Complete genome sequences and phylogenetic analysis of dengue virus in Southern Vietnam during 2014-2015

Original Research

Abstract

Objective: Dengue is an infectious disease that causes a worldwide health and economic burden despite the efforts to eradicate the disease. From 2013 to 2015, dengue epidemic significantly increased from 33,626 to 50,205 cases in Vietnam. This study aims to determine the genotype variations of dengue virus (DENV) circulating in Southern Vietnam during 2014-2015.

Methods: C6/36 cells were infected with twenty-four strains of dengue virus isolated in 2014-2015 and kept frozen. The complete nucleotide sequence of dengue virus genomes was obtained by polymerase chain reaction (PCR). The genome was sequenced in the MiSeq system and analyzed by the basic local alignment search tool (BLAST) program. Data from GeneBank was used to create the phylogenetic trees.

Results: Among the 17 analyzed strains from 8 southern provinces, four (23.53%) were DENV-1, three (17.65%) were DENV-2, five (29.41%) were DENV-3, and five (29.41%) DENV-4 were isolated. Four DENV-1 isolates belong to Asia genotype. Three DENV-2 strains were concentrated in a subgroup of Asian 1 genotype. Five DENV-3 isolates were identified as belonged to Asian 2 genotype and five DENV-4 isolates were found as belong to Asia 1 genotype. There were no amino acid mutations and the transition capacity between the nucleotide among four types of DENV serotypes suggested that the probability of conversion from C to T was the highest conversion rate.

Conclusions: These DENV isolates were genetically close to other previous strains isolated from Vietnam and its neighboring countries, including Thailand, China, Cambodia, and Singapore, Brazil, Sri Lanka due to dynamic transmission. 

Graphical abstract

Spontaneous massive hemopneumothorax: report of three cases

Case Study

Abstract

Spontaneous hemopneumothorax is a rare condition and may be a life-threatening condition that needs prompt diagnosis and urgent intervention. In this study, we reported three male cases of spontaneous hemopneumothorax, two cases presented with chest pain and one with epigastric pain. All cases were successfully treated by early surgical intervention. Total blood drainage was ranged from 1400 to 2000 mL. Video-assisted thoracoscopic surgery was performed successfully in two cases, however, one case was transferred to urgent thoracotomy due to excessive blood clotting in the pleura cavity and continuous bleeding. Leukocytosis was observed in two cases, mostly due to pneumonia or sepsis. The bleeding point was identified in all cases, however, the air leak area could not be identified in two cases. Length of hospital stay after admission was ranged from five to seven days. We recommend that video-assisted thoracoscopic surgery should be considered as a first choice due to its effectiveness in reducing postoperative complications and facilitating rapid recovery.

Graphical abstract

The prevalence and related factors of phantom vibration among medical students: A first look in Vietnam

Original Research

Abstract

Background: Phantom vibration (PV) is an illusionary perception in which people perceive their mobile phone vibrates while it actually does not. Recently, PV has attracted attention in psychology and medical field. There are several studies investigating the prevalence and risk factors associated with this phenomenon. However, the findings are inconsistent. The prevalence of PV fluctuates from 21% to 89% among different groups and its mechanism remains unclear. Further understanding is necessary to identify the settings in which PV may harm the population and warrant further exploration.

Objectives: This study aims to explore the prevalence of PV among medical students in Ho Chi Minh City and settings that PV can risk people’s health. Relationships between PV and phone usage habits as well as psychiatric disturbance also are investigated.

Methods: By using online questionnaire on 377 undergraduate medical students in Ho Chi Minh City, Vietnam, the cross-sectional study explored factors associated with PV, including demographic, behavioral phone usage, and mental/emotional factors using the Self Reporting Questionaire - 20 (SRQ-20). The descriptive and association analyses were employed using R software.

Results: The study found a significant association between mental/emotional factors (i.e. mental disturbance and phone attachment) and PV (OR=2.15, 95% CI=1.21-3.81, p value=0.009; OR=1.75, 95% CI=1.02-3.01, p value=0.043 respectively), which suggests an important role of mental/emotional factors in explaining the potential mechanism of PV. A high proportion of participants also experienced PV while driving (55.5%) within the last month. This implies the impact of PV possibly becomes significant, causing an increase in the risk of traffic accident due to distracted driving.

Graphical abstract

Quantitative Hepatitis B Surface Antigen in Different Phases of Chronic HBV Infection in Vietnamese Patients: The Preliminary Study

Original Research

Abstract

Quantitative serum HBsAg has been considered as a marker that reflects the immune effect on clearance of HBV. The HBsAg level varies in different genotypes and phases of infection. Therefore, we aimed to investigate the serum HBsAg level and its correlation with HBV DNA in different phases of Vietnamese CHB patients, predominately infected with genotype B and C. 267 chronic HBV treatment naïve patients (156 genotype B and 61 genotype C) were recruited in this cross-sectional study. Patients were categorized to 5 groups: immune tolerance (IT), HBeAg positive chronic hepatitis B (CHBe+), inactive carrier (IC), viral reactivation (VR), HBeAg negative chronic hepatitis B (CHBe-). The serum HBsAg level was measured by ECLIA method. Correlations between HBsAg and HBV DNA were analyzed by Spearman's correlation. The median HBsAg values were different between groups of CHB 4.56 log10 IU/mL (IT), 3.85 log10 IU/mL (CHBe+), 2.72 log10 IU/mL (IC), 3.21 log10 IU/mL (VR) and 3.09 log10 IU/mL (CHBe-) (p= 0.001). The significant correlations between HBsAg levels and HBV DNA were found in all CHB groups (r = 0.3 to 0.5). The ratios of HBsAg/HBV DNA were distributed around 0.5. The wide distribution of HBsAg and the highest ratio of HBsAg/HBV DNA were found in the IC groups. Our study demonstrated that serum HBsAg levels were significantly different in natural stages of CHB.  Significant correlations between HBsAg and HBV DNA were found in all CHB phases. The wide distribution of HBsAg in the IC group raises the question on the existence of HBsAg integration in CHB patients.

Graphical abstract

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