Objective: The risk of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from schoolchildren to their household and the protective effects of vaccination in these settings remain poorly understood. We assessed the transmission dynamics of schoolchildren with SARS-CoV-2 within their households and the protective effects of coronavirus disease (COVID-19) vaccination among household members in Viet Nam. Methods: We estimated the attack rate, vaccine effectiveness and adjusted risk ratio (aRR) of factors associated with SARS-CoV-2 transmission to household contacts of children confirmed to have COVID-19 who attended three schools in Ha Nam, Phu Tho and Thanh Hoa provinces between September and December 2021 using multivariable regression with household-level random effects. Results: This retrospective cohort study included 157 children infected with SARS-CoV-2 and their 540 household contacts. The attack rate among household contacts was 24.6% (133/540). Overall, vaccine effectiveness among household contacts was 39% (95% confidence interval [CI]: -1 to -63), higher among males than females and higher in adults aged >40 years. COVID-19 transmission was greater among female household contacts compared with males (aRR: 1.35, 95% CI: 0.94 to 1.95), although not statistically significant, and highest among those aged 19–39 years (aRR: 2.51, 95% CI: 1.50 to 4.21). Fully vaccinated household contacts had significantly lower infection risk (aRR: 0.46, 95% CI: 0.26 to 0.84). Discussion: We found substantial onward transmission of SARS-CoV-2 from schoolchildren to household members, and older people were more likely to be protected by vaccination. We recommend that schoolchildren and all household members living with schoolchildren receive at least two doses of a COVID-19 vaccine. Recognizing the role of schoolchildren in the onward transmission of COVID-19 is an important lesson learned by Viet Nam that can help not only in managing other outbreaks but also in protecting schoolchildren by predicting the progress of the outbreak and preparing for a timely response.

Objectives: Online misinformation has reached unprecedented levels during the coronavirus disease 2019 (COVID-19) pandemic. This study analyzed the magnitude and sentiment dynamics of misinformation and unverified information about public health interventions during a COVID-19 outbreak in Da Nang, Vietnam, between July and September 2020. Methods: We analyzed user-generated online information about five public health interventions during the Da Nang outbreak. We compared the volume, source, sentiment polarity, and engagements of online posts before, during, and after the outbreak using negative binomial and logistic regression, and assessed the content validity of the 500 most influential posts. Results: Most of the 54,528 online posts included were generated during the outbreak (n = 46,035; 84.42%) and by online newspapers (n = 32,034; 58.75%). Among the 500 most influential posts, 316 (63.20%) contained genuine information, 10 (2.00%) contained misinformation, 152 (30.40%) were non-factual opinions, and 22 (4.40%) contained unverifiable information. All misinformation posts were made during the outbreak, mostly on social media, and were predominantly negative. Higher levels of engagement were observed for information that was unverifiable (incidence relative risk [IRR] = 2.83; 95% confidence interval [CI], 1.33–0.62), posted during the outbreak (before: IRR = 0.15; 95% CI, 0.07–0.35; after: IRR = 0.46; 95% CI, 0.34-0.63), and with negative sentiment (IRR = 1.84; 95% CI, 1.23–2.75). Negatively toned posts were more likely to be misinformation (odds ratio [OR] = 9.59; 95% CI, 1.20–76.70) or unverified (OR = 5.03; 95% CI, 1.66–15.24). Conclusions Misinformation and unverified information during the outbreak showed clustering, with social media being particularly affected. This indepth assessment demonstrates the value of analyzing online “infodemics” to inform public health responses.

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.

BACKGROUND: In order to provide essential scientific evidence on the population's health status and social health determinants as well as the current capacity of the health care system in Vietnam to health policy makers and managers, Vietnam Ministry of Health, Hanoi University of Public Health, Hanoi Medical University, and Ho Chi Minh University of Medicine and Pharmacy collaborated with Seoul National University (Korea) and conducted a health system survey in the Quoc Oai district (of Hanoi capital) that represented northern rural Vietnam. METHODS: The study design was a cross-sectional study. The survey covered different topics (more than 200 questions) and was administered in three separate questionnaires: 1) Basic information of all household members; 2) Household characteristics; and 3) Individual characteristics. Socio-demographic characteristics among the households and individuals were collected from 2,400 households sampled by multi-stage cluster sampling method: more than 200 questions. RESULTS: The household size of Quoc Oai was larger than the national average and there was no significant difference in gender composition. In addition, the proportions of pre-elderly, age 55–64, and elderly group (65 years old and over) were higher than the national population statistics. In this context, demographic transition has begun in Quoc Oai. CONCLUSION: This study design description provides the basic information about a baseline survey of a future prospective cohort (as a part of a collaborative project on strengthening the health system in Vietnam) to the prospective data user of this survey.
Aged ; Cohort Studies ; Cross-Sectional Studies ; Delivery of Health Care ; Family Characteristics ; Health Policy ; Humans ; Methods ; Pharmacy ; Population Characteristics ; Population Dynamics ; Prospective Studies ; Public Health ; Seoul ; Surveys and Questionnaires ; Vietnam

Introduction: Mycobacterium tuberculosis resists rifampicin (RIF) because of mutations in the rpoB (the p subunit of RNA polymerase) gene, mostly in the 81 bp region. \r\n', u'Objectives: Identify the frequency and characteristics relative to drug - resistant rpoB gene mutation in RIF - resistant M. tuberculosis strains. \r\n', u'Subjects and method: 40 M. tuberculosis strains including 11 RIF - sensitive strains and 29 RIF - resistant strains. Some bio molecular techniques were used such as extracting mycobacterial DNA, PCR, cloning, sequencing and analyzing mutation related RIF - resistance on rpoB gene. \r\n', u'Results: No mutation was found on the 81 bp region of rpoB gene of the RIF - sensitive M. tuberculosis strains. The rate of mutation on rpoB gene of 29 RIF - resistant M. tuberculosis strains is 96.6%. We found 12 mutation codon positions on the 81 bp region of the rpoB gene, and the mutation codon positions with high frequency were 531 (51.7%) and 526 (31%). The mutation position found in only one strain is codon 519 (3.4%) but not found in other reports. There are 15 types of drug resistant mutations in which TCG531 TCG is the most common with 50%. Multi - drug resistance was seen in mutable and none mutable cases, with all codon positions and mutable forms. \r\n', u'Conclusion: No mutation was found on the 81 bp region of the rpoB gene of RtF - sensitive M. tuberculosis strains. The rate of mutation on the rpoB gene of RIF - resistant M. tuberculosis strains is 96.6%. The new mutation position found is codon 519. The mutation on the rpoB gene does not determine the multi - drug resistance of M. tuberculosis. \r\n', u'
Mutation ; rpoB gene ; Rifampicin - resistant M. tuberculosis

Background: Facing urgent requirements of the rapid diagnosis of tuberculosis nowadays, our laboratory have improved the multiple PCR for 3 target genes spontaneously (IS 1081, IS 6110, 23S rDNA) and developed into the multiplex PCR kit to improve the effects of diagnosis of tuberculosis. Objective: To evaluate the multiplex PCR kit for the 3 target genes (IS 1081, IS 6110, 23S rDNA) for the diagnosis of tuberculosis on standard panel and clinical specimens. Subjects and method: DNA extracted from M. tuberculosis strains and clinical specimens were amplified by multiplex PCR kit, comparison with singleplex PCR for each target gene. Results: On standard panel, sensitivity and specificity reached 100% and detected limitation was 100 fg DNA template (about 3 M. tuberculosis cells). Multiplex PCR kit detected 195/307 (63.52%) suspected clinical specimens compared with singleplex PCR which detected 106/307 (34.53%) for IS 1081, 182/307 (59.82%) for IS 6110 and 136/307 (44.30%) for 23S rDNA. Conclusions: PCR amplification with one target gene was insufficient for diagnosis of the tuberculosis strains in Viet Nam. Multiplex PCR kit for 3 target genes simultaneously (IS 1081, IS 6110, 23S rDNA) could detect all tuberculosis strains.
Tuberculosis ; PCR

Background: In 24 years, Expanded Programe on Immunization\r\n', u'(EPI) at Thua Thien Hue province achieve high efficiency, reduce remarkably infection rate of children disease in EPI. Objectives: Assessment of instruments and cold chain at City, District Health Center and Commune Health station. Assessment of knowledge and practice EPI of medical officers in districts and communes. Subjects and method: Instrument, cold chain system and officers at City, District Health Center and Commune Health station. Method: Cross-section descriptive study; Observe instruments and cold chain at Health stations and fill in available forms. Interview medical officers, observe practical manipulation and fill in available forms. Results: The rate of good knowledge varied from 61,64% to 94,55% and the rate of appropriate practice was from 45,70% to 80,92%. On average, each commune health station had 0,421 refrigeration; 0,128 ice cabinet; 0,258 cold box; 2,259 thermoses; 6,623 ice packs; 2,826 thermometers and11,321 safe boxes. All commune health stations have vaccine containing thermos; one station has no thermometer; two have no safe box and five have no ice pack. Conclusion: All commune health stations have essential instruments, cold chain. Very few health station lack of one or some types. Medical officers almost have basic knowledge about expandedimmunization, the rate of answering right theoretical questions from 61,64% to 94,55%. Practical manipulation had still many errors, rate of manipulation right only 45,70% to 80,92%. District officers manipulated right higher than commune officers.\r\n', u'
Refrigeration/ instrumentation ; Vaccination/ instrumentation ; mortality ; methods ; Health Knowledge ; Attitudes ; Practice ;

Background: Hue city is a cultural and tourism center of The middle and the whole country. Beside developing tourism services, food processing establishments, traditional specialities, eating and drinking services especially street food services more and more develop plentifully and multiform, satisfy daily demand of consumers. Objectives: Assessment on improvement level on some targets of street food safety and hygiene after 2 years intervention. Subjects and method: All street food processing establishments in 3 wards: V\u0129nh Ninh, Ph\xfa H\u1ed9i, V\ufffd?D\ufffd?of Hue city. Method: Cross-sectional study with comparison before and after intervention. Results: Kitchen utensils samples have met hygiene requirements and the proportion of food samples without borax both increase. The infection rate of bacteria in cook\ufffd?hands, kitchen utensils, cooked food were improved after 2 years carried out targeted model. Clean water for processing street food have not enough although 100% households use running water. The proportion of people were trained about food safety and hygiene knowledges and health examination increase. The situation of using food colourings and poisonous additives decrease remarkably. Salesclerks have more consciousness of preserving and covering food. 86,4% of food processing establishments have recycle bins obtain requirement to reduce polluted food. Conclusion: Street food is an important stage of food supplying network in 3 wards above. Somewhere having interest of Government and local authorities, Steering committee have efficient activities street food model develop conveniently.
Food Safety/ methods

Background: With the development of HIV/AIDS pandemic in community, amount of HIV/AIDS people more and more increase in prison. Objectives: Determine the rate of HIV/AIDS infection of prisoners at Binh Dien prison. Learning about related elements to HIV/AIDS infection. Subjects and method: Prisoners at Binh Dien prison. Method: 492 prisoners were chosen, interviewed directly and taken blood samples to HIV test. Using cross-sectional study on accidental samples. Techniques were used in this study: SERODIA-HIV and ELISA technique. Results: The rate of current HIV/AIDS infections was 21,74%, some HIV/AIDS related factors in the prison included sex, religion, income source, marrital status, common knowledge of HIV/AIDS, drug addiction history, needle sharing, sexually transmitted disease history, body tatoos and forskin inserted with metal balls, alcohol and beer drinking history, some factors such as: age and educational level were not associated with HIV/AIDS infection in prison. Conclusion: Strengthen interventional activities in prison to prevent HIV/AIDS spread between prisoners. To prisoners who were not infected HIV/AIDS: strengthen educational communication to they may prevent themselves from HIV/AIDS infection behaviors. To HIV/AIDS prisoners: Need to educate and consult especially to they have right behaviors, prevent HIV/AIDS spread for the others while they were in prison as well as they return to society.
HIV Infections/ blood ; complications ; epidemiology ;

Background: The combination medical between army and pepople in protection, healthcare for people and army in the whole country was a great policy of The Party and State. Objectives: Evaluate result of combination between armed forces in epidemic control and preventive medicine programs at mountainous and coastal areas of Thua Thien Hue in 2006. Studying knowledge, attitude, practice of army medical officers and men canvassed masses about epidemic control and preventive medicine programs. Subjects and method: Officers, men, army medical officers in 41 communes (28 coastal communes and 13 mountainous communes) of 5 district have combination medical between army and pepople. Using epidemiology method to description, analysis, cross-sectional study. Results: In 2006, home-flies spraying was carried out in 18 out of 20 markets; 1,030 all size restaurants and 18 residential areas of 5 districts. The number of chemically treated latrines in high epidemic areas was accounted fof 15,1%. A population-based latrine construction project was initiated to build 838 new latrines, contributing to minimize the invironmental pollution. 9,17% of waterwells and water tanks were hygienically treated; 11,434 people used clean water source; and 46,436 people washed their hands with soap. Studying knowledge, attitude, practice on preventive medicine programs of army medical officers showed very good results. Conclusion: The combination medical between army and pepople in preventive medicine, epidemic control gave wide efficiency for mountainous and coastal communes of Thua Thien Hue. It actively supported for Health station of 28 coastal communes and 13 mountainous communes in preventive medicine work.
Community Health Services/ ethics ; manpower ; Health Knowledge ; Attitudes ; Practice ;