Glacial changes in sea level modulated millennial-scale variability of Southeast Asian autumn monsoon rainfall.

Most paleoclimate studies of Mainland Southeast Asia hydroclimate focus on the summer monsoon, with few studies investigating rainfall in other seasons. Here, we present a multiproxy stalagmite record (45,000 to 4,000 years) from central Vietnam, a region that receives most of its annual rainfall in autumn (September-November). We find evidence of a prolonged dry period spanning the last glacial maximum that is punctuated by an abrupt shift to wetter conditions during the deglaciation at ~14 ka. Paired with climate model simulations, we show that sea-level change drives autumn monsoon rainfall variability on glacial-orbital timescales. Consistent with the dry signal in the stalagmite record, climate model simulations reveal that lower glacial sea level exposes land in the Gulf of Tonkin and along the South China Shelf, reducing convection and moisture delivery to central Vietnam. When sea level rises and these landmasses flood at ~14 ka, moisture delivery to central Vietnam increases, causing an abrupt shift from dry to wet conditions. On millennial timescales, we find signatures of well-known Heinrich Stadials (HS) (dry conditions) and Dansgaard-Oeschger Events (wet conditions). Model simulations show that during the dry HS, changes in sea surface temperature related to meltwater forcing cause the formation of an anomalous anticyclone in the Western Pacific, which advects dry air across central Vietnam, decreasing autumn rainfall. Notably, sea level modulates the magnitude of millennial-scale dry and wet phases by muting dry events and enhancing wet events during periods of low sea level, highlighting the importance of this mechanism to autumn monsoon variability.

Detection of Recombinant African Swine Fever Virus Strains of p72 Genotypes I and II in Domestic Pigs, Vietnam, 2023.

African swine fever virus (ASFV) genotype II is endemic to Vietnam. We detected recombinant ASFV genotypes I and II (rASFV I/II) strains in domestic pigs from 6 northern provinces in Vietnam. The introduction of rASFV I/II strains could complicate ongoing ASFV control measures in the region.

Novel Variant and Known Mutation in 23S rRNA Gene of Mycoplasma pneumoniae, Northern Vietnam, 2023.

During a 2023 outbreak of Mycoplasma pneumoniae-associated community-acquired pneumonia among children in northern Vietnam, we analyzed M. pneumoniae isolated from nasopharyngeal samples. In almost half (6 of 13) of samples tested, we found known A2063G mutations (macrolide resistance) and a novel C2353T variant on the 23S rRNA gene.

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.

Emerging Enterovirus A71 Subgenogroup B5 Causing Severe Hand, Foot, and Mouth Disease, Vietnam, 2023.

We report on a 2023 outbreak of severe hand, foot, and mouth disease in southern Vietnam caused by an emerging lineage of enterovirus A71 subgenogroup B5. Affected children were significantly older than those reported during previous outbreaks. The virus should be closely monitored to assess its potential for global dispersal.

Therapeutic efficacy of pyronaridine-artesunate (Pyramax) in treating Plasmodium vivax malaria in the central highlands of Vietnam.

The emergence and spread of chloroquine-resistant Plasmodium vivax have necessitated the assessment of alternative blood schizonticidal drugs. In Vietnam, chloroquine-resistant P. vivax malaria has been reported. In an open-label, single-arm trial, the safety, tolerability, and efficacy of pyronaridine-artesunate (Pyramax, PA) was evaluated in Dak Nong province, Vietnam. A 3-day course of PA was administered to adults and children (≥20 kg) infected with P. vivax. Patients also received primaquine (0.25 mg/kg daily for 14 days). PA was well tolerated with transient asymptomatic increases in liver transaminases. The per-protocol proportion of patients with day 42 PCR-unadjusted adequate clinical and parasitological response was 96.0% (95% CI, 84.9%-99.0%, n = 48/50). The median parasite clearance time was 12 h (range, 12-36 h), with a median fever clearance time of 24 h (range, 12-60 h). Single nucleotide polymorphisms (SNPs) as potential genetic markers of reduced drug susceptibility were analyzed in three putative drug resistance markers, Pvcrt-o, Pvmdr1, and PvK12. Insertion at position K10 of the Pvcrt-o gene was found in 74.6% (44/59) of isolates. Pvmdr1 SNPs at Y976F and F1076L were present in 61% (36/59) and 78% (46/59), respectively. Amplification of Pvmdr1 gene (two copies) was found in 5.1% (3/59) of parasite samples. Only 5.1% (3/59) of isolates had mutation 552I of the PvK12 gene. Overall, PA rapidly cleared P. vivax blood asexual stages and was highly efficacious in treating vivax malaria, with no evidence of artemisinin resistance found. PA provides an alternative to chloroquine treatment for vivax malaria in Vietnam. CLINICAL TRIALS: This study is registered with the Australian New Zealand Clinical Trials Registry as ACTRN12618001429246.

Barriers and enablers to people-centred viral hepatitis care in Vietnam and the Philippines: Results of a patient journey mapping study.

In Vietnam and the Philippines, viral hepatitis is the leading cause of cirrhosis and liver cancer. This study aims to understand the barriers and enablers of people receiving care for hepatitis B and C to support both countries' efforts to eliminate viral hepatitis as a public health threat by 2030. Retrospective, semi-structured interviews were conducted with a purposive, quota-based sample of 63 people living with hepatitis B or C in one province of Vietnam and one region of the Philippines. A rapid deductive approach to thematic analysis produced key findings among the three phases of care: (1) pre-awareness and testing, (2) linkage and treatment initiation and (3) ongoing treatment and recovery. The research found that participants followed five typical journeys, from a variety of entry points. Barriers during the pre-awareness and testing phase included limited awareness about hepatitis and its management, stigma and psychological impacts. Enablers included being familiar with the health system and/or patients benefiting from social connections within the health systems. During the linkage and treatment initiation phase, barriers included difficult physical access, complex navigation and inadequate counselling. In this phase, family support emerged as a critical enabler. During the ongoing treatment and recovery phase, the cost of care and socially and culturally informed perceptions of the disease and medication use were both barriers and enablers. Exploring peoples' journeys with hepatitis B and C in Vietnam and the Philippines revealed many similarities despite the different cultural and health system contexts. Insights from this study may help generate a contextualized, people-centred evidence base to inform the design and improvement of primary care services for hepatitis in both research sites.

The Relationship of Preterm and Small for Gestational Age with Child Cognition During School-Age Years.

BACKGROUND: Children born preterm and/or small for gestational age (SGA) are at increased risk of poor cognitive outcomes, particularly in low and middle-income countries (LMICs). OBJECTIVES: This study aimed to examine the cognitive and academic deficits during the school-age years in children born preterm or SGA compared with those in children born term adequate for gestational age (AGA) in rural Vietnam. METHODS: Children born to women in a preconception micronutrient supplementation trial in Vietnam were classified into 3 groups: preterm AGA (n =138), term SGA (n =169), and term AGA (n = 1134). Cognitive abilities were assessed using the Wechsler Intelligence Scale for Children, measuring 4 domains [verbal comprehension index (VCI), perceptual reasoning index (PRI), working memory index (WMI), and processing speed index (PSI) scores] and full-scale intelligence quotient (FSIQ) at 6-7 and 10-11 y. Academic achievement was assessed with mathematic and language tests. Analysis of variance and multiple regression models were used to analyze differences in cognitive function and academic achievement at 6-7 and 10-11 y by birth phenotypes. RESULTS: Compared with term AGA children, those born SGA had lower cognitive scores at both 6-7 y (VCI, -2.3; PRI, -3.7; PSI -2.1; and FSIQ, -2.9) and 10-11 y (VCI, -3.7; PRI, -3.5; WMI, -2.7; PSI, -1.9; and FSIQ, -3.9). Children born SGA also had poorer academic achievement with lower language (5.3) and mathematic (2.5) scores. Adjustments for maternal factors and home environment attenuated the associations, but the differences in VCI, PRI, FSIQ, and language at 10-11 y remained significant. There were no differences in cognitive function and academic achievement between children born preterm and AGA. CONCLUSIONS: Our findings highlight the enduring association of birth phenotype on cognitive functioning and academic achievement during the school years, despite adjustments for maternal education and family environment. Further research is needed to implement effective interventions to improve birth outcomes and optimize child health and development in LMICs. The trial was registered at clinicaltrials.gov as NCT01665378 (URL: https://clinicaltrials.gov/ct2/show/NCT01665378).

A real-world cohort study of first-line afatinib in patients with EGFR-mutant advanced non-small cell lung cancer in Vietnam.

BACKGROUND: This study aimed to evaluate the efficacy and side effects of first-line afatinib treatment in a real-world setting in Vietnam. METHODS: This retrospective study was conducted across nine hospitals in Vietnam. Advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients who received afatinib as first-line therapy between April 2018 and June 2022 were included, and patient medical records were reviewed. Key outcomes were overall response rate (ORR), time-to-treatment failure (TTF), and tolerability. RESULTS: A total of 343 patients on first-line afatinib were eligible for the study. EGFR exon 19 deletion (Del19) alone was detected in 46.9% of patients, L858R mutation alone in 26.3%, and other uncommon EGFR mutations, including compound mutations, in 26.8%. Patients with brain metastases at baseline were 25.4%. Patients who received 40 mg, 30 mg, and 20 mg as starting doses of afatinib were 58.6%, 39.9%, and 1.5%, respectively. The ORR was 78.1% in the overall population, 82.6% in the Del19 mutation subgroup, 73.3% in the L858R mutation subgroup, and 75.0% in the uncommon mutation subgroup (p > 0.05). The univariate and multivariate analyses indicate that the ORR increased when the starting dose was 40 mg compared to starting doses below 40 mg (83.9% vs. 74.3%, p = 0.034). The median TTF (mTTF) was 16.7 months (CI 95%: 14.8-18.5) in all patients, with a median follow-up time of 26.2 months. The mTTF was longer in patients in the common EGFR mutation subgroup (Del19/L858R) than in those in the uncommon mutation subgroup (17.5 vs. 13.8 months, p = 0.045) and in those without versus with brain metastases at baseline (17.5 vs. 15.1 months, p = 0.049). There were no significant differences in the mTTF between subgroups based on the starting dose of 40 mg and < 40 mg (16.7 vs. 16.9 months, p > 0.05). The most common treatment-related adverse events (any grade/grade ≥ 3) were diarrhea (55.4%/3.5%), rash (51.9%/3.2%), paronychia (35.3%/5.0%), and stomatitis (22.2%/1.2%). CONCLUSIONS: Afatinib demonstrated clinical effectiveness and good tolerability in Vietnamese EGFR-mutant NSCLC patients. In our real-world setting, administering a starting dose below 40 mg might result in a reduction in ORR; however, it might not have a significant impact on TTF.

Preconception Micronutrient Supplementation Affects Maternal BMI and Body Composition Postpartum: A Randomized Controlled Trial in Vietnam.

BACKGROUND: Although there is growing evidence on the role of preconception nutrition for birth outcomes, limited evidence exists for its effects on maternal health. OBJECTIVES: This study evaluates the impact of preconception micronutrient supplementation on maternal BMI (kg/m2) and body composition at 6 to 7 y postpartum (PP). METHODS: We followed females who participated in a randomized controlled trial of preconception supplementation in Vietnam and delivered live offspring (n = 1599). Females received weekly supplements containing either 2800 µg folic acid (FA) only, 60 mg iron and 2800 µg FA (IFA), or multiple micronutrients (MMs) (15 micronutrients including IFA) from baseline until conception followed by daily prenatal IFA supplements until delivery. Height, weight, mid-upper arm circumference, triceps skinfold, and waist-hip circumference were measured at recruitment and at 1, 2, and 6 to 7 y PP. Body fat was assessed using bioelectric impedance at 6 to 7 y PP (n = 867). Group comparisons were made using analysis of variance or chi-square tests and general linear models for adjusted models. RESULTS: At 6 to 7 y PP, we found significant differences (P < 0.05) by treatment group for mean percent fat (MM: 29.2%; IFA: 27.6%; FA: 27.8%), absolute fat mass (MM: 15.1 kg; IFA: 14.0 kg; FA: 14.3 kg), and prevalence of underweight based on BMI < 18.5 (MM: 5.8%; IFA: 10.3%; FA: 14.3%). Mean BMI and triceps skinfold thickness were higher in the MM group, but these differences were not statistically significant; the differences in absolute fat mass were also attenuated after controlling for body weight. No differences were observed for fat-free mass, prevalence of overweight (BMI >23), or other anthropometric measurements. CONCLUSIONS: Preconception MM supplementation was associated with lower prevalence of underweight and higher percent fat when compared with IFA and/or FA only. Preconception micronutrient interventions may have long-term effects on maternal health and merit further examination. This trial was registered at clinicaltrials.gov as NCT01665378.

Maternal and Perinatal Factors Associated With Childhood Brain Tumors: A Case-Control Study in Vietnam.

INTRODUCTION: Brain cancer is the leading cause of cancer-related deaths in children and the majority of childhood brain tumors are diagnosed without determination of their underlying etiology. Little is known about risk factors for childhood brain tumors in Vietnam. The objective of this case-control study was to identify maternal and perinatal factors associated with brain tumors occurring in young Vietnamese children and adolescents. METHODS: We conducted a hospital-based case-control study at Viet Duc University Hospital in Hanoi, Vietnam. Cases consisted of children with brain tumors aged 0-14 years old admitted to the hospital from January 2020 to July 2022 while the controls were age and sex-matched hospitalized children diagnosed with head trauma. Perinatal characteristics were abstracted from hospital medical records and maternal medical, behavioral, and sociodemographic factors were collected through in-person interviews. Conditional logistic regression models were used to examine maternal and perinatal factors associated with childhood brain tumors. RESULTS: The study sample included 220 children (110 cases and 110 controls) whose average age was 8.9 years and 41.8% were girls. Children born to mothers aged greater than 30 years at the time of the child's birth had a higher risk of childhood brain tumors compared to those born to mothers aged from 18 to 30 years old (OR = 2.55; 95% CI: 1.13-5.75). Additionally low maternal body mass index prior to the current pregnancy of <18.5 kg/m2 significantly increased the odds of having a child with a brain tumor in relation to normal maternal body mass index from 18.5-22.9 kg/m2 (OR = 3.19; 95% CI: 1.36 - 7.50). CONCLUSION: Advanced maternal age and being markedly underweight were associated with an increased odds of having a child with a brain tumor. A population-based study with larger sample size is needed to confirm and extend the present findings.

Bayesian spatio-temporal modelling of environmental, climatic, and socio-economic influences on malaria in Central Vietnam.

BACKGROUND: Despite the successful efforts in controlling malaria in Vietnam, the disease remains a significant health concern, particularly in Central Vietnam. This study aimed to assess correlations between environmental, climatic, and socio-economic factors in the district with malaria cases. METHODS: The study was conducted in 15 provinces in Central Vietnam from January 2018 to December 2022. Monthly malaria cases were obtained from the Institute of Malariology, Parasitology, and Entomology Quy Nhon, Vietnam. Environmental, climatic, and socio-economic data were retrieved using a Google Earth Engine script. A multivariable Zero-inflated Poisson regression was undertaken using a Bayesian framework with spatial and spatiotemporal random effects with a conditional autoregressive prior structure. The posterior random effects were estimated using Bayesian Markov Chain Monte Carlo simulation with Gibbs sampling. RESULTS: There was a total of 5,985 Plasmodium falciparum and 2,623 Plasmodium vivax cases during the study period. Plasmodium falciparum risk increased by five times (95% credible interval [CrI] 4.37, 6.74) for each 1-unit increase of normalized difference vegetation index (NDVI) without lag and by 8% (95% CrI 7%, 9%) for every 1ºC increase in maximum temperature (TMAX) at a 6-month lag. While a decrease in risk of 1% (95% CrI 0%, 1%) for a 1 mm increase in precipitation with a 6-month lag was observed. A 1-unit increase in NDVI at a 1-month lag was associated with a four-fold increase (95% CrI 2.95, 4.90) in risk of P. vivax. In addition, the risk increased by 6% (95% CrI 5%, 7%) and 3% (95% CrI 1%, 5%) for each 1ºC increase in land surface temperature during daytime with a 6-month lag and TMAX at a 4-month lag, respectively. Spatial analysis showed a higher mean malaria risk of both species in the Central Highlands and southeast parts of Central Vietnam and a lower risk in the northern and north-western areas. CONCLUSION: Identification of environmental, climatic, and socio-economic risk factors and spatial malaria clusters are crucial for designing adaptive strategies to maximize the impact of limited public health resources toward eliminating malaria in Vietnam.

Empowering Women Living with HIV/AIDS in Vietnam: A Hybrid Online-Offline Intervention to Combat Stigma.

Women living with HIV/AIDS (WLHA) encounter numerous challenges, such as stigma and gender disparities, that hinder their access to care, especially in patriarchal societies like Vietnam. We developed a hybrid intervention with online and offline (in-person) components to empower WLHA in Vietnam. The intervention was pilot tested with 91 WLHA in Hanoi. During baseline and 4-month, study investigators delivered two in-person sessions, one Zoom session, and 15 weeks of Zalo (social media platform) discussions to enhance positive coping strategies, treatment utilization and adherence, and engagement of support from family and peers. The participants continued their Zalo discussions from 4-month to 6-month without investigators' involvement. Intervention outcomes, including active coping and perceived barriers to care, were evaluated at baseline, 4-, and 6-month surveys. Mixed-effects regression models showed that the participants' active coping significantly increased from baseline (50.5 ± 9.4) to 4-month (53.8 ± 6.2; p = 0.0001), although there was a slight decrease at 6-month (52.8 ± 7.2), the change from 4-month to 6-month was not significantly significant (p = 0.3256). There was a significant reduction in participants' perceived barriers to care, from 19.8 ± 5.2 at baseline to 17.4 ± 5.2 at 4-month (p < 0.0001), which remained stable at 17.8 ± 4.3 at 6-month (p < 0.0001 compared to baseline). This intervention presents a promising model to empower WLHA in Vietnam and potentially in similar global contexts. Future interventions could benefit from leveraging natural peer leaders and adopting a more person-centered approach to meet WLHA's varying needs.

Prevalence, Trends and Correlates of HIV, Syphilis and HCV Infection Among Chinese Local and Cross-border Migrant Female Sex Workers in the Sino-Vietnam Border Area of Guangxi, 2016-2021.

Female sex workers (FSWs) are considered a high-risk group for sexually transmitted infections (STIs). However, limited data exist on the prevalence and trends of HIV, syphilis and HCV among FSWs in the Sino-Vietnam border area. To determine the prevalence, trends and correlates of STIs among Chinese local FSWs (CL-FSWs) and cross-border migrant FSWs (CM-FSWs), we conducted consecutive cross-sectional surveys from 2016 to 2021, recruiting 7747 CL-FSWs and 932 CM-FSWs. The overall HIV, syphilis and HCV prevalence declined from 1.0%, 8.8% and 1.7% to 0.1%, 0.9% and 0.3%, respectively. There was no significant downward trend in the overall HIV and syphilis prevalence. However, HCV prevalence showed a decreasing trend among CL-FSWs. CM-FSWs had higher HIV prevalence (2.5% vs. 0.6%). Similarities and differences in STIs-related factors existed between CM-FSWs and CL-FSWs. For instance, receiving HIV-related services in the last year reduced the risk of HIV infection (for CM-FSWs: aOR = 0.234, 95% CI: 0.055-0.993; for CL-FSWs: aOR = 0.182, 95% CI: 0.058-0.567). Serving male clients at least 50 years old increased the risk of syphilis infection (for CM-FSWs: aOR = 4.277, 95% CI: 1.535-11.917; for CL-FSWs: aOR = 1.404, 95% CI: 1.087-1.815). Moreover, CM-FSWs with past-year STIs history had a higher risk of HIV (aOR = 34.976, 95% CI: 5.338-229.176) and HCV infection (aOR = 17.649, 95% CI: 1.846-168.846), both of which were associated with multiple factors in CL-FSWs. It is therefore necessary to develop effective, accessible, high-quality and targeted interventions for CM-FSWs and CL-FSWs.

Efficacy of Two Evidence-Based Alcohol Consumption Interventions on Positive, Negative, and Neutral Days Among Hazardous Alcohol Users Living with HIV in Vietnam.

Social events and stressful settings can be catalysts for alcohol consumption. Motivational enhancement therapy (MET) and cognitive behavioral therapy (CBT) are widely used in alcohol interventions. We assessed how alcohol consumption varied across three types of days (positive/social, negative/stressful, and neutral) among hazardous alcohol users living with HIV in Vietnam. We further evaluated how those consumption patterns changed after two MET/CBT alcohol reduction interventions versus the standard of care (SOC). The 'combined' intervention offered 6 individual sessions and 3 group sessions; the 'brief' intervention offered 2 individual sessions and 2 phone calls. A 30-day timeline follow-back was administered at study visits, detailing daily drinks and events. Days were categorized as neutral, positive/social, or negative/stressful; negative binomial models and generalized estimating equations were used to estimate drinks consumed by type of day at baseline and 12 months. Prior to intervention, more drinks were consumed on positive/social days (5.2 drinks; 95% Confidence Interval [CI]:4.8, 5.7) than negative/stressful (1.5; 95% CI:1.3, 1.9) and neutral days (2.2; 95% CI: 1.9, 2.5). After the brief intervention, drinks consumed decreased on neutral days (ratio: 0.5: 95% CI: 0.4, 0.7). After the combined intervention, drinks consumed decreased on neutral days (ratio: 0.4; 95% CI: 0.3, 0.6), positive/social days (ratio: 0.6; 95% CI: 0.5, 0.7) and negative/stressful days (ratio: 0.3; 95% CI: 0.2, 0.6). No reductions in consumption were observed in the SOC group. Social/positive days had the highest alcohol consumption prior to intervention, and the combined intervention showed the greatest decrease in consumption on those days. CLINICAL TRIAL REGISTRATION: The study is registered at clinicaltrials.gov (NCT02720237).

Measuring health care continuum with multifaceted indicators for people who use drugs in Vietnam.

Continuum of care is a concept that has been widely applied in HIV prevention and treatment studies. However, measuring care continuum can be challenging because it involves multiple stages and multiple components or domains at each stage of care. In this study, we introduced an analytical framework to (1) estimate intervention effects overall and by domain using a multi-level modeling approach, and (2) learn possible patterns of domains over time utilizing a multi-layer heatmap visualization. Longitudinal data from an intervention study conducted among people who use drugs in Vietnam were used to construct Seek, Test, Treat, and Retain (STTR) domain and overall scores. Findings from the adjusted analysis showed that people who use drugs in the intervention exhibited a significantly greater improvement in the overall STTR score than those in the control (p-values < .0001). The multi-layer heatmap revealed different patterns of the individual domains over time and the inter-relationships among the individual domains. This study demonstrates the feasibility of constructing a general fulfillment score and domain specific scores to measure care continuum among people who use drugs. The analytical framework can be readily extended to evaluate service fulfillment outcomes in health services and treatment studies for other key populations.

Seroprevalence of anti-diphtheria toxoid antibody and implications for vaccination policy in Vietnam's South-central coast: a cross-sectional study.

BACKGROUND: Diphtheria is a re-emerging infectious disease and public health concern worldwide and in Vietnam with increasing cases in recent years. This study aimed to assess the anti-diphtheria toxoid antibodies status in Khanh Hoa Province and identify factors contributing to the vaccination policy in the south-central coast of Vietnam. METHODS: This was a cross-sectional study to evaluate the seroprevalence of anti-diphtheria toxoid antibodies among 1,195 participants, aged 5 - 40 years in Khanh Hoa Province, Vietnam. Immunoglobulin G antibody levels against diphtheria were detected using a commercial anti-diphtheria toxoid enzyme-linked immunosorbent assay (SERION ELISA classic Diphtheria Immunoglobulin G) and were categorized following the World Health Organization guidelines. RESULTS: The mean anti-diphtheria toxoid antibody levels were 0.07 IU/ml (95% Confidence Interval: 0.07-0.08). Anti-diphtheria toxoid antibody levels were found to be associated with age and history of diphtheria vaccination. The 5-15 years age group had the highest levels (0.09 IU/ml), while the older age group had the lowest antibody level (p < 0.001). Individuals who received three doses (adjusted Odds ratio: 2.34, 95%CI: 1.35 - 4.07) or 4+ doses (adjusted Odds ratio: 2.45, 95%CI: 1.29 - 4.64) had a higher antibody level compared to those who received only one dose regardless of age. CONCLUSION: It is crucial to promote routine vaccination coverage to over 95% for children under one year of age with three primary doses of the diphtheria-containing vaccine, including additional doses at 18 months and 7 years of age. Booster doses should be promoted and administered to adolescents and adults every 10 years.

Effects of antivirals on patients with COVID-19 breakthrough.

BACKGROUND: Antivirals have been given widely for patients with COVID-19 breakthrough in Asian countries, creating a "black market" for unapproved and unprescribed medications. More evidence is needed to clarify the benefits of antivirals in these settings. METHODS: We conducted a random-sampling retrospective cohort study at a general hospital in Vietnam. We recruited patients with mild-to-moderate COVID-19 breakthrough who were given either standard of care (SoC) alone or SoC + antiviral. Primary outcome was residual respiratory symptoms that lasted > 7 days. Secondary outcome was long COVID-19, diagnosed by specialized physicians. We used logistic regression to measure odds ratio (OR), in addition to a sensitivity and subgroup analyses to further explore the results. RESULTS: A total of 142 patients (mean age 36.2 ± 9.8) were followed. We recorded residual symptoms in 27.9% and 20.3% of the SoC and SoC + antiviral group, while the figures for long COVID-19 were 11.8% and 8.1%, respectively. Antiviral use was not significantly associated with lower the risks of residual symptoms (OR = 0.51, 95% CI: 0.22-1.20, p = 0.12) or long COVID-19 (OR = 0.55, 95% CI: 0.16-1.90, p = 0.35). The sensitivity and subgroup analyses did not show any significant differences between the study groups (all p > 0.05). CONCLUSION: Antivirals were not associated with faster resolution of respiratory symptoms or lower risks of long COVID-19. Further studies should focus on different antivirals to confirm their effects on different sub-populations. Meanwhile, antivirals should only be used in very high-risk patients to avoid excessive costs and harms.

Co-infections and secondary infections amid COVID-19 outbreaks in Vietnam.

BACKGROUND: The mortality risk of co-infections/secondary infections (CoI/ScI) is under-reported in patients with non-critical COVID-19, leading to the under-management of CoI/ScI and publication bias in the medical literature. We aimed to investigate the association between CoI/ScI and mortality in patients hospitalised with mild-to-severe COVID-19. METHODS: We conducted a retrospective cohort study at a COVID-19 treatment hospital in Vietnam and collected all eligible medical records, with CoI/ScI status as the exposure (non-CoI/ScI and CoI/ScI, with the latter including nature of pathogen [bacterial, fungal, or bacterial + fungal] and multidrug-resistance pathogen [no MDRp or ≥ 1 MDRp]). The outcome was all-cause mortality, defined as in-hospital death by all causes or being discharged under critical illness. We used time-dependent analysis to report rates of mortality with 95% confidence intervals (95% CI, Poisson regression) and hazard ratios (HR) with 95% CI (Cox proportional hazards regression with Holm's method for multiplicity control). RESULTS: We followed 1466 patients (median age 61, 56.4% being female) for a median of 9 days. We recorded 387 (26.4%) deaths (95/144 [66.0%] in the CoI/ScI group and 292/1322 [22.1%] in the non-CoI/ScI group). Adjusted mortality rates (per 100 person-days) of the CoI/ScI (6.4, 95% CI 5.3 to 7.8), including bacterial (8.0, 95% CI 7.2 to 8.9), no MDRp (5.9, 95% CI 4.8 to 7.4), and ≥ 1 MDRp (9.0, 95% CI 8.2 to 10.0) groups were higher than that of the non-CoI/ScI group (2.0, 95% CI 1.8 to 2.2). These corresponded to higher risks of mortality in the overall CoI/ScI (HR 3.27, 95% CI 2.58 to 4.13, adjusted p < 0.001), bacterial CoI/ScI (HR 3.79, 95% CI 2.97 to 4.83, adjusted p < 0.001), no MDRp CoI/ScI (HR 3.13, 95% CI 2.42 to 4.05, adjusted p < 0.001), and ≥ 1 MDRp CoI/ScI group (HR 3.89, 95% CI 2.44 to 6.21, adjusted p < 0.001). We could not attain reliable estimates for fungal and bacterial + fungal CoI/ScI. CONCLUSION: Compared with the non-CoI/ScI group, patients with CoI/ScI had a significantly higher risk of all-cause mortality, regardless of resistance status. More evidence is needed to confirm the mortality risks in patients with fungal or bacterial + fungal CoI/ScI.

Feasibility of wearable monitors to detect heart rate variability in children with hand, foot and mouth disease.

Hand foot and mouth disease (HFMD) is caused by a variety of enteroviruses, and occurs in large outbreaks in which a small proportion of children deteriorate rapidly with cardiopulmonary failure. Determining which children are likely to deteriorate is difficult and health systems may become overloaded during outbreaks as many children require hospitalization for monitoring. Heart rate variability (HRV) may help distinguish those with more severe diseases but requires simple scalable methods to collect ECG data.We carried out a prospective observational study to examine the feasibility of using wearable devices to measure HRV in 142 children admitted with HFMD at a children's hospital in Vietnam. ECG data were collected in all children. HRV indices calculated were lower in those with enterovirus A71 associated HFMD compared to those with other viral pathogens.HRV analysis collected from wearable devices is feasible in a low and middle income country (LMIC) and may help classify disease severity in HFMD.