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.

After-action reviews (AARs) are a qualitative evaluation methodology conducted after a public health event recommended by the World Health Organization. Of 86 screened articles, we identified eight using AARs to evaluate public health responses to infectious disease outbreaks. Our findings suggested the toolkit is suitable to evaluate responses to infectious disease outbreaks but needs to be adapted for use in particular settings.

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.

Ischemic colitis (IC) is an underreported chronic disease characterized by the hypoperfusion of the bowel mucosa. The diagnosis and treatment may be challenging because its clinical course resembles other colitis or even colorectal malignancies. This paper reports an untypical case to underline the diversity of IC manifestation. A 68-year-old man with several comorbidities was admitted because of abdominal pain with a 6-month duration and a mass in the left lower quadrant. Colonoscopy revealed erosive pseudomembranous colitis narrowed colon segments with ulcerated mucosa mimicking colorectal cancer and inflammatory bowel disease. The stool cultures and Clostridium difficile toxin tests were negative. After the failure of conservative therapy, the Hartmann procedure with temporary ileostomy was performed uneventfully. The histological results of the surgical specimens revealed IC with focal pseudomembranous areas.

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.

Objectives: Asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and test re-positivity after a negative test have raised concerns about the ability to effectively control the coronavirus disease 2019 (COVID-19) pandemic. We aimed to investigate the prevalence of COVID-19 asymptomatic and pre-symptomatic infections during the second wave of COVID-19 in Viet Nam, and to better understand the duration of SARS-CoV-2 infection and the dynamics between the evolution of clinical symptoms and SARS-CoV-2 test positivity among confirmed COVID-19 cases. Methods: We conducted a cohort analysis on the first 50 confirmed cases during the second COVID-19 wave in Viet Nam using clinical, laboratory and epidemiological data collected from 9 March to 30 April 2020. Kaplan-Meier estimates were used to assess time to clearance of SARS-CoV-2 infection, and log-rank tests were used to explore factors related to time to SARS-CoV-2 infection clearance. Results: Most cases (58%) had no typical signs or symptoms of COVID-19 at the time of diagnosis. Ten cases (20%) were re-positive for SARS-CoV-2 during infection. Eight cases (16%) experienced COVID-19 symptoms after testing negative for SARS-CoV-2. The median duration from symptom onset until clearance of infection was 14 days (range: 6–31); it was longer in re-positive and older patients and those with pre-existing conditions. Conclusion Asymptomatic and pre-symptomatic infections were common during the second wave of COVID-19 in Viet Nam. Re-positivity was frequent during hospitalization and led to a long duration of SARS-CoV-2 infection.

Background: Streptococcus pneumonia (S.pneumoniae) is the main cause of acquired pneumonia in the community along with otitis media, sinusitis, septicemia and meningitis. Objectives: The study determined antimicrobial resistance and serotype distribution of Streptococcus pneumonia isolates from hospitalized children at Hai Phong Children's Hospital, Vietnam. Subjects and method: From June 2006 to September 2007, 80 pneumococccal isolates were tested for susceptibility to the 13 antibiotics and 84 pneumococcal isolates were serotyped. Results:Seventy-five percent of strains showed multi-drug resistance. Ninety percent of strains showed resistance to penicillin (48% intermediate and 42% fully resistant). In addition, 100% of isolates were resistant to cotrimoxazole, 74% of isolates were resistant to cephalexin; 71 % of isolates were resistant to erythroomycin and 58% were resistant to cefuroxxime. Almost all the isolates were susceptible to amoxicillin, cefotaxime, ceftriaxone, ceefepime, ofloxacin and 100% of isolates were susceptible to vancomycin. Among the 84 serotypes, 82% were included in the 23 valent pneumococcal polysaccharide vaccine including: 19F (30%), 23F (21 %), 14 (13%) and 6B (13%). Six other serotypes (13, 15C, 18, 11A, 15B and 6A) accounted for 12% of strains and 9 (11%) strains were untypeable. Conclusion: Pneumococcal antibiotics is spreading most rapidly among children in Vietnam, especially strains typs 19F and 23 F. Concerted efforts are necessary to prevent it spreading.\r\n", u'\r\n', u'
Antimicrobial resistance ; streptococcus pneumonia

Background: Hepatitis B is an infectious illness caused by hepatitis B virus (HBV) which infects the liver of hominoidea, including humans, and causes an inflammation called hepatitis. Objectives: The aim of study is to clarify clinical features and molecular characteristics of HBV in chronic HBV-infected patients with A 1899 mutation. Subjects and method: HBV genotype, HBV-ONA level, HBeAg and anti-HBe in 29 chronic HBV-infected patients were determined by PCR-RFLP, Real-time PCR and ELISA, respectively. Mutations were analyzed by direct sequencing. Results: Mutations in core-promoter/precore regions of HBV genome can suppress HBeAg secretion and stimulate HBV-ONA replication. The prevalence of hepatocel- lular carcinoma (HCc): 10/29, liver cirrhosis (LC) : 15/29 are significantly higher than that in chronic hepatitis (CH) : 4/29 (P < 0.001). HbeAg seroconversion rate in CH (75%) is higher than that in HCC \r\n', u'(40%) and in LC (53.3%), but not significant (P > 0.05). ALT level is the highest in CH and the lowest in HCC \r\n', u'(P = 0.02), 8/10 (80%) HCC patients have normal range of ALT. HBV-ONA level in HCC and in LC is significantly higher than that in CH (P = 0.024). The emerging of A 1899 is often accompanied by C/G1753 mutation (37.9%) and dual core-promoter mutation T1762A1764 (79.3%). Conclusion: A1899 mutation can play a role in the pathogenesis of liver diseases in chronic HBV-infected Vietnamese.\r\n', u'
Hepatitis B virus/ growth & ; development ; physiology ; Hepatitis B ; Chronic/ pathology ; transmission

Background: Hepatocellular carcinoma (HCC) is the most common primary hepatic tumor and one of the most common cancers worldwide. HCC is a primary malignancy of hepatocellular origin. Objectives:The aim of study is to combinate therapy of transarterial chemoembolization and percutaneousethanol injection afterward emerging metatasis caused by fine needle aspiration cytology. Subjects and method: A 50 years old male patient with hepatocellular carcinoma having a diameter of tumor more than 5 cm was treated by combination of transarterial chemoembolization and percutaneous ethanol injection from December 2000. Results & Conclusion: Results of study showed that: Transarterial chemoembolization and percutaneous ethanol injection are the two of non-surgical methods for treatment of hepatocellular carcinoma which are most commonly available in applied clinical activities at present. Up to now, the patient's life expectancy after therapy is more than 6 years that means the result of treatment is very good. However, the emerging metatasis into the anterior-right-Iower chest wall that was caused by fine needle aspiration cytology should be reviewed for further evaluating clinical experience, especially in cases with quite clear imaging features of untrasonography and significantly elevated AFP level higher than 200 ng/rnl.
Carcinoma ; Hepatocellular/ pathology ; therapy

Background: Detection of BCR/ABL fusion gene has important significance in diagnosing and monitoring response to therapy in chronic myeloid leukemia. Objective: Application of FISH (Fluorescence In Situ Hybrydization) technique for detection of abl/bcr fusion gene in chronic myelogenous leukemia. Subjects and methods: The study included 10 patients of chronic myelogenous leukemia diagnosed by methods of morphology and cell chemistry. Peripheral blood and bone marrow samples of them were analyzed Philadelphia (Ph1) chromosome by cytogenetic technique. Among them, 5 patients were tested by FISH technique on the slide of interphase and remainders were tested by FISH technique on the slide of metaphase cell. Results: Results of analyzing chromosome of 10 patients showed that 8 patients had Ph1 chromosome. 2 patients without Ph1 chromosome were patients who had not high of leukocyte count: 28x109leukocyte/l and 36x109leukocyte/l, respectively. In the FISH on the slide of interphase, all 5 patients had Ph1 chromosome and abl/bcr fusion gene. In the FISH on the slide of metaphase cell, 3 patients had Ph1 chromosome and abl/bcr fusion gene. Conclusion: FISH technique has been applied successfully to detect ABL/BCR gene in patients with chronic myelogenous leukemia.\r\n', u'\r\n', u'
Leukemia ; Myelogenous ; Chronic ; BCR-ABL Positive/ pathology