Background: The VEGFA gene encodes vascular endothelial growth factor A (VEGF-A), which plays a key role in vasculogenesis and angiogenesis. The VEGFA rs3025039 (+936C>T) polymorphism is associated with many diseases. This study aimed to: (1) Apply PCR-RFLP technique to identify the VEGFA rs3025039 (+936C>T) polymorphism; (2) Primarily evaluate the distribution of genotypes and allele frequencies of the rs3025039 polymorphism in volunteers. Materials and methods: DNA extraction was isolated from peripheral blood of 60 volunteers. Determining the VEGFA rs3025039 (+936C>T) polymorphism by PCR-RFLP technique. Confirming the results of the genotypes randomly by Sanger sequencing. Results: All PCR-RFLP results of validated samples were in concordance with sequencing results. The distribution of CC, CT and TT genotypes by rs3025039 polymorphism accounted for 80%, 16.7% and 3.3%, respectively. The frequencies of C and T alleles were 88.3% and 11.7%, respectively. Conclusion: Successfully applying PCR-RFLP technique to determine the VEGFA rs3025039 (+936C>T) polymorphism, which establishes the groundwork for further research into the association between this polymorphism and various disorders.

Background: Lung cancer is a common cancer with a high mortality rate. The identification of prognostic factors in lung cancer patients in Vietnam is still limited and inconsistent in clinical practice. Objectives: To describe the clinical, paraclinical characteristics and m-LCPI index in patients with primary non-small cell lung cancer and evaluate the factors affecting overall survival in patients with primary non-small cell lung cancer. Methods: Prospective study of 210 cases of non-small cell lung cancer diagnosed with primary non-small cell lung cancer at the Oncology Department of Hue University of Medicine and Pharmacy Hospital and Hue Central Hospital from February 2020 to February 2023. Results: The majority of hospitalizations were at late stages, from stage IIIA (89%), group 3 and 4 in m-LCPI grading scale constituted the majority (80%). Average overall survival at 3 years was 20.0 ± 14 months, and gradually decreased to 54.8%, 40%, and 38.6% after 1 year, 2 years and 3 years, respectively. Regression analysis of COX model between m-LCPI and OS showed statistical significance with m-LCPI 4 (HR = 3.9, 95%CI = 1.57 - 9.69, p = 0.003), while m-LCPI 3 (HR = 2.44, 95% CI 0.97 - 6.13), p = 0.058) had a weak correlation. Conclusion: Our study shows that 38.6% of patients were still alive after 3 years of diagnosis. m-LCPI index is a good predictor of the patients’ overall survival.

Objective: Human respiratory syncytial virus (RSV) is a primary cause of paediatric severe acute respiratory infection (SARI) worldwide, especially in developing countries. We investigated the genetic characteristics of RSV in northern Viet Nam to determine the prevalence and distribution of subtypes as well as the diversity and transmission patterns of genotypes. Methods: In two facilities, from January 2017 to December 2020, 1563 clinical specimens were collected from paediatric patients hospitalized with SARI and tested for RSV. Selected positive samples underwent sequencing analysis targeting the second hypervariable region of the G gene using next-generation sequencing. Results: The RSV positivity rate was 28.02% (438/1563 samples), and prevalence was highest in children aged <1 year (43.84%; 192/438). Subtype RSV-A accounted for 53.42% (234/438) of cases, RSV-B for 45.89% (201/438), and there was coinfection in 0.68% (3/438). Both subtypes cocirculated and peaked during August–September in each year of the study. Phylogenetic analysis showed that RSV-A samples belonged to the ON1 genotype, which has three subgenotypes: ON1.1, ON1.2 and ON1.3. However, we did not find the 72-nucleotide duplication in the second hypervariable region of the G gene, a characteristic of genotype ON1, in any RSV-A samples. RSV-B samples belonged to genotype BA9. Discussion: Our results provide additional molecular characterization of RSV infections in Viet Nam. Specially, our study is the first to report the absence of the 72-nucleotide duplication in the G gene of RSV-A genotype ON1 in Viet Nam, which may help in understanding the genetic evolution of RSV and be useful for vaccine development in the future.

Background: Viet Nam confirmed its first case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on 23 January 2020 among travellers from Wuhan, China, and experienced several clusters of community transmission until September. Viet Nam implemented an aggressive testing, isolation, contact tracing and quarantine strategy in response to all laboratory-confirmed cases. We report the results of SARS-CoV-2 testing during the first half of 2020 in northern Viet Nam. Methods: Between January and May 2020, 15 650 upper respiratory tract specimens were collected from 14 470 suspected cases and contacts in northern Viet Nam. All were tested for SARS-CoV-2 by real-time RT-PCR. Individuals with positive specimens were tested every three days until two tests were negative. Positive specimens from 81 individuals were cultured. Results: Among 14 470 tested individuals, 158 (1.1%) cases of SARS-CoV-2 infection were confirmed; 89 were imported and 69 were associated with community transmission. Most patients (122, 77%) had negative results after two tests, while 11 and 4 still tested positive when sampled a third and fourth time, respectively. SARS-CoV-2 was isolated from 29 of 81 specimens (36%) with a cycle threshold (Ct) value <30. Seven patients who tested positive again after testing negative had Ct values >30 and negative cultures. Conclusion Early, widespread testing for SARS-CoV-2 in northern Viet Nam identified very few cases, which, when combined with other aggressive strategies, may have dramatically contained the epidemic. We observed rapid viral clearance and very few positive results after clearance. Large-scale molecular diagnostic testing is a critical part of early detection and containment of COVID-19 in Viet Nam and will remain necessary until vaccination is widely implemented.

Introduction: There are two methods of reverse transcription polymerase chain reaction (RT–PCR) that have been the common methods to detect influenza infections: conventional and real-time RT–PCR. From December 2017 to March 2018, several missed diagnoses of influenza A(H1)pdm09 using real-time RT–PCR were reported in northern Viet Nam. This study investigated how these missed detections occurred to determine their effect on the surveillance of influenza. Methods: The haemagglutinin (HA) segments of A(H1N1)pdm09 from both real-time RT-PCR positive and negative samples were isolated and sequenced. The primer and probe sets in the HA gene were checked for mismatches, and phylogenetic analyses were performed to determine the molecular epidemiology of these viruses. Results: There were 86 positive influenza A samples; 32 were A(H1)pdm09 positive by conventional RT–PCR but were negative by real-time RT–PCR. Sequencing was conducted on 23 influenza (H1N1)pdm09 isolates that were recovered from positive samples. Eight of these were negative for A(H1)pdm09 by real-time RT–PCR. There were two different mismatches in the probe target sites of the HA gene sequences of all isolates (n = 23) with additional mismatches only at position 7 (template binding site) identified for all eight negative real-time RT–PCR isolates. The prime target sites had no mismatches. Phylogenetic analysis of the HA gene showed that both the positive and negative real-time RT–PCR isolates were grouped in clade 6B.1; however, the real-time RT–PCR negative viruses were located in a subgroup that referred to substitution I295V. Conclusion Constant monitoring of genetic changes in the circulating influenza A(H1N1)pdm09 viruses is important for maintaining the sensitivity of molecular detection assays.

This article describes Viet Nam Ministry of Health’s (VMoH) activities to prepare for and respond to the threat Zika virus (ZIKV), including the adaptation of existing surveillance systems to encompass ZIKV surveillance.

Objective To characterize viral co-infections among representative hospitalized measles cases during the 2014 Hanoi outbreak. Methods Throat swabs were collected from 54 pediatric patients with confirmed measles, and molecular diagnostics performed for 10 additional viral respiratory pathogens (Influenza A/H1N1pdm09; A/H3N2 and influenza B; Parainfluenza 1, 2, 3; Respiratory Synctial Virus, RSV; human Metapneumovirus, hMPV; Adenovirus and Picornavirus). Results Twenty-one cases (38.9%) showed evidence of infection with other respiratory viruses: 15 samples contained measles plus one additional virus, and 6 samples contained measles plus 2 additional viruses. Adenovirus was detected as a predominant cause of co-infections (13 cases; 24.1%), followed by RSV (6 cases; 11.1%), A/H1N1pdm09 (3 cases; 5.6%), PIV3 (3 cases; 3.7%), Rhinovirus (3 cases; 3.7%) and hMPV (1 case; 1.96%). Conclusions Viral co-infections identified from pediatric measles cases may have contributed to increased disease severity and high rate of fatal outcomes. Optimal treatment of measles cases may require control of multiple viral respiratory pathogens.

Background: Currently, the World Health Organization is encouraging developing countries to establish a seed lot system of rotavirus vaccine for production of this vaccine. Objectives: To determine gene sequences of rotavirus strain that was used for vaccine production and to evaluate its stability. Materials and method: Master seed (G4P6MS), Working seed (G4P6WS) and vaccine strain (G4P6VX) of Rotavirus were used for analysis at the US Center for Disease Control and Prevention (CDC). Results: 855 base pairs of gene 4 (VP4); 1195 base pairs of gene 6 (VP6); 824 base pair of gene 9 (VP7) and 715 base pairs of gene 10 (NSP4) from seed lot system and vaccines of G4P6 strain were determined. The results demonstrated this seed lot system is completely stable during vaccine production. There is no difference for nucleotide and amino acid sequence in this seed lot system. Conclusion: G4P6 strain (2001019203) is completely stable during vaccine production.
gene sequences ; seed lot system ; G4P6 (2001019203) ; rotavirus vaccine

Background: Acute gastroenterophathy usually caused by the Rota virus for children under 5 years old. Objectives: To present various types of data on epidemiology of ROTA virus diarrhea in Ho Chi Minh city from 12/2006-11/2007. Material and method: The data were collected from 500 stool specimens of diarrhea diagnosed chilren hosptalised at Thuy Dien Pediatric hospital 1, Ho Chi Minh city from December/2006 to November /2007. Results:There were 322 rotavirus-positive specimens, representing 64.4%. The proportions of monthly distribution of cases with diarrhea due to rotavirus were 90.1%, 54.39%, 85.37%, 74.51%, 72.92%, 41.67%, 26.67%, 58.33%, 79.31%, 52.63%, 69.05% and 57.78%, respectively. The numbers of rotavirus-positive cases in male and female were 216 (65.26%) and 106 (62.72%), respectively. The proportions of Rota virus positive children compared to total number of diarrheal cases with age 0-3, 3-6, 6-12, 12-24, 24-36 and over 36 months were 2.80%, 7.76%, 40.06%, 40.68%, 5.28% and 3.42%, respectively.\r\n', u'The results of typing identification indicated that the phenotypes of 98 among 100 specimens were identified (98%) in which there were sixty-one specimens of G1P8 (61%), one specimen of G2P8 (1%), fourteen specimens of G3P8 (14%), four of specimens of G4P8 (4%), eighteen specimens of GmixedP8 (18%). There were only two specimens of GnontypeableP8 (2%). Conclusion: Further studies should be carried out to clear this issue.\r\n', u'
Rotavirus ; gel type.