Neurotoxic stimulation alters prosaposin levels in the salivary systems of rats.

Prosaposin (PSAP), a potent neurotrophic factor, is found in neuronal and non-neuronal tissues and various biological fluids. Neuropathological conditions often alter PSAP production in neural tissues. However, little is known about its alterations in non-neural tissues, particularly in the salivary glands, which are natural reservoirs of various neurotrophic factors. In this study, we explored whether neurotoxic stimulation by kainic acid (KA), a glutamate analog, altered PSAP levels in the salivary system of rats. The results revealed that KA injection did not alter total saliva production. However, KA-induced neurotoxic stimulation significantly increased the PSAP level in the secreted saliva but decreased it in the serum. In addition, KA-induced elevated immunoreactivities of PSAP and its receptors have been observed in the granular convoluted tubule (GCT) cells of the submandibular gland (SMG), a major salivary secretory organ. Indeed, a large number of PSAP-expressing immunogold particles were observed in the secretory granules of the SMG. Furthermore, KA-induced overexpression of PSAP was co-localized with secretogranin in secretory acini (mostly in GCT cells) and the ductal system of the SMG, suggesting the release of excess PSAP from the salivary glands into the oral cavity. In conclusion, the salivary system produces more PSAP during neurotoxic conditions, which may play a protective role in maintaining the secretory function of the salivary glands and may work in distant organs.

Systematic review: emotion dysregulation and challenging behavior interventions for children and adolescents on the autism spectrum with graded key evidence-based strategy recommendations.

Challenging behavior, such as aggression, is highly prevalent in children and adolescents on the autism spectrum and can have a devastating impact. Previous reviews of challenging behavior interventions did not include interventions targeting emotion dysregulation, a common cause of challenging behavior. We reviewed emotion dysregulation and challenging behavior interventions for preschoolers to adolescents to determine which evidence-based strategies have the most empirical support for reducing/preventing emotion dysregulation/challenging behavior. We reviewed 95 studies, including 29 group and 66 single case designs. We excluded non-behavioral/psychosocial interventions and those targeting internalizing symptoms only. We applied a coding system to identify discrete strategies based on autism practice guidelines with the addition of strategies common in childhood mental health disorders, and an evidence grading system. Strategies with the highest quality evidence (multiple randomized controlled trials with low bias risk) were Parent-Implemented Intervention, Emotion Regulation Training, Reinforcement, Visual Supports, Cognitive Behavioral/Instructional Strategies and Antecedent-Based Interventions. Regarding outcomes, most studies included challenging behavior measures, while few included emotion dysregulation measures. This review highlights the importance of teaching emotion regulation skills explicitly, positively reinforcing replacement/alternative behaviors, using visuals and metacognition, addressing stressors proactively, and involving parents. It also calls for more rigorously designed studies and for including emotion dysregulation as an outcome/mediator in future trials.

Tracking of Prosaposin, a Saposin Precursor, in Rat Testis.

We tracked prosaposin (PSAP), a trophic factor, using an antibody specific to its proteolytic portion and an antibody to sortilin that traffics PSAP only to the lysosome. Immunostaining revealed that PSAP was distributed mainly on the basal side of seminiferous tubules, where many Sertoli cells and pachytene spermatocytes contained PSAP and its distribution differed depending on the stage of the spermatogenic cycle. The PSAP-sortilin complex was sorted to large lysosomes in the basal cytoplasm of Sertoli cells, where it may be processed into saposins. In contrast, in the thinner apical cytoplasm of Sertoli cells, PSAP in small lysosomes was transported to the apical side around sperm heads or into the lumen for secretion. The results of in situ hybridization analyses suggested that immature tubular cells in young animals produce PSAP to self-stimulate proliferation. However, in adults, not only Sertoli cells but also pachytene spermatocytes produce and secrete PSAP around germ cells or into the tubular lumen to stimulate cell proliferation or differentiation in a paracrine or autocrine manner. In summary, PSAP is not only a precursor of lysosomal enzymes but also a pivotal trophic factor in organogenesis in the immature testis and spermatogenesis in the mature testis.

A randomized control trial to support smoke-free policy compliance in public housing.

BACKGROUND: Smoke-free housing policies in multiunit housing are increasingly widespread interventions to reduce smoking and secondhand smoke exposure. Little research has identified factors that impede compliance with smoke-free housing policies in low-income multiunit housing and test corresponding solutions. METHODS: We are using an experimental design to test two compliance support interventions: (A) a "compliance through reduction (via relocation and reduction in personal smoking) and cessation" intervention targets households with smokers and involves support to shift smoking practices to areas beyond the apartment or building setting, reduce personal smoking, and deliver in-residence smoking cessation support services via trained peer educators and (B) a "compliance through resident endorsement" intervention involving voluntary adoption of smoke-free living environments through personal pledges, visible door markers, and/or via social media. We will compare randomly sampled participants in buildings that receive A or B or A plus B to the NYCHA standard approach. DISCUSSION: This RCT addresses key gaps in knowledge and capitalizes on key scientific opportunities by (1) leveraging the federal mandate to ban smoking in a public housing system of more than sufficient size to conduct an adequately powered RCT; (2) expanding our understanding of smoke-free policy compliance beyond policy implementation by testing two novel treatments: (a) in-residence smoking cessation and (b) resident endorsement, while (3) addressing population and location-specific tobacco-related disparities. At the conclusion of the study, this RCT will have leveraged a monumental policy shift affecting nearly half a million NYC public housing residents, many of whom disproportionately experience chronic illness and are more likely to smoke and be exposed to secondhand smoke than other city residents. This first-ever RCT will test the effects of much-needed compliance strategies on resident smoking behavior and secondhand smoke exposure in multiunit housing. TRIAL REGISTRATION: Clinical Trials Registered, NCT05016505. Registered on August 23, 2021.

Aneurysmal Subarachnoid Hemorrhage and Cardiac Related Fatality: Who Dies and Why?

Medical complications are a notable source of in-hospital death following aneurysmal subarachnoid hemorrhage (aSAH). However, there is a paucity of literature examining medical complications on a national scale. This study uses a national dataset to analyze the incidence rates, case fatality rates, and risk factors for in-hospital complications and mortality following aSAH. We found that the most common complications in aSAH patients (N = 170, 869) were hydrocephalus (29.3%) and hyponatremia (17.3%). Cardiac arrest was the most common cardiac complication (3.2%) and was associated with the highest case fatality rate overall (82%). Patients with cardiac arrest also had the highest odds of in-hospital mortality [odds ratio (OR), 22.92; 95% confidence interval (CI), 19.24-27.30; P < 0.0001], followed by patients with cardiogenic shock (OR, 2.96; 95% CI, 2.146-4.07; P < 0.0001). Advanced age and National Inpatient Sample-SAH Severity Score were found to be associated with an increased risk of in-hospital mortality (OR, 1.03; 95% CI, 1.03-1.03; P < 0.0001 and OR, 1.70; 95% CI, 1.65-1.75; P < 0.0001, respectively). Renal and cardiac complications are significant factors to consider in aSAH management, with cardiac arrest being the strongest indicator of case fatality and in-hospital mortality. Further research is needed to characterize factors that have contributed to the decreasing trend in case fatality rates identified for certain complications.

Administration of prosaposin-derived neurotrophic factor to neural tube defects facilitates regeneration and restores neurological functions.

Neural tube defects (NTDs) cause fetal and pediatric deaths or lifelong neurological disabilities. No effective treatment is currently available for NTDs. We attempted to elucidate the pathogenesis of NTDs and propose a therapeutic strategy. Intra-amniotic treatment with prosaposin-derived 18-mer peptide (PS18) protected the spinal cord from secondary damage and rescued neurological function in an established chicken model of spina bifida aperta (SBA), the severe type of NTDs. PS18 promoted the formation of a neuroectodermal covering over the defective neural tube within 24-h after treatment, enhanced the regeneration/restoration process, and decreased apoptotic activity in the developing spinal cord. PS18 reduced the SBA wound and almost completely formed the spinal cord. SBA chicks that received PS18 exhibited relatively normal walking and sensorimotor responses, and reduced pain-associated behavior in postnatal life. In conclusion, PS18 is a promising therapeutic agent for NTDs and may be useful for treating other types of spinal cord injuries.

Systematic Review: Emotion Dysregulation and Challenging Behavior Interventions for Children andAdolescents with Autism with Graded Key Evidence-Based Strategy Recommendations.

Challenging behavior, such as aggression, is highly prevalent in children and adolescents with autism and can have a devastating impact. Previous reviews of challenging behavior interventions did not include interventions targeting emotion dysregulation, a common cause of challenging behavior. We reviewed emotion dysregulation and challenging behavior interventions for preschoolers to adolescents to determine which evidence-based strategies have the most empirical support for reducing/preventing emotion dysregulation/challenging behavior. We reviewed 95 studies, including 29 group and 66 single-case designs. We excluded non-behavioral/psychosocial interventions and those targeting internalizing symptoms only. We applied a coding system to identify discrete strategies based on autism practice guidelines with the addition of strategies common in childhood mental health disorders, and an evidence grading system. Strategies with the highest quality evidence (multiple randomized controlled trials with low bias risk) were Parent-Implemented Intervention, Emotion Regulation Training, Reinforcement, Visual Supports, Cognitive Behavioral/Instructional Strategies and Antecedent-Based Interventions. Regarding outcomes, most studies included challenging behaviors measures while few included emotion dysregulation measures. This review highlights the importance of teaching emotion-regulation skills explicitly, positively reinforcing replacement/alternative behaviors, using visuals and metacognition, addressing stressors proactively, and involving parents. It also calls for more rigorously-designed studies and for including emotion dysregulation as an outcome/mediator in future trials.

A Randomized Control Trial to support smoke-free policy compliance in public housing.

• Background Smoke-free housing policies in multiunit housing are increasingly widespread interventions to reduce smoking and secondhand smoke exposure. Little research has identified factors that impede compliance with smoke-free housing policies in low-income multiunit housing and test corresponding solutions. • Methods We are using an experimental design to test two compliance support interventions: (A) a "compliance through reduction (via relocation and reduction in personal smoking) and cessation" intervention targets households with smokers and involves support to shift smoking practices to designated areas, reduce personal smoking, and deliver in-residence smoking cessation support services via trained peer educators and (B) a "compliance through resident endorsement" intervention involving voluntary adoption of smoke-free living environments through personal pledges, visible door markers and/or via social media. We will compare randomly sampled participants in buildings that receive A or B or A plus B to the NYCHA standard approach, • Discussion This RCT addresses key gaps in knowledge and capitalizes on key scientific opportunities by: 1) leveraging the federal mandate to ban smoking in a public housing system of more than sufficient size to conduct an adequately powered RCT; 2) expanding our understanding of smoke-free policy compliance beyond policy implementation by testing two novel treatments: a) in-residence smoking cessation and b) resident endorsement, while 3) addressing population and location-specific tobacco-related disparities. At the conclusion of the study, this RCT will have leveraged a monumental policy shift affecting nearly half a million NYC public housing residents, many of whom disproportionately experience chronic illness and are more likely to smoke and be exposed to secondhand smoke than other city residents. This first-ever RCT will test the effects of much-needed compliance strategies on resident smoking behavior and secondhand smoke exposure in multiunit housing. Trial registration: Clinical Trials Registered, NCT05016505 Registered: August 23, 2021 https://clinicaltrials.gov/ct2/show/NCT05016505.

Exploring the self-preparedness of frontline healthcare workers in a low- and middle-income country from a humanitarian context during the COVID-19 pandemic: A constructivist grounded theory study.

Background: While research has been conducted on the availability, accessibility, and affordability of personal protective equipment for healthcare workers during the COVID-19 pandemic, little information is available on the ways in which health workers, especially those in humanitarian settings see themselves, and engage in self-preparedness for social, physical, and mental health and practical care in the pandemic. We sought to address this gap. Methods: We followed a constructivist grounded theory approach to guide in-depth interviews with 30 frontline doctors, nurses, and community healthcare workers recruited from the Rohingya refugee camps in Bangladesh using the purposive and snowball sampling methods. Analyses were carried out through the identification of codes in three phases: an initial line-by-line open coding, then focused axial coding, and finally selective coding. Findings: An emergent-grounded theory of "Navigating Self-Preparedness through Pandemics" was developed as we built a five-phased theoretical framework examining health worker responses with the following pillars: (a) pandemic shock; (b) pandemic awareness; (c) pandemic learning; (d) pandemic resilience, and (e) pandemic resurgence. Interpretation: The theory emerged as a realistic, socially, and culturally sensitive COVID-19 strategy to support healthcare workers. Self-preparedness was characterized by two interwoven processes: (1) the experiences of the daily life span of healthcare workers attempting to improve their own protection using all their potential while providing care for patients in a vulnerable setting and time and (2) the inseparable role of physical, psychological, social, and spiritual factors in each stage of learning during the pandemic to achieve better outcomes.

Prenatal exposure to a natural disaster and early development of psychiatric disorders during the preschool years: stress in pregnancy study.

BACKGROUND: Growing evidence shows an association between in utero exposure to natural disasters and child behavioral problems, but we still know little about the development of specific psychopathology in preschool-aged children. METHODS: Preschool children (n = 163, mean age = 3.19, 85.5% racial and ethnic minorities) and their parents (n = 151) were evaluated annually at ages 2-5 to assess the emergence of psychopathology using the Preschool Age Psychopathological Assessment (PAPA), a parent-report structured diagnostic interview developed for preschool-age children. Sixty-six (40.5%) children were exposed to Sandy Storm (SS) in utero and 97 (59.5%) were not. Survival analysis evaluated patterns of onset and estimated cumulative risks of psychopathology among exposed and unexposed children, in total and by sex. Analyses were controlled for the severity of objective and subjective SS-related stress, concurrent family stress, and demographic and psychosocial confounders, such as maternal age, race, SES, maternal substance use, and normative prenatal stress. RESULTS: Exposure to SS in utero was associated with a substantial increase in depressive disorders (Hazard Ratio (HR) = 16.9, p = .030), anxiety disorders (HR = 5.1, p < .0001), and attention-deficit/disruptive behavioral disorders (HR = 3.4, p = .02). Diagnostic rates were elevated for generalized anxiety disorder (GAD; HR = 8.5, p = .004), attention-deficit/hyperactivity disorder (ADHD; HR = 5.5, p = .01), oppositional-defiant disorder (ODD; HR = 3.8, p = .05), and separation-anxiety disorder (SAD; HR = 3.5, p = .001). Males had distinctively elevated risks for attention-deficit/disruptive behavioral disorders (HR = 7.8, p = .02), including ADHD, CD, and ODD, whereas females had elevated risks for anxiety disorders (HR = 10.0, p < .0001), phobia (HR = 2.8, p = .02) and depressive disorders (HR = 30.0, p = .03), including SAD, GAD, and dysthymia. CONCLUSIONS: The findings demonstrate that in utero exposure to a major weather-related disaster (SS) was associated with increased risk for psychopathology in children and provided evidence of distinct psychopathological outcomes as a function of sex. More attention is needed to understand specific parent, child, and environmental factors which account for this increased risk, and to develop mitigation strategies.

Acute ischemic strokes in patients with developmental disabilities: A cross-sectional analysis.

OBJECTIVE: Patients with developmental disabilities (DD) are frequently excluded from acute ischemic stroke (AIS) randomized control trials. We sought to evaluate the impact of having DD on this patient cohort. METHODS: The National Inpatient Sample was analyzed to explore the impact of AIS and treatment on discharge dispositions in patients with DD. Clinical characteristics, treatments, and outcomes were compared to fully-abled patients with AIS. RESULTS: 1,605,723 patients with AIS were identified from 2010-2019, of whom 4094 (0.30%) had a DD. AIS patients with DD were younger (60.31 vs 70.93 years, p < 0.01), less likely to be Caucasian (66.37%vs 68.09%, p = 0.01), and had higher AIS severity (0.63 vs 0.58, p < 0.01). Tissue plasminogen activator (tPA) was administered in 99,739 (6.2%) fully-abled patients and 196 (4.79%) of patients with DD (p < 0.01). Endovascular thrombectomy (EVT) was performed in 21,066 (1.31%) of fully-abled patients and 35 (0.85%) of patients with DD (p < 0.01). The presence of developmental disabilities were predictive of lower rates of tPA (OR:0.71,CI:0.56-0.87,p < 0.01) and EVT (OR:0.24,CI:0.16-0.36,p < 0.01). In a propensity score-matched cohort of all AIS patients who underwent EVT, there was no difference in functional outcome (p = 0.41), in-hospital mortality (0.10), and LOS (p = 0.79). CONCLUSION: AIS patients with DD were less likely to receive tPA and EVT compared to fully-abled patients. Individuals with DD had higher mortality and worse discharge disposition. There was no significant difference in post-EVT outcomes between fully-abled patients and patients with developmental disabilities. In the absence of prospective clinical trials, population based cross-sectional analyses such as the present study provide valuable clinical insight.

UK Dietary Practices for Tyrosinaemias: Time for Change.

In the UK, different dietary systems are used to calculate protein or tyrosine/phenylalanine intake in the dietary management of hereditary tyrosinaemia, HTI, II and III (HT), with no systematic evidence comparing the merits and inadequacies of each. This study aimed to examine the current UK dietary practices in all HTs and, using Delphi methodology, to reach consensus agreement about the best dietary management system. Over 12 months, five meetings were held with UK paediatric and adult dietitians working in inherited metabolic disorders (IMDs) managing HTs. Eleven statements on the dietary system for calculating protein or tyrosine/phenylalanine intake were discussed. Dietitians from 12 of 14 IMD centres caring for HT patients participated, and 7/11 statements were agreed with one Delphi round. Nine centres (three abstentions) supported a 1 g protein exchange system for all foods except fruit and vegetables. The same definitions used in the UK for phenylketonuria (PKU) were adopted to define when to calculate foods as part of a protein exchange system or permit them without measurement. Fruit and vegetables contain a lower amount of tyrosine/phenylalanine per 1 g of protein than animal and cereal foods. The correlation of tyrosine vs. phenylalanine (mg/100 g) for vegetables and fruits was high (r = 0.9). In Delphi round 2, agreement was reached to use the tyrosine/phenylalanine analyses of fruits/vegetables, for their allocation within the HT diet. This allowed larger portion sizes of measured fruits and vegetables and increased the variety of fruit and vegetables that could be eaten without measurement. In HTs, a combined dietary management system will be used: 1 g protein exchanges for cereal and milk protein sources and tyrosine/phenylalanine exchanges for fruit and vegetables. Intensive, systematic communication with IMD dietitians and reappraisal of the evidence has redefined and harmonised HT dietary practice across the UK.

COVID-19 Risk Perception and Prevention Practices among High- and Low-Density Populations in Bangladesh: A Mixed-Methods Study.

We aimed to explore coronavirus disease 2019 (COVID-19) risk perception and prevention practices among people living in high- and low-population density areas in Dhaka, Bangladesh. A total of 623 patients with confirmed COVID-19 agreed to participate in the survey. Additionally, we purposively selected 14 participants from diverse economic and occupational groups and conducted qualitative interviews for them accordingly. Approximately 70% of the respondents had low socioeconomic status. Among the 623 respondents, 146 were from low-density areas, and 477 were from high-density areas. The findings showed that study participants perceived COVID-19 as a punishment from the Almighty, especially for non-Muslims, and were not concerned about its severity. They also believed that coronavirus would not survive in hot temperatures or negatively impact Bangladeshis. This study revealed that people were reluctant to undergo COVID-19 testing. Family members hid if anyone tested positive for COVID-19 or did not adhere to institutional isolation. The findings showed that participants were not concerned about COVID-19 and believed that coronavirus would not have a devastating impact on Bangladeshis; thus, they were reluctant to follow prevention measures and undergo testing. Tailored interventions for specific targeted groups would be relevant in mitigating the prevailing misconceptions.

Suitability and Allocation of Protein-Containing Foods According to Protein Tolerance in PKU: A 2022 UK National Consensus.

Introduction: There is little practical guidance about suitable food choices for higher natural protein tolerances in patients with phenylketonuria (PKU). This is particularly important to consider with the introduction of adjunct pharmaceutical treatments that may improve protein tolerance. Aim: To develop a set of guidelines for the introduction of higher protein foods into the diets of patients with PKU who tolerate >10 g/day of protein. Methods: In January 2022, a 26-item food group questionnaire, listing a range of foods containing protein from 5 to >20 g/100 g, was sent to all British Inherited Metabolic Disease Group (BIMDG) dietitians (n = 80; 26 Inherited Metabolic Disease [IMD] centres). They were asked to consider within their IMD dietetic team when they would recommend introducing each of the 26 protein-containing food groups into a patient's diet who tolerated >10 g to 60 g/day of protein. The patient protein tolerance for each food group that received the majority vote from IMD dietetic teams was chosen as its tolerance threshold for introduction. A virtual meeting was held using Delphi methodology in March 2022 to discuss and agree final consensus. Results: Responses were received from dietitians from 22/26 IMD centres (85%) (11 paediatric, 11 adult). For patients tolerating protein ≥15 g/day, the following foods were agreed for inclusion: gluten-free pastas, gluten-free flours, regular bread, cheese spreads, soft cheese, and lentils in brine; for protein tolerance ≥20 g/day: nuts, hard cheeses, regular flours, meat/fish, and plant-based alternative products (containing 5−10 g/100 g protein), regular pasta, seeds, eggs, dried legumes, and yeast extract spreads were added; for protein tolerance ≥30 g/day: meat/fish and plant-based alternative products (containing >10−20 g/100 g protein) were added; and for protein tolerance ≥40 g/day: meat/fish and plant-based alternatives (containing >20 g/100 g protein) were added. Conclusion: This UK consensus by IMD dietitians from 22 UK centres describes for the first time the suitability and allocation of higher protein foods according to individual patient protein tolerance. It provides valuable guidance for health professionals to enable them to standardize practice and give rational advice to patients.

Targeting extracellular Hsp90: A unique frontier against cancer.

The molecular chaperone Heat Shock Protein-90 (Hsp90) is known to interact with over 300 client proteins as well as regulatory factors (eg. nucleotide and proteins) that facilitate execution of its role as a chaperone and, ultimately, client protein activation. Hsp90 associates transiently with these molecular modulators during an eventful chaperone cycle, resulting in acquisition of flexible structural conformations, perfectly customized to the needs of each one of its client proteins. Due to the plethora and diverse nature of proteins it supports, the Hsp90 chaperone machinery is critical for normal cellular function particularly in response to stress. In diseases such as cancer, the Hsp90 chaperone machinery is hijacked for processes which encompass many of the hallmarks of cancer, including cell growth, survival, immune response evasion, migration, invasion, and angiogenesis. Elevated levels of extracellular Hsp90 (eHsp90) enhance tumorigenesis and the potential for metastasis. eHsp90 has been considered one of the new targets in the development of anti-cancer drugs as there are various stages of cancer progression where eHsp90 function could be targeted. Our limited understanding of the regulation of the eHsp90 chaperone machinery is a major drawback for designing successful Hsp90-targeted therapies, and more research is still warranted.

Can You Hear Us Now? Equity in Global Advocacy for Palliative Care.

Evidence-based advocacy underpins the sustainable delivery of quality, publicly guaranteed, and universally available palliative care. More than 60 million people in low- and middle-income countries (LMICs) have no or extremely limited access to either palliative care services or essential palliative care medicines (e.g., opioids) on the World Health Organization Model List. Indeed, only 12% of the global palliative care need is currently being met. Palliative care advocacy works to bring this global public health inequity to light. Despite their expertise, palliative care practitioners in LMICs are rarely invited to health policymaking tables - even in their own countries - and are underrepresented in the academic literature produced largely in the high-income world. In this paper, palliative care experts from Bangladesh, Colombia, Egypt, Sudan, Uganda, and Zambia affiliated with the International Association for Hospice & Palliative Care Advocacy Focal Point Program articulate the urgent need for evidence-based advocacy, focusing on significant barriers such as urban/rural divides, cancer-centeredness, service delivery gaps, opioid formulary limitations, public policy, and education deficits. Their advocacy is situated in the context of an emerging global health narrative that stipulates palliative care provision as an ethical obligation of all health systems. To support advocacy efforts, palliative care evaluation and indicator data should assess the extent to which LMIC practitioners lead and participate in global and regional advocacy. This goal entails investment in transnational advocacy initiatives, research investments in palliative care access and cost-effective models in LMICs, and capacity building for a global community of practice to capture the attention of policymakers at all levels of health system governance.

Rapid antigen testing by community health workers for detection of SARS-CoV-2 in Dhaka, Bangladesh: a cross-sectional study.

OBJECTIVE: To evaluate the diagnostic performance and feasibility of rapid antigen testing for SARS-CoV-2 detection in low-income communities. DESIGN: We conducted a cross-sectional community-based diagnostic accuracy study. Community health workers, who were trained and supervised by medical technicians, performed rapid antigen tests on symptomatic individuals, and up to two additional household members in their households and diagnostic results were calibrated against the gold standard RT-PCR. SETTING: Low-income communities in Dhaka, Bangladesh. PARTICIPANTS: Between 19 May 2021 and 11 July 2021, 1240 nasal and saliva samples were collected from symptomatic individuals and 993 samples from additional household members (up to two from one household). RESULTS: The sensitivity of rapid antigen tests was 0.68 on nasal samples (95% CI 0.62 to 0.73) and 0.41 on saliva (95% CI 0.35 to 0.46), with specificity also higher on nasal samples (0.98, 95% CI 0.97 to 0.99) than saliva (0.87, 95% CI 0.85 to 0.90). Testing up to two additional household members increased sensitivity to 0.71 on nasal samples (95% CI 0.65 to 0.76), but reduced specificity (0.96, 95% CI 0.94 to 0.97). Sensitivity on saliva rose to 0.48 (95% CI 0.42 to 0.54) with two additional household members tested but remained lower than sensitivity on nasal samples. During the study period, testing in these low-income communities increased fourfold through the mobilisation of community health workers for sample collection. CONCLUSIONS: Rapid antigen testing on nasal swabs can be effectively performed by community health workers yielding equivalent sensitivity and specificity to the literature. Household testing by community health workers in low-resource settings is an inexpensive approach that can increase testing capacity, accessibility and the effectiveness of control measures through immediately actionable results.

Combining rapid antigen testing and syndromic surveillance improves community-based COVID-19 detection in a low-income country.

Diagnostics for COVID-19 detection are limited in many settings. Syndromic surveillance is often the only means to identify cases but lacks specificity. Rapid antigen testing is inexpensive and easy-to-deploy but can lack sensitivity. We examine how combining these approaches can improve surveillance for guiding interventions in low-income communities in Dhaka, Bangladesh. Rapid-antigen-testing with PCR validation was performed on 1172 symptomatically-identified individuals in their homes. Statistical models were fitted to predict PCR-status using rapid-antigen-test results, syndromic data, and their combination. Under contrasting epidemiological scenarios, the models' predictive and classification performance was evaluated. Models combining rapid-antigen-testing and syndromic data yielded equal-to-better performance to rapid-antigen-test-only models across all scenarios with their best performance in the epidemic growth scenario. These results show that drawing on complementary strengths across rapid diagnostics, improves COVID-19 detection, and reduces false-positive and -negative diagnoses to match local requirements; improvements achievable without additional expense, or changes for patients or practitioners.

Transmission of SARS-CoV-2 in the Population Living in High- and Low-Density Gradient Areas in Dhaka, Bangladesh.

Community transmission of SARS-CoV-2 in densely populated countries has been a topic of concern from the beginning of the pandemic. Evidence of community transmission of SARS-CoV-2 according to population density gradient and socio-economic status (SES) is limited. In June−September 2020, we conducted a descriptive longitudinal study to determine the community transmission of SARS-CoV-2 in high- and low-density areas in Dhaka city. The Secondary Attack Rate (SAR) was 10% in high-density areas compared to 20% in low-density areas. People with high SES had a significantly higher level of SARS-CoV-2-specific Immunoglobulin G (IgG) antibodies on study days 1 (p = 0.01) and 28 (p = 0.03) compared to those with low SES in high-density areas. In contrast, the levels of seropositivity of SARS-CoV-2-specific Immunoglobulin M (IgM) were comparable (p > 0.05) in people with high and low SES on both study days 1 and 28 in both high- and low-density areas. Due to the similar household size, no differences in the seropositivity rates depending on the population gradient were observed. However, people with high SES showed higher seroconversion rates compared to people with low SES. As no difference was observed based on population density, the SES might play a role in SARS-CoV-2 transmission, an issue that calls for further in-depth studies to better understand the community transmission of SARS-CoV-2.