Untreated chronic hepatitis B virus (HBV) infection can lead to chronic liver disease and may progress to cirrhosis or hepatocellular carcinoma (HCC). HBV infection has been prevalent in Vietnam, but there is little information available on the genotypes, sub-genotypes, and mutations of HBV in patients with HBV-related HCC confirmed by histopathological diagnosis. We studied the molecular characteristics of HBV and its genetic variants in Vietnamese HCC patients after liver tumor resection. We conducted a descriptive cross-sectional study on 107 HBV-related HCC hospitalized patients from October 2018 to April 2019. The specimens collected included EDTA anticoagulant blood and liver tissues. Extracted HBV DNA was subjected to whole genome sequencing by the Sanger method. We discovered 62 individuals (57.9%) with genotype B and 45 patients (42.1%) with genotype C, with only sub-genotypes B4 and C1. Among the mutations, the double mutation, A1762T-G1764A, had the most significant frequency (73/107 samples; 68.2%) and was higher in genotype C than in genotype B (p < 0.001). The most common genotypes found in HCC patients in this investigation were B and C, with sub-genotypes B4 and C1 for each. The prevalence of genotype B4 was greater in HBV-infected Vietnamese HCC patients.

Objective: To document the pattern of particulate matter 2.5 (PM2.5) concentration in urban and suburban schools in Ho Chi Minh City (HCMC) and to estimate the prevalence of wheezing and rhinitis among schoolchildren according to sociodemographic characteristics and school-related conditions.Material and Methods: A cross-sectional study was conducted in two suburban and two urban schools in HCMC. PM2.5 concentrations were monitored hourly from August to December in 2022. Children aged 9-13 years (N=1,033) provided data on wheezing and rhinitis symptoms in the previous year. The daily levels of PM2.5 were monitored in each school. Respiratory symptoms were compared between areas and across school-related conditions.Results: Geometric means of the daily PM2.5 concentration in the suburban and urban areas were 61.2 μg/m3 and 31.0 μg/m3, respectively (p-value<0.001). In both areas, PM2.5 levels increased in the evening to high levels at night and early morning. The prevalence of respiratory symptoms did not differ significantly between the suburban and urban areas: wheezing 20.6% and 16.9%, and rhinitis 55.7% and 61.5%, respectively. However, school-related conditions in which the prevalence was increased were travelling to school by bus, spending more than 15 minutes/day on the road and attending extra classes outside normal school hours.Conclusion: Despite the significantly higher PM2.5 levels in suburban schools, the prevalence of wheezing and rhinitis did not reveal significant differences between areas. However, respiratory symptoms were more common among those travelling by bus, having been infected with Coronavirus Disease-19 (COVID-19), spending longer time on the road and attending classes outside normal school hours.

In 2017, Global Initiative for Chronic Lung Disease (GOLD) made substantial changes to its ABCD group categorization. Although several studies had been conducted to assess the impact of the new GOLD category, there was no research on the change of the GOLD classification in Vietnam. This retrospective analysis was conducted at Asthma and COPD clinic at the University Medical Center in Ho Chi Minh City, Vietnam. Our study population comprised patients visiting Medical Center from January 2018 to January 2020. We categorized patients’ demographic, clinical characteristics and pharmacotherapy based on GOLD 2011 and 2017 guidelines. A comparison between the two versions was also determined. A total of 457 patients were included in this study. The percentage of groups A, B, C and D according to GOLD 2011 was 5%, 20.8%, 13.1% and 61.1%; and according to GOLD 2017 was 6.1%, 34.1%, 12% and 47.8%, respectively. In terms of gender, male patients constituted nearly 95% of the study’s population (433/457 patients). Regarding pharmacotherapy, approximately 20% of the low-risk group (group A-B) was overtreated with ICS components: LABA+ICS (15.8%) and LAMA+LABA+ICS (3.8%). There were 13.3% and 1.1% of patients transferred from D to B and from C to A, respectively. All of them had lower FVC% pred, FEV₁% pred and FEV₁/FVC than the patients remained in group B or A (p<0.005). This is the first research in Vietnam to show the distribution of COPD patients using both the GOLD 2011 and GOLD 2017 criteria. There was 14% of patients reclassified from high-risk groups to low-risk groups when changing from 2011 to 2017 version and discordance of medications between guidelines and real-life practice. Therefore, clinicians should use their clinical competence to consider patients' conditions before deciding the appropriate therapeutic approach. Consequently, further studies were required to evaluate the effect of the change in GOLD classification.

Managing chronic hepatitis B in children presents significant challenges, particularly due to the risk of antiviral resistance with prolonged lamivudine use. We report 3 pediatric cases in Vietnam who experienced virologic breakthrough after lamivudine therapy failure. Genotypic testing of the hepatitis B virus polymerase gene revealed resistance mutations: M204V/I in all 3 cases, L180M in 2 cases (cases 2 and 3), L80I in case 1, and M250L in case 2. After resistance was identified, switching to tenofovir disoproxil fumarate achieved complete viral suppression, whereas switching to entecavir resulted in a partial yet clinically meaningful virologic response, due to cross-resistance conferred by the M204V/I mutations. These cases provide clinical observations from a resource-limited setting, suggesting that tenofovir disoproxil fumarate may be preferable to entecavir for salvage therapy following lamivudine failure. This emphasizes the urgent need for accessible genotypic testing to guide treatment decisions and prevent the use of ineffective sequential monotherapies.