathy diagnosed clinically within 24 hours of birth in term or near-term infants born after intrapartum hypoxia-ischaemia defined as any of the following: (1) pH≤7.1 or base excess ≤-12 or lactate ≥6, (2) Apgar score ≤5 at 5 or 10 min, (3) continuing resuscitation at 5 or 10 min or (4) no cry from baby at 5 or 10 min. Peer-reviewed articles were searched from Ovid MEDLINE, Cochrane, Web of Science and WHO Global Index Medicus with date limits 1 November 2009 to 17 November 2021. Risk of bias was assessed using modified Newcastle Ottawa Scale. Inverse variance of heterogenicity was used for meta-analyses. RESULTS: There were 53 reports from 51 studies presenting data on 4181 children with intrapartum-related neonatal encephalopathy included in the review. Only five studies had data on incidence, which ranged from 1.5 to 20.3 per 1000 live births. Neonatal mortality was examined in 45 studies and in total 636 of the 3307 (19.2%) infants died. Combined outcome of death or moderate to severe neurodevelopmental disability was reported in 19 studies and occurred in 712 out of 1595 children (44.6%) with follow-up 1 to 3.5 years. CONCLUSION: Though there has been progress in some regions, incidence, case mortality and morbidity in intrapartum-related neonatal encephalopathy has been static in the last 10 years. PROSPERO REGISTRATION NUMBER: CRD42020177928.

A retrospective cohort study of pre-hospital agitation management by advanced paramedic practitioners in critical care.

Introduction: Pre-hospital clinicians can expect to encounter patients with agitation, including acute behavioural disturbance (ABD). These situations carry significant risk for patients and emergency medical services. Advanced paramedics within the London Ambulance Service (LAS) are frequently tasked to these incidents. At present, little evidence exists regarding clinical decision-making and management of this patient group. We sought to explore the demographics of patients presenting with potential ABD and quantify the degree of agitation, physical restraint, effectiveness of chemical sedation and any associated complications. Methods: A retrospective analysis of pre-hospital clinical records for patients coded with ABD and attended by LAS advanced paramedics between 1 October 2019 and 30 September 2020. Sedation assessment tool (SAT) scores were used as the primary outcome measure. Results: A total of 237 patient records were identified. Of the patients, 147 (62%) were physically restrained and 104 (44%) were chemically sedated. Sedation was more commonly administered where patients were exposed to physical restraint. High SAT scores were associated with the administration of sedative agents and at higher doses. Of patients undergoing sedation, 89 (85%) had a SAT score reduction of 2 points or a final score ≤ 0. The mean SAT score reduction was 2.72. Three cases of minor injury were reported following physical restraint. Conclusion: Advanced paramedics undertook sedation in less than half the cohort, suggesting that other strategies such as communication and positioning were utilised. Most patients were managed into a state between being restless and rousable, largely negating the need for ongoing physical restraint during hospital transfer. Appropriately trained advanced paramedics can utilise sedation safely and effectively in selected cases.

Field evaluation of typhoid conjugate vaccine in a catch-up campaign among children aged 9 months to 15 years in Sindh, Pakistan.

BACKGROUND: Typhoid conjugate vaccine (TCV) has recently been introduced in the expanded program for immunization (EPI) in Pakistan. Before its introduction in routine immunization, a onetime catchup campaign among children 9 months to 15 years old was conducted in November 2019. We performed field evaluation of TCV against culture confirmed Salmonella Typhi (S. Typhi) among 9 months to 15 years old children during the catch up campaign in Karachi and Hyderabad. METHODS: A rapid assessment of blood culture confirmed S. Typhi was performed. Age eligible cases of culture confirmed S. Typhi were identified from the laboratory networks of Aga Khan University Hospital Karachi and Hyderabad, Kharadar General Hospital Karachi, and Liaqat University of Medical & Health Sciences (LUMHS) Hyderabad. Information on sociodemographic, typhoid vaccination history and antimicrobial resistance was collected using a structured questionnaire. Patient medical records and lab reports were also reviewed to collect information on diagnosis and antimicrobial susceptibility information. Information about the population vaccination coverage during catch-up campaign was obtained from the provincial EPI office. Field performance of TCV in catchup campaign was measured by calculating the effectiveness using rapid screening method which is less resource-intensive technique of calculating vaccine effectiveness (VE). RESULTS: Overall, 968 culture confirmed typhoid cases were enrolled. Among them, 82% (793/968) were from Karachi and 18% (175/968) from Hyderabad. The average age of the participants was 5.68 years, and 54% (523/968) were male. 6% (62/968) of the culture confirmed S. Typhi cases were multidrug resistant (MDR), and 61% (586/968) were extensively drug resistant (XDR). The VE using the TCV coverage data provided by EPI was 98%. CONCLUSION: TCV is effective against culture confirmed S. Typhi among children aged 9 months to 15 years in the catch-up campaign setting. While typhoid vaccination can significantly decrease the burden of typhoid disease, improvements in sanitation and hygiene are necessary for the prevention of spread of enteric fever. Longer term follow up will be needed to assess the duration of protection and requirement for booster doses of TCV.

Reversible structural changes in the influenza hemagglutinin precursor at membrane fusion pH.

The subunits of the influenza hemagglutinin (HA) trimer are synthesized as single-chain precursors (HA0s) that are proteolytically cleaved into the disulfide-linked polypeptides HA1 and HA2. Cleavage is required for activation of membrane fusion at low pH, which occurs at the beginning of infection following transfer of cell-surface-bound viruses into endosomes. Activation results in extensive changes in the conformation of cleaved HA. To establish the overall contribution of cleavage to the mechanism of HA-mediated membrane fusion, we used cryogenic electron microscopy (cryo-EM) to directly image HA0 at neutral and low pH. We found extensive pH-induced structural changes, some of which were similar to those described for intermediates in the refolding of cleaved HA at low pH. They involve a partial extension of the long central coiled coil formed by melting of the preexisting secondary structure, threading it between the membrane-distal domains, and subsequent refolding as extended helices. The fusion peptide, covalently linked at its N terminus, adopts an amphipathic helical conformation over part of its length and is repositioned and packed against a complementary surface groove of conserved residues. Furthermore, and in contrast to cleaved HA, the changes in HA0 structure at low pH are reversible on reincubation at neutral pH. We discuss the implications of covalently restricted HA0 refolding for the cleaved HA conformational changes that mediate membrane fusion and for the action of antiviral drug candidates and cross-reactive anti-HA antibodies that can block influenza infectivity.