Aims: The objective of the study was to isolate bacteriophages and conduct a comprehensive analysis of their potential against Xanthomonas oryzae pv. oryzae (Xoo) strains in the Mekong Delta, Vietnam. Methodology and results: Twelve Xoo strains were isolated from rice fields located in the Mekong Delta, Vietnam. Among these strains, three strains Xoo L019, L020 and L024, showed the highest disease index of bacterial blight. Four phages specific to Xoo were isolated from soil, water and leaf samples, and their morphologies were determined. In a test against 12 Xoo strains, phage L541, MLA23 or W41 could infect 10 of the 12 Xoo strains, while phage LBH01 could infect 8 of the 12 Xoo strains. The stability of the phages to pH, organic solvents, UV-A and UV-B was also evaluated. Conclusion, significance and impact of study The initial characterization of the phages indicates their potential as biocontrol agents against bacterial blight in rice. The study is one of the very first studies about Xoo phages in rice in Vietnam.

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.

Objective: This study aims to enhance the capacity of dengue prediction by investigating the relationship of dengue incidence with climate and environmental factors in the Mekong Delta region (MDR) of Viet Nam by using remote sensing data. Methods: To produce monthly data sets for each province, we extracted and aggregated precipitation data from the Global Satellite Mapping of Precipitation project and land surface temperatures and normalized difference vegetation indexes from the Moderate Resolution Imaging Spectroradiometer satellite observations. Monthly data sets from 2000 to 2016 were used to construct autoregressive integrated moving average (ARIMA) models to predict dengue incidence for 12 provinces across the study region. Results: The final models were able to predict dengue incidence from January to December 2016 that concurred with the observation that dengue epidemics occur mostly in rainy seasons. As a result, the obtained model presents a good fit at a regional level with the correlation value of 0.65 between predicted and reported dengue cases; nevertheless, its performance declines at the subregional scale. Conclusion We demonstrated the use of remote sensing data in time-series to develop a model of dengue incidence in the MDR of Viet Nam. Results indicated that this approach could be an effective method to predict regional dengue incidence and its trends.

Objective: To correlate climatic and environmental factors such as land surface temperature, rainfall, humidity and normalized difference vegetation index with the incidence of dengue to develop prediction models for the Philippines using remote-sensing data. Methods: Time-series analysis was performed using dengue cases in four regions of the Philippines and monthly climatic variables extracted from Global Satellite Mapping of Precipitation for rainfall, and MODIS for the land surface temperature and normalized difference vegetation index from 2008-2015. Consistent dataset during the period of study was utilized in Autoregressive Integrated Moving Average models to predict dengue incidence in the four regions being studied. Results: The best-fitting models were selected to characterize the relationship between dengue incidence and climate variables. The predicted cases of dengue for January to December 2015 period fitted well with the actual dengue cases of the same timeframe. It also showed significantly good linear regression with a square of correlation of 0.869 5 for the four regions combined. Conclusion: Climatic and environmental variables are positively associated with dengue incidence and suit best as predictor factors using Autoregressive Integrated Moving Average models. This finding could be a meaningful tool in developing an early warning model based on weather forecasts to deliver effective public health prevention and mitigation programs.

Objective: To establish a surveillance in Dong Thap, at the border with Cambodia by assessing the presence of DENV serotypes and CHIKV among patients hospitalized at Dong Thap general hospital. Methods: Cross-sectional descriptive analysis was conducted on a cohort of 131 patients hospitalized with acute fever and symptoms compatible with dengue or chikungunya. The study was conducted from January 2012 to February 2013. The full clinical picture was established as well as serological and molecular detection. Serological analysis was sequentially performed on blood samples collected on admission and an average of seven days after admission. The detection of IgM antibody to DENV was performed by IgM capture ELISA and the detection of DENV and CHIKV RNA was done by reverse-transcription multiplex PCR. Results: 101 patients out of 131 (77%) were confirmed with dengue. All four dengue serotypes were detected with a predominance of DENV2 and DENV4. No chikungunya infection was detected although reported in neighboring Cambodia. A differential efficiency of serological dengue detection was observed. Efficiency was 29% upon admission and 53% after seven days on the same patients. 30 patients out of 131 (23%) were negative with both DENV and CHIKV. Conclusions: Dengue is at risk of being underestimated and chikungunya is not systematically detected. Changes in detection and surveillance procedures are therefore discussed to increase efficiency of dengue detection and continue the monitoring the emergence of CHIKV in Dong Thap province and in Vietnam.

In this report we describe a new approach in HIV sentinel surveillance that was piloted in Viet Nam in 2009 and is currently being rolled out in all provinces. It comprises a brief behavioural questionnaire added to the HIV sentinel surveillance surveys conducted routinely among people who inject drugs, female sex workers and men who have sex with men. Timely reporting of data from this system has resulted in improvements to HIV prevention efforts for most at-risk populations.

Objective: To record the human cases of dengue fever (DF) and investigate the Aedes mosquito species circulating during the Hanoi 2011 DF epidemics. Methods: 24 different outbreak points were recorded in 8 districts between August and December 2011. Results: 140 patients were hospitalized following dengue diagnostic with a predominance of males (59.3%) and the 15-34 age class. Only DENV-1 (11.27%) and DENV-2 (88.73%) serotypes were detected in human samples. Mosquito sampling performed in and around patients households revealed the predominance of Aedes aegypti (A. aegypti) (95.15%) versus Aedes albopictus (4.85%). Conclusions: There is a positive correlation between the population density of A. aegypti and the number of human cases and duration of outbreaks. This was not observed for Aedes albopictus. Three pools of A. aegypti were positive with dengue virus, two with DENV-1 and one with DENV-2.

The 5th outbreak of trichinosis occurred in a mountainous area of North Vietnam in 2012, involving 24 patients among 27 people who consumed raw pork together. Six of these patients visited several hospitals in Hanoi for treatment. Similar clinical symptoms appeared in these patients within 5-8 days after eating infected raw pork, which consisted of fever, muscle pain, difficult moving, edema, difficult swallowing, and difficult breathing. ELISA revealed all (6/6) positive reactions against Trichinella spiralis antigen and all cases showed positive biopsy results for Trichinella sp. larvae in the muscle. The larvae detected in the patients were identified as T. spiralis (Vietnamese strain) by the molecular analysis of the mitochondrial cytochrome c oxidase subunit III (cox3) gene.
Adult ; Animals ; Antigens, Helminth/analysis/immunology ; *Disease Outbreaks ; Electron Transport Complex IV/genetics ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Larva ; Male ; Meat/*parasitology ; Mitochondria/genetics ; Muscles/parasitology/pathology ; Swine ; Trichinella spiralis/genetics/immunology/*isolation & purification ; Trichinellosis/*epidemiology/parasitology/pathology ; Vietnam/epidemiology

Background: Statin and its derivate (simvastatin, autorvastatin, etc...) are used for dyslipidemia treatment and preventing thrombose. However, the mechanism of the antithrombotic action is still being studied. Objectives: (1) To study coagulation parameters in dyslipidemia. (2) To evaluate the effects of simvastatin on coagulation parameters in dyslipidemia patients. Subject and Method: A prospective study was carried out in a sample of 22 patients with primary hypercholesterolemia (type IIa), who were treated with simvastatin 20mg/d for 1 month. The lipid parameters (cholesterol, triglycerid, HDL, LDL) and coagulation parameters (PT, APTT, fibrinogen, factor II, V, VII, X, VIII, IX, XI) were compared between pre and post therapy, and to the control group (59 healthy people). Results: Most of coagulation parameter values (except factor VIII and X) of the pre treatment group were significantly change towards hypercoagulation (p<0.05%) when compared to the control group. After treatment, PT rate, APTT, APTT rate, fibrinogen, factor VII and IX were significantly changed towards coagulation when compared to pre treatment (p<0.05%). The plasma coagulation and lipid parameters of more than 50% of the hypercholesterolemia patients returned to normal values after treatment. Conclusions: Simvastatin therapy on dyslipidemia patients can reduce not only the level of serum lipid, but also coagulation, and proved its effectiveness in the prevention of thrombosis.
Simvastatin ; coagulation ; dyslipidemia

Background: Japanese Encephalitis (JE) is common in the plains and mountainous areas in Asia \u2013 Pacific. Japanese encephalitis vaccine shows effectiveness in protecting children from JE in some countries such as Japan and Korea. Objective: To evaluate the efficacy of Japanese Encephalitis (JE) vaccination in Thai Binh province during 2003-2007. Subject and Method: Prospective, retrospective and sero-epidemiological methods were carried out on 329 samples collected from viral encephalitis patients and tested by JE MAC-ELISA, the positive average was 41.6% (137/329). Result: It had dramatically dropped from 85.2% in 2003 to 8.5 % in 2007 related to the rate of JE vaccination for children from 1 to 5 years old increasing from 49 % in 2003 to 77 % in 2007. Most of JE confirmed cases were un-vaccinated. Conclusion: JE etiology cause viral encephalitis in children in Thai Binh province was reduced thanks to JE vaccination in EPI program for 1 to 5 year old children. But more than 96% (131/136) of viral encephalitis in 15 years old upward was unknown etiology, the need for further study of the etiology cause viral encephalitis in adults.
Japanese encephalitis ; virus encephalitis ; MAC-ELISA ; Vaccine