Characterizing Neisseria meningitidis in Southern Vietnam between 2012 and 2021: A predominance of the chloramphenicol-resistant ST-1576 lineage

Objectives

Our goal was to describe Invasive Meningococcal Disease (IMD) in Southern Vietnam over the last 10 years. We characterized 109 Neisseria meningitidis strains in Southern Vietnam isolated between 1980s to 2021, that were collected from IMD (n = 44), sexually transmitted infections (n = 2), and healthy carriage (n = 63).

Methods

IMD were confirmed by bacterial culture and/or real-time polymerase chain reaction at the national reference laboratory in Pasteur Institute of Ho Chi Minh City (PIHCM). Antimicrobial resistance was determined on 31 IMD and two sexually transmitted infection isolates with E-test for chloramphenicol (CHL), penicillin (PEN), ciprofloxacin (CIP), ceftriaxone (CRO), and rifampicin (RIF). Sequencing was performed for analyzing of multilocus-sequence-typing (MLST), porA, fetA, and antibiotic resistance genes, including gyrA, penA, and rpoB.

Results

The incidence rate during this period was 0.02 per 100,000 persons/year. Serogroup B accounted for over 90% of cases (50/54). ST-1576 were mainly responsible for IMD, 27/42 MLST profiles, and associated with CHL resistance. Resistance was prevalent among IMD isolates. Thirteen were resistant to CHL (minimum inhibitory concentration [MIC] ≥16 mg/l), 12 were intermediate to PEN (MIC between 0.19 and 0.5 mg/l), and five were CIP-resistant (MIC between 0.19 and 0.5 mg/l). Particularly, one was non-susceptible to CRO (MIC at 0.125 mg/l), belonging to ST-5571 lineage. The resistance was due to carrying resistant alleles of penA and gyrA genes, and catP gene. Notably, seven isolates were resistant/non-susceptible to two or more antibiotics.

Conclusion

Our results suggest the persistence of the circulating ST-1576 in Southern Vietnam, with a spread of antimicrobial resistance across the community.

Mother-to-Child Transmission of HBV Infection by Preventive Interventions in Southern Vietnam's Hospitals

INTRODUCTION

The World Health Organization (WHO) recommends tenofovir disoproxil fumarate (TDF) for pregnant women with hepatitis B virus (HBV) presenting with HBV DNA levels of 106 copies/mL or more to hinder mother-to-child transmission (MTCT). Moreover, it is suggested that neonates of HBV-infected mothers receive an HBV vaccine birth dose within 24 hours of birth to mitigate transmission risk.

METHODOLOGY

The study included 661 HBV-infected pregnant women and 316 infants from 3 hospitals in Southern Vietnam between October 2019 and November 2020. Infants were classified on the basis of their mothers' TDF prophylaxis into I-TDF (+) group (107 infants) whose mothers received TDF; I-TDF (-) group (56 infants) whose mothers missed TDF; and I-NTDF group (153 infants) whose mothers did not necessitate TDF. Almost all infants received an HBV vaccine birth dose with HBIG administered on the basis of parents' financial standing.

RESULTS

MTCT was found in 2.2% of the cases. The respective MTCT rates for I-TDF (+), I-TDF (-), and I-NTDF groups were 2.8%, 5.4%, and 0.7%. Immune response rates to the HBV vaccination in the total cohort, I-TDF (+), I-TDF (-), and I-NTDF groups, were 88.6%, 87.9%, 85.7%, and 90.2%, respectively. Vaccinated infants exhibited a statistically lower risk of HBV infection postbirth (aRR = 0.1; 95% confidence interval, 0.0-0.6; P = .01).

CONCLUSION

TDF can equate the MTCT risk in pregnant women with HBV DNA levels of 106 copies/mL or more to those with lower levels. Early administration of the HBV vaccine postbirth also effectively curtails MTCT. Thus, expanding TDF prophylaxis and vaccine coverage is pivotal to impede MTCT.

Prediction of effectiveness of universal rotavirus vaccination in Southwestern Vietnam based on a dynamic mathematical model

Vaccinating young children against rotavirus (RV) is a promising preventive strategy against rotavirus gastroenteritis (RVGE). We evaluated the relative risk reduction of RVGE induced by universal vaccination in Vietnam through dynamic model analysis. We developed an age-stratified dynamic Vaccinated-Susceptible-Infectious-Recovered-Susceptible model to analyze RV transmission and assess vaccine effectiveness (VE). We assumed 3 different vaccine efficacies: 55%, 70%, and 85%. For model calibration, we used a database of patients under 5 years of age admitted to Ho Chi Minh No.1 Hospital with RVGE between January 2013 and December 2018. Assuming a vaccination rate of 95%, the number of RVGE hospitalizations after 5 years from universal RV vaccination decreased from 92,502 cases to 45,626 with 85% efficacy, to 54,576 cases with 70% efficacy, and to 63,209 cases with 55% efficacy. Additionally, RVGE hospitalizations after 10 years decreased from 177,950 to 89,517 with 85% efficacy and to 121,832 cases with 55% efficacy. The relative risk reductions of RVGE after 10 years were 49.7% with 85% efficacy, 40.6% with 70% efficacy, and 31.5% with 55% efficacy. The VE was 1.10 times (95% CI, 1.01-1.22) higher in the 4-months to 1-year-old age group than in the other age groups (P = 0.038), when applying 85% efficacy with 95% coverage. In conclusion, despite its relatively lower efficacy compared to high-income countries, RV vaccination remains an effective intervention in Southwestern Vietnam. In particular, implementing universal RV vaccination with higher coverage would result in a decrease in RVGE hospitalizations among Vietnamese children under 5 years of age.

Clinical and technical factors in endoscopic skull base surgery associated with reconstructive success

BACKGROUND

In this study, we identified key discrete clinical and technical factors that may correlate with primary reconstructive success in endoscopic skull base surgery (ESBS).

METHODS

ESBS cases with intraoperative cerebrospinal fluid (CSF) leaks at four tertiary academic rhinology programs were retrospectively reviewed. Logistic regression identified factors associated with surgical outcomes by defect subsite (anterior cranial fossa [ACF], suprasellar [SS], purely sellar, posterior cranial fossa [PCF]).

RESULTS

Of 706 patients (50.4% female), 61.9% had pituitary adenomas, 73.4% had sellar or SS defects, and 20.5% had high-flow intraoperative CSF leaks. The postoperative CSF leak rate was 7.8%. Larger defect size predicted ACF postoperative leaks; use of rigid reconstruction and older age protected against sellar postoperative leaks; and use of dural sealants compared to fibrin glue protected against PCF postoperative leaks. SS postoperative leaks occurred less frequently with the use of dural onlay. Body-mass index, intraoperative CSF leak flow rate, and the use of lumbar drain were not significantly associated with postoperative CSF leak. Meningitis was associated with larger tumors in ACF defects, nondissolvable nasal packing in SS defects, and high-flow intraoperative leaks in PCF defects. Sinus infections were more common in sellar defects with synthetic grafts and nondissolvable nasal packing.

CONCLUSIONS

Depending on defect subsite, reconstructive success following ESBS may be influenced by factors, such as age, defect size, and the use of rigid reconstruction, dural onlay, and tissue sealants.

Efficient automated error detection in medical data using deep-learning and label-clustering

Medical datasets inherently contain errors from subjective or inaccurate test results, or from confounding biological complexities. It is difficult for medical experts to detect these elusive errors manually, due to lack of contextual information, limiting data privacy regulations, and the sheer scale of data to be reviewed. Current methods for training robust artificial intelligence (AI) models on data containing mislabeled examples generally fall into one of several categories-attempting to improve the robustness of the model architecture, the regularization techniques used, the loss function used during training, or selecting a subset of data that contains cleaner labels. This last category requires the ability to efficiently detect errors either prior to or during training, either relabeling them or removing them completely. More recent progress in error detection has focused on using multi-network learning to minimize deleterious effects of errors on training, however, using many neural networks to reach a consensus on which data should be removed can be computationally intensive and inefficient. In this work, a deep-learning based algorithm was used in conjunction with a label-clustering approach to automate error detection. For dataset with synthetic label flips added, these errors were identified with an accuracy of up to 85%, while requiring up to 93% less computing resources to complete compared to a previous model consensus approach developed previously. The resulting trained AI models exhibited greater training stability and up to a 45% improvement in accuracy, from 69 to over 99% compared to the consensus approach, at least 10% improvement on using noise-robust loss functions in a binary classification problem, and a 51% improvement for multi-class classification. These results indicate that practical, automated a priori detection of errors in medical data is possible, without human oversight.

Bioaccumulation and metabolic impact of environmental PFAS residue on wild-caught urban wetland tiger snakes (Notechis scutatus)

PFAS contamination of urban waters is widespread but understanding the biological impact of its accumulation is limited to humans and common ecotoxicological model organisms. Here, we combine PFAS exposure and bioaccumulation patterns with whole organism responses and omics-based ecosurveillance methods to investigate the potential impacts of PFAS on a top predator of wetlands, the tiger snake (Notechis scutatus). Tiger snakes (18 male and 17 female) were collected from four wetlands with varying PFAS chemical profiles and concentrations in Perth, Western Australia. Tiger snake livers were tested for 28 known PFAS compounds, and Σ28PFAS in liver tissues ranged between 322 ± 193 μg/kg at the most contaminated site to 1.31 ± 0.86 μg/kg at the least contaminated site. The dominant PFAS compound detected in liver tissues was PFOS. Lower body condition was associated with higher liver PFAS, and male snakes showed signs of high bioaccumulation whereas females showed signs of maternal offloading. Biochemical profiles of snake muscle, fat (adipose tissue), and gonads were analysed using a combination of liquid chromatography triple quadrupole (QqQ) and quadrupole time-of-flight (QToF) mass spectrometry methodologies. Elevated PFAS was associated with enriched energy production and maintenance pathways in the muscle, and had weak associations with energy-related lipids in the fat tissue, and lipids associated with cellular genesis and spermatogenesis in the gonads. These findings demonstrate the bioavailability of urban wetland PFAS in higher-order reptilian predators and suggest a negative impact on snake health and metabolic processes. This research expands on omics-based ecosurveillance tools for informing mechanistic toxicology and contributes to our understanding of the impact of PFAS residue on wildlife health to improve risk management and regulation.

Biochemical Failure in Intermediate Risk Prostate Cancer: Then What? Long-Term Data from a Phase III Trial

PURPOSE/OBJECTIVE(S)

Aiming to determine long-term outcomes post biochemical failure (BF) in patients (pts) treated for intermediate-risk prostate cancer, we analyzed data from our prospective randomized trial (PCS III).

MATERIALS/METHODS

From December 2000 to September 2010, 600 pts with intermediate risk prostate cancer (IRPC) received prostate radiotherapy (RT) with or without short-term (6 months) androgen deprivation therapy (ADT) on a Phase III trial. We report death rate from prostate cancer, rate and timing of BF plus the final clinical outcome of patients, alive or dead, with BF. Chi-squared test was used to compare BF and prostate cancer progression (PCP) rates between patient with or without ADT.

RESULTS

Median age at randomization was 71 years (IQR 66-74). With a median follow-up (FU) of 13.5 years (IQR 11.2-17.0), 74.5% (447/600) were free from BF at last FU. Of these, 211 died, 79 stopped FU after 10 years, 9 were lost to FU, 6 withdrew from the study and 142 are still on FU, at a median follow-up of 13.2 years (IQR = 10.9 - 16.2). A total of 153 pts (25.5%) developed BF at a median time of 6.5 years post-randomization. Among BF pts, 82/153 died: we documented 32 deaths from prostate cancer (DPC) at a median time of 6 years post-BF and 50/153 pts died from other causes at a median time of 4.7 years from BF. 48/153 BF pts continue on FU: 34 show no clinical evidence of cancer, 9 developed a second cancer and 5 show clinical evidence of PCP. 20/153 pts stopped FU after 10 years: 3 of them with PCP. 3/153 pts were lost to FU: 1 after 3 years with prostate bone metastasis and 2 after 13 years of FU. In the first 5 years post-randomization, 47 pts (7.8%) presented BF with 1 (0.2%) DPC; between 6 and 10 years, there were another 84 (14%) BFs and 11 (1.8%) DPC. Finally, after 10 years and beyond, we recorded an additional 22 (3.7%) BFs and 20 (3.3%) DPC. The rate of patients who received ADT was significantly lower in patients with BF (74/153 = 48.4%) compared to patients without BF (324/447 = 72.5%), p<0.001. The rate of patients who received ADT was also significantly lower in patients with PCP (19/48 = 39.6%) compared to patients without PCP (379/552 = 68.7%), p<0.001.

CONCLUSION

In our trial for intermediate-risk prostate cancer, a quarter of the pts developed BF. Most of the BFs occurred between 5- and 10- year post-randomization. Deaths due to prostate cancer post-BF occurred at a median time of 6 years, justifying the need for long-term FU. BF and PCP were significantly higher in patients not receiving ADT.

Outbreak of Sexually Transmitted Nongroupable Neisseria meningitidis-Associated Urethritis, Vietnam

We report on an outbreak of nongroupable Neisseria meningitidis-associated urethritis, primarily among men who have sex with men in southern Vietnam. Nearly 50% of N. meningitidis isolates were resistant to ciprofloxacin. This emerging pathogen should be considered in the differential diagnosis and management of urethritis.

Efficacy against pneumococcal carriage and the immunogenicity of reduced-dose (0 + 1 and 1 + 1) PCV10 and PCV13 schedules in Ho Chi Minh City, Viet Nam: a parallel, single-blind, randomised controlled trial

BACKGROUND

Interest in reduced-dose pneumococcal conjugate vaccine (PCV) schedules is growing, but data on their ability to provide direct and indirect protection are scarce. We evaluated 1 + 1 (at 2 months and 12 months) and 0 + 1 (at 12 months) schedules of PCV10 or PCV13 in a predominately unvaccinated population.

METHODS

In this parallel, single-blind, randomised controlled trial, healthy infants aged 2 months were recruited from birth records in three districts in Ho Chi Minh City, Vietnam, and assigned (4:4:4:4:9) to one of five groups: PCV10 at 12 months of age (0 + 1 PCV10), PCV13 at 12 months of age (0 + 1 PCV13), PCV10 at 2 months and 12 months of age (1 + 1 PCV10), PCV13 at 2 months and 12 months of age (1 + 1 PCV13), and unvaccinated control. Outcome assessors were masked to group allocation, and the infants' caregivers and those administering vaccines were not. Nasopharyngeal swabs collected at 6 months, 12 months, 18 months, and 24 months were analysed for pneumococcal carriage. Blood samples collected from a subset of participants (200 per group) at various timepoints were analysed by ELISA and opsonophagocytic assay. The primary outcome was the efficacy of each schedule against vaccine-type carriage at 24 months, analysed by intention to treat for all those with a nasopharyngeal swab available. This trial is registered at ClinicalTrials.gov, NCT03098628.

FINDINGS

2501 infants were enrolled between March 8, 2017, and July 24, 2018 and randomly assigned to study groups (400 to 0 + 1 PCV10, 400 to 0 + 1 PCV13, 402 to 1 + 1 PCV10, 401 to 1 + 1 PCV13, and 898 to control). Analysis of the primary endpoint included 341 participants for 0 + 1 PCV10, 356 0 + 1 PCV13, 358 1 + 1 PCV10, 350 1 + 1 PCV13, and 758 control. At 24 months, a 1 + 1 PCV10 schedule reduced PCV10-type carriage by 58% (95% CI 25 to 77), a 1 + 1 PCV13 schedule reduced PCV13-type carriage by 65% (42 to 79), a 0 + 1 PCV10 schedule reduced PCV10-type carriage by 53% (17 to 73), and a 0 + 1 PCV13 schedule non-significantly reduced PCV13-type carriage by 25% (-7 to 48) compared with the unvaccinated control group. Reactogenicity and serious adverse events were similar across groups.

INTERPRETATION

A 1 + 1 PCV schedule greatly reduces vaccine-type carriage and is likely to generate substantial herd protection and provide some degree of individual protection during the first year of life. Such a schedule is suitable for mature PCV programmes or for introduction in conjunction with a comprehensive catch-up campaign, and potentially could be most effective given as a mixed regimen (PCV10 then PCV13). A 0 + 1 PCV schedule has some effect on carriage along with a reasonable immune response and could be considered for use in humanitarian crises or remote settings.

FUNDING

Bill & Melinda Gates Foundation.

TRANSLATION

For the Vietnamese translation of the abstract see Supplementary Materials section.

Childhood Bacterial Meningitis Surveillance in Southern Vietnam: Trends and Vaccination Implications From 2012 to 2021

Background

This retrospective hospital-based surveillance aimed to assess the epidemiology, causative pathogens trend, and serotypes distribution of pneumococcal meningitis among children aged under 5 years with bacterial meningitis in Southern Vietnam after the introduction of pentavalent vaccine in the Expanded Program on Immunization (EPI).

Methods

From 2012 to 2021, cerebrospinal fluid samples were collected from children aged under 5 years with suspected bacterial meningitis at Children's Hospitals 1 and 2 in Ho Chi Minh City. Probable bacterial meningitis (PBM) cases were identified using biochemistry and cytology. Real-time polymerase chain reaction was used to confirm cases of confirmed bacterial meningitis (CBM) caused by Streptococcus pneumoniae, Haemophilus influenzae, or Neisseria meningitidis. Streptococcus pneumoniae serotyping was performed.

Results

Of the 2560 PBM cases, 158 (6.2%) were laboratory-confirmed. The CBM proportion decreased during the 10-year study and was associated with age, seasonality, and permanent residence. Streptococcus pneumoniae was the most common pathogen causing bacterial meningitis (86.1%), followed by H influenzae (7.6%) and N meningitidis (6.3%). The case-fatality rate was 8.2% (95% confidence interval, 4.2%-12.2%). Pneumococcal serotypes 6A/B, 19F, 14, and 23F were the most prevalent, and the proportion of pneumococcal meningitis cases caused by the 10-valent pneumococcal conjugate vaccine (PCV) serotypes decreased from 96.2% to 57.1% during the PCV eras.

Conclusions

Streptococcus pneumoniae is the most frequent causative agent of bacterial meningitis in children aged under 5 years in Southern Vietnam over the last decade. Policymakers may need to consider introducing PCVs into the EPI to effectively prevent and control bacterial meningitis.

The effect of medication event reminder monitoring on treatment adherence of TB patients

BACKGROUND: TB control remains a serious public health problem, compounded by poor treatment adherence, which increases the likelihood of onward transmission. We evaluated the effectiveness of medication event reminder monitoring (MERM) upon treatment adherence in a high TB burden setting.METHODS: We conducted an open-label parallel group randomised controlled trial among pulmonary TB adults. Participants were provided with a MERM device to store their medications. In the intervention arm, the devices were set to provide daily medication intake reminders. Primary outcome was the proportion of patient-months in which at least 6/30 doses were missed. Secondary outcomes included 1) the proportion of patient-months in which at least 14/30 doses were missed, and 2) the proportion of doses missed.RESULTS: Of 2,142 patients screened, 798 (37.3%) met the inclusion criteria and 250 participants were enrolled. The mean ratio (MR) for poor adherence between the intervention and control groups was 0.72 (95% CI 0.55-0.86). The intervention was also associated with a reduction in the proportion of patients missing at least 14/30 doses (MR 0.61, 95% CI 0.54-0.68) and the percentage of total doses missed (MR 0.75, 95% CI 0.68-0.80).CONCLUSION: MERM is effective in improving TB treatment adherence in a resource-limited environment.

Vitrified before and after genome editing via electroporation

BACKGROUND

Cryopreservation of bovine zygotes allows for a flexible schedule of genome editing via electroporation. However, vitrification-induced cell membrane damage may not only affect embryonic development but also genome mutation.

OBJECTIVE

To investigate the effects of vitrification of zygotes before and after electroporation treatments on the development and genome mutation of bovine presumptive zygotes.

MATERIALS AND METHODS

In vitro-derived bovine zygotes were electroporated with the CRISPR/Cas9 system immediately (Vitrified-EP) or 2 h after incubation (Vitrified-2h-EP) following vitrification and warming, or electroporated before vitrification (EP-vitrified).

RESULTS

The development rates of vitrified-warmed zygotes were significantly lower (p < 0.05) than those of control zygotes that were not vitrified. Moreover, no differences were observed in the mutation rates and mutation efficiency of the blastocysts resulting from electroporated zygotes, irrespective of the timing of electroporation treatment.

CONCLUSION

Our results suggest that vitrification before and after electroporation treatments does not affect the genome editing of zygotes.

Impact of COVID-19 Nonpharmaceutical Interventions on Pneumococcal Carriage Prevalence and Density in Vietnam

Nonpharmaceutical interventions (NPIs) implemented to contain SARS-CoV-2 have decreased invasive pneumococcal disease. Previous studies have proposed the decline is due to reduced pneumococcal transmission or suppression of respiratory viruses, but the mechanism remains unclear. We undertook a secondary analysis of data collected from a clinical trial to evaluate the impact of NPIs on pneumococcal carriage and density, drivers of transmission and disease, during the COVID-19 pandemic in Ho Chi Minh City, Vietnam. Nasopharyngeal samples from children aged 24 months were assessed in three periods - one pre-COVID-19 period (n = 1,537) and two periods where NPIs were implemented with increasing stringency (NPI period 1 [NPI-1, n = 307], and NPI period 2 [NPI-2, n = 262]). Pneumococci were quantified using lytA quantitative PCR and serotyped by DNA microarray. Overall, capsular, and nonencapsulated pneumococcal carriage and density were assessed in each NPI period compared with the pre-COVID-19 period using unadjusted log-binomial and linear regression. Pneumococcal carriage was generally stable after the implementation of NPIs. In contrast, overall pneumococcal carriage density decreased by 0.44 log10 genome equivalents/mL (95% confidence interval [CI]: 0.19 to 0.69) in NPI-1 and by 0.84 log10 genome equivalents/mL (95% CI: 0.55 to 1.13) in NPI-2 compared with the pre-COVID-19 period. Reductions in overall pneumococcal density were driven by reductions in capsular pneumococci, with no corresponding reduction in nonencapsulated density. As higher pneumococcal density is a risk factor for disease, the decline in density provides a plausible explanation for the reductions in invasive pneumococcal disease that have been observed in many countries in the absence of a substantive reduction in pneumococcal carriage. IMPORTANCE The pneumococcus is a major cause of mortality globally. Implementation of NPIs during the COVID-19 pandemic led to reductions in invasive pneumococcal disease in many countries. However, no studies have conducted a fully quantitative assessment on the impact of NPIs on pneumococcal carriage density, which could explain this reduction. We evaluated the impact of COVID-19 NPIs on pneumococcal carriage prevalence and density in 2,106 children aged 24 months in Vietnam and found pneumococcal carriage density decreased up to 91.5% after NPI introduction compared with the pre-COVID-19 period, which was mainly attributed to capsular pneumococci. Only a minor effect on carriage prevalence was observed. As respiratory viruses are known to increase pneumococcal carriage density, transmission, and disease, this work suggests that interventions targeting respiratory viruses may have the added benefit of reducing invasive pneumococcal disease and explain the reductions observed following NPI implementation.

Cardiovascular disease in older patients with end-stage renal disease and chronic dialysis in Vietnam

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with chronic kidney disease, especially end-stage renal disease, exhibit a very high cardiovascular risk. In Vietnam, chronic kidney disease and cardiovascular disease (CVD) are very common in older people. However, there is limited studies on the complexity of CVD and other geriatric syndromes in older patients with end-stage renal disease and chronic dialysis.

Purpose

In this study in older patients with end-stage renal disease and chronic dialysis, we aim to: (1) Examine the prevalence of CVD and its impact on hospitalization, and (2) Compare the burden of common geriatric syndromes in patients with and without CVD.

Methods

This is a prospective, observational, multi-centre study conducted at two dialysis units of two major hospitals in Vietnam. Consecutive patients aged 60 years or older who were diagnosed with end-stage renal disease and on chronic dialysis were recruited from November 2020 to June 2021. CVD was defined as having one of these conditions: heart failure, ischemic heart disease, and stroke. Participants were assessed for these common geriatric conditions: frailty (defined as a Clinical Frailty Scale total score ≥5), malnutrition (defined as a total score ≤7 from the Mini Nutritional Assessment Short Form), impairment in activities of daily living (defined as ADL score &lt;6), impairment in instrumental activities of daily living (defined as IADL score &lt;8), high risk of falls (assessed by the STEADI questionnaire), and polypharmacy (defined as the concurrent use of ≥5 medications). Participants were followed for 6 months after discharge. Multivariable logistic regression analysis was applied to examine the impact of CVD on 6-month hospitalization, adjusting for age, sex, and the geriatric conditions. Results were presented as odds ratios (ORs) and 95% confidence intervals (CIs).

Results

There were 175 participants (mean age 72.4 ± 8.5, 58.9% female). CVD was present in 80% of the participants (ischemic heart disease: 49.7%, heart failure: 60.0%, stroke 25.7%). Participants with CVD had significantly higher prevalence of geriatric syndromes compared to those without CVD (Table 1). During 6-month follow-up, 48.6% of the participants had at least one hospitalization. In multivariable logistic regression model, the presence of CVD increased the risk of hospitalization (adjusted OR 4.70, 95%CI 1.72 – 12.85), allowing for age, sex, frailty, ADL impairment, IADL impairment, fall risk, malnutrition, polypharmacy (Table 2).

Conclusion

In this study, there was a very high prevalence of CVD in older patients with end-stage renal disease and chronic dialysis. Participants with CVD had higher burden of geriatric syndromes and their risk of 6-month hospitalization increased by approximately 5 times.

Contrast induced nephropathy in older Vietnamese patients undergoing coronary angiography and intervention

Funding Acknowledgements

Type of funding sources: None.

Background

The prevalence of coronary heart disease increases with age and older people accounted for a large proportion of patients presenting with coronary heart disease. Advancement in percutaneous coronary intervention (PCI) has contributed to reduced mortality in patients with coronary artery disease. However, coronary angiography and percutaneous intervention have also increased the risk of developing contrast induced nephropathy (CIN), especially in older patients. More than ten risk assessment tools have been developed to predict CIN. Among these, the Mehran risk score has been the most commonly used in Vietnam. In recent years, new simple risk prediction models have been proposed, including the contrast volume-to-glomerular filtration rate ratio (CV/GFR ratio). The CV/GFR ratio is calculated as the ratio of contrast medium quantity to glomerular filtration rate.

Purpose

The aim of this study was to (1) examine the incidence of CIN in a cohort of older patients undergoing coronary angiography and/or PCI at a tertiary hospital in Vietnam, (2) compare the validity of the CV/GFR ratio and the Mehran score in predicting CIN, and (3) to identify optimal cut-off points of these scales by which can help identify older patients with high risk of developing CIN in this population.

Methods

A prospective observational study was conducted in patients aged ≥ 60 years at a tertiary hospital in Vietnam from September 2019 to May 2020. CIN was defined as 25% increase in serum creatinine from baseline or 0.5mg/dL absolute increase in serum creatinine occurring within 48 hours post IV contrast administration. The CV/GFR ratio and the Mehran score were applied for predicting risk of CIN. Previous studies suggest Mehran score &gt;5 or CV/GFR ratio &gt;3.7 as a predictor of an early abnormal increase in serum creatinine after PCI. Receiver Operator Characteristic (ROC) was applied to evaluate area under the curve (AUC) of the CV/GFR ratio and Mehran score in predicting CIN, and the sensitivity, specificity for common cut-off points that were suggested in previous studies.

Results

A total of 170 participants were included in this study. They had a mean age of 70 years, 33.1% were women. The incidence of CIN was 9.4%. Participants with CIN had higher prevalence of chronic kidney disease, heart failure and anaemia at admission. The AUC of the CV/GFR ratio against CIN was 0.79 (95%CI 0.65-0.92), and of the Mehran score against CIN was 0.65 (95%CI 0.51-0.82) (Figure 1). The sensitivity and specificity for common cut-off points of the CV/GFR ratio and Mehran score are presented in Figure 2.

Conclusions

Our study found that CIN was common in older patients after PCI. Both CV/GFR ratio and Mehran score had good diagnostic value for predicting CIN in the study participants.

Development of an artificial intelligence model for predicting the likelihood of human embryo euploidy based on blastocyst images from multiple imaging systems during IVF

STUDY QUESTION

Can an artificial intelligence (AI) model predict human embryo ploidy status using static images captured by optical light microscopy?

SUMMARY ANSWER

Results demonstrated predictive accuracy for embryo euploidy and showed a significant correlation between AI score and euploidy rate, based on assessment of images of blastocysts at Day 5 after IVF.

WHAT IS KNOWN ALREADY

Euploid embryos displaying the normal human chromosomal complement of 46 chromosomes are preferentially selected for transfer over aneuploid embryos (abnormal complement), as they are associated with improved clinical outcomes. Currently, evaluation of embryo genetic status is most commonly performed by preimplantation genetic testing for aneuploidy (PGT-A), which involves embryo biopsy and genetic testing. The potential for embryo damage during biopsy, and the non-uniform nature of aneuploid cells in mosaic embryos, has prompted investigation of additional, non-invasive, whole embryo methods for evaluation of embryo genetic status.

STUDY DESIGN, SIZE, DURATION

A total of 15 192 blastocyst-stage embryo images with associated clinical outcomes were provided by 10 different IVF clinics in the USA, India, Spain and Malaysia. The majority of data were retrospective, with two additional prospectively collected blind datasets provided by IVF clinics using the genetics AI model in clinical practice. Of these images, a total of 5050 images of embryos on Day 5 of in vitro culture were used for the development of the AI model. These Day 5 images were provided for 2438 consecutively treated women who had undergone IVF procedures in the USA between 2011 and 2020. The remaining images were used for evaluation of performance in different settings, or otherwise excluded for not matching the inclusion criteria.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The genetics AI model was trained using static 2-dimensional optical light microscope images of Day 5 blastocysts with linked genetic metadata obtained from PGT-A. The endpoint was ploidy status (euploid or aneuploid) based on PGT-A results. Predictive accuracy was determined by evaluating sensitivity (correct prediction of euploid), specificity (correct prediction of aneuploid) and overall accuracy. The Matthew correlation coefficient and receiver-operating characteristic curves and precision-recall curves (including AUC values), were also determined. Performance was also evaluated using correlation analyses and simulated cohort studies to evaluate ranking ability for euploid enrichment.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall accuracy for the prediction of euploidy on a blind test dataset was 65.3%, with a sensitivity of 74.6%. When the blind test dataset was cleansed of poor quality and mislabeled images, overall accuracy increased to 77.4%. This performance may be relevant to clinical situations where confounding factors, such as variability in PGT-A testing, have been accounted for. There was a significant positive correlation between AI score and the proportion of euploid embryos, with very high scoring embryos (9.0-10.0) twice as likely to be euploid than the lowest-scoring embryos (0.0-2.4). When using the genetics AI model to rank embryos in a cohort, the probability of the top-ranked embryo being euploid was 82.4%, which was 26.4% more effective than using random ranking, and ∼13-19% more effective than using the Gardner score. The probability increased to 97.0% when considering the likelihood of one of the top two ranked embryos being euploid, and the probability of both top two ranked embryos being euploid was 66.4%. Additional analyses showed that the AI model generalized well to different patient demographics and could also be used for the evaluation of Day 6 embryos and for images taken using multiple time-lapse systems. Results suggested that the AI model could potentially be used to differentiate mosaic embryos based on the level of mosaicism.

LIMITATIONS, REASONS FOR CAUTION

While the current investigation was performed using both retrospectively and prospectively collected data, it will be important to continue to evaluate real-world use of the genetics AI model. The endpoint described was euploidy based on the clinical outcome of PGT-A results only, so predictive accuracy for genetic status in utero or at birth was not evaluated. Rebiopsy studies of embryos using a range of PGT-A methods indicated a degree of variability in PGT-A results, which must be considered when interpreting the performance of the AI model.

WIDER IMPLICATIONS OF THE FINDINGS

These findings collectively support the use of this genetics AI model for the evaluation of embryo ploidy status in a clinical setting. Results can be used to aid in prioritizing and enriching for embryos that are likely to be euploid for multiple clinical purposes, including selection for transfer in the absence of alternative genetic testing methods, selection for cryopreservation for future use or selection for further confirmatory PGT-A testing, as required.

STUDY FUNDING/COMPETING INTEREST(S)

Life Whisperer Diagnostics is a wholly owned subsidiary of the parent company, Presagen Holdings Pty Ltd. Funding for the study was provided by Presagen with grant funding received from the South Australian Government: Research, Commercialisation, and Startup Fund (RCSF). 'In kind' support and embryology expertise to guide algorithm development were provided by Ovation Fertility. 'In kind' support in terms of computational resources provided through the Amazon Web Services (AWS) Activate Program. J.M.M.H., D.P. and M.P. are co-owners of Life Whisperer and Presagen. S.M.D., M.A.D. and T.V.N. are employees or former employees of Life Whisperer. S.M.D, J.M.M.H, M.A.D, T.V.N., D.P. and M.P. are listed as inventors of patents relating to this work, and also have stock options in the parent company Presagen. M.V. sits on the advisory board for the global distributor of the technology described in this study and also received support for attending meetings.

TRIAL REGISTRATION NUMBER

N/A.

Understanding the transmission dynamics of a large-scale measles outbreak in Southern Vietnam

OBJECTIVES

During 2018-2020, Southern Vietnam experienced a large measles outbreak of over 26,000 cases. We aimed to understand and quantify the measles spread in space-time dependence and the transmissibility during the outbreak.

METHODS

Measles surveillance reported cases between 1/2018 and 6/2020, vaccination coverage, and population data at provincial level were used. To illustrate the spatiotemporal pattern of disease spread, we employed the endemic-epidemic multivariate time series model decomposing measles risk additively into autoregressive, spatiotemporal, and endemic component. Likelihood-based estimation procedures were performed to determine the time-varying reproductive number R_e of measles.

RESULTS

Our analysis shows that measles incidence was associated with vaccination coverage heterogeneity and spatial interaction between provincial units. The risk of infections was dominated by between-province transmission (36.1% to 78.8%), followed by local endogenous transmission (4.1% to 61.5%) whereas the endemic behavior had a relatively small contribution (2.1% to 33.4%) across provinces. In the exponential phase of the epidemic, R_e was above the threshold with a maximum value of 2.34 (95%CI: 2.20-2.46).

CONCLUSION

Local vaccination coverage and human mobility are important factors contributing to the measles dynamics in Southern Vietnam and the high risk of inter-provincial transmission is of most concern. Strengthening disease surveillance is recommended, and further research is essential to understand the relative contribution of population immunity and control measures in measles epidemics.

A novel decentralized federated learning approach to train on globally distributed, poor quality, and protected private medical data

Training on multiple diverse data sources is critical to ensure unbiased and generalizable AI. In healthcare, data privacy laws prohibit data from being moved outside the country of origin, preventing global medical datasets being centralized for AI training. Data-centric, cross-silo federated learning represents a pathway forward for training on distributed medical datasets. Existing approaches typically require updates to a training model to be transferred to a central server, potentially breaching data privacy laws unless the updates are sufficiently disguised or abstracted to prevent reconstruction of the dataset. Here we present a completely decentralized federated learning approach, using knowledge distillation, ensuring data privacy and protection. Each node operates independently without needing to access external data. AI accuracy using this approach is found to be comparable to centralized training, and when nodes comprise poor-quality data, which is common in healthcare, AI accuracy can exceed the performance of traditional centralized training.

Predictive performance of the Garvan Fracture Risk Calculator: a registry-based cohort study

The G arvan Fracture Risk Calculator predicts risk of osteoporotic fractures. We evaluated its predictive performance in 16,682 women and 2839 men from Manitoba, Canada, and found significant risk stratification, with a strong gradient across scores. The tool outperformed clinical risk factors and bone mineral density for fracture risk stratification.

INTRODUCTION

The optimal model for fracture risk estimation to guide treatment decision-making remains controversial. Our objective was to evaluate the predictive performance of the Garvan Fracture Risk Calculator (FRC) in a large clinical registry from Manitoba, Canada.

METHODS

Using the population-based Manitoba Bone Mineral Density (BMD) registry, we identified women and men aged 50-95 years undergoing baseline BMD assessment from September 1, 2012, onwards. Five-year Garvan FRC predictions were generated from clinical risk factors (CRFs) with and without femoral neck BMD. We identified incident non-traumatic osteoporotic fractures (OFs) and hip fractures (HFs) from population-based healthcare data sources to March 31, 2018. Fracture risk was assessed from area under the receiver operating characteristic curve (AUROC). Cox regression analysis and calibration ratios (5-year observed/predicted) were assessed for risk quintiles. All analyses were sex stratified.

RESULTS

We included 16,682 women (mean age 66.6 + / - SD 8.7 years) and 2839 men (mean age 68.7 + / - SD 10.2 years). During a mean observation time of 2.6 years, incident OFs were identified in 681 women and 140 men and HFs in 199 women and 22 men. AUROC showed significant fracture risk stratification with the Garvan FRC. Tool predictions without BMD were better than from age or decreasing weight, and the tool with BMD performed better than BMD alone. Garvan FRC with BMD performed better than without BMD, especially for HF prediction (AUROC 0.86 in women, 0.82 in men). There was a strong gradient of increasing risk across Garvan FRC quintiles (highest versus lowest, hazard ratios women 5.75 and men 3.43 for any OF; women 101.6 for HF). Calibration differences were noted, with both over- and underestimation in risk.

CONCLUSIONS

Garvan FRC outperformed CRFs and BMD alone for fracture risk stratification, particularly for HF, but may require recalibration for accurate predictions in this population.

Seroprevalence of SARS-CoV-2 Neutralizing Antibodies among Blood Donors in Ho Chi Minh City, Vietnam, August-November 2020

Relatively little is known about the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies and COVID-19-related behaviors in the general population in Vietnam, where the first case of COVID-19 was detected on January 22, 2020. We surveyed a group of 885 blood donors at community blood donation sessions in Ho Chi Minh City from August 27 to November 7, 2020. Blood was collected to test for SARS-CoV-2 IgG antibodies using the plaque reduction neutralization test. We adjusted the seroprevalence by weight for ages 18 to 59 years old obtained from the 2019 population census. The weighted seroprevalence estimate for SARS-CoV-2 neutralizing IgG antibodies was 0.20% (95% CI, 0.05-0.81). Reports of usually or always using a mask in public places were observed at high levels of 28.6% and 67.5%, respectively. The percentages of usually or always washing hands with soap or disinfecting with hand sanitizer after touching items in public places were 48.0% and 37.6%, respectively. Although our findings suggest undocumented exposure to the virus, the seroprevalence of SARS-CoV-2 IgG antibodies among blood donors was low in this city.

Simplified 0+1 and 1+1 pneumococcal vaccine schedules in Ho Chi Minh City, Vietnam: protocol for a randomised controlled trial

INTRODUCTION

Reduced-dose schedules offer a more efficient and affordable way to use pneumococcal conjugate vaccines (PCVs). Such schedules rely primarily on the maintenance of herd protection. The Vietnam Pneumococcal Trial II (VPT-II) will evaluate reduced-dose schedules of PCV10 and PCV13 utilising an unvaccinated control group. Schedules will be compared in relation to their effect on nasopharyngeal carriage and immunogenicity.

METHODS AND ANALYSIS

VPT-II is a single-blind open-label randomised controlled trial of 2500 infants in three districts of Ho Chi Minh City, Vietnam. Eligible infants have no clinically significant maternal or perinatal history and are born at or after 36 weeks' gestation. Participants are recruited at 2 months of age and randomly assigned (4:4:4:4:9) using block randomisation, stratified by district, to one of five groups: four intervention groups that receive PCV10 in a 0+1 (at 12 months) or 1+1 (at 2 and 12 months) schedule or PCV13 in the same 0+1 or 1+1 schedule; and a control group (that receives a single dose of PCV10 at 24 months). Participants are followed up to 24 months of age. The primary outcome is vaccine-type pneumococcal carriage at 24 months of age. Secondary outcomes are carriage at 6, 12 and 18 months of age and the comparative immunogenicity of the different schedules in terms of antibody responses, functional antibody responses and memory B cell responses.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Human Research Ethics Committee of the Royal Children's Hospital Melbourne and the Vietnam Ministry of Health Ethics Committee. The results, interpretation and conclusions will be presented to parents and guardians, at national and international conferences and published in peer-reviewed open access journals.

TRIAL REGISTRATION NUMBER

NCT03098628.

Immune Profiling of Cord Blood From Preterm and Term Infants Reveals Distinct Differences in Pro-Inflammatory Responses

Background

Preterm infants are highly vulnerable to infectious disease. While many factors are likely to contribute to this enhanced susceptibility, the immature nature of the preterm immune system is postulated as one key factor.

Methods

In our study, we used high-dimensional flow cytometry and cytokine assays to characterise the immune profiles in 25 preterm (range: 30.4-34.1 weeks gestational age) and 25 term infant (range: 37-40 weeks gestational age) cord blood samples.

Results

We found that preterm infants exhibit reduced frequencies of monocytes, CD56^bright NK cells, CD8+ T-cells, γδ T-cells and an increased frequency of intermediate monocytes, CD4+ T-cells, central memory CD4+ and CD8+ T-cells, Tregs and transitional B-cells compared to term infants. Pro-inflammatory cytokines IL-1β, IL-6 and IL-17A were lower in preterm infants in addition to chemokines IL-8, eotaxin, MIP-1α and MIP-1β. However, IL-15 and MCP-1 were higher in preterm infants.

Conclusion

Overall, we identify key differences in pro-inflammatory immune profiles between preterm and term infants. These findings may help to explain why preterm infants are more susceptible to infectious disease during early life and facilitate the development of targeted interventions to protect this highly vulnerable group.

Development and validation of the risk engine for an Australian Health Economics Model of Osteoporosis

The Australian Health Economics Model of Osteoporosis (AusHEMO) has shown good face, internal and cross validities, and can be used to assist healthcare decision-making in Australia.

PURPOSE

This study aimed to document and validate the risk engine of the Australian Health Economics Model of Osteoporosis (AusHEMO).

METHODS

AusHEMO is a state-transition microsimulation model. The fracture risks were simulated using fracture incidence rates from the Dubbo Osteoporosis Epidemiology Study. The AusHEMO was validated regarding its face, internal and cross validities. Goodness-of-fit analysis was conducted and Lin's coefficient of agreement and mean absolute difference with 95% limits of agreement were reported.

RESULTS

The development of AusHEMO followed general and osteoporosis-specific health economics guidelines. AusHEMO showed good face validity regarding the model's structure, evidence, problem formulation and results. In addition, the model has been proven good internal and cross validities in goodness-of-fit test. Lin's coefficient was 0.99, 1 and 0.94 for validation against the fracture incidence rates, Australian life expectancies and residual lifetime fracture risks, respectively.

CONCLUSIONS

In summary, the development of the risk engine of AusHEMO followed the best practice for osteoporosis disease modelling and the model has been shown to have good face, internal and cross validities. The AusHEMO can be confidently used to predict long-term fracture-related outcomes and health economic evaluations when costs data are included. Health policy-makers in Australia can use the AusHEMO to select which osteoporosis interventions such as medications and public health interventions represent good value for money.

Anal human papillomavirus prevalence and risk factors among men who have sex with men in Vietnam

•

HPV infection in men having sex with men (MSM) was studied in two cities of Vietnam

•

Prevalence of any HPV and HPV16/18 among MSM was 32.3% and 11.0%, respectively

•

High-risk HPV infections in MSM were associated with risky sexual behaviours

•

A targeted HPV vaccination strategy would be beneficial for MSM in Vietnam

Objectives

Men who have sex with men (MSM) are at risk of human papillomavirus (HPV)-related cancers, while published data are scarce. This study determined HPV prevalence and risk factors in MSM in Vietnam to inform HPV prevention strategies in this key population.

Methods

A cross-sectional study of 799 MSM aged 16-50 years was conducted in Vietnam in 2017-2018. Information was collected on risk behaviours, and knowledge of HPV and anal cancer; rectal swabs were taken to detect anal HPV infection. An in-house polymerase chain reaction and Genoflow HPV array test kit were used for HPV detection and genotyping.

Results

The median age of the study participants was 25 years (range 18-52). Overall prevalence of any HPV and HPV16/18 infection was 32.3% and 11.0%, respectively. A higher prevalence of high-risk HPV infection to all 14 types tested was found in Ho Chi Minh City (30.9%) than in Hanoi (18.4%). High-risk HPV infection was associated with inconsistent condom use and history of engaging in sex under the influence of drugs (adjusted odds ratio (aOR), 2.27; 95% CI, 1.48-10.67), as well as having multiple sexual partners (aOR, 1.01; 95% CI, 1.00–1.02).

Conclusions

High-risk anal HPV infections in Vietnamese MSM were significantly associated with risky sexual behaviours. A targeted HPV vaccination strategy would have substantial benefit for MSM in Vietnam.

Development of the Asia Pacific Consortium on Osteoporosis (APCO) Framework: clinical standards of care for the screening, diagnosis, and management of osteoporosis in the Asia-Pacific region

Guidelines for doctors managing osteoporosis in the Asia-Pacific region vary widely. We compared 18 guidelines for similarities and differences in five key areas. We then used a structured consensus process to develop clinical standards of care for the diagnosis and management of osteoporosis and for improving the quality of care.

PURPOSE

Minimum clinical standards for assessment and management of osteoporosis are needed in the Asia-Pacific (AP) region to inform clinical practice guidelines (CPGs) and to improve osteoporosis care. We present the framework of these clinical standards and describe its development.

METHODS

We conducted a structured comparative analysis of existing CPGs in the AP region using a "5IQ" model (identification, investigation, information, intervention, integration, and quality). One-hundred data elements were extracted from each guideline. We then employed a four-round Delphi consensus process to structure the framework, identify key components of guidance, and develop clinical care standards.

RESULTS

Eighteen guidelines were included. The 5IQ analysis demonstrated marked heterogeneity, notably in guidance on risk factors, the use of biochemical markers, self-care information for patients, indications for osteoporosis treatment, use of fracture risk assessment tools, and protocols for monitoring treatment. There was minimal guidance on long-term management plans or on strategies and systems for clinical quality improvement. Twenty-nine APCO members participated in the Delphi process, resulting in consensus on 16 clinical standards, with levels of attainment defined for those on identification and investigation of fragility fractures, vertebral fracture assessment, and inclusion of quality metrics in guidelines.

CONCLUSION

The 5IQ analysis confirmed previous anecdotal observations of marked heterogeneity of osteoporosis clinical guidelines in the AP region. The Framework provides practical, clear, and feasible recommendations for osteoporosis care and can be adapted for use in other such vastly diverse regions. Implementation of the standards is expected to significantly lessen the global burden of osteoporosis.

An Evaluation of the Rabies Surveillance in Southern Vietnam

Introduction: Rabies is endemic in Vietnam and has been a statutory notifiable infectious disease since 1998. We, herein, assessed the performance of rabies surveillance in Southern Vietnam and identified areas for improvement.

Materials and Methods: We analyzed data on human rabies cases reported during 1991–2018. We adapted guidelines from the U.S. Centers for Disease Control and Prevention to evaluate attributes of surveillance. Between June and November 2018, we interviewed a total of 145 staff from hospitals, preventive medicine centers, and animal health offices at provincial and district levels in five southern provinces.

Results: Between 2009 and 2018, an average of nine cases of human rabies (range: 4–20 cases) was reported annually in Southern Vietnam, representing an incidence of 2.7 cases per 10 million population. The highest incidence was observed in 2018 (5.5 cases per 10 million population). Survey data suggested that only 24% (13/53) of participants agreed that the monthly report template was easy to complete and that 42% (23/55) indicated that the change from the paper-based to the electronic case notification systems was easy. Only 7% (2/29) of human rabies cases were reported timely, and 65% (13/20) successfully collected specimens. Approximately 39% (56/144) of staff were aware of turning surveillance data into prevention activities, and 21% (31/145) witnessed data used for strategic program decision making.

Conclusions: Although rabies surveillance was quite simple, flexible, and accepted in southern Vietnam, simplifying the report forms, training staff, and improving the timeliness of reporting and data usage are highly recommended for a better implementation of rabies surveillance.

Rotavirus genotype trends from 2013 to 2018 and vaccine effectiveness in southern Vietnam

OBJECTIVES

Rotavirus (RV) genotypes vary geographically, and this can affect vaccine effectiveness (VE). This study investigated the genotype distribution of RV and explored VE before introducing the RV vaccine to the national immunization programme in Vietnam.

METHODS

This hospital-based surveillance study was conducted at Children's Hospital 1, Ho Chi Minh City in 2013-2018. Stool samples and relevant data, including vaccination history, were collected from children aged <5 years who were hospitalized with gastroenteritis. RV was detected using enzyme immunoassays and then genotyped. Children aged ≥6 months were included in the VE analysis.

RESULTS

Overall, 5176 children were included in this study. RV was detected in 2421 children (46.8%). RV positivity decreased over the study period and was associated with age, seasonality, location and previous vaccination. Among 1105 RV-positive samples, G3P[8] was the most prevalent genotype (43.1%), followed by G8P[8] (19.7%), G1P[8] (12.9%) and G2P[4] (12.9%). Overall VE was 69.7% [95% confidence interval (CI) 53.3-80.6%] in fully vaccinated children and 58.6% (95% CI 44.1-69.4%) in children who had received at least one dose of RV vaccine. VE was highest for G3P[8] (95% CI 75.1-84.5%) and lowest for G2P[4] (95% CI 32.4-57.2%).

CONCLUSIONS

RV remains a major cause of acute gastroenteritis requiring hospitalization in southern Vietnam. The RV vaccine is effective, but its effectiveness varies with RV genotype.

In the interest of public safety: rapid response to the COVID-19 epidemic in Vietnam

We describe the status of the COVID-19 epidemic in Vietnam, major response successes, factors that prompted implementation of certain public health actions, and the impact of these actions. In addition, information for three case studies is reported, with crucial learnings to inform future response. Findings from this study suggest that as early as 20 January 2020, Vietnam held a national risk assessment, established a national COVID-19 Response Plan and Technical Treatment and Care Guidelines, and prepared public health laboratories to accurately diagnose cases and hospitals to effectively treat patients. The first COVID-19 case was detected on 23 January. As of 30 September, there had been three waves of the COVID-19 epidemic totalling 1095 cases, and resulting in 35 deaths all among people with underlying health conditions. Evidence of potential transmission of SARS-CoV-2 from a commercial passenger flight inbound to Vietnam was reported. This study also highlights the importance of early technical preparedness, strong political commitment, multisectoral and multilevel efforts, increased resourcing and coordination towards an effective COVID-19 response. Controlling outbreaks in settings, such as crowded public places (bars and hospitals), within certain villages and over cities, required early detection, aggressive trace-test-quarantine efforts, a geographically extensive lockdown area and an adoption of several non-pharmaceutical interventions. Many low-income and middle-income countries have experienced their second or third wave of the COVID-19 epidemic, and they can learn from Vietnam's response across the three epidemic waves. Swift governmental action, strict border control measures, effective communication of health promotion measures, widespread community engagement, expanded testing capacity and effective social measures to slow the spread of SARS-CoV-2, are highly important in these locations.

Assessing the clinical utility of genetic profiling in fracture risk prediction: a decision curve analysis

Using decision curve analysis on 2188 women and 1324 men, we found that an osteogenomic profile constructed from 62 genetic variants improved the clinical net benefit of fracture risk prediction over and above that of clinical risk factors and BMD.

INTRODUCTION

Genetic profiling is a promising tool for assessing fracture risk. This study sought to use the decision curve analysis (DCA), a novel approach to determine the impact of genetic profiling on fracture risk prediction.

METHODS

The study involved 2188 women and 1324 men, aged 60 years and above, who were followed for up to 23 years. Bone mineral density (BMD) and clinical risk factors were obtained at baseline. The incidence of fracture and mortality were recorded. A weighted individual genetic risk score (GRS) was constructed from 62 BMD-associated genetic variants. Four models were considered: CRF (clinical risk factors); CRF + GRS; Garvan model (GFRC) including CRF and femoral neck BMD; and GFRC + GRS. The DCA was used to evaluate the clinical net benefit of predictive models at a range of clinically reasonable risk thresholds.

RESULTS

In both women and men, the full model GFRC + GRS achieved the highest net benefits. For 10-year risk threshold > 18% for women and > 15% for men, the GRS provided net benefit above those of the CRF models. At 20% risk threshold, adding the GRS could help to avoid 1 additional treatment per 81 women or 1 per 24 men compared with the Garvan model. At lower risk thresholds, there was no significant difference between the four models.

CONCLUSIONS

The addition of genetic profiling into the clinical risk factors can improve the net clinical benefit at higher risk thresholds of fracture. Although the contribution of genetic profiling was modest in the presence of BMD + CRF, it appeared to be able to replace BMD for fracture prediction.

IQ driving QI: the Asia Pacific Consortium on Osteoporosis (APCO): an innovative and collaborative initiative to improve osteoporosis care in the Asia Pacific

Asia Pacific Consortium on Osteoporosis (APCO) comprises of clinical experts from across the Asia Pacific region, uniting to develop solutions to problems facing osteoporosis management and care. The vision of APCO is to reduce the burden of osteoporosis and fragility fractures in the Asia Pacific region.

INTRODUCTION

The Asia Pacific (AP) region comprises 71 countries with vastly different healthcare systems. It is predicted that by 2050, more than half the world's hip fractures will occur in this region. The Asia Pacific Consortium on Osteoporosis (APCO) was set up in May 2019 with the vision of reducing the burden of osteoporosis and fragility fractures in the AP region.

METHODS

APCO has so far brought together 39 clinical experts from countries and regions across the AP to develop solutions to challenges facing osteoporosis management and fracture prevention in this highly populous region of the world. APCO aims to achieve its vision by engaging with relevant stakeholders including healthcare providers, policy makers and the public. The initial APCO project is to develop and implement a Framework of pan-AP minimum clinical standards for the screening, diagnosis and management of osteoporosis.

RESULTS AND CONCLUSIONS

The Framework will serve as a platform upon which new national clinical guidelines can be developed or existing guidelines be revised, in a standardised fashion. The Framework will also facilitate benchmarking for provision of quality of care. It is hoped that the principles underlying the formation and functioning of APCO can be adopted by other regions and that every health care facility and progressively every country in the world can follow our aspirational path and progress towards best practice.

Estimated Number of People who Inject Drugs in Ho Chi Minh City, Vietnam: Findings from a Two-survey Capture-Recapture Population Size Estimation Exercise

BACKGROUND

HIV/AIDS program managers in Ho Chi Minh City (HCMC), Vietnam have always relied on the police reports and the UNAIDS Estimation and Projection Package for population size estimation of People Who Inject Drugs (PWID).

METHODS

We used Respondent-driven Sampling (RDS) to implement a two-source capture-recapture study to estimate the population size of PWID in HCMC in 2017. The study was implemented in seven out of 24 districts and included men and women ages 18 years and older who reported injecting illicit drugs in the last 90 days, and who had lived in the city for the past six months. Estimates of the PWID population size for each of the seven districts were calculated accounting for the RDS sampling design. These were then adjusted to account for the district sampling probabilities to give an estimate for HCMC. Chapman two-source capture-recapture estimates of population size, based on simple random sampling assumptions, were also calculated for comparison.

RESULTS

The estimates resulted in a population size for HCMC of 19,155 [95% Confidence Interval (CI): 17,006-25,039] using the RDS approach and 17,947 (95% CI: 15,968-19,928), using the Chapman approach.

CONCLUSION

The two-survey capture-recapture exercise provided estimates of PWID in HCMC - based on Chapman estimator and RDS approach - are similar. For planning HIV prevention and care service needs among PWID in HCMC, both estimates may need to be taken into consideration together with size estimates from other sources.

A critical review on life cycle assessment and plant-wide models towards emission control strategies for greenhouse gas from wastewater treatment plants

For decades, there has been a strong interest in mitigating greenhouse gas (GHG) emissions from wastewater treatment plants (WWTPs). Numerous models were developed to measure the emissions and propose the quantification. Existing studies looked at the relationship between GHG emissions and operational cost (OCI), which is one of the most important indicators for decision-makers. Other parameters that can influence the control strategies include the effluent quality (EQI) and total environmental impacts. Plant-wide models are reliable methods to examine the OCI, EQI and GHG emissions while Life cycle assessment (LCA) works to assess the potential environmental impacts. A combined LCA and plant-wide model proved to be a valuable tool evaluating and comparing strategies for the best performance of WWTPs. For this study involving a WWTP, the benchmark model is used while LCA is the decision tool to find the most suitable treatment strategy. LCA adds extra criteria that complement the existing criteria provided by such models. Complementing the cost/performance criteria is proposed for plant-wide models, including environmental evaluation, based on LCA, which provides an overall better assessment of WWTPs. It can capture both the dynamic effects and potential environmental impacts. This study provides an overview of the integration between plant-wide models and LCA.

Association between trabecular bone score and type 2 diabetes: a quantitative update of evidence

Patients with type 2 diabetes have an increased risk of fracture despite having a higher areal bone mineral density. This meta-analysis showed that compared with controls, diabetic patients had a lower trabecular bone score (TBS) than non-diabetic individuals, suggesting that TBS can be a useful measurement for the assessment of fracture risk in diabetic patients.

INTRODUCTION

The association between type 2 diabetes and trabecular bone score (TBS) has not been clear. The present study sought to answer the specific question of whether patients with type 2 diabetes have a lower TBS than those without diabetes.

METHODS

Using electronic and manual search, we identified 12 studies that had examined the association between type 2 diabetes and TBS between 2013 and 2019. These studies involved 35,546 women and 4962 men aged 30 years and older. We extracted the mean and standard deviation of TBS for patients with and without diabetes. The synthesis of effect sizes was done by the random effects meta-analysis model.

RESULTS

Patients with diabetes had significantly lower TBS than those without diabetes, with standardized mean difference being - 0.31 (95% CI, - 0.45 to - 0.16). The difference was greater in women (- 0.50; 95% CI, - 0.69 to - 0.32) than in men (- 0.04; 95% CI, - 0.17 to 0.10). Compared with normal individuals, those with prediabetes had significantly lower TBS (d = - 0.13; 95% CI, - 0.23 to - 0.04; P = 0.005). There was heterogeneity between the studies, with the index of inconsistency (I²) ranging from 92% (in women) to 69.5% (in men).

CONCLUSION

Patients with type 2 diabetes have a lower TBS than non-diabetic individuals, suggesting that TBS can be a useful measurement for the assessment of fracture risk in diabetic patients.

A spatial-temporal statistical analysis of health seasonality: explaining HFMD infections within a children population along the Vietnamese south central coast

Background

Various neglected tropical diseases show spatially changing seasonality at small areas. This phenomenon has received little scientific attention so far. Our study contributes to advancing the understanding of its drivers. This study focuses on the effects of the seasonality of increasing social contacts on the incidence proportions at multiple district level of the childhood hand-foot-mouth disease in Da Nang city, Viet Nam from 2012 to 2016.

Methods

We decomposed the nonstationary time series of the incidence proportions for the nine spatial-temporal (S-T) strata in the study area, where S indicates the spatial and T the temporal stratum. The long-term trends and the seasonality are presented by the Fourier series. To study the effects of the monthly average ambient temperature and the period of preschooling, we developed a spatial-temporal autoregressive model.

Results

Seasonality of childhood hand-foot-mouth disease incidence proportions shows two peaks in all spatial strata annually: large peaks synchronously in April and small ones asynchronously during the preschooling period. The peaks of the average temperature are asynchronous with the seasonal peaks of the childhood hand-foot-mouth disease incidence proportions in the period between January and May, with the negative values of the regression coefficients for all spatial strata, respectively: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\beta}_{{\mathrm{T}}_11}^{S_1}=-0.18\pm 0.07;{\beta}_{{\mathrm{T}}_11}^{S_2}=-0.25\pm 0.09;{\beta}_{{\mathrm{T}}_11}^{S_3}=-0.14\pm 0.05 $$\end{document}βT11S1=−0.18±0.07;βT11S2=−0.25±0.09;βT11S3=−0.14±0.05. The increasingly cumulative preschooling period and the seasonal component of the incidence proportions are negatively correlated in the period between August and December, with the negative values of the regression coefficients for all temporal strata, respectively: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\beta}_{{\mathrm{T}}_32}^{S_1}=-0.40\pm 0.01;{\beta}_{{\mathrm{T}}_32}^{S_2}=-0.29\pm 0.00;{\beta}_{{\mathrm{T}}_32}^{S_3}=-0.25\pm 0.01 $$\end{document}βT32S1=−0.40±0.01;βT32S2=−0.29±0.00;βT32S3=−0.25±0.01.

Conclusions

The study shows that social contact amongst children under five years of age is the important driving factor of the dynamics of the childhood hand-foot-mouth disease outbreaks in the study area. The preschooling season when children’s contact with each other increases stimulates the geographical variation of the seasonality of childhood hand-foot-mouth disease infections at small areas in the study area.

Mortality risk reduction differs according to bisphosphonate class: a 15-year observational study

In this prospective cohort of 6120 participants aged 50+, nitrogen-bisphosphonates but not non-nitrogen bisphosphonates were associated with a significant 34% mortality risk reduction compared to non-treated propensity score matched controls. These findings open new avenues for research into mechanistic pathways.

INTRODUCTION

Emerging evidence suggests that bisphosphonates (BP), first-line treatment of osteoporosis, are associated with reduced risks for all-cause mortality. This study aimed to determine the association between different BP types and mortality risk in participants with or without a fracture.

METHODS

A prospective cohort study of users of different BPs matched to non-users by propensity score (age, gender, co-morbidities, fragility fracture status) and time to starting the BP medication from the population-based Canadian Multicentre Osteoporosis Study from nine Canadian centres followed from 1995 to 2013. Mortality risk for bisphosphonate users vs matched non-users was assessed using pairwise multivariable Cox proportional hazards models.

RESULTS

There were 2048 women and 308 men on BP and 1970 women and 1794 men who did not receive medication for osteoporosis. The relationship between BP and mortality risk was explored in three separate 1:1 propensity score-matched cohorts of BP users and no treatment (etidronate, n = 599, alendronate, n = 498, and risedronate n = 213). Nitrogen BP (n-BP) (alendronate and risedronate) was associated with lower mortality risks [pairwise HR, 0.66 (95% CI, 0.48-0.91)] while the less potent non-n-BP, etidronate, was not [pairwise HR: 0.89 (95% CI, 0.66-1.20)]. A direct comparison between n-BP and etidronate (n = 340 pairs) also suggested a better survival for n-BP [paired HR, 0.47 (95%CI, (95% CI, 031-0.70)] for n-BP vs. etidronate].

CONCLUSION

Compared to no treatment, nitrogen but not non-nitrogen bisphosphonates appear to be associated with better survival.

Evaluation of the Efficacy of Commercial Disinfectants Against Fusarium oxysporum f. sp. cubense Race 1 and Tropical Race 4 Propagules

Panama disease caused by Fusarium oxysporum f. sp. cubense has devastated banana production worldwide. This work aimed to determine effective disinfectants against two races of F. oxysporum f. sp. cubense, race 1 and tropical race 4 (TR4), for implementation with on-farm biosecurity procedures against this disease following the outbreak of TR4 in North Queensland in 2015. A total of 32 commercial disinfectants were screened and their activity was assessed after ≤30 s, 5 min, 30 min, and 24 h of contact with an F. oxysporum f. sp. cubense suspension containing 10⁵ chlamydospores/ml without and with soil added (0.05 g/ml). Of the disinfectants tested, the quaternary ammonium compounds containing ≥10% active ingredient were found to be the most effective against both F. oxysporum f. sp. cubense races. These products, when used at a 1:100 dilution, completely inhibited the survival of all F. oxysporum f. sp. cubense propagules across all the contact times regardless of the absence or presence of soil. The bioflavonoid product EvoTech 213 and bleach (10% sodium hypochlorite) used at a 1:10 dilution also eliminated all F. oxysporum f. sp. cubense propagules across all the contact times. None of the detergent-based or miscellaneous products tested were completely effective against both F. oxysporum f. sp. cubense races even used at a 1:10 dilution. Soil decreases the efficacy of disinfectants and therefore must be removed from contaminated items before treatments are applied.

Population Size Estimation of Venue-Based Female Sex Workers in Ho Chi Minh City, Vietnam: Capture-Recapture Exercise

Background

There is limited population size estimation of female sex workers (FSWs) in Ho Chi Minh City (HCMC)—the largest city in Vietnam. Only 1 population size estimation among venue-based female sex workers (VFSWs) was conducted in 2012 in HCMC. Appropriate estimates of the sizes of key populations are critical for resource allocation to prevent HIV infection.

Objective

The aim of this study was to estimate the population size of the VFSWs from December 2016 to January 2017 in HCMC, Vietnam.

Methods

A multistage capture-recapture study was conducted in HCMC. The capture procedures included selection of districts using stratified probability proportion to size, mapping to identify venues, approaching all VFSWs to screen their eligibility, and then distribution of a unique object (a small pink makeup bag) to all eligible VFSWs in all identified venues. The recapture exercise included equal probability random selection of a sample of venues from the initial mapping and then approaching FSWs in those venues to determine the number and proportion of women who received the unique object. The proportion and associated confidence bounds, calculated using sampling weights and accounting for study design, were then divided by the number of objects distributed to calculate the number of VFSWs in the selected districts. This was then multiplied by the inverse of the proportion of districts selected to calculate the number of VFSWs in HCMC as a whole.

Results

Out of 24 districts, 6 were selected for the study. Mapping identified 573 venues across which 2317 unique objects were distributed in the first capture. During the recapture round, 103 venues were selected and 645 VFSWs were approached and interviewed. Of those, 570 VFSWs reported receiving the unique object during the capture round. Total estimated VFSWs in the 6 selected districts were 2616 (95% CI 2445-3014), accounting for the fact that only 25% (6/24) of total districts were selected gives an overall estimate of 10,465 (95% CI 9782-12,055) VFSWs in HCMC.

Conclusions

The capture-recapture exercise provided an estimated number of VFSWs in HCMC. However, for planning HIV prevention and care service needs among all FSWs, studies are needed to assess the number of sex workers who are not venue-based, including those who use social media platforms to sell services.

Contribution of bone turnover markers to the variation in bone mineral density: a study in Vietnamese men and women

The present cross-sectional study constructed reference ranges for bone resorption marker beta isomerized form of C-terminal crosslinking telopeptides of type I collagen (beta-CTX) and bone formation marker procollagen type 1 N-terminal propeptide (PINP) for the Vietnamese population. We have further shown that for a given age and weight, higher levels of beta-CTX were significantly associated with bone mineral density in men and women.

INTRODUCTION

Normal bone is constantly renewed by two opposing processes of resorption and formation which can be reflected by bone turnover markers (BTMs). This study sought to define the contribution of BTMs to the variation in bone mineral density (BMD) in normal individuals.

METHODS

The study involved 205 men and 432 women aged between 18 and 87, who were randomly selected from various districts within Ho Chi Minh City, Vietnam. Fasting serum levels of PINP and beta-CTX were determined by electrochemiluminescence (Roche, ECLIA). BMD at the lumbar spine (LS) and femoral neck (FN) was measured by dual-energy x-ray absorptiometry (Hologic, Waltham, MA, USA).

RESULTS

Among those aged < 50 years, women had lower PINP and beta-CTX levels than men, but among those aged > 50 years, women had higher PINP and beta-CTX levels than men. In the multiple linear regression analysis, beta-CTX-but not PINP-was significantly associated with both femoral neck (P = 0.008) and lumbar spine BMD (P = 0.008) and the association was independent of gender, age, and body weight. The proportion of variance in BMD attributable to beta-CTX was 1% for femoral neck BMD and 2% for lumbar spine BMD.

CONCLUSION

The elevation in bone formation marker PINP and bone resorption marker beta-CTX in postmenopausal women was greater than in elderly men. However, only beta-CTX was modestly but significantly associated with BMD.

Expanding severe acute respiratory infection (SARI) surveillance beyond influenza: The process and data from 1 year of implementation in Vietnam

BACKGROUND

In 2016, as a component of the Global Health Security Agenda, the Vietnam Ministry of Health expanded its existing influenza sentinel surveillance for severe acute respiratory infections (SARI) to include testing for 7 additional viral respiratory pathogens. This article describes the steps taken to implement expanded SARI surveillance in Vietnam and reports data from 1 year of expanded surveillance.

METHODS

The process of expanding the suite of pathogens for routine testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) included laboratory trainings, procurement/distribution of reagents, and strengthening and aligning SARI surveillance epidemiology practices at sentinel sites and regional institutes (RI).

RESULTS

Surveillance data showed that of 4003 specimens tested by the RI laboratories, 20.2% (n = 810) were positive for influenza virus. Of the 3193 influenza-negative specimens, 41.8% (n = 1337) were positive for at least 1 non-influenza respiratory virus, of which 16.2% (n = 518), 13.4% (n = 428), and 9.6% (n = 308) tested positive for respiratory syncytial virus, rhinovirus, and adenovirus, respectively.

CONCLUSIONS

The Government of Vietnam has demonstrated that expanding respiratory viral surveillance by strengthening and building upon an influenza platform is feasible, efficient, and practical.

Type 2 diabetes is associated with higher trabecular bone density but lower cortical bone density: the Vietnam Osteoporosis Study

It is not clear why type 2 diabetes (T2D) has an increased risk of fracture despite higher areal bone mineral density. This study showed that compared with controls, T2D patients had higher trabecular bone density but lower cortical bone density, resulting in a lower bone strength.

INTRODUCTION

To define the association between type 2 diabetes and bone architecture and measures of bone strength.

METHODS

The study was part of the Vietnam Osteoporosis Study, in which 1115 women and 614 men aged ≥ 30 were randomly recruited from Ho Chi Minh City. HbA_1c levels were measured with analyzers ADAMS™ A_1c HA-8160 (Arkray, Kyoto, Japan). The diagnosis of T2D was made if HbA1c was ≥ 6.5%. Trabecular and cortical volumetric bone density (vBMD) was measured in the forearm and leg by a pQCT XCT2000 (Stratec, Germany). Polar stress strain index (pSSI) was derived from the pQCT measurements. Difference in bone parameters between T2D and non-diabetic individuals was assessed by the number of standard deviations (effect size [ES]) by the propensity score analysis.

RESULTS

The prevalence of T2D was ~ 8%. The results of propensity score matching for age, sex, and body mass index in 137 pairs of diabetic and non-diabetic individuals showed that T2D patients had significantly higher distal radius trabecular vBMD (ES 0.26; 95% CI, 0.02 to 0.50), but lower cortical vBMD (ES - 0.22; - 0.46 to 0.00) and reduced pSSI (ES - 0.23; - 0.47 to - 0.02) compared with non-diabetic individuals. Multiple linear regression analysis based on the entire sample confirmed the results of the propensity score analysis.

CONCLUSION

Compared with non-diabetic individuals, patients with T2D have greater trabecular but lower cortical vBMD which leads to lower bone strength.

Effects of Antifreeze Protein Supplementation on the Development of Porcine Morulae Stored at Hypothermic Temperatures

BACKGROUND

Short-term storage is valuable method to reuse manipulated embryos.

OBJECTIVE

The present study evaluated the effects of antifreeze protein (AFP) supplementation on the quality and development of in vitro-produced porcine morulae after short-term storage (24 h).

MATERIALS AND METHODS

The morulae were stored with various concentrations of AFP type III for 24 h at 5, 15 and 25C.

RESULTS

Supplementation of AFP type III (1.0 microgram per mL) improved the developmental competence of embryos stored at 25C. The proportions of DNA-fragmented nuclei in the blastocysts did not differ between the embryos stored at 25C and the control embryos without storage treatment. However, the developmental competence of embryos stored at hypothermic temperatures decreased relative to that of the control embryos.

CONCLUSION

Supplementation of AFP type III (1.0 microgram per mL) maintained the quality of embryos stored at 25C, but did not have beneficial effects on the development of embryos stored at hypothermic temperatures.

[A man with severe skin rash]

A 31-year-old man visited the outpatient clinic Dermatology with an exacerbation of his atopic eczema. Since a few day vesicles and crusts had appeared and his eyelids were swollen. He was known to have eczema, for which he was treated with ciclosporin 200 mg 2 times a day (4 mg/kg per day) since four months. Under this treatment the eczema used to be under control. There were no neurological symptoms or vision problems. At physical examination we saw erythematous papules, vesicles, superficial erosions and crusts on all body regions, but especially on the trunk and in the main neck region. The patient was diagnosed with eczema herpeticum and he was treated with intravenous aciclovir 1000 mg 3 times a day (10 mg/kg 3 dd) and flucloxacillin 1000 mg 4 times a day for seven days.

The steroid metabolome in women with premenstrual dysphoric disorder during GnRH agonist-induced ovarian suppression: effects of estradiol and progesterone addback

Clinical evidence suggests that symptoms in premenstrual dysphoric disorder (PMDD) reflect abnormal responsivity to ovarian steroids. This differential steroid sensitivity could be underpinned by abnormal processing of the steroid signal. We used a pharmacometabolomics approach in women with prospectively confirmed PMDD (n=15) and controls without menstrual cycle-related affective symptoms (n=15). All were medication-free with normal menstrual cycle lengths. Notably, women with PMDD were required to show hormone sensitivity in an ovarian suppression protocol. Ovarian suppression was induced for 6 months with gonadotropin-releasing hormone (GnRH)-agonist (Lupron); after 3 months all were randomized to 4 weeks of estradiol (E2) or progesterone (P4). After a 2-week washout, a crossover was performed. Liquid chromatography/tandem mass spectrometry measured 49 steroid metabolites in serum. Values were excluded if >40% were below the limit of detectability (n=21). Analyses were performed with Wilcoxon rank-sum tests using false-discovery rate (q<0.2) for multiple comparisons. PMDD and controls had similar basal levels of metabolites during Lupron and P4-derived neurosteroids during Lupron or E2/P4 conditions. Both groups had significant increases in several steroid metabolites compared with the Lupron alone condition after treatment with E2 (that is, estrone-SO4 (q=0.039 and q=0.002, respectively) and estradiol-3-SO4 (q=0.166 and q=0.001, respectively)) and after treatment with P4 (that is, allopregnanolone (q=0.001 for both PMDD and controls), pregnanediol (q=0.077 and q=0.030, respectively) and cortexone (q=0.118 and q=0.157, respectively). Only sulfated steroid metabolites showed significant diagnosis-related differences. During Lupron plus E2 treatment, women with PMDD had a significantly attenuated increase in E2-3-sulfate (q=0.035) compared with control women, and during Lupron plus P4 treatment a decrease in DHEA-sulfate (q=0.07) compared with an increase in controls. Significant effects of E2 addback compared with Lupron were observed in women with PMDD who had significant decreases in DHEA-sulfate (q=0.065) and pregnenolone sulfate (q=0.076), whereas controls had nonsignificant increases (however, these differences did not meet statistical significance for a between diagnosis effect). Alterations of sulfotransferase activity could contribute to the differential steroid sensitivity in PMDD. Importantly, no differences in the formation of P4-derived neurosteroids were observed in this otherwise highly selected sample of women studied under controlled hormone exposures.

Risk factors for low birth weight in a socio-economically disadvantaged population: parity, marital status, ethnicity and cigarette smoking

Low birth weight (LBW) is a public health problem, because it is associated with increased risk of morbidity and mortality. The principal aim of this study was to assess risk factors for LBW in a large multi-ethnic and socio-economically disadvantaged population. Data from 3242 mothers, who attended the Well Baby Clinic (Southwestern Sydney, Australia) for the first time, were analysed in relation to their demographic characteristics and socio-economic indices. The overall birthweight was 3377 +/- 577 g (mean +/- SD). In multiple linear regression analysis, smoking during pregnancy, marital status, parity, and country of birth were independently associated with birth weight. According to this analysis, lower birth weight was associated with mothers who had smoked during pregnancy (by 215.2 +/- 18.6 g), who were single (46.9 +/- 21 g), and of Asian background (108.5 +/- 38.2 g). However, higher parity was associated with significantly higher birth weight. The presence of each factor was coded as 1 and the absence, 0. A 'risk score' was then derived by summing up the individual scores. When birth weight was classified as 'low birth weight' (defined as those with birth weight being less than 2500 g) or normal birth weight, the overall prevalence of LBW was 1.9%. Each unit increase in the risk score was associated with a 1.9-fold (95% confidence interval: 1.5-2.6) increase in the risk of LBW. These data suggest that apart from marital status, ethnicity and parity, maternal smoking is the single most important preventable risk factors for LBW.

Projecting the epidemiological effect, cost-effectiveness and transmission of HIV drug resistance in Vietnam associated with viral load monitoring strategies

OBJECTIVES

The objective of this study was to investigate the potential epidemiological impact of viral load (VL) monitoring and its cost-effectiveness in Vietnam, where transmitted HIV drug resistance (TDR) prevalence has increased from <5% to 5%-15% in the past decade.

METHODS

Using a population-based mathematical model driven by data from Vietnam, we simulated scenarios of various combinations of VL testing coverage, VL thresholds for second-line ART initiation and availability of HIV drug-resistance tests. We assessed the cost per disability-adjusted life year (DALY) averted for each scenario.

RESULTS

Projecting expected ART scale-up levels, to approximately double the number of people on ART by 2030, will lead to an estimated 18 510 cases (95% CI: 9120-34 600 cases) of TDR and 55 180 cases (95% CI: 40 540-65 900 cases) of acquired drug resistance (ADR) in the absence of VL monitoring. This projection corresponds to a TDR prevalence of 16% (95% CI: 11%-24%) and ADR of 18% (95% CI: 15%-20%). Annual or biennial VL monitoring with 30% coverage is expected to relieve 12%-31% of TDR (2260-5860 cases), 25%-59% of ADR (9620-22 650 cases), 2%-6% of HIV-related deaths (360-880 cases) and 19 270-51 400 DALYs during 2015-30. The 30% coverage of VL monitoring is estimated to cost US$4848-5154 per DALY averted. The projected additional cost for implementing this strategy is US$105-268 million over 2015-30.

CONCLUSIONS

Our study suggests that a programmatically achievable 30% coverage of VL monitoring can have considerable benefits for individuals and leads to population health benefits by reducing the overall national burden of HIV drug resistance. It is marginally cost-effective according to common willingness-to-pay thresholds.