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Background: Vietnam implemented various public health interventions such as contact tracing and testing, mandatory quarantine, and lockdowns in response to coronavirus disease 2019 (COVID-19). However, the effects of these measures on the epidemic remain unclear. Methods: This article describes the public health interventions in relation to COVID-19 incidence. Maximum likelihood estimations were used to assess containment delays (time between symptom onset and start of isolation) and multivariable regression was employed to identify associated factors between interventions and COVID-19 incidence. The effective reproductive numbers (Rt) were calculated based on transmission pairs. Results: Interventions were introduced periodically in response to the epidemic. Overall, 817 (55.4%) among 1474 COVID-19 cases were imported. Based on a serial interval of 8.72 ± 5.65 days, it was estimated that Rt decreased to below 1 (lowest at 0.02, 95% CI 0–0.12) during periods of strict border control and contact tracing, and increased ahead of new clusters. The main method to detect cases shifted over time from passive notification to active case-finding at immigration or in lockdown areas, with containment delays showing significant differences between modes of case detection. Conclusions: A combination of early, strict, and consistently implemented interventions is crucial to control COVID-19. Low-middle income countries with limited capacity can contain COVID-19 successfully using non-pharmaceutical interventions.

Following a rubella outbreak in 2011, Vietnam implemented a mass measles-rubella vaccination campaign for children aged 1–14 years in 2014–2015, further expanding the target age to 16–17 years in 2016; routine vaccination was introduced in 2014. However, there was concern that a substantial proportion of women of child-bearing age were still susceptible to rubella, with the fear of congenital rubella emergence. Thus, we conducted a prospective cohort study in Nha Trang, Vietnam, from 2017–2018 to investigate pregnant women’s susceptibility to rubella infection, the incidence of congenital rubella infection, and factors associated with susceptibility. Cord blood was tested for rubella-specific immunoglobulin M (IgM) and IgG; neonatal saliva and cord blood specimens were examined for rubella-RNA. We analyzed 2013 mother-baby pairs. No baby was rubella-IgM or rubella-RNA positive. Overall, 20.4% of mothers were seronegative (95% confidence interval, 18.6%–22.1%). The seronegativity was significantly low among mothers aged

A birth cohort study was conducted in Khan Hoa Province, central Vietnam between 2009 and 2012 to determine the seroprevalence of hepatitis B virus (HBV) in pregnant women and their children, and associated risk factors. We enrolled 1987 pregnant women with their babies at the birth phase, and 12.6% (95% confidence interval [CI]: 11.1–14.0) of mothers were hepatitis B surface antigen (HBsAg)+. At 2-year follow-up phase, 1339 (67.4%) children were enrolled of whom 76.6% completed hepatitis B vaccines (HepB) and 1.9% (95% CI: 1.2–2.7) were HBsAg+. When mothers were hepatitis B e antigen (HBeAg)+, 28.3% of children have got infected even with complete HepB. HBV infection in mothers, hepatitis B surface antibody (anti-HBs antibody) below the seroprotective level in children, and mothers with pre-pregnancy low body mass index were associated with HBV infection in children. Meanwhile, HBV infection in children, older maternal age, no or incomplete doses of HepB, and boys were associated with anti-HBs antibody below the seroprotective level in children. Our birth cohort study determined a low rate of congenital HBV infection and associated risk factors in Vietnam, however further studies are needed to advance prevention including anti-viral therapy in pregnant women at high risk., Scientific Reports, 11, art. no. 8676; 2021

Trade protection may have significant impacts on sectors other than those targeted by the protection policies, especially when the target sector produces goods that are essential inputs to downstre...

BackgroundInfants are at highest risk of pneumococcal disease. Their added protection through herd effects is a key part in the considerations on optimal pneumococcal vaccination strategies. Yet, little is currently known about the main transmission pathways to this vulnerable age group.Methods and findingsWe conducted a nested cross-sectional contact and nasopharyngeal swabbing survey in randomly selected infants across all 27 communes of Nha Trang, Vietnam. Bayesian logistic regression models were used to estimate age specific carriage prevalence in the population, a proxy for the probability that a contact of a given age could lead to pneumococcal exposure for the infant. We used another Bayesian logistic regression model to estimate the correlation between infant carriage and the probability that at least one of their reported contacts carried pneumococci, controlling for age and locality. In total 1583 infants between 4 and 13 months old participated, with 7428 contacts reported. Few infants (5%) attended day care and carriage prevalence was 22%. Most infants (61%) had less than a 25% probability to have had close contact with a pneumococcal carrier on the surveyed day. Pneumococcal infection risk and contact behavior were highly correlated: if adjusted for age and locality the odds of an infant’s carriage increased by 22% (95%CI:15-29) per 10 percentage points increase in the probability to have had close contact with at least one pneumococcal carrier. Two to six year old children contributed 51% (95%CI: 39-63) to the total pneumococcal exposure risks to infants in this setting.ConclusionsCross-sectional contact and infection studies can help identify pneumococcal transmission routes. In Nha Trang, preschool age children are the largest reservoir for pneumococcal transmission to infants.

We analyzed 2 clusters of 12 patients in Vietnam with severe acute respiratory syndrome coronavirus 2 infection during January–February 2020. Analysis indicated virus transmission from a traveler from China. One asymptomatic patient demonstrated virus shedding, indicating potential virus transmission in the absence of clinical signs and symptoms.

Using a three-round panel dataset of more than 3,000 households, the paper estimates the impacts of electricity reliability improvement on the welfare and economic decisions of rural Vietnamese households. The number of days without power outages in communes per annum is used to proxy for electricity reliability. We employ a fixed effect regression with an instrumental variable to deal with the endogeneity issue, led by the simultaneous causal relationship between the reliability of electricity and household outcomes along with the unobservable variables. We use the similar electricity quality variable but measured in other communes within the same province as an instrumental variable. Results from this model show that an improvement in electricity reliability plays an important role in enhancing incomes, durable consumption, access to credit and land investment decisions of rural households.

Rubella vaccination programs have dramatically reduced the incidence of rubella and congenital rubella syndrome (CRS) in developed countries. However, CRS prevalence is still rising in developing countries where rubella-containing vaccines (RCV) are not included in the immunization program and even in some countries where a part of the population lacks immunity to rubella despite the presence of RCV in the regular immunization program. This review aimed to summarize the clinical features of CRS using data from our studies conducted between 2011 and 2015 in Vietnam,wherein we examined clinical manifestations in Vietnamese children with CRS who were born after the large rubella outbreak of 2011; a series of studies dealing with CRS in North America and Europe after the 1960s epidemic; and those from countries before introduction of RCVs. This review shows that children with CRS have a variety of disabilities such as hearing, visual, developmental, behavioral, cardiac, and endocrine impairments, which have variable severity and may appear in different combinations. Some of these impairments can appear or worsen later in the lives of these children.Physicians should thus complete pediatric, cardiac, auditory, ophthalmologic, and neurologic examinations along with laboratory diagnostic testing soon after birth. These assessments should be repeated during follow-up if congenital rubella infection is suspected in a neonate. Timely intervention for cardiac defects can be lifesaving. Early introduction and continuation of speech, occupational, physical, and behavior therapies and training with appropriate medical interventions by a multidisciplinary team approach are required to maximize quality of life., Vaccine, 37(1), pp.202-209; 2019

Background: Influenza B is one of the major etiologies for acute respiratory infections (ARI) among children worldwide; however, its clinical-epidemiological information is limited. We aimed to investigate the hospitalization incidence and clinical-epidemiological characteristics of influenza B-associated paediatric ARIs in central Vietnam. Methods: We collected clinical-epidemiological information and nasopharyngeal swabs from ARI children hospitalized at Khanh Hoa General Hospital, Nha Trang, Vietnam from February 2007 through June 2013. Nasopharyngeal samples were screened for 13 respiratory viruses using Multiplex-PCRs. Influenza B-confirmed cases were genotyped by Haemagglutinin gene sequencing. We analyzed the clinical-epidemiological characteristics of influenza B Lineages (Victoria/Yamagata) and WHO Groups. Results: In the pre-A/H1N1pdm09 period, influenza B-associated ARI hospitalization incidence among children under five was low, ranging between 14.7 and 80.7 per 100 000 population. The incidence increased to between 51.4 and 330 in the post-A/H1N1pdm09. Influenza B ARI cases were slightly older with milder symptoms. Both Victoria and Yamagata lineages were detected before the A/H1N1pdm09 outbreak; however, Victoria lineage became predominant in 2010-2013 (84% Victoria vs 16% Yamagata).Victoria and Yamagata lineages did not differ in demographic and clinical characteristics. In Victoria lineage, Group1 ARI cases were clinically more severe compared to Group5, presenting a greater proportion of wheeze, tachypnea, and lower respiratory tract infection. Conclusions: The current results highlight the increased incidence of influenza B-related ARI hospitalization among children in central Vietnam in the post-A/H1N1pdm09 era. Furthermore,the difference in clinical severity between Victoria lineage Group1 and 5 implies the importance of influenza B genetic variation on clinical presentation., Influenza and other Respiratory Viruses, 13(3), pp. 248-261; 2018

Background: Respiratory viruses cause acute respiratory illness (ARI) in early childhood, but their effect on subsequent ARI admissions is not fully understood. This study aimed to determine the association between initial ARI admission because of viruses including human rhinovirus (HRV), respiratory syncytial virus (RSV), human adenovirus (HAdV) and human metapneumovirus (hMPV) and the risk of ARI readmission in children.Methods: Clinical information and nasopharyngeal swab samples were collected from children, The Pediatric infectious disease journal, 37(12), pp.1217-1222; 2018

Conjunctival pneumococcal serotypes among members of a community have not been investigated well. We determined the prevalence and association of Streptococcus pneumoniae in the nasopharynx and conjunctiva among children in a community before pneumococcal conjugate vaccine introduction. In October 2016, conjunctival and nasopharyngeal swabs were collected from children (< 24 months old) and nasopharyngeal swabs from mothers in Nha Trang, Vietnam. Quantitative lytA PCR and DNA microarray were performed to detect and serotype S. pneumoniae. The association between S.pneumoniae in the nasopharynx and conjunctiva was evaluated using multivariable logistic regression model. Among 698 children,62 (8.9%, 95% CI 6.9–11.2%) were positive for S. pneumoniae in the conjunctiva. Non-encapsulated S. pneumoniae were most commonly identified,followed by serotypes 6A, 6B, and 14. Nasopharyngeal and conjunctival detection were positively associated (aOR 47.30, 95% CI 24.07–92.97). Low birth-weight, day-care attendance, and recent eye symptoms were independently associated with S. pneumoniae detection in the conjunctiva (aOR 11.14, 95% CI 3.76–32.98, aOR 2.19, 95% CI 1.45–3.31, and aOR 3.59, 95% CI 2.21–5.84, respectively). Serotypes and genotypes in the conjunctiva and nasopharynx matched in 87% of the children. Three mothers’ nasopharyngeal pneumococcal samples had matched serotype and genotype with their child’s in the conjunctiva and nasopharynx. S. pneumoniae presence in nasopharynx and conjunctiva were strongly associated. The high concordance of serotypes suggests nasopharyngeal carriage may be a source of transmission to the conjunctiva., Scientific Reports, 11(1), art.no.337; 2021

Background International air travel plays an important role in the global spread of SARS-CoV-2, and tracing of close contacts is an integral part of the public health response to COVID-19. We aimed to assess the timeliness of contact tracing among airline passengers arriving in Vietnam on flights containing COVID-19 cases and investigated factors associated with timeliness of contact tracing. Methods We included data from 2228 passengers on 22 incoming flights between 2 and 19 March 2020. Contact tracing duration was assessed separately for the time between the date of index case confirmation and date of contact tracing initiation (interval I), and the date of contact tracing initiation and completion (interval II). We used log-rank tests and multivariable Poisson regression models to identify factors associated with timeliness. Results The median duration of interval I and interval II was one (IQR: 1–2) and 3 days (IQR: 2–5), respectively. The contact tracing duration was shorter for passengers from flights where the index case was identified through mandatory testing directly upon arrival (median = 4; IQR: 3–5) compared to flights with index case detection through self-presentation at health facilities after arrival (median = 7; IQR: 5–8) (p-value = 0.018). Cumulative hazards for successful tracing were higher for Vietnamese nationals compared to non-Vietnamese nationals (p Conclusions Contact tracing among flight passengers in the early stage of the COVID-19 epidemic in Vietnam was timely though delays occurred on high workload days. Mandatory SARS-CoV-2 testing at arrival may reduce contact tracing duration and should be considered as an integrated screening tool for flight passengers from high-risk areas when entering low-transmission settings with limited contact tracing capacity. We recommend a standardized risk-based contact tracing approach for flight passengers during the ongoing COVID-19 epidemic.

PURPOSE Otitis media with effusion (OME) commonly occurs and persists in young children. It can cause hearing impairment and damage to the tympanic membrane without treatment. We aimed to determine the prevalence and association of Streptococcus pneumoniae in the nasopharynx of healthy children before the introduction of a pneumococcal conjugate vaccine. METHODS In October 2016, nasopharyngeal swabs collection and otoscope examinations by an otolaryngologist were conducted in children aged less than 24 months in Nha Trang, Vietnam. OME was diagnosed as the presence of middle ear fluid using a digital otoscope equipped with a pneumatic otoscope. Quantitative PCR targeting pneumococci-specific lytA (the major autolysis gene) and bacterial culture were performed to detect S. pneumoniae. The point prevalence of OME in the study area was estimated. The association between OME and S. pneumoniae in the nasopharynx was evaluated using a multivariable logistic regression model. RESULTS Among the 274 children who underwent bilateral ear examinations and nasopharyngeal swab collections, 47 had OME (17.2%, 95% confidence interval [CI] 12.9-22.1%) and 96 were colonized with S. pneumoniae (35.0%, 29.4-41.0%). OME and nasopharyngeal S. pneumoniae carriage were positively associated in children aged less than 12 months (adjusted odds ratio [aOR] 3.83, 1.40-10.51). Day-care attendance and living in a rural area were independently associated with OME (aOR 5.87, 2.31-14.91, and aOR 3.77, 1.58-8.99, respectively). CONCLUSIONS The nasopharyngeal pneumococcal carriage was associated with OME among children aged

The Caesarean section rate in urban Vietnam is 43% in 2014, which is more than twice the recommended rate (10%&ndash, 15%) by the World Health Organization. This qualitative study aims to identify the perceptions of pregnant mothers and health care professionals on the medical and social factors related to the increased Caesarean section rate in Vietnam. A qualitative descriptive study was conducted among pregnant mothers and healthcare professionals at two public hospitals in Nha Trang city. A content analysis was adopted in order to identify social and medical factors. As a result, 29 pregnant women and 19 health care professionals were invited to participate in the qualitative interviews. Private interviews were conducted with 10 women who wished to have a Caesarean section, and the others participated in focus group interviews. The main themes of the social factors were &lsquo, request for Caesarean section,&rsquo, &lsquo, mental strain of obstetricians,&rsquo, and &lsquo, decision-making process.&rsquo, To conclude, this qualitative study suggests that there were unnecessary caesarean sections without a clear medical indication, which were requested by women and family members. Psychological fear occurred among women and family, and doctors were the main determinants for driving the requests for Caesarean section, which implies that education and emotional encouragement is necessary by midwives. In addition, a multi-faced approach including a mandatory reporting system in clinical fields and involving family members in antenatal education is important.

Background: Few studies describe the community-acquired pneumonia (CAP) burden in children in Asia. We estimated the proportion of all CAP hospitalizations in children from nine hospitals across the Republic of Korea (high-income), Indonesia, Malaysia (middle-income), and Vietnam (low/middle-income). Methods: Over a one or two-year period, children

Background: Infant contact information (skin-to-skin contact between infants and others) is important to understand Streptococcus pneumoniae transmission patterns. A few studies have investigated infant contact patterns by asking the mother/guardian to record all contacts a child makes in one day. However, this approach does not capture contact behaviour in day-care. Our study describes the frequency and nature of physical contacts of infants in day-care to understand infant infection risk in day-care in Nha Trang, central Vietnam. Methods: This cross-sectional study enrolled infants aged less than 12 months, attending 10 randomly selected day-care centres in Nha Trang. Physical contacts of each infant for one day at the day-care centre were observed and recorded. The mean number of contacts of infants and its factors were assessed using negative binomial regression. Results: In total 14 infants, aged 6 to 11 months, were enrolled, and a total of 96 contacts were observed. The mean number of contacts an infant made in one day was 6.9. Infants who walked independently (age-adjusted rate ratio 1.68, 95% confidence interval 1.06-2.68) and those cared for in a larger group (1.99, 1.42-2.79) had more contacts at day-care. About 50% of infants made contact with at least one person from a commune different from the infant's, and 50% made contact with at least one other infant at day-care. Conclusion: This study found that day-care attendance may be one factor that increases contact rates of infants in Nha Trang and diversifies them in terms of age and geographical spread. In this study, day-care attendance not only increased contact rates beyond those usually experienced by young children cared at home but specifically increased the contact rates with other children and adults from other communes. Day-care may play a key role in the transmission of respiratory pathogens like Streptococcus pneumoniae to infants., Wellcome Open Research, 4, 75; 2019

This paper considers the effects of social network on income and employment dynamics of rural-urban migrants in Vietnam. Estimation of a causal effect is challenging because unobserved factors affects both employment performances and social networks. I address this endogeneity problem by using instrumental variable method. The results suggest that social networks improve migrant’s earnings and make wage earners willing to change their jobs.

Many studies have found that social trust plays crucial roles in economic development through their facilitation of cooperation and network connections amongst the members of a community. However, there are few studies that examine the relationship between the natural environment and social trust. In this paper, we examine empirically the hypothesis that the development of trust is based on the demand for cooperation to cope with natural weather fluctuations, which are considered as the main risks for agricultural activities. To test our hypothesis, we use data from the 2008 Vietnam Access to Resources Household Survey to investigate the relationship between weather variability in the past and current trust. The result shows that individuals who are heavily threatened by negative weather fluctuation seem to have higher level of trust in neighbours and others within their close group. The evidence shows that the relationship between weather variation on social trust may be transmitted through strengthening the cooperation amongst village peasants and family ties as they cope with risk and uncertainty. There is also evidence that households with a higher proportion of agricultural income tend to trust people more.

Background. Maternal vaccination with an acellular pertussis (aP)-containing vaccine is a recommended strategy in a growing number of industrialized countries, to protect young infants from disease. Little is known on the effect of this strategy in low-and middle-income countries. Following a previous report on the effect of adding a pertussis and diphtheria component to the tetanus vaccination program in pregnant women in Vietnam, we report on infant immune responses to a booster aP vaccine dose in this randomized controlled clinical trial. Methods. Thirty infants of Tdap (tetanus, diphtheria, and acellular pertussis)-vaccinated pregnant women and 37 infants of women vaccinated with a tetanus-only vaccine received a fourth aP-containing vaccine dose in the second year of life. Blood was taken 1 month after the fourth infant dose. Immunoglobulin G (IgG) antibodies against pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (Prn), tetanus toxoid (TT), and diphtheria toxoid (DT) were measured using commercially available enzyme-linked immunosorbent assays (ELISA). Results. One month after the booster dose, significantly lower antibody titers were measured in the Tdap group for anti-TT IgG (P < .001) only. Anti-DT IgG, anti-PT IgG, anti-Prn IgG, and anti-FHA IgG antibody titers were comparable for both groups. A rise in antibody concentrations was elicited for all (except DT) antigens after boosting. Conclusions. The present results indicate that the blunting of infant pertussis responses induced by maternal immunization, measured after a primary series of aP vaccines, was resolved with the booster aP vaccine dose. These results add to the evidence for national and international decision makers on maternal immunization as a vaccination strategy for protection of young infants against infectious diseases. This work was supported by VLIR-UOS (Flemish Interuniversity Council) (ZEIN2012Z131) and Fund for Scientific Research-Flanders (FWO) (G.A032.12N) together with the National Foundation for Science and Technology Development-NAFOSTED (FWO.2011.03) and the Antwerp Study Centre for Infectious Diseases (ASCID). E. L. is beneficiary of a postdoctoral mandate fellowship from the FWO (FWO 12D6114N). N. H. gratefully acknowledges support from the University of Antwerp scientific chair in Evidence-Based Vaccinology, financed in 2009-2016 by a gift of Pfizer. R. N. C. was partially funded by BELSPO (Federal Service Science Policy). Part of this work was performed in the frame of the Belgian National Reference Centre for Bordetella pertussis, supported by the Belgian Ministry of Social Affairs through a fund within the Health Insurance System.

Aim: A better understanding of the hearing disability situation would advance hearing health care in the developing world. Vietnam is a lower middle income country with hearing health care in its early stages of development. This study examined the situation (degree, types, and causes) of hearing impairment, the effects of age and gender on hearing impairment, and the age of identification and its relationship with degree of hearing impairment, in a sample of Vietnamese children with hearing loss.Method: Sixty-nine participants aged from 20 to 129 months with prelingual-onset hearing loss were assessed during Global Foundation For Children With Hearing Loss international partnership activities. Data on hearing assessment findings, including case history and pure-tone audiometric outcomes, were analyzed.Results: Results showed that the hearing loss of participants ranged from moderate to profound levels (mean pure-tone average in better ear = 95.9 dB HL, range = 51.7–125.0 dB, SD = 17.37). Sensorineural pa...

Background: The cesarean section rate in Vietnam has been increasing especially in urban area. However, limited evidence identified regarding socio-demographic factors of the cesarean section birth. The objective of this study was to determine the current cesarean birth rate and the associated socio-demographic factors among mothers in Nha Trang city, south-central Vietnam. Methods: A community-based cross-sectional study was conducted between October and November in 2016 as part of a Streptococcus pneumoniae carriage survey conducted in 27 communes of Nha Trang city. From each commune, 120 mothers and their children less than 2 years old were randomly selected. Mothers were asked to answer standardized questions regarding socio-demographic information and mode of birth. Multivariate logistic regression was adopted to examine associations between socio-demographic variables and mode of birth. Results: Of 3148 participants, the number of cesarean births was 1396 (44.3 %). Older maternal age (? 30 years old), having another child going to school or kindergarten, monthly income more than 644 USD, gestational weeks at birth over 42 weeks, and low (< 2500 g) or high (? 3500 g) birth weight were associated with higher likelihood of cesarean births. Conclusion: The CS rate obtained in this study was more than twice of what is recommended by the World Health Organization, which is consistent with the previous nation-wide study in Viet Nam. Further monitoring is suggested to examine the non-medical reason for the increased CS rate., Tropical Medicine and Health, 48(1), art.no.57; 2020

This paper examines how the interaction of social trust and institutions, such as land administration, affects household economic decisions in Viet Nam. Using a panel dataset of rural households from 2008 to 2014, we show that negative consequences of the duration of land administration on agricultural investment have been lower in rural households with higher level of trust. Higher-trust households, when facing higher barrier from land administration, tend to invest more on agricultural land compared to low-trust households where household heads are male. We also find that high-trust households enhance land property rights when facing obstacles from land administration.

This paper examines how the interaction of social trust and institutions, such as land administration, affects household economic decisions in Vietnam. Using a panel dataset of rural households from 2008 to 2014, we show that negative consequences of the duration of land administration on credit access, agricultural investment, and land use rights have been mitigated in communes with higher level of trust. These results support the view that trust complements formal institutions.

Few studies have investigated possible causative and protective factors associated with allergic diseases in resource-limited countries, Southeast Asia. We estimated the current prevalence of asthma, rhinoconjunctivitis, and eczema among 6-year-old children,and identified anthropometric factors associated with asthma, rhinoconjunctivitis and eczema, in South-Central Vietnam. A birth cohort study recruited 1,999 children born at a provincial hospital in Nha Trang, Vietnam between May 2009 and May 2010.A 6-year follow-up survey was conducted where clinical, familial, and environmental information was collected by interviewing caregivers using a standardized form based on the International Study of Asthma and Allergies in Childhood,Phase Three Core and Environmental Questionnaire for 6?7-year-old children. The odds ratios of asthma, rhinoconjunctivitis, and eczema for anthropometric factors were estimated using logistic regression analysis. In total, 1202 children participated in the follow-up survey. The proportions of children who had current asthma, rhinoconjunctivitis, and eczema were 5.1% (95% confidence interval [CI] 3.9?6.5%), 11.5% (9.7?13.4%), and 6.7% (5.3?8.2%),respectively. Low birthweight (adjusted odds ratio 5.12, 95% CI 1.92?13.64) was independently associated with increased risk of eczema.Further studies are necessary to understand the involved mechanism., Scientific Reports, 9(1), art.no.2655; 2019

Highlights • The burden of Hib pneumonia in Southeast Asia has been quantified in few studies. • We estimate the impact of routine vaccination against Hib in Nha Trang. • Population-based surveillance allowed statistical adjustment for confounding viral pneumonia. • Hib vaccination has substantially reduced the burden of childhood pneumonia., Introduction Despite the global success of Hib vaccination in reducing disease and mortality, uncertainty about the disease burden and the potential impact of Hib vaccination in Southeast Asia has delayed the introduction of vaccination in some countries in the region. Hib vaccination was introduced throughout Vietnam in July 2010 without catch-up. In an observational, population based surveillance study we estimated the impact of routine Hib vaccination on all cause radiologically confirmed childhood pneumonia in Nha Trang, Vietnam. Materials and methods In 2007 active hospital based surveillance was established in Khanh Hoa General Hospital, the only hospital in Nha Trang, Khanh Hoa province. Nasopharyngeal samples and chest radiographs are taken routinely from all children diagnosed with acute respiratory illness on admission. For admissions between 02/2007 and 03/2012 chest radiographs were interpreted for the presence of WHO primary endpoint pneumonia and nasopharyngeal swabs were analysed by PCR for the presence of Influenza A or B, RSV and rhinovirus. We employed Poisson regression to estimate the impact of Hib vaccination on radiologically confirmed pneumonia (RCP) while statistically accounting for potential differences in viral circulation in the post vaccination era which could have biased the estimate. Results Of 3151 cases admitted during the study period, 166 had RCP and major viruses were detected in 1601. The adjusted annual incidence of RCP in children younger than 5 years declined by 39% (12–58%) after introduction of Hib vaccination. This decline was most pronounced in children less than 2 years old, adjusted IRR: 0.52 (0.33–0.81), and no significant impact was observed in the 2–4 years old who were not eligible for vaccination, adjusted IRR: 0.96 (0.52–1.72). Discussion We present early evidence that the burden of Hib associated RCP in Nha Trang before vaccination was substantial and that shortly after introduction to the routine childhood immunisation scheme vaccination has substantially reduced that burden.

This paper evaluates the impact of Chinese import penetration on the innovation of Vietnamese manufacturing firms from 2011 to 2015, exploiting variations in import exposure by industry specialization and instrumenting for Chinese import penetration using Chinese global exports. Contrary to the existing literature, the paper finds no systematic evidence that rising imports from China make domestic firms adopt new technologies or innovations in their products.

Contains fulltext : 170312.pdf (Publisher’s version ) (Open Access) Acinetobacter baumannii is an important cause of multidrug-resistant hospital acquired infections in the world. Here, we investigate the presence of NDM-1 and other carbapenemases among carbapenem-resistant A. baumannii isolated between August 2010 and December 2014 from three large hospitals in Hanoi, Vietnam. We identified 23/582 isolates (4 %) (11 from hospital A, five from hospital B, and seven from hospital C) that were NDM-1 positive, and among them 18 carried additional carbapenemase genes, including seven isolates carrying NDM-1, IMP-1, and OXA-58 with high MICs for carbapenems. Genotyping indicated that NDM-1 carrying A. baumannii have expanded clonally in these hospitals. Five new STs (ST1135, ST1136, ST1137, ST1138, and ST1139) were identified. One isolate carried NDM-1 on a plasmid belonging to the N-repA replicon type; no NDM-1-positive plasmids were identified in the other isolates. We have shown the extent of the carbapenem resistance and the local clonal spread of A. baumannii carrying NDM-1 in these hospitals; coexistence of NDM-1 and IMP-1 is reported for the first time from Vietnam here, and this will further seriously limit future therapeutic options.

To determine the incidence of radiologically-confirmed pneumonia (RCP) and Haemophilus influenzae type b (Hib) carriage in central Vietnam as a baseline data before Hib conjugate vaccine introduction.In the context of ongoing population-based prospective, hospitalized acute respiratory infection surveillance study, a cross-sectional Hib carriage study was conducted among 1000 children5 years of age living in NhaTrang, Vietnam in June 2010, 1 month before the nationwide introduction of Hib conjugate vaccine in Vietnam.The incidence of RCP hospitalizations among children5 years of age was 3.3 per 1000 children. The highest incidence was observed among children 12-23 month age group (8.3 per 1000). Haemophilus influenzae carriage was detected in 37% of the children and Hib carriage rate was 3%. Eighty-two percent of the Haemophilus influenzae had TEM β-lactamase resistance gene. The presence of 6 or more family members was associated with an increased rate of Hib carriage (P = .04).Incidence of RCP and Hib carriage in this cross-sectional survey are lower compared with other studies. Continued surveillance for invasive Hib disease and sequential Hib carriage surveys are needed to support future assessments of the impact of Hib conjugate vaccine in Vietnam.

Background Rotavirus is the most common etiology of diarrhea-associated hospitalizations and clinic visits in Vietnamese children

Since the initial discovery of RSV-A ON1 in Canada in 2010, ON1 has been reported worldwide, yet information regarding its clinical impact and severity has been controversial. To investigate the clinical relevance of RSV-A ON1,acute respiratory infection (ARI) cases enrolled to our population-based prospective pediatric ARI surveillance at Khanh Hoa General Hospital, Central Vietnam from January 2010 through December 2012 were studied. Clinical-epidemiological information and nasopharyngeal samples were collected. Multiplex PCR assays were performed for screening 13 respiratory viruses. RSV-positive samples were further tested for subgroups (A/B) and genotypes information by sequencing the G-glycoprotein 2nd hypervariable region. Statistical analysis was performed to evaluate the clinical-epidemiological characteristics of RSV-A ON1. A total of 1854 ARI cases were enrolled and 426 (23.0%) of them were RSV-positive. During the study period, RSV-A and B had been co-circulating. NA1 was the predominant RSV-A genotype until the appearance of ON1 in 2012. RSV-related ARI hospitalization incidence significantly increased after the emergence of ON1. Moreover, multivariate analysis revealed that risk of lower respiratory tract infection was 2.26 (95% CI: 1.37–3.72) times, and radiologically-confirmed pneumonia was 1.98 (95% CI: 1.01–3.87) times greater in ON1 compared to NA1 cases. Our result suggested that ON1 ARI cases were clinically more severe than NA1.

PROBLEM: The potential for misidentification of trial participants, leading to misclassification, is a threat to the integrity of randomized controlled trials. The correct identification of study subjects in large trials over prolonged periods is of vital importance to those conducting clinical trials. Currently used means of identifying study participants, such as identity cards and records of name, address, name of household head and demographic characteristics, require large numbers of well-trained personnel, and still leave room for uncertainty. APPROACH: We used fingerprint recognition technology for the identification of trial participants. This technology is already widely used in security and commercial contexts but not so far in clinical trials. LOCAL SETTING: A phase 2 cholera vaccine trial in SonLa, Viet Nam. RELEVANT CHANGES: An optical sensor was used to scan fingerprints. The fingerprint template of each participant was used to verify his or her identity during each of eight follow-up visits. LESSONS LEARNED: A system consisting of a laptop computer and sensor is small in size, requires minimal training and on average six seconds for scanning and recognition. All participants' identities were verified in the trial. Fingerprint recognition should become the standard technology for identification of participants in field trials. Fears exist, however, regarding the potential for invasion of privacy. It will therefore be necessary to convince not only trial participants but also investigators that templates of fingerprints stored in databases are less likely to be subject to abuse than currently used information databases.

This study investigated the features of developmental difficulties combined with sensory defects in children with congenital rubella syndrome (CRS). Following a large rubella outbreak in Khanh Hoa Province, Vietnam, in 2011, we enrolled 41 children with CRS from September 2011 through May 2013. Fourteen participants died and six became untraceable by October 2013; the remaining 21 children were followed up from 2013 to 2015. Thirteen and seven participants had hearing and functional ophthalmological impairment, respectively. Developmental difficulties were suspected in 19 (95%) children who failed in at least one area of the Ages and Stages Questionnaire (ASQ) and/or Denver II in 2013 and/or 2015. Developmental difficulties were frequently identified in the ASQ communication domain (n = 14 in 2013) and Denver II language area (n = 13 in 2013). Seven (41%) participants were suspected of having autism spectrum disorder (ASD) in 2013 by the Modified Checklist for Autism in Toddlers. In 2015, proportions of children failing the problem-solving (62%) and personal-social (62%) domains had increased and two of 13 were diagnosed with ASD by the Childhood Autism Rating Scale, Second Edition. Developmental difficulties were suspected in most children with CRS, including autism largely combined with sensory dysfunction., Scientific Reports, 7, 46483; 2017

OBJECTIVE: Outbreaks of rubella and congenital rubella syndrome (CRS) continue to arise in various countries where a rubella-containing vaccine is not included in the national immunization program. After a large-scale rubella outbreak in 2011, CRS cases emerged in Vietnam. The aim of this study was to clarify the clinical features of these cases with an emphasis on cardiovascular complications and outcomes. METHODS: From October 2011 to September 2012, we conducted a prospective surveillance study of infants RESULTS: We enrolled 38 cases of CRS characterized by a low birth weight (71%), cardiovascular defects (72%), cataracts (13%), hearing impairment (93%), purpura (84%), hepatosplenomegaly (68%), and thrombocytopenia (76%). Patent ductus arteriosus, the most common cardiovascular complication, was often associated with progressive pulmonary hypertension (PH). As of January 2013, 13 infants (34%) had died, and PH was significantly more frequent among the fatalities (P = .004); however, therapeutic closure of the ductus reversed the PH in several cases. CONCLUSIONS: PH-associated mortality is high among infants who have CRS in Vietnam. Providing proper assessments, continuous follow-up, and timely intervention for cardiovascular defects is critical for the management of CRS patients. Echocardiography is of diagnostic and prognostic value and can support better clinical management of CRS, even in a developing country setting.

Hospitalized Vietnamese children with acute respiratory infection were investigated for 13 viral pathogens using multiplex-polymerase chain reaction. We enrolled 958 children of whom 659 (69%) had documented viral infection: rhinovirus (28%), respiratory syncytial virus (23%), influenza virus (15%), adenovirus (5%), human metapneumo virus (4.5%), parainfluenza virus (5%), and bocavirus (2%). These Vietnamese children had a range of respiratory viruses which underscores the need for enhanced acute respiratory infection surveillance in tropical developing countries., The Pediatric infectious disease journal, 29(1), pp.75-77; 2010

Comprehensive population-based data on the role of respiratory viruses in the development of lower respiratory tract infections (LRTIs) remain unclear. We investigated the incidence and effect of single and multiple infections with respiratory viruses on the risk of LRTIs in Vietnam. Population-based prospective surveillance and a case-control study of hospitalised paediatric patients with acute respiratory infection (ARI) were conducted from April 2007 through to March 2010. Healthy controls were randomly recruited from the same community. Nasopharyngeal samples were collected and tested for 13 respiratory viruses using multiplex PCRs. 1992 hospitalised ARI episodes, including 397 (19.9%) with LRTIs, were enrolled. Incidence of hospitalised LRTIs among children aged

We tested a candidate live, oral, rotavirus vaccine (Rotavin-M1™) derived from an attenuated G1P [8] strain (KH0118-2003) isolated from a child in Vietnam. The vaccine was tested first for safety in 29 healthy adults. When deemed safe, it was further tested for safety and immunogenicity in 160 infants (4 groups) aged 6-12 weeks in a dose and schedule ranging study. The vaccine was administered in low titer (10(6.0)FFU/dose) on a 2-dose schedule given 2 months apart (Group 2L) and on a 3-dose schedule given 1 month apart (Group 3L) and in high titer (10(6.3)FFU/dose) in 2 doses 2 months apart (Group 2H) and in 3 doses 1 month apart (Group 3H). For comparison, 40 children (group Rotarix™) were given 2 doses of the lyophilized Rotarix™ vaccine (10(6.5)CCID(50)/dose) 1 month apart. All infants were followed for 30 days after each dose for clinical adverse events including diarrhea, vomiting, fever, abdominal pain, irritability and intussusception. Immunogenicity was assessed by IgA seroconversion and viral shedding was monitored for 7 days after administration of each dose. Two doses of Rotavin-M1 (10(6.3)FFU/dose) were well tolerated in adults. Among infants (average 8 weeks of age at enrollment), administration of Rotavin-M1 was safe and did not lead to an increased rate of fever, diarrhea, vomiting or irritability compared to Rotarix™, indicating that the candidate vaccine virus had been fully attenuated by serial passages. No elevation of levels of serum transaminase, blood urea, or blood cell counts were observed. The highest rotavirus IgA seroconversion rate (73%, 95%CI (58-88%)) was achieved in group 2H (2 doses--10(6.3)FFU/dose, 2 months apart). The 2 dose schedules performed slightly better than the 3 dose schedules and the higher titer doses performed slightly better than the lower titer doses. These rates of seroconversion were similar to that of the Rotarix™ group (58%, 95%CI (42-73%)). However more infants who received Rotarix™ (65%) shed virus in their stool after the first dose than those who received Rotavin-M1 (44-48%) (p

Background Several countries have applied the Haemophilus influenzae type b (Hib) rapid assessment tool (RAT) to estimate the burden of Hib disease where resources for hospital- or population-based surveillance are limited. In Vietnam, we used the Hib RAT to estimate the burden of Hib pneumonia and meningitis prior to Hib vaccine introduction. Methods Laboratory, hospitalization and mortality data were collected for the period January 2004 through December 2005 from five representative hospitals. Based on the WHO Hib RAT protocol, standardized MS Excel spreadsheets were completed to generate meningitis and pneumonia case and death figures. Results We found 35 to 77 Hib meningitis deaths and 441 to 957 Hib pneumonia deaths among children < 5 years of age annually in Vietnam. Overall, the incidence of Hib meningitis was estimated at 18/100,000 (95% confidence interval, CI, 15.1-21.6). The estimated Hib meningitis incidence in children < 5 years age was higher in Ho Chi Minh City (22.5/100,000 [95% CI, 18.4-27.5]) compared to Hanoi (9.8/100,000 [95% CI, 6.5-14.8]). The Hib RAT suggests that there are a total of 883 to 1,915 cases of Hib meningitis and 4,414 to 9,574 cases of Hib pneumonia per year in Vietnam. Conclusions In Hanoi, the estimated incidence of Hib meningitis for children < 5 years of age was similar to that described in previous population-based studies of Hib meningitis conducted from 1999 through 2002. Results from the Hib RAT suggest that there is a substantial, yet unmeasured, disease burden associated with Hib pneumonia in Vietnamese children.