A framework for controllable Pareto front learning with completed scalarization functions and its applications.

Pareto Front Learning (PFL) was recently introduced as an efficient method for approximating the entire Pareto front, the set of all optimal solutions to a Multi-Objective Optimization (MOO) problem. In the previous work, the mapping between a preference vector and a Pareto optimal solution is still ambiguous, rendering its results. This study demonstrates the convergence and completion aspects of solving MOO with pseudoconvex scalarization functions and combines them into Hypernetwork in order to offer a comprehensive framework for PFL, called Controllable Pareto Front Learning. Extensive experiments demonstrate that our approach is highly accurate and significantly less computationally expensive than prior methods in term of inference time.

Indoor Aeroallergen Sensitization and Associated Factors in Hospitalized Children with Asthma Exacerbations.

Background: Allergic asthma represents the most popular phenotype of childhood asthma and is characterized by eosinophilic airway inflammation associated with specific immunoglobulin E (IgE) antibodies sensitization to various allergens, as evidenced by serology or skin prick test.2 Sensitization to indoor aeroallergens is associated with severe asthma and severe asthma exacerbations. Objective: This study aimed to identify the prevalence of aeroallergen sensitization and its associated factors in children with an asthma exacerbation in Vietnam. Methods: A cross-sectional study was conducted at Children's Hospital 1, Ho Chi Minh City (HCMC). Children who were aged 3 to 15 and admitted to the hospital with moderate or severe asthma exacerbation were recruited to the study. Data was collected from interviews and medical records. SPT was used to identify aeroallergen sensitization. The association between school-age, living area, and passive smoking with the odds of aeroallergen sensitization was assessed using a multivariable logistic regression. Results: The prevalence of aeroallergen sensitization was 82.6% and this figure in school-age children was higher than that in preschool-age ones (93.8% vs 72.1%, p=0.001). School-age, living in HCMC, and passive smoking significantly increased the odds of aeroallergen sensitization in asthmatic children with adjusted OR [95%CI] as 6.9 [2.1-23.3], 4.1 [1.5-11.5], and 2.9 [1.0-8.4], respectively. Asthmatic children with aeroallergen sensitization required more hours to resolve an asthma exacerbation than those without (22.4 vs 15.2, p=0.006). Conclusion: Aeroallergen sensitization was common in hospitalized children with moderate or severe asthma exacerbation. It is necessary to establish environmental policy and screening practices of aeroallergen sensitization to improve the quality of asthma management for Vietnamese children.

Generation patterns and consumer behavior of single-use plastic towards plastic-free university campuses.

This study was conducted to estimate the generation of single-use plastics (SUPs) and elucidate consumer behavior towards a plastic-free university. The results show that the consumption rate of plastic bottles was the highest at 1.39 g per student per day (g.s-1.d-1), followed by plastic cups (0.20 g s-1.d-1), and plastic bags (0.14 g s-1.d-1). Approximately 94.41% of students were highly aware of the negative impacts of SUPs. More than four-fifths of the students (82.32%) assumed that they were responsible for the SUP pollution issue, whereas 59.52% considered SUP reduction (or lack thereof) by individuals, governments, and producers/businesses be important factors. Approximately 19.03% of the students supported implementing a high fine, one-tenth agreed for a total ban on SUPs, while nearly one-fifth believed reducing SUP consumption was unnecessary. Strategies for plastic-free universities was initiated by establishing the goal of "plastic-free university" and implementing integrated actions including a ban (plastic cups and bags) awareness-raising, and suitable alternatives.

Alzheimer's diagnosis using deep learning in segmenting and classifying 3D brain MR images.

BACKGROUND AND OBJECTIVES: Dementia is one of the brain diseases with serious symptoms such as memory loss, and thinking problems. According to the World Alzheimer Report 2016, in the world, there are 47 million people having dementia and it can be 131 million by 2050. There is no standard method to diagnose dementia, and consequently unable to access the treatment effectively. Hence, the computational diagnosis of the disease from brain Magnetic Resonance Image (MRI) scans plays an important role in supporting the early diagnosis. Alzheimer's Disease (AD), a common type of Dementia, includes problems related to disorientation, mood swings, not managing self-care, and behavioral issues. In this article, we present a new computational method to diagnosis Alzheimer's disease from 3D brain MR images. METHODS: An efficient approach to diagnosis Alzheimer's disease from brain MRI scans is proposed comprising two phases: I) segmentation and II) classification, both based on deep learning. After the brain tissues are segmented by a model that combines Gaussian Mixture Model (GMM) and Convolutional Neural Network (CNN), a new model combining Extreme Gradient Boosting (XGBoost) and Support Vector Machine (SVM) is used to classify Alzheimer's disease based on the segmented tissues. RESULTS: We present two evaluations for segmentation and classification. For comparison, the new method was evaluated using the AD-86 and AD-126 datasets leading to Dice 0.96 for segmentation in both datasets and accuracies 0.88, and 0.80 for classification, respectively. CONCLUSION: Deep learning gives prominent results for segmentation and feature extraction in medical image processing. The combination of XGboost and SVM improves the results obtained.

Modeling Respiratory Signals by Deformable Image Registration on 4DCT Lung Images.

The lung organ of human anatomy captured by a medical device reveals inhalation and exhalation information for treatment and monitoring. Given a large number of slices covering an area of the lung, we have a set of three-dimensional lung data. And then, by combining additionally with breath-hold measurements, we have a dataset of multigroup CT images (called 4DCT image set) that could show the lung motion and deformation over time. Up to now, it has still been a challenging problem to model a respiratory signal representing patients' breathing motion as well as simulating inhalation and exhalation process from 4DCT lung images because of its complexity. In this paper, we propose a promising hybrid approach incorporating the local binary pattern (LBP) histogram with entropy comparison to register the lung images. The segmentation process of the left and right lung is completely overcome by the minimum variance quantization and within class variance techniques which help the registration stage. The experiments are conducted on the 4DCT deformable image registration (DIR) public database giving us the overall evaluation on each stage: segmentation, registration, and modeling, to validate the effectiveness of the approach.

Imatinib augments standard malaria combination therapy without added toxicity.

To egress from its erythrocyte host, the malaria parasite, Plasmodium falciparum, must destabilize the erythrocyte membrane by activating an erythrocyte tyrosine kinase. Because imatinib inhibits erythrocyte tyrosine kinases and because imatinib has a good safety profile, we elected to determine whether coadministration of imatinib with standard of care (SOC) might be both well tolerated and therapeutically efficacious in malaria patients. Patients with uncomplicated P. falciparum malaria from a region in Vietnam where one third of patients experience delayed parasite clearance (DPC; continued parasitemia after 3 d of therapy) were treated for 3 d with either the region's SOC (40 mg dihydroartemisinin + 320 mg piperaquine/d) or imatinib (400 mg/d) + SOC. Imatinib + SOC-treated participants exhibited no increase in number or severity of adverse events, a significantly accelerated decline in parasite density and pyrexia, and no DPC. Surprisingly, these improvements were most pronounced in patients with the highest parasite density, where serious complications and death are most frequent. Imatinib therefore appears to improve SOC therapy, with no obvious drug-related toxicities.

Giant Cerebellar Ganglioglioma Mimicking a Pilocytic Astrocytoma.

A benign brain tumor, called a ganglioglioma (GG), can sometimes be found in the cerebrum. We describe an unusual pediatric case of GG in the cerebellum in this article. An 11-year-old male patient had a headache and epilepsy disorder. The head magnetic resonance imaging results revealed a giant cyst with an enhancing mural nodule in the right cerebellar hemisphere that flattened the fourth ventricle. Pilocytic astrocytoma was the provisional diagnosis based on clinical and imaging details. After radical mass eradication, a GG was demonstrated through histopathological analysis. Even though GG is an uncommon tumor, it should be included in the differential diagnosis for a cerebellar mass with both cystic and solid components in children.

A case of traumatic anterior cerebral artery-cavernous sinus fistula.

Direct anterior cerebral artery-cavernous sinus fistula is an extremely rare complication of head trauma. We describe a male patient (age 49 years) with a history of head trauma 15 years ago who was hospitalised for a bulging red eye and tinnitus. Digital subtraction angiography showed a direct anterior cerebral artery (fork junction A1 - prior passage)-cavernous sinus fistula. The patient was treated with arterial endovascular intervention, complete sealing of the fistula orifice using coils. He was discharged 5 days later with no symptoms of a bulging red eye, ringing in the ears, or nerve paralysis. Re-examination after 3 months of stable clinical features did not show recurrent fistula. In conclusion, anterior cerebral artery-cavernous sinus fistula is an extremely rare lesion, and arterial endovascular intervention using coils is a safe and effective method for treatment of such lesion.

A unique case of medulla oblongata epidermoid cyst.

Epidermoid cysts (ECs) are slow-growing, benign tumors that represent <2% of all intracranial tumors. ECs can be divided into following two types: extra-axial and intra-axial. Extra-axial ECs are most often positioned in the cerebellopontine angle. Intra-axial ECs, which are also referred to as intraparenchymal ECs, are most commonly found in supratentorial structures, such as the frontal and temporal lobes, accounting for <2% of all intracranial ECs and are especially rare in children. In this report, we described a unique case of medulla oblongata EC in a child, to contribute this knowledge to the existing body of literature.

Cement Leakage in Percutaneous Vertebroplasty for Multiple Osteoporotic Vertebral Compression Fractures: A Prospective Cohort Study.

PURPOSE: This study аims to explore cement leаkаge аs а complication of percutаneous vertebroplаsty (PVP) in the treаtment of multiple osteoporotic vertebrаl compression frаctures (MOVF). PATIENTS AND METHODS: This prospective study wаs cаrried out on 32 consecutive pаtients with osteoporotic frаctures of аt leаst two vertebrаe (VB). Аll pаtients were over 50 yeаrs old аnd women аccounted for 29 out of the 32 pаtients (90.6%). PVP wаs performed under digitаl subtrаction аngiogrаphy (DSА) of аt leаst three VB, аnd 97 collаpsed VB аnd 105 VB were exаmined by PVP. Аll pаtients hаd postoperаtive computerized tomogrаphy (CT) to diаgnose аnd clаssify the complicаtions. RESULTS: One hundred аnd five vertebrаe were exаmined with PVP, аnd 36/105 (34.3%) exhibited complicаtions of cement leаkаge. Type B cement leаkаge wаs the most common complicаtion, with 19/105 (18.1%) cаses; type C аccounted for 8/105 (7.6%) cаses; аnd type S аccounted for 9/105 (8.6%) cаses. There wаs only one (0.95%) cаse of cement leаkаge moving to the pulmonаry аrtery. Аll complicаtions hаd no clinicаl symptoms аnd did not require treаtment. CONCLUSION: Cement leаkаge is quite а common complicаtion, but it usuаlly hаs no clinicаl symptoms аnd does not require treаtment. Therefore, PVP is а sаfe аnd successful technique for the treаtment of multiple osteoporotic vertebrаl compression frаctures.

The clinical and subclinical features of spinal cord injury on magnetic resonance imaging of patients with N2O intoxication.

Nitrous oxide (N2O) is a weak anesthetic gas that was first used in 1844 in the field of dental anesthesia. However, currently, N2O is being abused for entertainment purposes in the form of N2O-filled balloons, called funky balls, which can cause many adverse effects, especially nervous system injury. This study aimed to investigate the detailed clinical and subclinical features associated with N2O intoxication. We retrospectively reviewed 47 patients diagnosed with N2O intoxication, from May 2018 to July 2019, and collected demographic data, clinical and laboratory tests, and spinal cord magnetic resonance imaging (MRI) findings. The mean time of funky ball use was 8.8 months, with a mean use of 36.3 balls per day. All patients presented with superficial sensory disorders. Reductions in muscle strength, decreased vibration sensation, and decreased or lost tendon reflexes were the most common clinical signs of N2O intoxication. Romberg sign and Lhermitte sign were observed in 39 patients (83%) and 21 patients (44.7%), respectively. Spinal cord lesions on MRI were observed in 32 patients (68.1%), which mostly presented with an inverted V sign. The total duration of N2O use, the number of days of using N2O per week, and the presence of Lhermitte sign (P<0.05) were significantly different between patients with and without spinal cord lesions on MRI. Serum levels of homocysteine and vitamin B12 were significantly different between the time of admission and discharge (P<0.05). Our study indicated that the days of using N2O per week was significantly associated with Spinal Cord Injuries (SCI) on MRI. According to the Receiver Operating Characteristic (ROC) curve analysis, a cutoff days of using per week value of 2.5 days could predict SCI with a sensitivity of 81.3%, a specificity of 73.3%, and an area under the ROC curve (AUC) of 0.813. Changes in the serum levels of homocysteine and vitamin B12 were effective markers for the evaluation of treatment response.

Safety and Efficacy of a Direct Aspiration First-Pass Technique with Large-Bore Catheters for Acute Ischemic Stroke in Vietnam: Experience of a Single Center.

PURPOSE: The purpose of this study was to evaluate the safety and efficacy of mechanical thrombectomy with a direct aspiration first-pass technique (ADAPT) using large-bore catheters in patients with acute ischemic stroke due to large vessel occlusion (LVO) in a hospital in Vietnam. METHODS: This was a retrospective review of patients with acute ischemic stroke due to LVO who were diagnosed and underwent mechanical thrombectomy using ADAPT with large-bore catheters at Bach Mai Hospital from January 2017 to June 2018. RESULTS: Seventy-three patients (47.9% female; age: 61.29 ± 14.49 years) met study criteria. The average procedure duration was 45.09 ± 38.26 min. Successful recanalization post-ADAPT (thrombolysis in cerebral infarction 2b-3) was achieved in 72.6% (53/73) of patients. Good functional outcome (Modified Rankin Scale 0-2) at 3 months was achieved in 50.7% (37/73), with poor functional outcome in 24.7% (18/73). The 90-day mortality rate was 24.7% (18/73). The hemorrhagic transformation rate was 31.6%, in which 19.2% were symptomatic. Vessel perforation occurred in 5.5% (4/73) of patients but in all cases was associated with the guidewire and not the reperfusion catheter. Vessel dissection occurred in 1.4% (1/73) and vasospasm in 5.5% (4/73) of patients. CONCLUSION: Mechanical thrombectomy using ADAPT with large-bore catheters for acute ischemic stroke due to LVO is a method that yielded good results in recanalization and clinical recovery in a Vietnamese patient population.

Comparing the Efficacy of Radiofrequency Ablation Versus Laser Ablation for Chronic Venous Insufficiency in the Lower Extremities: a Vietnamese Report.

INTRODUCTION: Chronic venous insufficiency (CVI) is a chronic condition, triggered by reflux through the saphenous vein network. AIM: To determine the efficacy of endovenous laser ablation (LA) and radiofrequency ablation (RFA) for CVI treatment in the lower extremities, at the Bach Mai Radiology Center. METHODS: This retrospective study was approved by the institutional review board of Bach Mai Hospital. The study recruited 49 people, from August 2016 to April 2018, with recurrent venous insufficiency in the lower extremities and measured 56 ablated veins. RESULTS: In this study, 8 patients (10 veins, with a mean diameter of 5.83 ± 0.96 mm) were treated with RFA, and 41 patients (46 veins, with a mean diameter of 7.96 ± 3.47 mm) were treated with LA. The occlusion rates for LA- and RFA-treated veins were very effective, at 95.7% and 90%, respectively. No significant differences in occlusion rates or clinical improvements were observed between the two ablation methods. On the first day post-treatment, the visual analog score (VAS) value for the LA group was significantly higher than that for the RFA group. Furthermore, ecchymosis, 1 day after treatment, and hyperpigmentation, paresthesia, and numbness, 1 month after treatment, were only observed in the LA group. CONCLUSION: Both LA and RFA were minimally-invasive and safe therapies. No serious complications requiring further interventions were reported and the treatment effectively improved the clinical symptoms of patients. Based on our study, we recommend that RFA should be considered for moderate dilated saphenous vein cases, whereas LA should be indicated for large dilated saphenous vein cases, with or without aneurysm.

Massive Dissecting Aneurysm in the Basilar Tip Artery Treated with Intra-aneurysm and Basilar Artery Coiling.

INTRODUCTION: Deconstructive versus reconstructive technique remains controversial on the management of acute basilar tip artery dissection. AIM: We introduced a case report of massive dissecting aneurysm in the basilar tip artery treated with intra-aneurysm and basilar artery coiling. RESULTS: A 30-year-old male presented with sudden headache and severe vomiting. Radiographic study showed a large unruptured dissecting aneurysm in the basilar tip artery involving bilateral P1 segment. This aneurysm was treated with intra-aneurysm and basilar artery coiling. Patient was discharge after 7 days without any neurological deficits. Post-operatively, the patient received 75 mg aspirin and 75 mg clopidogrel PO per day for 3 months - then 75 mg aspirin per day for up to 1 year. Angiographic follow-up at 3 months showed a complete occlusion of aneurysmal sac and basilar tip artery without any deficits (mRS 0). Cerebral arteriography at 6 months follow-up confirmed a stable occlusion of aneurysmal sac with a minor recurrence of aneurysm in left P1 segment. CONCLUSION: Intra-aneurysm and basilar artery coiling is valuable alternative technique to treat complex basilar tip dissecting aneurysm in case of infeasible reconstructive technique. Clinical presentation, aneurysm characteristics and collateral circulation have to be investigated on each case to adopt this technique.

Flow diverter stent for treatment of cerebral aneurysms: A report of 130 patients with 134 aneurysms.

BACKGROUND: This study aims to report our experience with cerebral aneurysms, which may improve in the treatment with the flow-diverter stent and follow up. METHODS: This study was conducted in a consecutive series of 130 patients. 134 procedures were performed for treating these patients in Hanoi Medical University Hospital and Bach Mai Hospital from January 2012 to April 2017. 143 flow diverter stents (Pipeline, FRED and SILK) were used. Aneurysm morphology, stent patency and cerebral parenchyma before and after intervention were analyzed on images of digital subtraction angiography (DSA), computed tomography (CT) and magnetic resonance (MR). The follow-up data after 3-6 months and 12 months were recorded. RESULTS: In 130 patients (31 men, 99 women), aneurysms of internal carotid artery were mostly common (92.6%), especially in cavernous (35.1%) and in para-ophthalmic (40.3%) segments. 83 cases (61.9%) had wide-neck aneurysms, and 16 cases (11.9%) had multiple aneurysms, and only 5 cases (3.7%) had blister-liked aneurysms. Endovascular treatment was successfully performed at rate of 94.8%. In 3 patients, the stent could not be delivered. Mortality and morbidity rates were 1.5% and 3.7%, respectively. MRI and MSCT follow-up at 3 months showed complete or incomplete occlusions of aneurysms was 7.4% or 17.5%, respectively. 3 patients experienced a thromboembolic event (4.3%). CONCLUSIONS: Intracranial aneurysms of cavernous and para-ophthalmic segments of internal carotid artery are mostly common with wide-neck and multi aneurysms. Deployment of flow diverter stent is safe and effective with high rate of successful and low procedural complications.

Clinical impact of the two ART resistance markers, K13 gene mutations and DPC3 in Vietnam.

BACKGROUND: In Vietnam, a rapid decline of P. falciparum malaria cases has been documented in the past years, the number of Plasmodium falciparum malaria cases has rapidly decreased passing from 19.638 in 2012 to 4.073 cases in 2016. Concomitantly, the spread of artemisinin resistance markers is raising concern on the future efficacy of the ACTs. An evaluation of the clinical impact of the artemisinin resistance markers is therefore of interest. METHODS: The clinical effectiveness of dihydroartemisinin-piperaquine therapy (DHA-PPQ) has been evaluated in three districts characterized by different rates of ART resistance markers: K13(C580Y) mutation and delayed parasite clearance on day 3 (DPC3). Patients were stratified in 3 groups a) no markers, b) one marker (suspected resistance), c) co-presence of both markers (confirmed resistance). In the studied areas, the clinical effectiveness of DHA-PPQ has been estimated as malaria recrudescence within 60 days. RESULTS: The rate of K13(C580Y) ranged from 75.8% in Krong Pa to 1.2% in Huong Hoa district. DPC3 prevalence was higher in Krong Pa than in Huong Hoa (86.2% vs 39.3%). In the two districts, the prevalence of confirmed resistance was found in 69.0% and 1.2% of patients, respectively. In Thuan Bac district, we found intermediate prevalence of confirmed resistance. Treatment failure was not evidenced in any district. PPQ resistance was not evidenced. Confirmed resistance was associated to the persistence of parasites on day 28 and to 3.4-fold higher parasite density at diagnosis. The effectiveness of malaria control strategies was very high in the studied districts. CONCLUSION: No treatment failure has been observed in presence of high prevalence of ART resistance and in absence of PPQ resistance. K13(C580Y) was strongly associated to higher parasitemia at admission, on days 3 and 28. Slower parasite clearance was also observed in younger patients.

Sample checklist of Gastropoda and Bivalvia in Cham Islands, Vietnam.

BACKGROUND: Cham Islands (Cu Lao Cham) is a group of 8 small islands in the Quang Nam province, Central Vietnam. There is only one study that mentioned the diversity of marine molluscs in this area. However, the data on species composition have not been digitised and not stored or shared for other purposes. Our paper aims to share the checklist of marine mollusc species (Bivalvia and Gastropoda) species that we collected from the littoral zone of Cham Islands in May 2017. This is the first digitised and online data of marine molluscs in Vietnam. It is very important for researchers in various fields such as the structure and function of ecology and biodiversity monitoring. NEW INFORMATION: This study provides a checklist of the marine bivalves and snails in the Cham Islands of Vietnam. Moreover, this first widely shared data of biodiversity in Vietnam can trigger biodiversity data papers in this data-poor country.The data of this study will be important inputs for better understanding biodiversity on the Cham Islands and Vietnam as well as for forming the basis for monitoring, exploitation and conservation of biodiversity in this area.In total, 145 taxa were recorded, 46 bivalve taxa and 99 snail taxa, from which 128 were identified to the species level and 17 were identified to the genus level. There are 116 new species records for the Cham Islands.The specimens are currently deposited in the Institute of Ecology and Biological Resources (IEBR), Vietnam Academy of Science and Technology (VAST).

Clinical and Molecular Epidemiology of Human Parainfluenza Viruses 1-4 in Children from Viet Nam.

HPIVs are serologically and genetically grouped into four species that account for up to 10% of all hospitalizations due to acute respiratory infection in children under the age of five. Genetic and epidemiological data for the four HPIVs derived from two pediatric cohorts in Viet Nam are presented. Respiratory samples were screened for HPIV1-4 by real-time PCR. Demographic and clinical data of patients infected with different HPIV were compared. We used a hemi-nested PCR approach to generate viral genome sequences from HPIV-positive samples and conducted a comprehensive phylogenetic analysis. In total, 170 samples tested positive for HPIV. HPIV3 was most commonly detected in our cohort and 80 co-detections of HPIV with other respiratory viruses were found. Phylogenetic analyses suggest local endemic circulation as well as punctuated introductions of new HPIV lineages. Viral gene flow analysis revealed that Viet Nam is a net importer of viral genetic diversity. Epidemiological analyses imply similar disease severity for all HPIV species. HPIV sequences from Viet Nam formed local clusters and were interspersed with sequences from diverse geographic regions. Combined, this new knowledge will help to investigate global HPIV circulation patterns in more detail and ultimately define more suitable vaccine strains.

Conventional digital subtractional vs non-invasive MR angiography in the assessment of brain arteriovenous malformation.

OBJECTIVES: Digital subtractional angiography (DSA) is the standard method for diagnosis, assessment and management of arteriovenous malformation in the brain. Conventional DSA (cDSA) is an invasive imaging modality that is often indicated before interventional treatments (embolization, open surgery, gamma knife). Here, we aimed to compare this technique with a non-invasive MR angiography (MRI DSA) for brain arteriovenous malformation (bAVM). PATIENTS AND METHODS: Fourteen patients with ruptured brain AVM underwent embolization treatment pre-operation. Imaging was performed for all patients using MRI (1.5 T). After injecting contrast Gadolinium, dynamic MRI was performed with 40 phases, each phase of a duration of 1.2 s and having 70 images. The MRI results were independently assessed by experienced radiologist blinded to the cDSA. RESULTS: The AVM nidus was depicted in all patients using cDSA and MRI DSA; there was an excellent correlation between these techniques in terms of the maximum diameter and Spetzler Martin grading. Of the fourteen patients, the drainage vein was depicted in 13 by both cDSA and MRI DSA showing excellent correlation between the techniques used. CONCLUSION: MRI DSA is a non-invasive imaging modality that can give the images in dynamic view. It can be considered as an adjunctive method with cDSA to plan the strategy treatment for bAVM.

Retrospective analysis assessing the spatial and temporal distribution of paediatric acute respiratory tract infections in Ho Chi Minh City, Vietnam.

BACKGROUND: Acute respiratory tract infections (ARIs) are the leading cause of morbidity and mortality in young children in low/middle-income countries. Using routine hospital data, we aimed to examine the spatial distribution, temporal trends and climatic risk factors of paediatric ARIs in Vietnam. METHODS: Data from hospitalised paediatric (<16 years) patients with ARIs residing in Ho Chi Minh City (HCMC) between 2005 and 2010 were retrieved from the two main Children's Hospitals and the Hospital for Tropical Diseases in HCMC. Spatial mapping and time series analysis were performed after disaggregating data into upper respiratory tract infections (URIs) and lower respiratory tract infections (LRIs). RESULTS: Over the study period, there were 155 999 paediatric patients admitted with ARIs (33% of all hospital admissions). There were 68 120 URIs (14%) and 87 879 LRIs (19%). The most common diagnoses were acute pharyngitis (28% of all ARI), pneumonia (21%), bronchitis (18%) and bronchiolitis (16%). A significant increasing trend over time was found for both URIs (mean weekly incidence per 1000 population, I=3.12), incidence rate ratio for 1-week increase in time (RR 1.0, 95% CI 1.02 to 1.17) for URI and (I=4.02, RR 1.08 (95% CI 1.006 to 1.16)) for LRI. The weekly URI incidence peaked in May-June and was significantly associated with lags in weekly URI incidence and the average humidity, rainfall and water level. The weekly LRI incidence exhibited significant seasonality (P<0.0001), with an annual peak in September-October and was significantly associated with lags in weekly LRI incidence and lags in weekly average temperature, rainfall and water level. CONCLUSIONS: ARIs are a leading cause of childhood hospitalisation in HCMC, Vietnam. The incidence of ARIs was higher in the wet season and in specific HCMC districts. These results may guide health authorities in where and when to effectively allocate resources for the prevention and control of ARIs.