Introduction Environmental tobacco smoke (ETS) is generally known as secondhand smoke. Assessing the magnitude of children’s exposure to ETS from early infancy is essential for public health and research endeavours. Urinary cotinine is now widely recognised as the primary indicator for assessing exposure to ETS across all age groups. This systematic review and meta-analysis aim to synthesise all the published evidence on the urinary cotinine cut-off concentrations used to categorise children under 5 years as being exposed to ETS. Methods and analysis We will conduct a systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A comprehensive search will be conducted from various databases including PubMed, EMBASE, Scopus and Cochrane Library. This search will be performed from the earliest published articles up to the latest available studies until February 2025. We will include all the experimental and observational studies, such as cohort, case–control and cross-sectional, that measure urinary cotinine concentrations in children under 5 years old. Data extraction will be conducted using a standardised data extraction form, and the study quality will be evaluated according to the guidelines specified by the Newcastle-Ottawa Scale. The extracted data will be pooled and combined for meta-analysis. Two reviewers will independently screen, select and assess the quality of the included study. The result will be tabulated in a table of characteristics of the included study, which consists of the cut-off cotinine concentrations, analytical technique, method referred, study design, study area and respondents’ characteristics. Ethics and dissemination Ethics approval is not required as this is a review of collected published data. Findings will be disseminated in peer-reviewed publications and conference presentations, as well as with key stakeholders, health policymakers and healthcare professionals. PROSPERO registration number CRD42024556969.

Background: Long-chain omega-3 polyunsaturated fatty acids (LCPUFAs) are essential fatty acids that protect cellular structures and provide energy, particularly for fetal growth and development. The maternal supplementations of omega-3 LCPUFA may affect the rate of intelligence in early childhood development. Objective: This systematic review aims to synthesize available evidence on the impact of omega-3 LCPUFA supplementation during pregnancy toward intelligence in early childhood development by analyzing the outcomes specifying the aspects of intelligence such as neurodevelopment, social-emotional, language, attention, behavior, cognition, vision, hearing, and motor skills. Methods: We will only include randomized controlled trials on pregnant women supplemented with omega-3 LCPUFA interventions and the outcome measured is the children’s intelligence. Based on the World Health Organization's definition of early childhood, we will include children aged 8 years or younger. Children’s intelligence can be indicated using several tools measuring their intelligence index, such as neurodevelopment, social-emotional, language, attention, behavior, cognition, vision, hearing, and motor skills. Irrelevant and unavailable studies will be excluded. A systematic search will be conducted in 3 electronic databases, namely PubMed, Scopus, and Cochrane using relevant and synonymous terms. Study screening and selection will be conducted by the authors based on eligibility criteria. Upon encountering conflicting decisions, a discussion will be held to reach a consensus. The screening and selection process will be recorded using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flowchart. The included studies will be subjected to bias and quality assessment in accordance with the Critical Appraisal Skills Programme (CASP) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessment tool for randomized controlled trials. Results: An initial search was conducted on November 1, 2023, which returned 1998 studies for screening. The extracted data will be classified into groups and subgroups according to the indicator of intelligence measured in the study. Next, the extracted data will be summarized using tables of evidence. Whenever possible, a meta-analysis of homogeneous groups of studies will be conducted using statistical software such as RevMan (version 5.4; Cochrane Collaboration). Studies with significant heterogeneity will be discussed narratively. The systematic review is estimated to be published in November 2025. Conclusions: This systematic review will systematically pool the evidence on the potential use of omega-3 LCPUFA supplementation to improve children’s intelligence status. This review is also important in addressing any existing knowledge gaps on this topic. Finally, a deeper understanding of the association between the consumption of omega-3 LCPUFA supplementation during pregnancy and children’s intelligence will aid policy makers, health care practitioners, and mothers with more informed evidence-based decisions. Trial Registration: PROSPERO CRD42023463910; https://www.crd.york.ac.uk/PROSPERO/view/CRD42023463910 International Registered Report Identifier (IRRID): DERR1-10.2196/60417

Background: The COVID-19 pandemic significantly affected the mental health of frontline healthcare workers. This study investigated the mental health and occupational stressors faced by frontline workers in Selangor during the pandemic. Methods: A cross-sectional study was conducted using secondary data from the Mental Health and Psychosocial Support Services team, collected from March to August 2020. A total of 4593 frontline workers participated in the Depression, Anxiety, and Stress Scale screening. Results: Mental health symptoms were common among frontline workers during the COVID-19 pandemic, with 14.8% reporting stress, 30.7% anxiety, and 20.4% depression. Female workers had significantly higher odds of all three conditions, with adjusted odds ratios (aOR) of 1.35 (95% CI: 1.10–1.66) for stress, 1.25 (95% CI: 1.07–1.47) for anxiety, and 1.23 (95% CI: 1.03–1.47) for depression. Workers aged 18–30 had higher odds of stress (aOR 1.88; 95% CI: 1.42–2.47), anxiety (aOR 1.74; 95% CI: 1.43–2.12), and depression (aOR 1.80; 95% CI: 1.43–2.27) compared with those over 40. Employment in hospitals was associated with increased odds of all three conditions, with aORs ranging from 1.71 to 2.05. Among 711 respondents who reported occupational stressors, lack of mental health support was the strongest predictor (aORs 4.91–5.20), followed by poor work rotation and conflict with supervisors. Conclusions: Women, younger staff, and hospital workers were more vulnerable to mental health symptoms during the pandemic. Organizational factors, especially limited support and poor work arrangements, played a major role. Targeted mental health services and improved working conditions are needed to support healthcare workers in future emergencies.

During the COVID-19 pandemic, persons under surveillance (PUS) were isolated in quarantine centres instead of at home. However, there is limited knowledge regarding the mental health issues experienced by these persons. This study aimed to assess mental health outcomes and associated factors among PUS and frontline workers at quarantine centres. This study conducted an analysis of secondary data from a cross-sectional survey carried out by the Mental Health and Psychosocial Support Services (MHPSS). The MHPSS employed the Depression, Anxiety, and Stress Scale (DASS-21) to evaluate mental health outcomes across 49 quarantine centres in Malaysia. The study included a total of 4577 respondents. The prevalence of stress, anxiety, and depression was found to be 0.9%, 11.4%, and 10.2%, respectively. Frontline workers and being part of the younger age group were found to be associated with depression, anxiety, and stress. Other factors associated with mental health issues were being female, staying at an institution-type centre, and a longer duration of the stay or work at the centre. In conclusion, assessing the mental health status and its associated factors among quarantine centre occupants is crucial for developing future strategies to safeguard their mental well-being.

Dengue fever, with a high proportion of asymptomatic infections, poses a major global public health challenge that traditional surveillance systems frequently underestimate. Wastewater-based epidemiology (WBE) has emerged as a promising approach to monitoring infectious diseases beyond enteric viruses. Dengue virus is shed in urine, feces, and saliva, providing a biological basis for wastewater detection alongside clinical surveillance. This systematic review and meta-analysis synthesize current evidence on dengue virus (DENV) detection in wastewater and evaluate methodological factors influencing detection success in WBE. A systematic literature search using selected databases and predetermined keywords, followed by eligibility screening, resulted in ten studies being included, covering community surveillance and experimental trials. DENV ribonucleic acids (RNA) were most consistently detected and enriched in wastewater solids, indicating this matrix as the most reliable for surveillance. Among concentration methods, ultrafiltration achieved the highest viral recovery efficiency, while reverse transcription digital polymerase chain reaction (RT-dPCR) demonstrated superior sensitivity and precision compared to those of reverse transcription quantitative polymerase chain reaction (RT-qPCR), particularly at low viral concentrations. Storage at −80 °C was critical for preserving RNA integrity. The meta-analysis yielded a pooled DENV positivity rate of 24% (95% CI: 20–28%) after exclusion of outliers. Overall, solid-phase analysis combined with RT-dPCR represents the most sensitive methodological approach across the included studies. Harmonized protocols are needed to support future translation of dengue WBE into community surveillance as current evidence mainly demonstrates methodological feasibility and provides a technical foundation for future public health integration. Therefore, further longitudinal and multi-site validation is required to establish its broader applicability for dengue surveillance.

BACKGROUND Long-chain omega-3 polyunsaturated fatty acids (LCPUFAs) are essential fatty acids that protect cellular structures and provide energy, particularly for fetal growth and development. The maternal supplementations of omega-3 LCPUFA may affect the rate of intelligence in early childhood development. OBJECTIVE This systematic review aims to synthesize available evidence on the impact of omega-3 LCPUFA supplementation during pregnancy toward intelligence in early childhood development by analyzing the outcomes specifying the aspects of intelligence such as neurodevelopment, social-emotional, language, attention, behavior, cognition, vision, hearing, and motor skills. METHODS We will only include randomized controlled trials on pregnant women supplemented with omega-3 LCPUFA interventions and the outcome measured is the children’s intelligence. Based on the World Health Organization's definition of early childhood, we will include children aged 8 years or younger. Children’s intelligence can be indicated using several tools measuring their intelligence index, such as neurodevelopment, social-emotional, language, attention, behavior, cognition, vision, hearing, and motor skills. Irrelevant and unavailable studies will be excluded. A systematic search will be conducted in 3 electronic databases, namely PubMed, Scopus, and Cochrane using relevant and synonymous terms. Study screening and selection will be conducted by the authors based on eligibility criteria. Upon encountering conflicting decisions, a discussion will be held to reach a consensus. The screening and selection process will be recorded using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flowchart. The included studies will be subjected to bias and quality assessment in accordance with the Critical Appraisal Skills Programme (CASP) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessment tool for randomized controlled trials. RESULTS An initial search was conducted on November 1, 2023, which returned 1998 studies for screening. The extracted data will be classified into groups and subgroups according to the indicator of intelligence measured in the study. Next, the extracted data will be summarized using tables of evidence. Whenever possible, a meta-analysis of homogeneous groups of studies will be conducted using statistical software such as RevMan (version 5.4; Cochrane Collaboration). Studies with significant heterogeneity will be discussed narratively. The systematic review is estimated to be published in November 2025. CONCLUSIONS This systematic review will systematically pool the evidence on the potential use of omega-3 LCPUFA supplementation to improve children’s intelligence status. This review is also important in addressing any existing knowledge gaps on this topic. Finally, a deeper understanding of the association between the consumption of omega-3 LCPUFA supplementation during pregnancy and children’s intelligence will aid policy makers, health care practitioners, and mothers with more informed evidence-based decisions. CLINICALTRIAL PROSPERO CRD42023463910; https://www.crd.york.ac.uk/PROSPERO/view/CRD42023463910 INTERNATIONAL REGISTERED REPORT DERR1-10.2196/60417