Age-specific prevalence of IgG against measles/rubella and the impact of routine and supplementary immunization activities - a multistage random cluster sampling study with mathematical modelling.

BACKGROUND: Vietnam continues to have measles and rubella outbreaks following supplementary immunization activities (SIA) and routine immunization despite both having high reported coverage. To evaluate immunization activities, age-specific immunity against measles and rubella, and the number of averted Congenital Rubella Syndrome (CRS) cases, must be estimated. METHODS: Dried blood spots were collected from 2,091 randomly selected individuals aged 1-39 years. Measles and rubella virus-specific immunoglobulin G (IgG) were measured by enzyme immunoassay. Results were considered positive at ≥120 mIU/mL for measles and ≥10 IU/mL for rubella. The number of CRS cases averted by immunization since 2014 were estimated using mathematical modelling. RESULTS: OVERALL IGG SEROPREVALENCE WAS 99.7% (95%CI: 99.2-99.9) FOR MEASLES AND 83.6% (95%CI: : 79.3-87.1) for rubella. Rubella IgG seroprevalence was higher among age groups targeted in the SIA than in non-targeted young adults (95.4% [95%CI: 92.9-97.0] vs. 72.4% [95%CI: 63.1-80.1]; P < 0.001). The estimated number of CRS cases averted in 2019 by immunization activities since 2014 ranged from 126 (95%CI: 0-460) to 883 (95%CI: 0-2271) depending on the assumed post-vaccination reduction in the force of infection. CONCLUSIONS: The results suggest the SIA was effective, while young adults born before 1998 who remain unprotected for rubella require further vaccination.

Comparison of waist circumference and waist-to-height ratio as predictors of clustering of cardiovascular risk factors among middle-aged people in rural Khanh Hoa, Vietnam.

OBJECTIVE: Given the population-level variation in stature, a universal cut-off for waist circumference (WC) may not be appropriate for some populations. We compared the performance of WC and waist-to-height ratio (WHtR) to detect the clustering of cardiovascular disease (CVD) risk factors in rural Vietnam. METHODS: We obtained data from a baseline survey of the Khanh Hoa Cardiovascular Study comprising 2942 middle-aged residents (40-60 years). We used areas under the receiver operating characteristics curve (AUROC), net reclassification index (NRI), and integrated discrimination improvement (IDI) to compare the performance of WC and WHtR in predicting CVD risk clustering (≥2 of the following risk factors: hypertension, diabetes, dyslipidemia, and elevated C-reactive protein). RESULTS: The optimal cut-off values for WC were 81.8 and 80.7 cm for men and women, respectively. Regarding the clustering of CVD risk factors, the AUROC (95% CI) of WC and WHtR were 0.707 (0.676 to 0.739) and 0.719 (0.689 to 0.749) in men, and 0.682 (0.654 to 0.709) and 0.690 (0.663 to 0.717) in women, respectively. Compared with WC, WHtR had a better NRI (0.229; 0.102-0.344) and IDI (0.012; 0.004-0.020) in men and a better NRI (0.154; 0.050-0.257) in women. CONCLUSIONS: The optimal WC cut-off for Vietnamese men was approximately 10 cm below the recommended Asian cut-off. WHtR might perform slightly better in predicting the clustering of CVD risk factors among the rural population in Vietnam.

Association of green tea consumption with prediabetes, diabetes and markers of glucose metabolism in rural Vietnam: a cross-sectional study.

The literature on green tea consumption and glucose metabolism has reported conflicting findings. This cross-sectional study examined the association of green tea consumption with abnormal glucose metabolism among 3000 rural residents aged 40-60 years in Khánh Hòa province in Vietnam. Multinomial logistic regression analysis was conducted to examine the association of green tea consumption (0, < 200, 200-< 400, 400-< 600 or ≥ 600 ml/d) with prediabetes and diabetes (based on the American Diabetes Association criteria). Linear regression analysis was performed to examine the association between green tea consumption and the log-transformed homeostatic model assessment of insulin resistance (HOMA-IR) (a marker of insulin resistance) and the log-transformed homeostatic model assessment of ß-cell function (HOMA-ß) (a marker of insulin secretion). The OR for prediabetes and diabetes among participants who consumed ≥ 600 ml/d v. those who did not consume green tea were 1·61 (95 % CI = 1·07, 2·42) and 2·04 (95 % CI = 1·07, 3·89), respectively. Higher green tea consumption was associated with a higher level of log-transformed HOMA-IR (Pfor trend = 0·04) but not with a lower level of log-transformed HOMA-ß (Pfor trend = 0·75). Higher green tea consumption was positively associated with the prevalence of prediabetes, diabetes and insulin resistance in rural Vietnam. The findings of this study indicated prompting the need for further research considering context in understanding the link between green tea consumption and glucose metabolism, especially in rural settings in low- and middle-income countries.

Sex differences in the association between socioeconomic status and untreated hypertension among residents with hypertension in rural Khánh Hòa, Vietnam: a post-hoc analysis.

BACKGROUND: Several studies have examined the association between socioeconomic status (SES) and the proportion of untreated hypertension, but have produced conflicting findings. In addition, no study has been conducted to determine sex differences in the association between SES and untreated hypertension. Thus, the aim of this study was to examine whether the associations between SES and the proportion of untreated hypertension differed by sex in Vietnam. METHODS: This study was conducted using the data of 1189 individuals (558 males and 631 females) who were judged to have hypertension during the baseline survey of a prospective cohort study of 3000 residents aged 40-60 years in the Khánh Hòa Province. A multilevel Poisson regression model with a robust variance estimator was used to examine whether sex and SES indicators (household income and educational attainment) interacted in relation to untreated hypertension. RESULTS: The proportion of untreated hypertension among individuals identified as hypertensive was 69.1%. We found significant interaction between sex and SES indicators in relation to untreated hypertension (education: p < 0.001; household income: p < 0.001). Specifically, the association between SES and untreated hypertension was inverse among males while it was rather positive among females. CONCLUSIONS: Our finding suggests that the role of SES in the proportion of untreated hypertension might differ by sex.

Estimates of the global burden of Congenital Rubella Syndrome, 1996-2019.

OBJECTIVES: Many countries introduced rubella-containing vaccination (RCV) after 2011, following changes in recommended World Health Organization (WHO) vaccination strategies and external support. We evaluated the impact of these introductions. METHODS: We estimated the country-specific, region-specific, and global Congenital Rubella Syndrome (CRS) incidence during 1996-2019 using mathematical modeling, including routine and campaign vaccination coverage and seroprevalence data. RESULTS: In 2019, WHO African and Eastern Mediterranean regions had the highest estimated CRS incidence (64 [95% confidence intervals (CI): 24-123] and 27 [95% CI: 4-67] per 100,000 live births respectively), where nearly half of births occur in countries that have introduced RCV. Other regions, where >95% of births occurred in countries that had introduced RCV, had a low estimated CRS incidence (<1 [95% CI: <1 to 8] and <1 [95% CI: <1 to 12] per 100,000 live births in South-East Asia [SEAR] and the Western Pacific [WPR] respectively, and similarly in Europe and the Americas). The estimated number of CRS births globally declined by approximately two-thirds during 2010-2019, from 100,000 (95% CI: 54,000-166,000) to 32,000 (95% CI: 13,000-60,000), representing a 73% reduction since 1996, largely following RCV introductions in WPR and SEAR, where the greatest reductions occurred. CONCLUSIONS: Further reductions can occur by introducing RCV in remaining countries and maintaining high RCV coverage.

COVID-19 vaccination program in Cambodia: Achievements and remaining challenges.

Since Cambodia has been recognized as one of the low- and middle-income countries with a successful COVID-19 vaccine program, its program approaches were reviewed based mainly on press articles and announcements from the Ministry of Health. From the beginning, the government's proactive approach to securing vaccines and its flexibility prior to WHO Emergency Use Listing (EUL) contributed greatly to the success of the program. Vaccines were provided by COVAX and other countries, but more than half of the vaccines secured were Chinese vaccines purchased with government funds. The rollout of the vaccine has also been flexible, moving from a strategy of prioritizing risk groups and essential workers to one of expanding the campaign from population centers to rural areas, as well as gradually expanding the target age group, eventually targeting the population age 3 and older. As a result of this high level of commitment by the government and its flexible response, Cambodia has achieved 95% primary series coverage of the entire population, including those not eligible for vaccination. Although the sixth booster is now being administered in Cambodia and vaccination every six months was recommended, several challenges might be anticipated in continuing this program, including the lack of clear global guidance on how to sustain and modify the COVID-19 immunization program and vaccine fatigue after COVID-19 outbreaks have been controlled. How these challenges are overcome and how the COVID-19 vaccine program remains need to be carefully observed into the future.

Different associations of occupational and leisure-time physical activity with the prevalence of hypertension among middle-aged community dwellers in rural Khánh Hòa, Vietnam.

BACKGROUND: In contrast to high-income countries where physical activity (PA), particularly leisure-time PA, has been shown to be protective against hypertension, few studies have been conducted in low- and middle-income countries. We examined the cross-sectional association between PA and hypertension prevalence among rural residents in Vietnam. METHODS: We used data collected in the baseline survey of a prospective cohort study, among 3000 people aged 40-60 years old residing in rural Khánh Hòa, Vietnam. Hypertension was defined as systolic blood pressure ≥ 140 mmHg, diastolic blood pressure ≥ 90 mmHg, or the use of antihypertensive medication. We assessed occupational PA and leisure-time PA using the Global Physical Activity Questionnaire. A robust Poisson regression model was used to investigate the associations, with adjustment for covariates. RESULTS: The prevalence of hypertension was 39.6%. After adjusting for socio-demographic and lifestyle-related variables, leisure-time PA was positively associated with hypertension prevalence (prevalence ratio [PR]: 1.03 per 10 MET-hour/week, 95% confidence interval [CI] 1.01-1.06). Occupational PA was inversely associated with hypertension prevalence (PR: 0.98 per 50 MET-hour/week, 95% CI = 0.96-0.996). After adjusting for BMI and other health-related variables, the association related to occupational PA became statistically non-significant, while the association related to leisure-time PA remained statistically significant. CONCLUSION: In contrast to previous studies in high-income countries, we found that leisure-time PA was positively associated with hypertension prevalence and occupational PA was associated with a lower hypertension prevalence. This suggests that the association between PA and hypertension might differ depending on the context.

Eating speed and abdominal adiposity in middle-aged adults: a cross-sectional study in Vietnam.

BACKGROUND: Several studies have associated fast eating speed with the risk of general obesity, but there are inadequate data on the association between eating speed and abdominal adiposity which may pose a higher threat to health than general obesity. The present study aimed to investigate the association between eating speed and abdominal obesity in a Vietnamese population. METHODS: Between June 2019 and June 2020, the baseline survey of an ongoing prospective cohort study on the determinants of cardiovascular disease in Vietnamese adults was conducted. A total of 3,000 people aged 40-60 years old (1,160 men and 1,840 women) were recruited from eight communes in the rural district of Cam Lam, Khanh Hoa province, in Central Vietnam. Self-reported eating speed was assessed on a 5-point Likert scale, and responses were collapsed into the following three categories: slow, normal, and fast. Abdominal obesity was defined as a waist-to-height ratio of ≥ 0.5. Poisson regression with a robust variance estimator was used to assess the association between eating speed and abdominal obesity. RESULTS: Compared with slow eating speed, the adjusted prevalence ratio (95% confidence interval) for abdominal obesity was 1.14 (1.05, 1.25)1.14 (1.05, 1.25) for normal eating speed and 1.30 (1.19, 1.41) for fast eating speed (P for trend < 0.001). CONCLUSION: A faster eating speed was associated with a higher prevalence of abdominal obesity in a middle-aged population in rural Vietnam.

Association between parental absence during childhood and metabolic syndrome during adulthood: A cross-sectional study in rural Khanh Hoa, Vietnam.

BACKGROUND: This study aimed to determine the association between parental absence during childhood and metabolic syndrome (MetS) in adulthood among middle-aged adults in rural Khanh Hoa province, Vietnam. Given that broader literature on adverse childhood experiences (ACEs) suggests a strong positive association between ACEs and cardiometabolic risk or diseases, we hypothesized that parental absence during childhood, which is a major component of ACEs, is more likely to cause MetS in adulthood. METHODS: Data were obtained from the baseline survey of the Khanh Hoa Cardiovascular Study, in which 3000 residents aged between 40 to 60 years participated. MetS was assessed using the modified Adult Treatment Panel III (ATP III) criteria. It was considered parental absence if the participants had experienced parental absence due to death, divorce, or out-migration before three or between three to 15 years. We used multiple logistic regression analyses to examine the association between parental absence during childhood and metabolic syndrome during adulthood. RESULTS: There was no significant association between parental absence and MetS; adjusted odds ratio [AOR] was 0.97 (95% confidence interval [CI] = 0.76-1.22) for those who experienced parental absence between three to 15 years and the corresponding figure for those who experienced it before three years was 0.93 (95% CI = 0.72-1.20). No significant associations were observed when these were examined for the causes of parental absence. CONCLUSION: This study did not support our hypothesis of an association between parental absence during childhood and metabolic syndrome during adulthood. Parental absence may not be a predictor of MetS among Vietnamese people in rural communities.

Comparison of population-based measles-rubella immunoglobulin G antibody prevalence between 2014 and 2019 in Lao People's Democratic Republic: Impacts of the national immunization program.

OBJECTIVES: We evaluated the effectiveness of the Lao People's Democratic Republic's measles-rubella immunization program using the seroprevalence from two cross-sectional surveys. METHODS: The nationwide surveys occurred in 2014 and 2019 using a multistage cluster sampling, both requiring samples from 2184 individuals from 52 randomly selected villages. Immunoglobulin G titers, measured using enzyme-linked immunosorbent assay, were considered positive at ≥120 mIU/ml (measles) and ≥10 IU/ml (rubella). We calculated the vaccination-related reduction in the force of rubella infection and the number of congenital rubella syndrome cases averted in 2019. RESULTS: We collected 2135 (women: 55.2%, mean age: 23.2 years) and 2001 (52.7%, 23.1 years) samples in 2014 and 2019, respectively. During 2014-2019, immunoglobulin G prevalence increased from 83.9% (95% confidence interval [CI]: 83.8-84.0) to 98.3% (97.7-98.8) for measles and from 75.4% (75.3-75.5) to 87.8% (86.4-89.2) for rubella. The most plausible reduction in the average force of rubella infection was 100% (95% CI: 28-100) since vaccination started, averting 78 (95% CI: 42-128) congenital rubella syndrome cases in 2019. CONCLUSION: This is the first population-based study for measles and rubella at two different time points in developing countries. Measles and rubella seroprevalence increased significantly during 2014-2019, greatly exceeding the immunity thresholds for their elimination.

Red meat consumption is associated with prediabetes and diabetes in rural Vietnam: a cross-sectional study.

OBJECTIVE: To examine the association between red/processed meat consumption and glycaemic conditions (i.e. prediabetes (preDM) and diabetes mellitus (DM)) among middle-aged residents in rural Khánh Hòa, Vietnam. DESIGN: In this cross-sectional study, a multinomial logistic regression model was used to examine the association between daily consumption of red/processed meat (0-99 g, 100-199 g or ≥ 200 g) and preDM/DM with adjustments for socio-demographic, lifestyle-related and health-related variables. SETTING: Khánh Hòa Province, Vietnam. PARTICIPANTS: The study used data collected through a baseline survey conducted during a prospective cohort study on CVD among 3000 residents, aged 40-60 years, living in rural communes in Khánh Hòa Province. RESULTS: The multinomial regression model revealed that the relative-risk ratios for DM were 1·00 (reference), 1·11 (95 % CI = 0·75, 1·62) and 1·80 (95 % CI = 1·40, 2·32) from the lowest to the highest red/processed meat consumption categories (Ptrend = 0·006). The corresponding values for preDM were 1·00 (reference), 1·25 (95 % CI = 1·01, 1·54) and 1·67 (95 % CI = 1·20, 2·33) (Ptrend = 0·004). We did not find any evidence of statistical significance in relation to poultry consumption. CONCLUSION: Increased red/processed meat consumption, but not poultry consumption, was positively associated with the prevalence of preDM/DM in rural communes in Khánh Hòa Province, Vietnam. Dietary recommendations involving a reduction in red/processed meat consumption should be considered in low- and middle-income countries.

Parental absence during childhood and weight status in adulthood among middle-aged community dwellers in rural Vietnam.

OBJECTIVES: While adverse childhood experiences (ACEs) have been shown to be associated with adulthood obesity, less is known about their association with underweight. We examined the associations between parental absence (i.e., a major component of ACEs) and both underweight and excess weight among middle-aged rural community dwellers in Vietnam, where experiences of parental absence was not uncommon during and after the Vietnam War (1955-1975). METHODS: Data came from 3000 middle-aged adults who participated in the baseline survey of Khánh Hòa Cardiovascular Study. Parental absence was defined as parental absence due to death, divorce, or out-migration. Using information on the timing of such events, we categorized participants into those who experienced parental absence before the age of 3, between the ages of 3 and 15, and those without such experiences. BMI was calculated based on measured height and weight (kg/m2 ) and categorized into three groups: underweight <18.5; normal 18.5-24.9; excess weight ≥ 25. Multinomial logistic regression was then used to investigate the association between parental absence and adult weight status. RESULTS: Parental absence that occurred before the age of 3 was marginally significantly associated with underweight (relative risk ratio [RRR] = 1.44, 95% confidence interval [CI] 0.95, 2.20) but not with overweight/obesity. Parental divorce was associated with overweight/obesity (RRR = 2.48, 95% CI 1.28, 4.81), but not parental absence due to migratory work. CONCLUSIONS: While previous studies in Western settings focused almost exclusively on the risk of obesity in relation to exposure to ACEs, our findings point to the potential importance of considering the risk of underweight in low- and middle-income countries.

How did COVID-19 impact development assistance for health? - The trend for country-specific disbursement between 2015 and 2020.

This study aimed to examine the changes that took place between 2015-2019 and 2020 and reveal how the COVID-19 pandemic affected financial contributions from donors. We used the Creditor Reporting System database of the Organization for Economic Cooperation and Development to investigate donor disbursement. Focusing on the Group of Seven (G7) countries and the Bill and Melinda Gates Foundation (BMGF), we analyzed their development assistance for health (DAH) in 2020 and the change in their disbursement between 2015 and 2020. As a result, total disbursements for all sectors increased by 14% for the G7 and the BMGF. In 2020, there was an increase in DAH for the BMGF and the G7 except for the United States. The total disbursement amount for the "COVID-19" category by G7 countries and the BMGF was approximately USD 3 billion in 2020, which was 3 times larger than for Malaria, 8.5 times larger for Tuberculosis, and 60% smaller for STDs including HIV/AIDS for the same year. In 2020 as well, the United States, the United Kingdom, Japan, Italy, and Canada saw their disbursements decline for more than half of 26 sectors. In conclusion, the impact of COVID-19 was observed in the changes in DAH disbursement for three major infectious diseases and other sectors. To consistently address the health needs of low- and middle-income countries, it is important to perform a follow-up analysis of their COVID-19 disbursements and the influence of other DAH areas.

Impact of hepatitis B vaccination programs in Vietnam evaluated by estimating HBsAg prevalence.

Background: Vietnam introduced a 3-dose hepatitis B (HBV) immunization program comprising 1 dose immediately after birth and 2 or 3 in infancy in the past 20 years, but the impact of the vaccine has not been systematically evaluated. Thus, we conducted this survey aiming to estimate the age-specific chronic HBV prevalence in the general population and to evaluate HBV immunization effectiveness. Methods: Population-based, four-stage cluster sampling was used in the South Central Coast region of Vietnam. The point-of-care Determine rapid test was used to assess hepatitis B surface antigen (HBsAg) positivity. Results: A total of 2,075 samples were included in the study. HBsAg prevalence was significantly higher among adults aged 20-39 years than in the population aged 1-19 years (8.0% [95% confidence interval 5.0-12.0] vs. 2.0% [95% confidence interval 1.0-6.0], p<0.01). HBsAg prevalence decreased after implementation of the 3-dose vaccination schedule during infancy from 1997 to 2002, whereas the change in prevalence after implementation of the birth dosing was not significant. A slight increase in HBsAg prevalence was observed for the cohort born in 2011, 2012, and 2013, when there was a vaccine shortage and media reports of immunization resistance. Conclusions: This is the first population-based assessment of the introduction of the HBV vaccine in Vietnam performed by estimating the HBsAg prevalence across a wide range of ages. The results showed that the HBV immunization policy effectively reduces HBsAg prevalence in general, although birth dosing of the vaccine and low immunization coverage should be carefully monitored.

Prevalence of hepatitis B and C virus infections in Lao People's Democratic Republic: The first national population-based cross-sectional survey.

Population-based seroprevalence of chronic hepatitis B and C infections has not been examined in Lao People's Democratic Republic (PDR). Therefore, this study aimed to estimate the seroprevalence of these infections in the general population of Lao PDR and perform subgroup analysis. A nationwide seroprevalence survey was conducted in Lao PDR in June 2019 using the multistage cluster sampling method. Dried blood spot samples were collected onto WhatmanTM 903 filter paper by finger prick. A chemiluminescent microparticle immunoassay was used to measure the levels of hepatitis B surface antigen (HBsAg) and hepatitis C antibody (HCV-Ab). Samples in which the HBsAg level was above 0.05 IU/ml and HCV-Ab was above the signal/cutoff ratio of 1.0 were considered positive based on comparisons with the relative light unit value of a calibration sample. A total of 1,927 samples (male: 47.3%, mean age: 23.0 years) were included in the analysis. The prevalence was estimated to be 4.2% (95% confidence interval [CI]: 2.7-6.3) for HBsAg and 1.6% (95% CI: 0.5-5.3) for HCV-Ab. Multivariable analysis revealed that those aged 20-24 years (adjusted odds ratio (AOR): 2.3, 95% CI: 1.1-4.6), those aged 25-29 years (AOR: 2.7, 95% CI: 1.3-5.6), those from the Northern region (AOR: 2.8, 95% CI: 1.2-6.6), and those who were Khmu (AOR: 3.6, 95% CI: 2.0-6.8) or Hmong (AOR: 5.0, 95% CI: 3.3-7.5) were significantly more likely to be positive for HBsAg. Although there were no statistically significant differences in the HCV-Ab prevalence according to each variable, males (2.9%, 95% CI: 0.7-10.7), those aged ≥40 years (6.1%, 95% CI: 2.1-16.8), and those from the Southern region (3.3%, 95% CI: 0.6-15.3) tended to have a higher prevalence. This novel population-based survey found differences in the prevalence of chronic hepatitis B and hepatitis C virus infections in Lao PDR according to sex, age group, region, and ethnicity; however, the results of this study should be confirmed in future studies, and relevant responses tailored for each target also need to be determined to control the transmission of hepatitis B and C infections.

The determinants of immunization coverage among children aged between 12 and 35 months: a nationwide cross-sectional study in Lao People's Democratic Republic.

BACKGROUND: Immunization is one of the most important public health interventions for reducing morbidity and mortality in children. However, factors contributing to low immunization coverage are not fully understood in the Lao People's Democratic Republic (Lao PDR). Therefore, this study aimed to identify factors associated with full immunization coverage among children between 12 and 35 months, providing up-to-date information for immunization programs in Lao PDR. METHODS: We analyzed the subpopulation of a nationwide cross-sectional survey using a multistage cluster sampling procedure to evaluate the measles and rubella seroepidemiology. In addition, we categorized children aged between 12 and 35 months into two groups: "fully immunized" children with a birth dose of Bacillus Calmette and Guérin vaccine, hepatitis B vaccine (Hep B), one and three doses for the measles-containing vaccine (MCV) and pentavalent vaccine and pneumococcal conjugate vaccine (PCV) and "partially immunized" children who missed any dose of vaccine. Immunization coverage was calculated as the ratio of "fully immunized" to the total. We compared the groups' demographic characteristics and health service utilization as independent variables. Multivariate logistic regression was used to assess the relationship between immunization coverage, various demographic factors, and health service utilization. RESULTS: Overall, 256 of the 416 targeted pairs were included in the analysis. In total, 67.6% of the children were fully immunized. Childbirth at hospitals or health facilities (adjusted odds ratio: 9.75, 95% confidence interval: 5.72-16.62, p < 0.001) was the predictor of full immunization coverage. The 83 children in the partially immunized groups were attributed to Hep B at birth (46, 55.4%), three doses of PCV (34, 41.0%), and the first dose of the MCV (27, 32.5%). CONCLUSION: Our study elucidated that the immunization status among children aged between 12 and 35 months in Lao PDR is satisfactory in improving access to healthcare by strengthening communication with residents regarding health service utilization, and expanding mobile outreach services may play a pivotal role in this endeavor. Further research is warranted to evaluate efforts to increase immunization coverage and target populations with limited access to healthcare.

Comparison between a rapid diagnostic test and dried blood spot-based immunoassay for hepatitis B surface antigen testing: Performance and cost implications in a population-based serosurvey in Vietnam.

OBJECTIVES: This study aimed to determine the agreement between a rapid diagnostic test (RDT) and a dried blood spot (DBS)-based electrochemiluminescence immunoassay (ECLIA) of hepatitis B surface antigen and to compare the costs of conducting serosurveys using RDTs and DBS in a field setting. METHODS: A serosurvey was conducted in the South Central Coast region of Vietnam in May 2019. Participants aged 1-39 years were recruited using a four-stage random sampling method and tested for hepatitis B surface antigen using an RDT kit (Alere Determine) and a DBS-based ECLIA. The agreement between the RDT and the DBS-based ECLIA was assessed using cross-tabulation and Cohen kappa. Cost data were categorized by input (personnel, transportation, field consumables, laboratory consumables, and capital item/overhead) and survey phase (survey preparation, data/biospecimen collection, laboratory testing, and coordination). RESULTS: A total of 2072 participants were analyzed. There was a 99% agreement between the RDT and the DBS-based ECLIA results, with a Cohen kappa of 0.9. The estimated cost of conducting a serosurvey by DBS was UD $75,291, whereas RDT was $53,182. CONCLUSION: RDTs and DBS-based ECLIA provide test results with high agreements. RDTs are a better option in terms of cost, whereas the DBS-based ECLIA may be useful when evaluating multiple infectious diseases.

Effectiveness of immunization activities on measles and rubella immunity among individuals in East Sepik, Papua New Guinea: A cross-sectional study.

Objectives: This study aimed to assess measles and rubella immunity by measuring virus-specific immunoglobulin G (IgG) prevalence among individuals and evaluate the effectiveness of recent supplementary immunization activities (SIAs) by comparing the antibody positivity rates of the SIA target age groups in 2015 with those in 2019 as measles and rubella are endemic in Papua New Guinea. Methods: A cross-sectional study. The measles- and rubella-specific IgG levels of patients aged ≥1 year at two clinics in East Sepik province, Papua New Guinea were assessed with commercially available virus-specific IgG EIA kits. Results: In total, 297 people participated in the study and 278 samples with sufficient volume, relevant information, and age inclusion criteria were analyzed. The overall IgG prevalence rates were 62.6% for measles and 82.0% for rubella. The age groups targeted in the 2019 SIAs had a higher IgG prevalence than those targeted in the 2015 SIAs for both the infectious diseases. Moreover, the IgG prevalence for rubella was higher than measles in these groups. Conclusions: The anti-measles and anti-rubella IgG prevalence in the target groups were lower than those required for herd immunity. The immunization program should be emphasized to eliminate measles and rubella. Further population-based studies are warranted.

Association between parental absence during childhood and depressive symptoms in adulthood in rural Vietnam.

BACKGROUND: While parental absence during childhood has been linked to depression/depressive symptoms in adulthood, no research has been conducted on this association in Vietnam, where many children were separated from their parents during and after the Vietnam War (1955-1975). We examined the association between parental absence in childhood and depressive symptoms among rural community dwellers in Khanh Hoa Province, Vietnam. METHODS: Data came from 3000 individuals aged 40-60 years old who participated in the baseline survey of the Khanh Hoa Cardiovascular Study. Depressive symptoms were assessed with the 11-item Center for Epidemiologic Studies Depression Scale. Self-reported information on parental absence due to death, divorce, or outmigration to other locations before the age of 15 was also obtained. A Poisson regression analysis with a robust variance estimator was used to examine associations. RESULTS: Experiencing parental absence at 3 - < 15 years old and before 3 years old was associated with a 1.21 times (95% confidence interval [CI] = 1.02-1.43) and 1.41 times (95% CI = 1.15-1.73) higher prevalence of depressive symptoms, respectively (p trend <0.001). When examining the associations by the different reasons for the parental absence, the strongest association was found for parental absence due to outmigration to other locations. LIMITATIONS: We had no information on who respondents lived with after they experienced parental absence. In addition, self-reported information on childhood experiences was subject to recall bias. CONCLUSIONS: In rural Vietnam, parental absence during childhood was associated with a significantly increased prevalence of depressive symptoms in middle adulthood.