A Self-Cascade Penetrating Brain Tumor Immunotherapy Mediated by Near-Infrared II Cell Membrane-Disrupting Nanoflakes via Detained Dendritic Cells.

Immunotherapy can potentially suppress the highly aggressive glioblastoma (GBM) by promoting T lymphocyte infiltration. Nevertheless, the immune privilege phenomenon, coupled with the generally low immunogenicity of vaccines, frequently hampers the presence of lymphocytes within brain tumors, particularly in brain tumors. In this study, the membrane-disrupted polymer-wrapped CuS nanoflakes that can penetrate delivery to deep brain tumors via releasing the cell-cell interactions, facilitating the near-infrared II (NIR II) photothermal therapy, and detaining dendritic cells for a self-cascading immunotherapy are developed. By convection-enhanced delivery, membrane-disrupted amphiphilic polymer micelles (poly(methoxypoly(ethylene glycol)-benzoic imine-octadecane, mPEG-b-C18) with CuS nanoflakes enhances tumor permeability and resides in deep brain tumors. Under low-power NIR II irradiation (0.8 W/cm2), the intense heat generated by well-distributed CuS nanoflakes actuates the thermolytic efficacy, facilitating cell apoptosis and the subsequent antigen release. Then, the positively charged polymer after hydrolysis of the benzoic-imine bond serves as an antigen depot, detaining autologous tumor-associated antigens and presenting them to dendritic cells, ensuring sustained immune stimulation. This self-cascading penetrative immunotherapy amplifies the immune response to postoperative brain tumors but also enhances survival outcomes through effective brain immunotherapy.

Investigating demic versus cultural diffusion and sex bias in the spread of Austronesian languages in Vietnam.

Austronesian (AN) is the second-largest language family in the world, particularly widespread in Island Southeast Asia (ISEA) and Oceania. In Mainland Southeast Asia (MSEA), groups speaking these languages are concentrated in the highlands of Vietnam. However, our knowledge of the spread of AN-speaking populations in MSEA remains limited; in particular, it is not clear if AN languages were spread by demic or cultural diffusion. In this study, we present and analyze new data consisting of complete mitogenomes from 369 individuals and 847 Y-chromosomal single nucleotide polymorphisms (SNPs) from 170 individuals from all five Vietnamese Austronesian groups (VN-AN) and five neighboring Vietnamese Austroasiatic groups (VN-AA). We found genetic signals consistent with matrilocality in some, but not all, of the VN-AN groups. Population affinity analyses indicated connections between the AN-speaking Giarai and certain Taiwanese AN groups (Rukai, Paiwan, and Bunun). However, overall, there were closer genetic affinities between VN-AN groups and neighboring VN-AA groups, suggesting language shifts. Our study provides insights into the genetic structure of AN-speaking communities in MSEA, characterized by some contact with Taiwan and language shift in neighboring groups, indicating that the expansion of AN speakers in MSEA was a combination of cultural and demic diffusion.

Dengue viremia kinetics and effects on platelet count and clinical outcomes: An analysis of 2340 patients from Vietnam.

Background: Viremia is a critical factor in understanding the pathogenesis of dengue infection, but limited data exist on viremia kinetics. This study aimed to investigate the kinetics of viremia and its effects on subsequent platelet count, severe dengue, and plasma leakage. Methods: We pooled data from three studies conducted in Vietnam between 2000 and 2016, involving 2340 dengue patients with daily viremia measurements and platelet counts after symptom onset. Viremia kinetics were assessed using a random effects model that accounted for left-censored data. The effects of viremia on subsequent platelet count and clinical outcomes were examined using a landmark approach with a random effects model and logistic regression model with generalized estimating equations, respectively. The rate of viremia decline was derived from the model of viremia kinetics. Its effect on the clinical outcomes was assessed by logistic regression models. Results: Viremia levels rapidly decreased following symptom onset, with variations observed depending on the infecting serotype. DENV-1 exhibited the highest mean viremia levels during the first 5-6 days, while DENV-4 demonstrated the shortest clearance time. Higher viremia levels were associated with decreased subsequent platelet counts from day 6 onwards. Elevated viremia levels on each illness day increased the risk of developing severe dengue and plasma leakage. However, the effect size decreased with later illness days. A more rapid decline in viremia is associated with a reduced risk of the clinical outcomes. Conclusions: This study provides comprehensive insights into viremia kinetics and its effect on subsequent platelet count and clinical outcomes in dengue patients. Our findings underscore the importance of measuring viremia levels during the early febrile phase for dengue studies and support the use of viremia kinetics as outcome for phase-2 dengue therapeutic trials. Funding: Wellcome Trust and European Union Seventh Framework Programme.

Human-aided dispersal and population bottlenecks facilitate parasitism escape in the most invasive mosquito species.

During biological invasion process, species encounter new environments and partially escape some ecological constraints they faced in their native range, while they face new ones. The Asian tiger mosquito Aedes albopictus is one of the most iconic invasive species introduced in every inhabited continent due to international trade. It has also been shown to be infected by a prevalent yet disregarded microbial entomoparasite Ascogregarina taiwanensis. In this study, we aimed at deciphering the factors that shape the global dynamics of A. taiwanensis infection in natural A. albopictus populations. We showed that A. albopictus populations are highly colonized by several parasite genotypes but recently introduced ones are escaping it. We further performed experiments based on the invasion process to explain such pattern. To that end, we hypothesized that (i) mosquito passive dispersal (i.e. human-aided egg transportation) may affect the parasite infectiveness, (ii) founder effects (i.e. population establishment by a small number of mosquitoes) may influence the parasite dynamics, and (iii) unparasitized mosquitoes are more prompt to found new populations through active flight dispersal. The two first hypotheses were supported as we showed that parasite infection decreases over time when dry eggs are stored and that experimental increase in mosquitoes' density improves the parasite horizontal transmission to larvae. Surprisingly, parasitized mosquitoes tend to be more active than their unparasitized relatives. Finally, this study highlights the importance of global trade as a driver of biological invasion of the most invasive arthropod vector species.

Willingness to Pay for a Quality-Adjusted Life Year among Gastrointestinal Cancer Patients at a Tertiary Hospital of Vietnam, 2022.

BACKGROUND: Gastrointestinal (GI) cancer burden in Asia is increasing, and Vietnam is no exception. Assessing the affordability of achieving a quality-adjusted life year (QALY) in gastrointestinal cancer patients Vietnam, as well as identifying predictors of willingness to pay (WTP) per QALY, is crucial to decision-making around medical intervention prioritization and performing medical technology assessments for these cancers. OBJECTIVES: Our study aimed to estimate WTP/QALY gained and associated factors among patients diagnosed with GI cancer at a tertiary hospital in Hue, Vietnam. METHODS: A cross-sectional descriptive study, using contingent valuation methodology was conducted among 231 patients at tertiary hospital in 2022. A double limited dichotomous choice and the EQ-5D-5L were utilised to estimate WTP and QALY, respectively. Quantile regression was applied to determine predictors of WTP/QALY. RESULTS: The mean and median maximum WTP/QALY gained among GI patients was $15,165.6 (42,239.6) and $4,365.6 (IQR: 1,586.5-14,552.0), respectively, which was equal to 3.68 times the 2022 gross domestic product (GDP) per capita in Vietnam.  Additionally, cancer severity was found to have a significant impact  on WTP per QALY gained, with a higher amount identified among patients with earlier stages of GI cancer. Furthermore, living in an urban dwelling and patients' treatment modalities were significantly associated with WTP/QALY. CONCLUSION: Evidence from our study can be used to inform how decision-makers in Vietnam to determine the cost-effectiveness of GI cancer interventions.

Imidazole[1,5-a]pyridine derivatives as EGFR tyrosine kinase inhibitors unraveled by umbrella sampling and steered molecular dynamics simulations.

Although the use of the tyrosine kinase inhibitors (TKIs) has been proved that it can save live in a cancer treatment, the currently used drugs bring in many undesirable side-effects. Therefore, the search for new drugs and an evaluation of their efficiency are intensively carried out. Recently, a series of eighteen imidazole[1,5-a]pyridine derivatives were synthetized by us, and preliminary analyses pointed out their potential to be an important platform for pharmaceutical development owing to their promising actions as anticancer agents and enzyme (kinase, HIV-protease,…) inhibitors. In the present theoretical study, we further analyzed their efficiency in using a realistic scenario of computational drug design. Our protocol has been developed to not only observe the atomistic interaction between the EGFR protein and our 18 novel compounds using both umbrella sampling and steered molecular dynamics simulations, but also determine their absolute binding free energies. Calculated properties of the 18 novel compounds were in detail compared with those of two known drugs, erlotinib and osimertinib, currently used in cancer treatment. Inspiringly the simulation results promote three imidazole[1,5-a]pyridine derivatives as promising inhibitors into a further step of clinical trials.

Flavonoids Biotransformation by Human Gut Bacterium Dorea sp. MRG-IFC3 Cell-Free Extract.

Human gut bacterium Dorea sp. MRG-IFC3 is unique in that it is capable of metabolizing puerarin, an isoflavone C-glycoside, whereas it shows broad substrate glycosidase activity for the various flavonoid O-glycosides. To address the question on the substrate specificity, as well as biochemical characteristics, cell-free biotransformation of flavonoid glycosides was performed under various conditions. The results showed that there are two different enzyme systems responsible for the metabolism of flavonoid C-glycosides and O-glycosides in the MRG-IFC3 strain. The system responsible for the conversion of puerarin was inducible and comprised of two enzymes. One enzyme oxidizes puerarin to 3"-oxo-puerarin and the other enzyme converts 3"-oxo-puearin to daidzein. The second enzyme was only active toward 3"-oxo-puerarin. The activity of puerarin conversion to daidzein was enhanced in the presence of Mn2+ and NAD+. It was concluded that the puerarin C-deglycosylation by Dorea sp. MRG-IFC3 possibly adopts the same biochemical mechanism as the strain PUE, a species of Dorea longicatena.

Relationship between Flavonoid Chemical Structures and Their Antioxidant Capacity in Preventing Polycyclic Aromatic Hydrocarbons Formation in Heated Meat Model System.

The relationship between the chemical structures of six flavonoids and their abilities to inhibit the formation of polycyclic aromatic hydrocarbons (PAHs) in a heated meat model system was investigated. The PAH8 forming in samples was analyzed by using QuEChERS coupled GC-MS. Inhibitory effects of PAHs were myricetin (72.1%) > morin (55.7%) > quercetin (57.3%) > kaempferol (49.9%) > rutin (32.7%) > taxifolin (30.2%). The antioxidant activities of these flavonoids, assessed through (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activity assay (DPPH), [2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid)] free radical scavenging activity assay (ABTS) and ferric ion reducing antioxidant power assay (FRAP) assays, exhibited a significant negative correlation with PAH reduction. Notably, myricetin that contained three hydroxyl groups on the B-ring, along with a 2,3-double bond in conjugation with a 4-keto moiety on the C-ring, demonstrated strong antioxidant properties and free radical scavenging abilities, which significantly contributed to their ability to inhibit PAH formation. However, rutin and taxifolin, substituted at the C-3 position of the C-ring, decreased the PAH inhibitory activity. The ABTS assay proved the most effective in demonstrating the correlation between flavonoid antioxidant properties and their capacity to inhibit PAH formation in heated meat model systems. Thus, the inhibition of PAHs can be achieved by dietary flavonoids according to their chemical structures.

Age-time-specific transmission of hand-foot-and-mouth disease enterovirus serotypes in Vietnam: A catalytic model with maternal immunity.

Hand, foot and mouth disease (HFMD) is highly prevalent in the Asia Pacific region, particularly in Vietnam. To develop effective interventions and efficient vaccination programs, we inferred the age-time-specific transmission patterns of HFMD serotypes enterovirus A71 (EV-A71), coxsackievirus A6 (CV-A6), coxsackievirus A10 (CV-A10), coxsackievirus A16 (CV-A16) in Ho Chi Minh City, Vietnam from a case data collected during 2013-2018 and a serological survey data collected in 2015 and 2017. We proposed a catalytic model framework with good adaptability to incorporate maternal immunity using various mathematical functions. Our results indicate the high-level transmission of CV-A6 and CV-A10 which is not obvious in the case data, due to the variation of disease severity across serotypes. Our results provide statistical evidence supporting the strong association between severe illness and CV-A6 and EV-A71 infections. The HFMD dynamic pattern presents a cyclical pattern with large outbreaks followed by a decline in subsequent years. Additionally, we identify the age group with highest risk of infection as 1-2 years and emphasise the risk of future outbreaks as over 50% of children aged 6-7 years were estimated to be susceptible to CV-A16 and EV-A71. Our study highlights the importance of multivalent vaccines and active surveillance for different serotypes, supports early vaccination prior to 1 year old, and points out the potential utility for vaccinating children older than 5 years old in Vietnam.

Synergistic effect of metformin and vitamin D3 on osteogenic differentiation of human adipose tissue-derived mesenchymal stem cells under high d-glucose conditions.

Introduction: Vitamin D3 plays a vital role in bone health, with low levels of vitamin D3 being related to skeletal fragility, fractures, and metabolic disorders such as diabetes. Metformin is known as an antihyperglycemic agent for regulating blood sugar. A correlation between diabetes mellitus and osteoporosis is attracting considerable interest, and research to find the prevention and treatment is gradually being studied. In this study, we investigated the effect of metformin and vitamin D3 on osteogenic differentiation of human adipose tissue-derived mesenchymal stem cells (AT-MSCs) under high d-glucose concentrations and optimized by combining vitamin D3 and metformin in the process. Methods: ROS production of AT-MSCs under high d-glucose conditions was measured by DCFH-DA assay. The differentiated AT-MSCs were analyzed by Alizarin Red S staining and optical density measurement. The investigation involved the examination of osteogenic master genes' expressions using quantitative reverse transcription polymerase chain reaction (qRT-PCR) techniques. Results: Interestingly, the results have shown that human AT-MSCs will exhibit high ROS accumulation and low osteogenic differentiation capabilities, indicated by low calcium deposition, as well as low expression of indicative genes such as ALP, Runx-2 under high d-glucose conditions. The combination of vitamin D3 and metformin remarkedly accelerated the osteogenic differentiation of AT-MSCs under high d-glucose concentrations more effectively than the administration of either agent. Conclusions: This study partially explains an aspect of an in vitro model for pre-clinical drug screening for osteoporosis-related diabetic pathological mechanisms, which can be applied for further research on the prevention or treatment of osteoporosis in diabetic patients.

Comtrifosides A and B, two new triterpenoid saponins from the leaves of Combretum trifoliatum.

The phytochemical composition of the Combretum trifoliatum leaves was studied for the first time. Two new triterpenoid saponins, named comtrifoside A (1) and comtrifoside B (2), together with two other saponins (3-4) were purified by variously chromatographic techniques. For the first time, compound 3 was informed from the Combretum genus, as well as all of the isolated compounds (1-4) were reported from C. trifoliatum. The chemical structures of them were clearly characterised using extensive UV-VIS, IR, HRMS-ESI, and NMR experimental data. The in vitro anti-inflammatory activities of 1 & 2 were examined against NO overproduction in LPS activation of RAW264.7.

Endothelial and inflammatory pathophysiology in dengue shock: New insights from a prospective cohort study in Vietnam.

Dengue shock (DS) is the most severe complication of dengue infection; endothelial hyperpermeability leads to profound plasma leakage, hypovolaemia and extravascular fluid accumulation. At present, the only treatment is supportive with intravenous fluid, but targeted endothelial stabilising therapies and host immune modulators are needed. With the aim of prioritising potential therapeutics, we conducted a prospective observational study of adults (≥16 years) with DS in Vietnam from 2019-2022, comparing the pathophysiology underlying circulatory failure with patients with septic shock (SS), and investigating the association of biomarkers with clinical severity (SOFA score, ICU admission, mortality) and pulmonary vascular leak (daily lung ultrasound for interstitial and pleural fluid). Plasma was collected at enrolment, 48 hours later and hospital discharge. We measured biomarkers of inflammation (IL-6, ferritin), endothelial activation (Ang-1, Ang-2, sTie-2, VCAM-1) and endothelial glycocalyx breakdown (hyaluronan, heparan sulfate, endocan, syndecan-1). We enrolled 135 patients with DS (median age 26, median SOFA score 7, 34 required ICU admission, 5 deaths), together with 37 patients with SS and 25 healthy controls. Within the DS group, IL-6 and ferritin were associated with admission SOFA score (IL-6: ßeta0.70, p<0.001 & ferritin: ßeta0.45, p<0.001), ICU admission (IL-6: OR 2.6, p<0.001 & ferritin: OR 1.55, p<0.001) and mortality (IL-6: OR 4.49, p = 0.005 & ferritin: OR 13.8, p = 0.02); both biomarkers discriminated survivors and non-survivors at 48 hours and all patients who died from DS had pre-mortem ferritin ≥100,000ng/ml. IL-6 most strongly correlated with severity of pulmonary vascular leakage (R = 0.41, p<0.001). Ang-2 correlated with pulmonary vascular leak (R = 0.33, p<0.001) and associated with SOFA score (ß 0.81, p<0.001) and mortality (OR 8.06, p = 0.002). Ang-1 was associated with ICU admission (OR 1.6, p = 0.005) and mortality (OR 3.62, p = 0.006). All 4 glycocalyx biomarkers were positively associated with SOFA score, but only syndecan-1 was associated with ICU admission (OR 2.02, p<0.001) and mortality (OR 6.51, p<0.001). This study highlights the central role of hyperinflammation in determining outcomes from DS; the data suggest that anti-IL-1 and anti-IL-6 immune modulators and Tie2 agonists may be considered as candidates for therapeutic trials in severe dengue.

A volumetric asymmetry study of gray matter in individuals with and without dyslexia.

Brain imaging work aimed at increased classification of dyslexia has underscored an important relationship between anterior (i.e., the inferior frontal gyrus; IFG) and posterior (i.e., superior temporal gyrus and supramarginal gyrus) brain regions. The extent to which the three components of the inferior frontal gyrus, namely the pars orbitalis, triangularis, and opercularis, are differentially related to the posterior regions, namely the superior temporal gyrus and supramarginal gyrus, needs further elucidation. Information about the nature of the anterior-posterior connections would facilitate our understanding of the neural underpinnings associated with dyslexia. Adult participants (N = 38; 16 with dyslexia) took part in an MRI study, whereby high-resolution structural scans were obtained. Volumetric asymmetry of the three regions of the IFG, the superior temporal gyrus, and the supramarginal gyrus was extracted. Significant differences were found for each of the three IFG regions, such that skilled readers had a greater leftward asymmetry of the orbitalis and triangularis, and greater rightward asymmetry of the opercularis, when compared to individuals with dyslexia. Furthermore, the pars triangularis was significantly associated with leftward asymmetry of the superior temporal gyrus for skilled but not dyslexic participants. For individuals with dyslexia, the cortical asymmetry of the IFG, and the corresponding connections with other reading-related brain regions, is inherently different from skilled readers. We discuss our findings in the context of the print-to-speech framework to further our understanding of the neural underpinnings associated with dyslexia.

Tinctoric acid A-B, two new hopan-type triterpenoids from the Vietnamese lichen, Parmotrema tinctorum (Despr. ex Nyl.) hale with α-glucosidase inhibitory activity.

Two new hopan-type triterpenoids, namely tinctoric acid A-B (1-2), were isolated from the lichen Parmotrema tinctorum (Despr. ex Nyl.) Hale. Their structures were elucidated by extensive spectroscopic analyses (1D and 2D NMR). The absolute configuration at C-22 of 1 was established through DP4 probability. Compounds 1-2 were evaluated for their inhibitory activity against α-glucosidase and found to be more potent than those of positive control (acarbose, IC50 168 µM) with values IC50 74.7 and 98.2 µM, respectively. Both of these compounds interacted well with enzyme α-glucosidase MAL32 through H-bonds and hydrophobic interaction.

A comprehensive review of Langya virus and framework for future zoonotic disease control.

First reported in August 2022, the Langya virus (LayV) has emerged as a potential global health threat in the post-COVID-19 era. Preliminary reports show that 35 patients near Shandong and Henan, China experienced a febrile acute LayV infection. We conducted this review following the PRISMA protocol to synthesise current knowledge on LayV's characteristics in terms of molecular, clinical, and public health perspectives. This virus belongs to the Paramyxoviridae family and carries a non-segmented, single-stranded negative-sense RNA genome. Shrews may be the natural reservoir of the virus. Clinical symptoms range from mild flu-like symptoms to severe manifestations involving pneumonia, haematological disorders, and organ dysfunction. Diagnostic methods include PCR and ELISA assays. Despite the absence of established treatments, antiviral drugs such as ribavirin and chloroquine may be useful in some cases. In light of prevention, a comprehensive approach that emphasises multidisciplinary collaboration is crucial for early surveillance and response. Urgent global efforts are needed for vaccine development and preparedness against this potential pandemic threat. As the viral dynamics remain uncertain, a proactive approach is vital to mitigate the impact of not only LayV but also future threats on a large scale in long term.

Genetic engineering employing MPB70 and its promoter enables efficient secretion and expression of foreign antigen in bacillus Calmette Guérin (BCG) Tokyo.

Vaccination is an important factor in public health. The recombinant bacillus Calmette Guérin (rBCG) vaccine, which expresses foreign antigens, is expected to be a superior vaccine against infectious diseases. Here, we report a new recombination platform in which the BCG Tokyo strain is transformed with nucleotide sequences encoding foreign protein fused with the MPB70 immunogenic protein precursor. By RNA-sequencing, mpb70 was found to be the most transcribed among all known genes of BCG Tokyo. Small oligopeptide, namely, polyhistidine tag, was able to be expressed in and secreted from rBCG through a process in which polyhistidine tag fused with intact MPB70 were transcribed by an mpb70 promoter. This methodology was applied to develop an rBCG expressing the receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2. Immunoblotting images and mass spectrometry data showed that RBD was also secreted from rBCG. Sera from mice vaccinated with the rBCG showed a tendency of weak neutralizing capacity. The secretion was retained even after a freeze-drying process. The freeze-dried rBCG was administered to and recovered from mice. Recovered rBCG kept secreting RBD. Collectively, our recombination platform offers stable secretion of foreign antigens and can be applied to the development of practical rBCGs.

Deliberately making miskates: Behavioural consistency under win maximization and loss maximization conditions.

We argue that the feedback traditionally used to indicate negative outcomes causes future detrimental performance because of the default goal of win maximization. In gaming paradigms where participants intentionally performed as well (win maximization) and as poorly (loss maximization) as possible, we showed a double dissociation where actions following wins were more consistent during win maximization, but actions following losses were more consistent during loss maximization. This broader distinction between goal-congruent and goal-incongruent feedback suggests that individuals are able to flexibly redefine their definition of 'success', and provide a reconsideration of the way we think about 'losing'.

Climate change and human health in Vietnam: a systematic review and additional analyses on current impacts, future risk, and adaptation.

This study aims to investigate climate change's impact on health and adaptation in Vietnam through a systematic review and additional analyses of heat exposure, heat vulnerability, awareness and engagement, and projected health costs. Out of 127 reviewed studies, findings indicated the wider spread of infectious diseases, and increased mortality and hospitalisation risks associated with extreme heat, droughts, and floods. However, there are few studies addressing health cost, awareness, engagement, adaptation, and policy. Additional analyses showed rising heatwave exposure across Vietnam and global above-average vulnerability to heat. By 2050, climate change is projected to cost up to USD1-3B in healthcare costs, USD3-20B in premature deaths, and USD6-23B in work loss. Despite increased media focus on climate and health, a gap between public and government publications highlighted the need for more governmental engagement. Vietnam's climate policies have faced implementation challenges, including top-down approaches, lack of cooperation, low adaptive capacity, and limited resources.

The Unmet Needs of Pancreatic Cancer Carers Are Associated with Anxiety and Depression in Patients and Carers.

Pancreatic cancer has one of the lowest survival rates, and patients experience debilitating symptoms. Family carers provide essential daily care. This study determined the prevalence of and risk factors for unmet supportive care needs among carers for pancreatic cancer patients and examined which carer needs were associated with anxiety and depression in carers and patients. Eighty-four pancreatic cancer patients and their carers were recruited. The carers completed a needs survey (SCNS-P&C). Both carers and patients completed the Hospital Anxiety and Depression Scale. Log binomial regression was used to identify associations between carer needs and anxiety and depression among carers and patients. The top 10 moderate-to-high unmet needs reported by ≥28% of carers were related to healthcare (e.g., discussing concerns with doctors) and information need domains (e.g., information about a patient's physical needs), plus one other item related to hospital parking. Being male or caring for a patient within 4 months of their diagnosis were associated with greater unmet needs. Some unmet needs, including 'accessing information about treatments' and 'being involved in patient care', were associated with both carers and patients having anxiety and depression. Carers should be involved in health care consultations and provided with information and opportunities to discuss concerns.

A combination of annual and nonannual forces drive respiratory disease in the tropics.

INTRODUCTION: It is well known that influenza and other respiratory viruses are wintertime-seasonal in temperate regions. However, respiratory disease seasonality in the tropics is less well understood. In this study, we aimed to characterise the seasonality of influenza-like illness (ILI) and influenza virus in Ho Chi Minh City, Vietnam. METHODS: We monitored the daily number of ILI patients in 89 outpatient clinics from January 2010 to December 2019. We collected nasal swabs and tested for influenza from a subset of clinics from May 2012 to December 2019. We used spectral analysis to describe the periodic signals in the system. We evaluated the contribution of these periodic signals to predicting ILI and influenza patterns through lognormal and gamma hurdle models. RESULTS: During 10 years of community surveillance, 66 799 ILI reports were collected covering 2.9 million patient visits; 2604 nasal swabs were collected, 559 of which were PCR-positive for influenza virus. Both annual and nonannual cycles were detected in the ILI time series, with the annual cycle showing 8.9% lower ILI activity (95% CI 8.8% to 9.0%) from February 24 to May 15. Nonannual cycles had substantial explanatory power for ILI trends (ΔAIC=183) compared with all annual covariates (ΔAIC=263) in lognormal regression. Near-annual signals were observed for PCR-confirmed influenza but were not consistent over time or across influenza (sub)types. The explanatory power of climate factors for ILI and influenza virus trends was weak. CONCLUSION: Our study reveals a unique pattern of respiratory disease dynamics in a tropical setting influenced by both annual and nonannual drivers, with influenza dynamics showing near-annual periodicities. Timing of vaccination campaigns and hospital capacity planning may require a complex forecasting approach.