Background: Salmonella typhi (S.typhi) is the major cause of human typhoid fever outbreaks. In fact, there were various typhoid fever outbreaks that occurred in China, and India that was caused by S.typhi strain without Vi antigen. Objective: To determine whether the S.typhi strains with mutation of gene encoding Vi antigen exists in Vietnam and the rate of mutation (if they exists). Subject and methods: 450 S.typhi isolates were collected in the Northern, Central and Southern Region of Vietnam during 1995 and 2005. The isolates were analyzed by the PCR method in order to detect mutants by using 2 primer pairs of tviB and DE. Results and Conclusion: There was no clear evidence on the relationship between the widely used Typhi Vi vaccine in Vietnam and the existence and spread of the mutation of gene encoding Vi antigen of S.typhi. 30 out of 450 isolates mutated losing the gene encoding of Vi antigen, making it 6.67%. These isolates were spread out between 1995 and 2005 throughout the Northern, Central and Southern Regions of Vietnam, with a peak in 1999. A noteworthy point was the rate of mutation of S.typhi losing the gene encoding of Vi antigen in Vietnam during the period of study. However, the mutation rate of S.typhi in Vietnam was still higher than the ratio of similar mutations being published in the other countries worldwide and higher than the recommended level of the World Health Organization.
gene mutation ; Salmonella typhi

Background: A/H5N1 influenza virus spreads from birds to humans and cause influenza diseases with high mortality rate. Vaccination is the most effective way to protect communities from pandemic, reduce morbidity and mortality. The study of creating A/H5N1 influenza vaccines in conformity with Vietnam was the urgent need. Institute of Vaccine\u2019s Achievement (IVAC) studied production of inactivated influenza vaccine for human on egg-grown from reassortants NIBRG-14. Objectives: In order to produce experimentally A/H5N1 influenza vaccine for human in accordance with WHO requirements and set up a viable process for production of the vaccines. Subjects and method: 10 days embryonated eggs and NIBRG-14 strains were served to the study with LAL method to check endotoxin, Kijehdal method to test total protein. Results: IVAC had produced successfully 5 lots of absorbed vaccine A/H5N1 (FLUVAC) using NIBRG-14 strains and embryonated eggs. Initially, production and quality control processes had been set up at IVAC by applying the recommendations of WHO. Conclusion: The success of the study was a basis of the approval of the government to establish a influenza vaccine manufacturing facilities.
Influenza A Virus ; H5N1 Subtype ; Influenza Vaccines ; Humans ; Eggs

Papiliotrema huenov was previously reported to be highly tolerant of a range of extremely toxic heavy metals. This study aimed to identify the potential of P. huenov to remove manganese and copper from aqueous solution. Physical conditions which affect removal of Mn(II) and Cu(II) were determined. Optimal temperature for adsorption of both metal ions was 30°C, and optimal pH for maximum uptake of Mn(II) and Cu(II) were 5 and 6, respectively. Under these conditions, living cells of P. huenov accumulated up to 75.58% of 110 mg/ L Mn(II) and 70.5% of 128 mg/L Cu(II) over 120 h, whereas, the removal efficiency of metal ions by dead cells over 1 h was 60.3% and 56.5%, respectively. These results indicate that living cells are more effective than dead biomass for bioremediation, but that greater time is required. The experimental data extends the potential use of P. huenov in biosorption and bioaccumulation of toxic heavy metals to copper and manganese, two of the most common industrial contaminants.

As the associations of sperm DNA fragmentation with morphology have not been examined in detail, this study aimed to investigate the relationship between abnormalities of morphological details and DNA integrity in human sperm. Methods: In this cross-sectional study, men from infertile couples were enrolled at Hue Center for Reproductive Endocrinology and Infertility, Vietnam. Conventional semen parameters, including morphological details, were analyzed following the World Health Organization 2010 criteria. Sperm DNA fragmentation was evaluated using a sperm chromatin dispersion assay. The relationships and correlations between semen parameters, sperm morphology, and the type of halosperm and the DNA fragmentation index (DFI) were analyzed. Results: Among 130 men in infertile couples, statistically significant differences were not found in the sperm halo type between the normal and abnormal sperm morphology groups. The percentage of round-head spermatozoa was higher in the DFI >15% group (16.98%±12.50%) than in the DFI ≤15% group (13.13% ±8.82%), higher values for amorphous heads were found in the DFI >15% group, and lower values for tapered heads were observed in the DFI ≤15% group; however, these differences were not statistically significant. Small-halo sperm and the DFI were positively correlated with round-head sperm (r=0.243, p=0.005 and r=0.197, p=0.025, respectively). Conclusion: The rate of general sperm morphological abnormalities in semen analysis was not related to sperm DNA integrity. However, round sperm heads were closely associated with sperm DNA fragmentation.

Objective: This study aimed to compare the efficacy of physiological intracytoplasmic sperm injection (PICSI) and intracytoplasmic sperm injection (ICSI) in terms of the fertilization rate and embryo quality using sibling oocyte cycles. Methods: This prospective, cross-sectional study collected data from 76 couples who underwent their first cycle at the Hue Center for Reproductive Endocrinology and Infertility, Vietnam, between May 2019 and November 2021. The inclusion criteria were cycles with at least eight oocytes and a sperm concentration of 5×106/mL. Sperm parameters, sperm DNA fragmentation (SDF), fertilization, and the quality of cleavage-stage embryos on day 2 and blastocysts on day 5 were examined. Results: From 76 ICSI cycles, 1,196 metaphase II (MII) oocytes were retrieved, half of which were randomly allocated to either the PICSI (n=592) or ICSI (n=604) treatment group. The results showed no significant difference between the two groups in terms of fertilization (72.80% vs. 75.33%, p=0.32), day 2 cleavage rate (95.13% vs. 96.04%, p=0.51), blastulation rate (52.68% vs. 57.89%), and high-quality blastocyst rate (26.10% vs. 31.13%, p=0.13). However, in cases where SDF was low, 59 cycles consisting of 913 MII oocytes produced a considerably higher blastulation rate with PICSI than with ICSI (50.49% vs. 35.65%, p=0.00). There were no significant differences between the pregnancy outcomes of the PICSI and ICSI embryo groups following embryo transfer. Conclusion Using variable sperm quality provided no benefit for PICSI versus ICSI in terms of embryo outcomes. When SDF is low, PICSI appears to be able to produce more blastocysts.

Objectives: The prevalence of posttraumatic stress disorder (PTSD) has increased, particularly among individuals who have recovered from coronavirus disease 2019 (COVID-19) infection. Health literacy is considered a “social vaccine” that helps people respond effectively to the pandemic. We aimed to investigate the association between long COVID-19 and PTSD, and to examine the modifying role of health literacy in this association. Methods: A cross-sectional study was conducted at 18 hospitals and health centers in Vietnamfrom December 2021 to October 2022. We recruited 4,463 individuals who had recovered from COVID-19 infection for at least 4 weeks. Participants provided information about their sociodemographics, clinical parameters, health-related behaviors, health literacy (usingthe 12-item short-form health literacy scale), long COVID-19 symptoms and PTSD (Impact Event Scale-Revised score of 33 or higher). Logistic regression models were used to examine associations and interactions. Results: Out of the study sample, 55.9% had long COVID-19 symptoms, and 49.6% had PTSD.Individuals with long COVID-19 symptoms had a higher likelihood of PTSD (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.63–2.12; p < 0.001). Higher health literacy was associated with a lower likelihood of PTSD (OR, 0.98; 95% CI, 0.97–0.99; p = 0.001). Compared to those without long COVID-19 symptoms and the lowest health literacy score, those with long COVID-19 symptoms and a 1-point health literacy increment had a 3% lower likelihood of PTSD (OR, 0.97; 95% CI, 0.96–0.99; p = 0.001). Conclusion Health literacy was found to be a protective factor against PTSD and modified the negative impact of long COVID-19 symptoms on PTSD.

Anaplasma marginale and A. platys were detected and characterized (16S rDNA sequence analysis) from dairy and indigenous cattle, and the latter in domestic dogs in Vietnam. A phylogenetic tree was inferred from 26 representative strains/species of Anaplasma spp. including 10 new sequences from Vietnam. Seven of our Vietnamese sequences fell into the clade of A. marginale and 3 into A. platys, with strong nodal support of 99 and 90%, respectively. Low genetic distances (0.2–0.4%) within each species supported the identification. Anaplasma platys is able to infect humans. Our discovery of this species in cattle and domestic dogs raises considerable concern about zoonotic transmission in Vietnam. Further systematic investigations are needed to gain data for Anaplasma spp. and members of Anaplasmataceae in animal hosts, vectors and humans across Vietnam.
Anaplasma marginale ; Anaplasma ; Anaplasmataceae ; Animals ; Asian Continental Ancestry Group ; Cattle ; DNA, Ribosomal ; Dogs ; Humans ; Phylogeny ; Trees ; Vietnam

Objective: This study aimed to develop a configurable clean room paradigm with low air pressure for assisted reproductive technology (ART) clinics and demonstrate the concept’s efficacy using in vitro fertilization (IVF) treatment. Methods: A high-standard clean room system with positive pressure (13 Pa) was built using accessible materials and equipment for ART laboratories. Methods for controlling and evaluating the clean room’s characteristics were developed and implemented for quality assessment and calibration to maximize efficiency. The feasibility of the flexible clean room concept was assessed by analyzing the key performance indicators of embryo culture and IVF treatment. Results: After 3 weeks of testing, the concentration of particles ≥0.5 μm was 6.04 times lower than the International Organization for Standardization (ISO) class 5 standard (3,520 particles/m3) in the IVF laboratory. Air pressure, noise, temperature, and humidity were controlled stably and appropriately. Five days after installation and handover, the volatile organic compound concentration dropped to 0.00 ppm. With blastocysts and a respectable blastocyst rate, embryonic culture with female patients younger than 40 matched the criteria (63.5% and 38.9%, respectively). After vitrified blastocysts were transferred, the pregnancy and implantation rates were 58.5% and 36.2%, respectively, demonstrating a high degree of treatment success. Conclusion Our customizable, high-quality, low-air-pressure clean room model can be implemented to achieve positive outcomes for infertility treatment.

Objective: This study aimed to develop a configurable clean room paradigm with low air pressure for assisted reproductive technology (ART) clinics and demonstrate the concept’s efficacy using in vitro fertilization (IVF) treatment. Methods: A high-standard clean room system with positive pressure (13 Pa) was built using accessible materials and equipment for ART laboratories. Methods for controlling and evaluating the clean room’s characteristics were developed and implemented for quality assessment and calibration to maximize efficiency. The feasibility of the flexible clean room concept was assessed by analyzing the key performance indicators of embryo culture and IVF treatment. Results: After 3 weeks of testing, the concentration of particles ≥0.5 μm was 6.04 times lower than the International Organization for Standardization (ISO) class 5 standard (3,520 particles/m3) in the IVF laboratory. Air pressure, noise, temperature, and humidity were controlled stably and appropriately. Five days after installation and handover, the volatile organic compound concentration dropped to 0.00 ppm. With blastocysts and a respectable blastocyst rate, embryonic culture with female patients younger than 40 matched the criteria (63.5% and 38.9%, respectively). After vitrified blastocysts were transferred, the pregnancy and implantation rates were 58.5% and 36.2%, respectively, demonstrating a high degree of treatment success. Conclusion Our customizable, high-quality, low-air-pressure clean room model can be implemented to achieve positive outcomes for infertility treatment.

Objective: This study aimed to develop a configurable clean room paradigm with low air pressure for assisted reproductive technology (ART) clinics and demonstrate the concept’s efficacy using in vitro fertilization (IVF) treatment. Methods: A high-standard clean room system with positive pressure (13 Pa) was built using accessible materials and equipment for ART laboratories. Methods for controlling and evaluating the clean room’s characteristics were developed and implemented for quality assessment and calibration to maximize efficiency. The feasibility of the flexible clean room concept was assessed by analyzing the key performance indicators of embryo culture and IVF treatment. Results: After 3 weeks of testing, the concentration of particles ≥0.5 μm was 6.04 times lower than the International Organization for Standardization (ISO) class 5 standard (3,520 particles/m3) in the IVF laboratory. Air pressure, noise, temperature, and humidity were controlled stably and appropriately. Five days after installation and handover, the volatile organic compound concentration dropped to 0.00 ppm. With blastocysts and a respectable blastocyst rate, embryonic culture with female patients younger than 40 matched the criteria (63.5% and 38.9%, respectively). After vitrified blastocysts were transferred, the pregnancy and implantation rates were 58.5% and 36.2%, respectively, demonstrating a high degree of treatment success. Conclusion Our customizable, high-quality, low-air-pressure clean room model can be implemented to achieve positive outcomes for infertility treatment.