Who is exposed to smoke at home? A population-based cross-sectional survey in central Vietnam

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喫煙は小胞体ストレスを惹起し、RhoAの活性化を介してefferocytosisを抑制する

長崎大学学位論文 [学位記番号]博（医歯薬）甲第1295号 [学位授与年月日]令和2年12月2

Evaluation of the effect of reduced-dose pneumococcal conjugate vaccine schedules on vaccine serotype carriage in children and their caretakers in a naïve population in Vietnam: Protocol for a cluster randomized non-inferiority trial [version 1; peer review: 2 approved, 1 approved with reservations]

Introduction: The WHO currently recommends giving pneumococcal conjugate vaccines (PCVs) as three doses – either three doses in infancy with Pentavalent vaccine (3p+0), or two doses in infancy followed by a booster around 12 months (2p+1). However, their high price is a barrier to introduction and sustainability in low and middle-income countries. We hypothesize that a schedule with a single priming and a booster dose (1p+1) may maintain similar levels of protection for the community by sustaining herd immunity, once circulation of vaccine types has been controlled. Methods and analysis: We will conduct a cluster randomized trial with four intervention arms (1p+1, 0p+1, 2p+1, 3p+0) and three unvaccinated clusters in the 27 communes of Nha Trang, central Vietnam. A PCV catch-up vaccination campaign to all children under three years of age will be performed at the start of the trial. The primary endpoint is non-inferiority of the1p+1 schedule if compared to the WHO standard 2p+1 and 3p+0 schedules in reducing vaccine serotype carriage prevalence in infants. We will also explore impact of 0p+1 schedule. A baseline and annual pneumococcal carriage surveys of 6480 participants per survey covering infants, toddlers and their mothers will be conducted. Ethics and dissemination: Ethical approvals were obtained from the ethical review committees of Institute of Tropical Medicine, Nagasaki University (151203149-2) and the Ministry of Health, Vietnam (1915/QD-BYT). The results, interpretation and conclusions will be presented at national and international conferences, and published in peer-reviewed open access journals. Trial registration number: NCT0296123

Predicting the impact of pneumococcal conjugate vaccine programme options in Vietnam.

Although catch-up campaigns (CCs) at the introduction of pneumococcal conjugate vaccines (PCVs) may accelerate their impact, supply constraints may limit their benefit if the need for additional PCV doses results in introduction delay. We studied the impact of PCV13 introduction with and without CC in Nha Trang, Vietnam - a country that has not yet introduced PCV - through a dynamic transmission model. We modelled the impact on carriage and invasive pneumococcal disease (IPD) of routine vaccination (RV) only and that of RV with CCs targeting <1y olds (CC1), <2y olds (CC2) and <5y olds (CC5). The model was fitted to nasopharyngeal carriage data, and post-PCV predictions were based on best estimates of parameters governing post-PCV dynamics. With RV only, elimination in carriage of vaccine-type (VT) serotypes is predicted to occur across all age groups within 10 years after introduction, with near-complete replacement by non-VT. Most of the benefit of CCs is predicted to occur within the first 3 years with the highest impact at one year, when IPD incidence is predicted to be 11% (95%CrI 9 - 14%) lower than RV with CC1, 25% (21 - 30 %) lower with CC2 and 38% (32 - 46%) lower with CC5. However, CCs would only prevent more cases of IPD insofar as such campaigns do not delay introduction by more than about 6, 12 and 18 months for CC1, CC2 and CC5. Those findings are important to help guide vaccine introduction in countries that have not yet introduced PCV, particularly in Asia

Reasons for Increased Caesarean Section Rate in Vietnam: A Qualitative Study among Vietnamese Mothers and Health Care Professionals.

The Caesarean section rate in urban Vietnam is 43% in 2014, which is more than twice the recommended rate (10%-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 'request for Caesarean section,' 'mental strain of obstetricians,' and 'decision-making process.' 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

Role of temperature, influenza and other local characteristics in seasonality of mortality: a population-based time-series study in Japan

Objectives: To investigate the extent to which temperature and influenza explained seasonality of mortality in Japan and to examine the association of the seasonality with prefecture-specific characteristics.Design: We conducted time-series analysis to estimate the seasonal amplitude before and after adjusting for temperature and/or influenza-like illness (ILI). Next, we applied linear mixed effect models to investigate the association of seasonal amplitudes with each indicator on prefecture-specific characteristics on climate, demographic and socioeconomic factors and adaptations.Setting: 47 prefectures in JapanParticipants: Deaths for all-cause, circulatory, and respiratory disease between 1999 and 2015.Outcome measures: Peak-to-trough ratio (PTR, a measure of seasonal amplitude).Results: The nationwide unadjusted-PTRs for all-cause, circulatory and respiratory mortality were 1.29 (95% CIs: 1.28 to 1.31), 1.55 (95% CI: 1.52 to 1.57) and 1.45 (95% CI: 1.43 to 1.48), respectively. These PTRs reduced substantially after adjusting for temperature but very little after a separate adjustment for ILI. Furthermore, seasonal amplitudes varied between prefectures. However, there was no strong evidence for the associations of PTR with the indicators on prefecture-specific characteristics.Conclusions: Seasonality of mortality is primarily driven by temperature in Japan. The spatial variation in seasonal amplitudes was not associated with prefecture-specific characteristics. Although further investigations are required to confirm our findings, this study can help us gain a better understanding of the mechanisms underlying seasonality of mortality

Seasonality of respiratory viruses causing hospitalizations for acute respiratory infections in children in Nha Trang, Vietnam.

BACKGROUND: Acute respiratory infections (ARIs) are the most common causes of death in children under 5 years of age. While the etiology of most pneumonia and ARI episodes is undiagnosed, a broad range of ARI-causing viruses circulate widely in South East Asia. However, the patterns and drivers of the seasonal transmission dynamics are largely unknown. Here we identify the seasonal patterns of multiple circulating viruses associated with hospitalizations for ARIs in Nha Trang, Vietnam. METHODS: Hospital based enhanced surveillance of childhood ARI is ongoing at Khanh Hoa General Hospital in Nha Trang. RT-PCR was performed to detect 13 respiratory viruses in nasopharyngeal samples from enrolled patients. Seasonal patterns of childhood ARI hospital admissions of various viruses were assessed, as well as their association with rainfall, temperature, and dew point. RESULTS: Respiratory syncytial virus peaks in the late summer months, and influenza A in April to June. We find significant associations between detection of human parainfluenza 3 and human rhinovirus with the month's mean dew point. Using a cross-wavelet transform we find a significant out-of-phase relationship between human parainfluenza 3 and temperature and dew point. CONCLUSIONS: Our results are important for understanding the temporal risk associated with circulating pathogens in Southern Central Vietnam. Specifically, our results can inform timing of routing seasonal influenza vaccination and for when observed respiratory illness is likely viral, leading to judicious use of antibiotics in the region

Using Seroprevalence and Immunisation Coverage Data to Estimate the Global Burden of Congenital Rubella Syndrome, 1996-2010: A Systematic Review.

BACKGROUND: The burden of Congenital Rubella Syndrome (CRS) is typically underestimated in routine surveillance. Updated estimates are needed following the recent WHO position paper on rubella and recent GAVI initiatives, funding rubella vaccination in eligible countries. Previous estimates considered the year 1996 and only 78 (developing) countries. METHODS: We reviewed the literature to identify rubella seroprevalence studies conducted before countries introduced rubella-containing vaccination (RCV). These data and the estimated vaccination coverage in the routine schedule and mass campaigns were incorporated in mathematical models to estimate the CRS incidence in 1996 and 2000-2010 for each country, region and globally. RESULTS: The estimated CRS decreased in the three regions (Americas, Europe and Eastern Mediterranean) which had introduced widespread RCV by 2010, reaching <2 per 100,000 live births (the Americas and Europe) and 25 (95% CI 4-61) per 100,000 live births (the Eastern Mediterranean). The estimated incidence in 2010 ranged from 90 (95% CI: 46-195) in the Western Pacific, excluding China, to 116 (95% CI: 56-235) and 121 (95% CI: 31-238) per 100,000 live births in Africa and SE Asia respectively. Highest numbers of cases were predicted in Africa (39,000, 95% CI: 18,000-80,000) and SE Asia (49,000, 95% CI: 11,000-97,000). In 2010, 105,000 (95% CI: 54,000-158,000) CRS cases were estimated globally, compared to 119,000 (95% CI: 72,000-169,000) in 1996. CONCLUSIONS: Whilst falling dramatically in the Americas, Europe and the Eastern Mediterranean after vaccination, the estimated CRS incidence remains high elsewhere. Well-conducted seroprevalence studies can help to improve the reliability of these estimates and monitor the impact of rubella vaccination

An alarmingly high nasal carriage rate of Streptococcus pneumoniae serotype 19F non-susceptible to multiple beta-lactam antimicrobials among Vietnamese children.

BackgroundUnderstanding the relationship between serotype epidemiology and antimicrobial susceptibility of Streptococcus pneumoniae is essential for the effective introduction of pneumococcal conjugate vaccines (PCVs) and control of antimicrobial-resistant pneumococci.MethodsWe conducted a community-based study in Nha Trang, central Vietnam, to clarify the serotype distribution and pattern of S. pneumoniae antimicrobial susceptibility in children under 5 years of age and to identify risk factors for carrying antimicrobial-resistant strains. Nasopharyngeal swabs collected from children with acute respiratory infections (ARIs) hospitalized between April 7, 2008, and March 30, 2009, and from healthy children randomly selected in July 2008 were subjected to bacterial culture. Minimum inhibitory concentrations (MICs) against S. pneumoniae were determined, and multiplex-polymerase chain reaction (PCR) serotyping assays were performed. Logistic regression was applied to identify risk factors.ResultsWe collected 883 samples from 331 healthy children and 552 ARI cases; S. pneumoniae was isolated from 95 (28.7%) healthy children and 202 (36.6%) ARI cases. Age and daycare attendance were significantly associated with pneumococcal carriage. In total, 18.0, 25.8 and 75.6% of the isolates had high MICs for penicillin (≥4 μg/ml), cefotaxime (≥2 μg/ml) and meropenem (≥0.5 μg/ml), respectively. The presence of pneumococci non-susceptible to multiple beta-lactams was significantly associated with serotype 19F (Odds Ratio: 4.23) and daycare attendance (Odds Ratio: 2.56) but not ARIs, age or prior antimicrobial use. The majority of isolates non-susceptible to multiple beta-lactams (90%) were PCV13 vaccine serotypes.ConclusionsS. pneumoniae serotype 19F isolates non-susceptible to multiple beta-lactams are widely prevalent among Vietnamese children. Vaccine introduction is expected to significantly increase drug susceptibility