Genetic diversity of G9, G3, G8 and G1 rotavirus group A strains circulating among children with acute gastroenteritis in Vietnam from 2016 to 2021.

Rotavirus group A (RVA) is the most common cause of severe childhood diarrhea worldwide. The introduction of rotavirus vaccination programs has contributed to a reduction in hospitalizations and mortality caused by RVA. From 2016 to 2021, we conducted surveillance to monitor RVA prevalence and genotype distribution in Nam Dinh and Thua Thien Hue (TT Hue) provinces where a pilot Rotavin-M1 vaccine (Vietnam) implementation took place from 2017 to 2020. Out of 6626 stool samples, RVA was detected in 2164 (32.6%) by ELISA. RT-PCR using type-specific primers were used to determine the G and P genotypes of RVA-positive specimens. Whole genome sequences of a subset of 52 specimens randomly selected from 2016 to 2021 were mapped using next-generation sequencing. From 2016 to 2021, the G9, G3 and G8 strains dominated, with detected frequencies of 39%, 23%, and 19%, respectively; of which, the most common genotypes identified were G9P[8], G3P[8] and G8P[8]. G1 strains re-emerged in Nam Dinh and TT Hue (29.5% and 11.9%, respectively) from 2020 to 2021. G3 prevalence decreased from 74% to 20% in TT Hue and from 21% to 13% in Nam Dinh province between 2017 and 2021. The G3 strains consisted of 52% human typical G3 (hG3) and 47% equine-like G3 (eG3). Full genome analysis showed substantial diversity among the circulating G3 strains with different backgrounds relating to equine and feline viruses. G9 prevalence decreased sharply from 2016 to 2021 in both provinces. G8 strains peaked during 2019-2020 in Nam Dinh and TT Hue provinces (68% and 46%, respectively). Most G8 and G9 strains had no genetic differences over the surveillance period with very high nucleotide similarities of 99.2-99.9% and 99.1-99.7%, respectively. The G1 strains were not derived from the RVA vaccine. Changes in the genotype distribution and substantial diversity among circulating strains were detected throughout the surveillance period and differed between the two provinces. Determining vaccine effectiveness against circulating strains over time will be important to ensure that observed changes are due to natural secular variation and not from vaccine pressure.

Spatial Analysis of Drug-Susceptible and Multidrug-Resistant Cases of Tuberculosis, Ho Chi Minh City, Vietnam, 2020-2023.

We characterized the spatial distribution of drug-susceptible (DS) and multidrug-resistant (MDR) tuberculosis (TB) cases in Ho Chi Minh City, Vietnam, a major metropolis in southeastern Asia, and explored demographic and socioeconomic factors associated with local TB burden. Hot spots of DS and MDR TB incidence were observed in the central parts of Ho Chi Minh City, and substantial heterogeneity was observed across wards. Positive spatial autocorrelation was observed for both DS TB and MDR TB. Ward-level TB incidence was associated with HIV prevalence and the male proportion of the population. No ward-level demographic and socioeconomic indicators were associated with MDR TB case count relative to total TB case count. Our findings might inform spatially targeted TB control strategies and provide insights for generating hypotheses about the nature of the relationship between DS and MDR TB in Ho Chi Minh City and the wider southeastern region of Asia.

Invasive meningococcal disease in Malaysia, Philippines, Thailand, and Vietnam: An Asia-Pacific expert group perspective on current epidemiology and vaccination policies.

Invasive meningococcal disease (IMD) imposes a significant burden on the global community due to its high case fatality rate (4-20%) and the risk of long-term sequelae for one in five survivors. An expert group meeting was held to discuss the epidemiology of IMD and immunization policies in Malaysia, Philippines, Thailand, and Vietnam. Most of these countries do not include meningococcal immunization in their routine vaccination programs, except for high-risk groups such as immunocompromised people and pilgrims. It is difficult to estimate the epidemiology of IMD in the highly diverse Asia-Pacific region, but available evidence indicate serogroup B is increasingly dominant. Disease surveillance systems differ by country. IMD is not a notifiable disease in some of them. Without an adequate surveillance system in the region, the risk and the burden of IMD might well be underestimated. With the availability of new combined meningococcal vaccines and the World Health Organization roadmap to defeat bacterial meningitis by 2030, a better understanding of the epidemiology of IMD in the Asia-Pacific region is needed.

Hydatid disease (Echinococcosis granulosis) diagnosis from skeletal osteolytic lesions in an early seventh-millennium BP forager community from preagricultural northern Vietnam.

OBJECTIVES: Con Co Ngua is a complex, sedentary forager site from northern Vietnam dating to the early seventh millennium BP. Prior research identified a calcified Echinococcus granulosis cyst, which causes hydatid disease. Osteolytic lesions consistent with hydatid disease were also present in this individual and others. Hydatid disease is observed in high frequencies in pastoralists, and its presence in a hunter-gatherer community raises questions regarding human-animal interaction prior to farming. The objective of this article is to identify and describe the epidemiology of hydatid disease in the human skeletal assemblage at Con Co Ngua. MATERIALS AND METHODS: One hundred and fifty-five individuals were macroscopically assessed for lesions. Of these, eight individuals were radiographed. Hydatid disease was diagnosed using a new threshold criteria protocol derived from clinical literature, which prioritizes lesions specific to the parasite. RESULTS: Twenty-two individuals (14.2%) presented with osteolytic lesions consistent with hydatid disease, affecting the distal humerus, proximal femur and forearm, and pelvis. Seven individuals radiographed (4.5%) had multilocular cystic lesions strongly diagnostic for hydatid disease. All probable cases had lesions of the distal humerus. The remaining lesions were macroscopically identical to those radiographed and were considered possible cases. DISCUSSION: While hydatid disease has previously been found in pre-agricultural communities, the high prevalence at Con Co Ngua is non-incidental. We propose that the presence of wild canids and management of wild buffalo and deer increased the risk of disease transmission. These findings further reveal subsistence complexity among hunter-gatherers living millennia prior to the adoption of farming in Southeast Asia.

Mosquito Larvicidal Activity of the Essential Oil of Zingiber collinsii against Aedes albopictus and Culex quinquefasciatus.

The chemical composition and larvicidal activity of essential oils from the leaves and rhizomes of Zingiber collinsii Mood & Theilade (Zingiberaceae) were reported. The main compounds in the leaf oil were α-pinene (25.6%), ß-caryophyllene (16.8%), ß-pinene (16.1%) and bicyclogermacrene (6.9%) while the rhizome oil consist mainly of camphene (22.5%), ß-pinene (16.3%), α-pinene (9.0%) and humulene oxide II (9.0%). The rhizome oil demonstrated larvicidal effects towards fourth instant larvae of mosquito vectors. The highest mortality (100%) was observed at 24 h exposure against Aedes albopictus (concentration 100 µg/mL) and 48 h (concentration of 50 and 100 µg/mL), while the highest mortality (100%) was observed for Culex quinquefasciatus at 24 h and 48 h at concentration of 100 µg/mL. The 24 h mosquito larvicidal activity of the rhizome oil against Ae. albopictus were LC50 = 25.51 µg/mL; LC90 = 40.22 µg/mL and towards Cx. quinquefasciatus with LC50 = 50.11 µg/mL and LC90 = 71.53 µg/mL). However, the 48 h larvicidal activity were LC50 = 20.03 µg/mL and LC90 = 24.51 µg/mL (Ae. albopictus), as well as LC50 = 36.18 µg/mL and LC90 = 55.11 µg/mL (Cx. quinquefasciatus). On the other hand, no appreciable mortality and larvicidal activity was observed for the leaf oil. The larvicidal activity of the essential oils of Z. collinsii was being reported for the first time.

Validation of the Job Content Questionnaire among hospital nurses in Vietnam.

OBJECTIVES: The aim of this study was to examine the reliability and validity of the Job Content Questionnaire (JCQ) in Vietnamese among hospital nursing staff. METHODS: The 22-items version of the JCQ was used. This includes four scales: (a) psychological demands (5 items); (b) job control (9 items); (c) supervisor support (4 items); and (d) coworker support (4 items). All 1258 nurses in a general hospital in Vietnam, excluding 11 who were due to retire, were invited to complete the cross-sectional survey. The internal consistency reliability was estimated using Cronbach's α. Construct validity was examined using exploratory factor analysis (EFA). Convergent validity was evaluated by calculating correlations between the JCQ scores and DASS 21 and overtime work. RESULTS: In total, 949 (75%) of the 1258 eligible nurses completed the survey. Cronbach's α values demonstrated acceptable internal consistency in two scales (supervisor support α = .87; coworker support α = .86), while Cronbach's α was below the acceptable threshold of 0.70 for job control (α = .45) and job demand (α = .50). EFA assuming a four-factor structure showed a factor structure that was almost identical to the original JCQ, with two items loading on other scales. The subscales of depression, anxiety, and stress response of DASS 21 and the subscales of JCQ were significantly correlated, as expected. CONCLUSION: The results suggest that the JCQ in Vietnamese can be used with some reliability and validity for examining psychosocial work environment among nurses. Further studies should be done to confirm and expand our findings in a variety of occupational groups and in other Asian low- and middle-income countries.

Deficiency in the amino aldehyde dehydrogenase encoded by GmAMADH2, the homologue of rice Os2AP, enhances 2-acetyl-1-pyrroline biosynthesis in soybeans (Glycine max L.).

2-Acetyl-1-pyrroline (2AP), the volatile compound that provides the 'popcorn-like' aroma in a large variety of cereal and food products, is widely found in nature. Deficiency in amino aldehyde dehydrogenase (AMADH) was previously shown to be the likely cause of 2AP biosynthesis in rice (Oryza sativa L.). In this study, the validity of this mechanism was investigated in soybeans (Glycine max L.). An assay of AMADH activity in soybeans revealed that the aromatic soybean, which contains 2AP, also lacked AMADH enzyme activity. Two genes, GmAMADH1 and GmAMADH2, which are homologous to the rice Os2AP gene that encodes AMADH, were characterized. The transcription level of GmAMADH2 was lower in aromatic varieties than in nonaromatic varieties, whereas the expression of GmAMADH1 did not differ. A double nucleotide (TT) deletion was found in exon 10 of GmAMADH2 in all aromatic varieties. This variation caused a frame-shift mutation and a premature stop codon. Suppression of GmAMADH2 by introduction of a GmAMADH2-RNAi construct into the calli of the two nonaromatic wild-type varieties inhibited the synthesis of AMADH and induced the biosynthesis of 2AP. These results suggest that deficiency in the GmAMADH2 product, AMADH, plays a similar role in soybean as in rice, which is to promote 2AP biosynthesis. This phenomenon might be a conserved mechanism among plant species.

Smoking media literacy in Vietnamese adolescents.

BACKGROUND: Smoking media literacy (SML) has been found to be independently associated with reduced current smoking and reduced susceptibility to future smoking in a sample of American adolescents, but not in other populations of adolescents. Thus, the purpose of this study was to assess SML in Vietnamese adolescents and to determine the association with smoking behavior and susceptibility to future smoking. METHODS: A cross-sectional survey of 2000 high school students completed the SML scale, which is based on an integrated theoretical framework of media literacy, and items assessing cigarette use. Ordinal logistic regression was used to determine the association of SML with smoking and susceptibility to future smoking. Ordinal logistic regression was also to determine whether smoking in the past 30 days was associated with the 8 domains/core concepts of media literacy which comprise the SML. RESULTS: Smoking media literacy was lower among the Vietnamese adolescents than what has been previously reported in American adolescents. Ordinal logistic regression analysis results showed that in the total sample SML was associated with reduced smoking, but there was no association with susceptibility to future smoking. Further analysis showed that results differed according to school and grade level. There did not appear to be association of smoking with the specific domains/concepts that comprise the SML. CONCLUSIONS: The association of SML with reduced smoking suggests the need for further research involving SML, including the testing of media literacy training interventions, in Vietnamese adolescents and also other populations of adolescents.

High mortality during tuberculosis treatment does not indicate long diagnostic delays in Vietnam: a cohort study.

BACKGROUND: Delay in tuberculosis diagnosis and treatment initiation may increase disease severity and mortality. In evaluations of tuberculosis control programmes high fatality rates during tuberculosis treatment, are used as an indicator of long delays in low HIV-prevalence settings. However, data for this presumed association between delay and fatality are lacking. We assessed the association between diagnostic delay and mortality of new smear-positive pulmonary tuberculosis patients in Vietnam. METHODS: Follow-up of a patient cohort included in a survey of diagnostic delay in 70 randomly selected districts. Data on diagnosis and treatment were extracted from routine registers. Patients who had died during the course of treatment were compared to those with reported cure, completed treatment or failure (survivors). RESULTS: Complete data were available for 1881/2093 (89.9%) patients, of whom 82 (4.4%) had died. Fatality was 4.5% for patients with < or = 4 weeks delay, 5.0% for 5- < or = 8 weeks delay (aOR 1.11, 95%CI 0.67-1.84) and 3.2% for > 9 weeks delay (aOR 0.69, 95%CI 0.37-1.30). Fatality tended to decline with increasing delay but this was not significant. Fatality was not associated with median diagnostic delay at district level (Spearman's rho = -0.08, P = 0.5). CONCLUSION: Diagnostic delay is not associated with treatment mortality in Vietnam at individual nor district level, suggesting that high case fatality should not be used as an indicator of long diagnostic delay in national tuberculosis programmes.

Mortality and failure among tuberculosis patients who did not complete treatment in Vietnam: a cohort study.

BACKGROUND: Tuberculosis treatment failure and death rates are low in the Western Pacific Region, including Vietnam. However, failure or death may also occur among patients who did not complete treatment, i.e. reported as default or transfer-out. We aimed to assess the proportion failures and deaths among new smear-positive pulmonary tuberculosis patients with reported default or transfer-out. Treatment outcomes rates were 1.4% default, 3.0% transfer-out, 0.4% failure and 2.6% death in northern Vietnam in 2003. METHODS: Tuberculosis patients in 32 randomly selected district tuberculosis units in northern Vietnam were followed up 1 to 3 years after treatment initiation for survival, recent treatment history and bacteriologically confirmed tuberculosis. RESULTS: Included were 85 transferred patients and 42 who defaulted. No information was available of 41 (32%), 28 (22%) had died. Fifty-eight were available for follow-up (46%); all had sputum smear results. Tuberculosis was recorded in 11 (13%), including 6 (7%) with positive sputum smears, 3 (3%) with negative smears but positive culture and 2 (2%) who had started re-treatment for bacteriologically confirmed tuberculosis. Fifteen (17%, 95%CI 10-27%) had died within 8 months after treatment initiation. Of 86 patients with known study outcomes, 39 (45%, 95%CI 35-56%) had died or had bacteriologically confirmed tuberculosis. This was recorded for 29/53 (55%, 95%CI 40-68%) transferred patients and 10/33 (30%, 95%CI 16-49%) patients who defaulted. CONCLUSION: The total failure and death rates are 0.6% and 0.8% higher than based on routine reporting in northern Vietnam. Although this was a large proportion of treatment failures and deaths, failure and death rates were low. Defaulting and transfer carry a high risk of failure and in particular death.

Delays in the diagnosis and treatment of tuberculosis patients in Vietnam: a cross-sectional study.

BACKGROUND: Treatment delay is an important indicator of access to tuberculosis diagnosis and treatment. Analyses of patient delay (i.e. time interval between onset of symptoms and first consultation of a health care provider) and health care delay (i.e. time interval between first consultation and start of treatment) can inform policies to improve access. This study assesses the patient, health care provider and total delay in diagnosis and treatment of new smear-positive pulmonary tuberculosis patients, and the risk factors for long delay, in Vietnam. METHODS: A cross-sectional survey of new patients treated by the National Tuberculosis Control Programme was conducted in 70 randomly selected districts in Vietnam. All consecutively registered patients in one quarter of 2002 were interviewed using a pre-coded structured questionnaire. RESULTS: Median (range) delay was 4 weeks (1-48) for total, 3 (1-48) weeks for patient and 1 (0-25) week for health care delay. Patients with long total delay (> or = 12 weeks, 15%) accounted for 49% of the cumulative number of delay-weeks. Independent risk factors (p < 0.05) for long total delay were female sex, middle age, remote setting, residence in the northern or central area, and initial visit to the private sector. For long patient delay (> or = 6 weeks) this was female sex, belonging to an ethnic minority, and living at > 5 km distance from a health facility or in the northern area. For long health care delay (> or = 6 weeks) this was urban setting, residence in the central area and initial visit to a communal health post, TB hospital or the private sector. CONCLUSION: Analyses of patient and treatment delays can indicate target groups and areas for health education and strengthening of the referral system, in particular between the private sector and the NTP.

Antituberculosis drug resistance in the south of Vietnam: prevalence and trends.

BACKGROUND: There is limited evidence that the DOTS (directly observed therapy, short course) strategy for tuberculosis (TB) control can contain the emergence and spread of drug resistance in the absence of second-line treatment. We compared drug-resistance levels between 1996 and 2001 in the south of Vietnam, an area with a well-functioning DOTS program. METHODS: Sputum specimens were collected from consecutively diagnosed patients with smear-positive TB at 40 randomly selected public TB clinics. Mycobacterium tuberculosis isolates were tested for susceptibility to first-line drugs. RESULTS: Among 888 new patients in 2001, resistance to any drug was observed in 238 (26.3%), resistance to isoniazid was observed in 154 (16.6%), resistance to rifampin was observed in 22 (2.0%), resistance to ethambutol was observed in 12 (1.1%), resistance to streptomycin was observed in 173 (19.4%), and resistance to both isoniazid and rifampicin (multidrug resistance [MDR]) was observed in 20 (1.8% [95% confidence interval, 1.0%-3.3%]). Among 136 previously treated patients in 2001, any resistance was observed in 89 (62.9%), and MDR was observed in 35 (23.2%). The prevalence of any drug resistance and of streptomycin resistance among new patients had decreased significantly (P<.01) since 1996; there was no increase in the prevalence of MDR. CONCLUSION: The prevalence of drug resistance decreased despite high initial levels of resistance to isoniazid and streptomycin and despite the absence of second-line treatment. Therefore, a DOTS program can contain drug-resistant TB in this setting.