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Background: In Vietnam, PrEP was introduced in 2017 and scaled up from 2019. Private sector engagement (PSE) in PrEP service delivery was deployed as a strategy from the start to increase PrEP access. We assessed the effectiveness of this approach to inform ongoing efforts to accelerate epidemic control by 2030. Methods: We implemented a process evaluation with longitudinal design using retrospective programmatic data collected and uploaded onto a secure online system (HMED) from 23 public and 17 private PrEP clinics in Hanoi, Ho Chi Minh City (HCMC), and Dong Nai. We measured the effectiveness of PrEP service delivery by PrEP initiation/reinitiation, uptake, persistence, discontinuation, and HIV seroconversion. We used the Kaplan-Meier time-to-event approach to estimate PrEP persistence and mixed-effects logistic regression analysis to assess factors associated with the PrEP persistence. Results: From October 2017 to September 2023, 29,944 individuals initiated PrEP, and among these, 79.3% started PrEP at a private sector clinic while 20.7% initiated in a public sector clinic. The median duration of PrEP use persistence at private clinics was significantly longer than that at public clinics (268 days vs. 148 days, respectively). Mixed-effects logistic regression analysis results indicated a significant statistical association between PrEP persistence for at least three months and initiating PrEP at a private clinic [adjusted odds ratio [aOR] = 4.28; 95% confidence interval [CI]: 2.96–6.19], opting for TelePrEP (aOR = 3.42; 95% CI: 2.12–5.53), or being 20 years of age or older (aOR = 1.86; 95% CI: 1.62–2.13). HIV seroconversion was significantly lower among PrEP users at private clinics compared to public clinics (0.03 vs. 0.13 per 100 person-years, respectively; p < 0.01). Conclusion: Offering choice in PrEP service delivery options is essential to increase access and uptake. Private-sector PrEP providers play a pivotal role in increasing PrEP uptake and coverage in Vietnam, and will be critical to delivery of new long-acting options. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFASs) are a group of concerned persistent toxic substances, especially for their application or unintentional formation in food contact materials (FCMs). However, information about the occurrence, sources, and fate of these pollutants in food packaging materials from Vietnam as well as Southeast Asian countries is probably still obscured. In this study, levels of 13 perfluoroalkyl carboxylic acids (PFCAs) and 4 sulfonates (PFSs) were determined in various types of food packaging samples collected from Vietnamese markets. Generally low concentrations of total 17 PFASs (median 0.341; max 624 ng/g) suggested that these compounds were mainly inadvertently produced rather than intentionally added to the packaging materials. A few mochi paper tray samples had relatively high PFAS levels (372–624 ng/g), which were dominated by long-chain (C8–C12) PFCAs. A comprehensive and updated overview of PFASs in FCMs from different countries in the world was also provided. Current database could not provide conclusive trends of PFAS concentrations and profiles in FCMs between continents and countries. The highest levels up to ppm were reported for PFCAs (e.g., PFBA, PFHxA, PFOA, and PFDA) and several fluorotelomer alcohols and carboxylic acids, while PFSs were almost absent in FCMs. FPASs can emit from FCMs, migrate to food, and then contribute to dietary exposure in humans and animals. Additional investigations on the occurrence, sources, behavior and fate, and impacts of PFASs in FCMs are critically needed, especially in emerging and developing countries. [ABSTRACT FROM AUTHOR]

Myopia prevention and anti-myopia treatment is of great importance in South East Asia. To evaluate the prevalence and related factors of myopic retinopathy in Vietnam. A cross-sectional study was conducted on 168 eyes of 88 patients with high myopia presenting to the Refraction Department of Vietnam National Eye Hospital. Inclusion criteria were high myopia (≤−6.00D with cycloplegic retinoscopy). Consecutive presenting patients recruited between January 2020 and August 2020 consented to participate. Participant age range was 12–47 years. Peripapillary atrophy was present in 70.2% of participants, most commonly atrophy of one-quarter of the disc (38.7%). Central retinal changes were present in 66.1% of participants, subclassified as tessellated fundus in 60.7%, diffuse chorioretinal atrophy in 4.2% and patchy chorioretinal atrophy in 1.2%. Peripheral retinal lesions were present in 43.5% of participants, consisting of white-without-pressure in 32.1%, lattice degeneration in 16.1%, snail track degeneration in 4.2% and microcystoid degeneration in 1.2%. Myopia ≤−8.00D and axial length ≥26.5 mm were associated with additional risk of posterior ocular complications. Furthermore, age ≥19 years increased risk of central myopic retinopathy and ≥10 years since initial myopia diagnosis increased the risk of peripapillary atrophy and central retinal changes. Other factors such as the age of onset of myopia and family myopia history did not appear to alter the risk of peripheral retina damage. Retinal disorders were common in Vietnamese people with high myopia. Within the current cohort with high myopia, myopia ≤−8.00D and axial length ≥26.5 mm were associated with a significant further elevation of risk. [ABSTRACT FROM AUTHOR]

The WRF-Chem (Weather Research and Forecasting with Chemistry) model is implemented and validated against ground-based observations for meteorological and atmospheric variables for the first time in Northern Vietnam. The WRF-Chem model was based on HTAPv2 emission inventory with MOZCART chemical-aerosol mechanism to simulate atmospheric variables for winter (January) and summer (July) of 2014. The model satisfactorily reproduces meteorological fields, such as temperature 2 m above the ground and relative humidity 2 m above the ground at 45 NCHMF meteorological stations in January, but lower agreement was found in those simulations of July. PM10 and PM2.5 concentrations in January showed good temporal and spatial agreements to observations recorded at three CEM air monitoring stations in Phutho, Quangninh, and Hanoi, with correlation coefficients of 0.36 and 0.59. However, WRF-Chem model was underestimated with MFBs from − 27.9 to − 118.7% for PM10 levels and from − 34.2 to − 115.1% for PM2.5 levels. It has difficulty in capturing day-by-day variation of PM10 and PM2.5 concentrations at each station in July, but MFBs were in the range from − 27.1 to − 40.2% which is slightly lower than those in January. It suggested that further improvements of the model and local emission data are needed to reduce uncertainties in modeling the distribution of atmospheric pollutants. Assessment of biomass burning emission on air quality in summer was analyzed to highlight the application aspect of the WRF-Chem model. The study may serve as a reference for future air quality modeling using WRF-Chem in Vietnam. [ABSTRACT FROM AUTHOR]

• CV-A6 and CV-A16 were two major non-EV-A71 enteroviruses causing HFMD in Vietnam, 2008–2017. • Vietnamese CV-A6 and CV-A16 belonged to the largest sub-genogroups, D3 and B1, respectively. • Vietnamese strains have been evolving in a manner similar to the strains circulating worldwide. • Amino acid residues of the functional loops on VPs of Vietnamese strains were highly conserved. • The functional loop patterns of VP1 were similar to the dominant patterns found worldwide. Development of multivalent hand, foot, and mouth disease (HFMD) vaccines against enterovirus A71 (EV-A71) and several non-EV-A71 enteroviruses is needed for this life-threatening disease with a huge economic burden in Asia-Pacific countries. Comprehensive studies on the molecular epidemiology and genetic and antigenic characterization of major causative enteroviruses will provide information for rational vaccine design. Compared with molecular studies on EV-A71, that for non-EV-A71 enteroviruses remain few and limited in Vietnam. Therefore, we conducted a 10-year study on the circulation and genetic characterization of coxsackievirus A16 (CV-A16) and CV-A6 isolated from patients with HFMD in Northern Vietnam between 2008 and 2017. Enteroviruses were detected in 2228 of 3212 enrolled patients. Of the 42 serotypes assigned, 28.4% and 22.4% accounted for CV-A6 and CV-A16, being the second and the third dominant serotypes after EV-A71 (31.7%), respectively. The circulation of CV-A16 and CV-A6 showed a wide geographic distribution and distinct periodicity. Phylogenetic analyses revealed that the majority of Vietnamese CV-A6 and CV-A16 strains were located within the largest sub-genotypes or sub-genogroups. These comprised strains isolated from patients with HFMD worldwide during the past decade and the Vietnamese strains have been evolving in a manner similar to the strains circulating worldwide. Amino acid sequences of the putative functional loops on VP1 and other VPs among Vietnamese CV-A6 and CV-A16 isolates were highly conserved. Moreover, the functional loop patterns of VP1 were similar to the dominant patterns found worldwide, except for the T164K substitution on the EF loop in Vietnamese CV-A16. The findings suggest that the development of a universal HFMD vaccine, at least in Vietnam, must target CV-A6 and CV-A16 as two of the three major HFMD-causing serotypes. Vietnamese isolates or their genome sequences can be considered for rational vaccine design. [ABSTRACT FROM AUTHOR]

Hanoi, the capital of Vietnam, frequently experiences heavy air pollution episodes in the winter, causing health concerns for the 7.5 million people living there. Spatial-temporal variations in PM 2.5 levels can provide useful information about the sources and transportation of PM 2.5. However, the published spatial-temporal data in the area are limited. In this research, PM 2.5 concentrations at two sites in Hanoi and a site in Thai Nguyen (60 km north of Hanoi) were observed from October 2017 to April 2018, using newly available low-cost sensors. Hourly concentrations of PM 2.5 at the three sites were similar on average (57.5, 54.9, and 53.6 μg m−3) and clearly co-varied, suggesting remarkable large-scale effects. The contribution of long-range transport and meteorological factors on PM 2.5 levels were investigated with a machine learning technique based on a random forest (RF) algorithm and concentration weight trajectory (CWT). The results showed that the contribution of long-range transport from the north and northeast to local PM 2.5 levels was significant. Moreover, weather normalized PM 2.5 concentrations and partial plots of meteorological factors on the levels of PM 2.5 showed that meteorological conditions play a significant role in the formation of winter haze events. Image 1 • Observation of PM 2.5 levels at three sites using sensors. • Moderate to good correlation factors among PM 2.5 at sites showed regional effects. • Partial effects of meteorological and temporal factors on PM 2.5 were determined by a machine learning approach. • Contribution of meteorological factors on haze revealed by weather normalized PM 2.5 • PM 2.5 long-range transport investigated by CWT and partial trajectory correlation. [ABSTRACT FROM AUTHOR]

Background: Afatinib, a second-generation epidermal growth factor receptor(EGFR) tyrosine kinase, has proven effective for non-small-cell lung cancer (NSCLC) patients with EGFR mutations through randomized controlled trials and real-world studies. Elderly patients exhibit unique characteristics in terms of physical condition and comorbidities, leading to differences in clinical practice for selecting the initial dosage and making dose adjustments compared to younger patients. This study aims to evaluate the effectiveness and adverse effects of first-line Afatinib treatment in elderly patients with NSCLC harboring EGFR mutations in Vietnam in a real-world context., Methods: We conducted a retrospective analysis of 135 patients, aged 65 years and older, across nine cancer centers in Vietnam. These patients, who harbored drug-sensitive EGFR mutations (excluding de novo T790M), received first-line Afatinib treatment between April 2018 and June 2022. The primary endpoints, time to treatment failure (TTF), and overall survival (OS) were assessed using the Kaplan-Meier method, and comparisons were conducted using the log-rank test. Secondary endpoints included the overall response rate (ORR) according to RECIST 1.1 and adverse effects as classified by CTCAE 4.0., Results: The median age was 71.2 years (SD ± 5.3). Comorbidities included cardiovascular disease (20.7%), diabetes (5.2%), chronic obstructive pulmonary disease (2.2%), and hepatitis B (0.7%). Common mutations constituted 71.9% of cases, with uncommon mutations representing 28.1%. Brain metastases were observed in 24.4% of patients. Initial treatment doses were 40 mg for 35.6% of patients and 30 mg for 62.2%. With a median follow-up of 34.3 months, the median TTF was 16.3 months (95% CI: 15.4-19.5), and the median OS was 32.9 months (95% CI: 28.9-37.5). Factors associated with decreased OS included poor performance status, current smoking, and the presence of uncommon mutations. The ORR was 77.8%, with a complete response of 11.1% and a disease control rate of 94.1%. The most common toxicities were dermatologic and mucosal, including diarrhea (55.6%), rash (48.9%), and stomatitis (40.7%), predominantly in grades 1 and 2. Initiating treatment at doses below 40 mg significantly reduced most toxicities compared to the 40 mg dose. The presence of brain metastases did not significantly affect ORR, TTF, or OS. Starting treatment at doses below 40 mg significantly lowered the response rate but did not impact TTF or OS., Conclusion: First-line treatment with Afatinib in elderly patients with NSCLC and EGFR mutations demonstrates significant efficacy and manageable toxicity in a Vietnamese multicenter real-life setting. The effectiveness of Afatinib was confirmed, with known and well-controlled adverse effects, supporting its use in this patient population.

Concentrations and profiles of unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs) were analyzed in airborne particulate matter (PM) samples collected from high-traffic roads in Hanoi urban area. Levels of PAHs and Me-PAHs ranged from 210 to 660 (average 420) ng/m 3 in total PM, and these pollutants were mainly associated with fine particles (PM 2.5 ) rather than coarser ones (PM > 10 and PM 10 ). Proportions of high-molecular-weight compounds (i.e., 5- and 6-ring) increased with decreasing particle size. Benzo[b+k]fluoranthene, indeno[1,2,3-cd]pyrene, and benzo[ghi]perylene were the most predominant compounds in the PM 2.5 samples. In all the samples, Me-PAHs were less abundant than unsubstituted PAHs. The PAH-CALUX assays were applied to evaluate aryl hydrocarbon receptor (AhR) ligand activities in crude extracts and different fractions from the PM samples. Benzo[a]pyrene equivalents (BaP-EQs) derived by the PAH-CALUX assays for low polar fractions (mainly PAHs and Me-PAHs) ranged from 300 to 840 ng/m 3 , which were more consistent with theoretical values derived by using PAH-CALUX relative potencies (270-710 ng/m 3 ) rather than conventional toxic equivalency factor-based values (22-69 ng/m 3 ). Concentrations of PAHs and Me-PAHs highly correlated with bioassay-derived BaP-EQs. AhR-mediated activities of more polar compounds and interaction effects between PAH-related compounds were observed. By using PAH-CALUX BaP-EQs, the ILCR values ranged from 1.0 × 10 -4 to 2.8 × 10 -4 for adults and from 6.4 × 10 -5 to 1.8 × 10 -4 for children. Underestimation of cancer risk can be eliminated by using effect-directed method (e.g., PAH-CALUX) rather than chemical-specific approach., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

PM 0.1 has been believed to have adverse short- and long-term effects on human health. However, the information of PM 0.1 that is needed to fully evaluate its influence on human health and environment is still scarce in many developing countries. This is a comprehensive study on the levels, chemical compositions, and source apportionment of PM 0.1 conducted in Hanoi, Vietnam. Twenty-four-hour samples of PM 0.1 were collected during the dry season (November to December 2015) at a mixed site to get the information on mass concentrations and chemical compositions. Multiple linear regression analysis was utilized to investigate the simultaneous influence of meteorological factors on fluctuations in the daily levels of PM 0.1 . Multiple linear regression models could explain about 50% of the variations of PM 0.1 concentrations, in which wind speed is the most important variable. The average concentrations of organic carbon (OC), elemental carbon (EC), water-soluble ions (Ca 2+ , K + , Mg 2+ , Na + , NH 4 + , Cl - , NO 3 - , SO 4 2- , C 2 O 4 2- ), and elements (Be, Al, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba, Tl, Pb, Na, Fe, Mg, K, and Ca) were 2.77 ± 0.90 μg m -3 , 0.63 ± 0.28 μg m -3 , 0.88 ± 0.39 μg m -3 , and 0.05 ± 0.02 μg m -3 , accounting for 51.23 ± 9.32%, 11.22 ± 2.10%, 16.28 ± 2.67%, and 1.11 ± 0.94%, respectively. A positive matrix factorization model revealed the contributions of five major sources to the PM 0.1 mass including traffic (gasoline and diesel emissions, 46.28%), secondary emissions (31.18%), resident/commerce (12.23%), industry (6.05%), and road/construction (2.92%).

This research investigated the distribution and contribution of polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) bound to particulate matter (PM) emitted from open burning of rice straw (RS) into the atmosphere in the north of Vietnam. The experiments were conducted to collect PM 2.5 and total suspended particulates (TSP) prior to and during burning in the period of 2016-2018 in suburban areas of Hanoi. Nine PAHs and 18 NPAHs were determined using the HPLC-FL system. The results showed that the proportion of RS burning seasonally affects the variation of PAHs emission in atmospheric environment. The levels of nine PAHs from RS burning were 254.4 ± 87.8 µg g -1 for PM 2.5 and 209.7 ± 89.5 µg g -1 for TSP. We observed the fact that, although fluoranthene (Flu) was the most abundant PAH among detected PAHs both in PM 2.5 and TSP, the enrichment of Flu in TSP from burning smoke was higher than that in PM 2.5 while the contribution of benzo[ a ]pyrene (B a P) and indeno[ 1,2,3- cd ]pyrene (IDP) in PM 2.5 from burning smoke were much higher than those in TSP. This research found that 1-nitropyrene (1-NP) and 6-nitrochrysene (6-NC) emit from RS burning with the same range with those from wood burning. The 2-nitrofluorene (2-NF) and 2-nitropyrene (2-NP) released from RS burning as the secondary NPAHs. This research provides a comprehensive contribution characterization of PAHs and NPAHs in PM with different size emitted from traditional local rice straw burning in the north of Vietnam. The results help to clarify the environmental behavior of toxic organic compounds from RS burning in Southeast Asia.