Pham Quang Thai

Background Understanding human movement patterns and their association with risk factors for the acquisition and transmission of pathogens can inform guidance for disease control. In Vietnam, acute encephalitis syndrome (AES) has a wide-ranging etiology; however, it is hypothesized that many causes are due to vector-borne diseases. Methods We undertook a study in Ha Nam province, northern Vietnam, to determine the acceptability and feasibility of using i-gotU GT-120 GPS devices to understand the mobility patterns of healthy residents and evaluate the time spent in areas deemed to be at risk of bites from vectors. Focus group discussions (FGDs) were carried out to understand the knowledge and perceptions of GPS devices. Following this, 48 participants wore a GPS device for eight 72-hour periods over a year from which movement data and feedback were obtained. Results Concerns about the GPS included risks to privacy and health, and losing the device. However, compliance was good with 80,831 unique coordinates obtained and participants carrying the devices for 13,411 km over the study period. All groups of participants (adults and children, and those from urban and rural settings) travelled outside of Ha Nam province however, most spent the greatest proportion of time in areas with a low normalized difference vegetation index (NDVI) which was associated with a decreased risk of bites from vectors. Conclusions Our study demonstrates that the use of GPS devices in this setting was a feasible method for collecting data on movement patterns. However, for future studies, given the cost and logistics of using the GPS devices, we recommend exploring methods which allow for a larger sample size.

Nghiên cứu cắt ngang được thực hiện trên 206 người dân tại huyện Mèo Vạc, Hà Giang nhằm mô tả kiếnthức, thái độ, thực hành (KAP) về bệnh than và xác định một số yếu tố liên quan đến thực hành phòngchống bệnh. Kết quả cho thấy, trong nhóm người dân đã từng nghe về bệnh than, tỷ lệ có kiến thức đạtvà thái độ tích cực tương đối cao (> 60,0% và 77,1%). Tuy nhiên, tính trên toàn bộ đối tượng, chỉ 28,6%lựa chọn đúng các biện pháp thực hành dự phòng. Người trong nhóm tuổi 41 - 50 có khả năng thực hànhphòng chống bệnh đúng cao hơn 3,1 lần so với nhóm 18 - 30 tuổi (95% CI: 1,1 - 8,2), trong khi nhóm 51- 60 tuổi có khả năng cao hơn 3,7 lần (95% CI: 1,2 - 11,0). Người dân từng nghe về bệnh than lựa chọnđúng các biện pháp thực hành dự phòng bệnh than cao hơn 2,3 lần so với nhóm chưa nghe (95% KTC:1,2 - 4,2). Cần có biện pháp truyền thông nâng cao nhận thức cho người dân về các biện pháp thực hànhphòng bệnh than phù hợp văn hóa, ngôn ngữ của người H’Mông tại từng địa phương.

Nghiên cứu cắt ngang định lượng kết hợp định tính thực hiện trên 737 người chăm sóc (NCS) học sinh lớp1 (Đắk Glong n = 371, Gia Nghĩa n = 366) nhằm mô tả một số yếu tố ảnh hưởng đến tiêm đủ mũi (TĐM)trước nhập học tại Đắk Nông. Yếu tố ảnh hưởng bao gồm không được quản lý trên Hệ thống thông tin Tiêmchủng Quốc gia (NIIS) OR = 27,51 (6,67 - 113,45), dân tộc H’Mông OR = 2,11 (1,24 – 3,58), hộ > 3 con OR= 2,18 (1,24 – 3,86), sống tại Đắk Glong OR = 1,65 (1,23 - 2,21) và hình thức tiêm chủng dịch vụ (TCDV)aOR = 4,52 (1,50 - 13,60) hoặc TCDV phối hợp tiêm chủng mở rộng aOR = 1,82 (1,07 - 3,10). Có sự phânhoá yếu tố nguy cơ giữa 2 địa bàn Gia Nghĩa và Đắk Glong. Kết quả định tính cho thấy tại Đắk Glong ràocản thuộc nhóm cá nhân, kinh tế - xã hội, văn hoá (sinh tại nhà, đổi tên), tín ngưỡng và khó quản lý trênNIIS. Ở Gia Nghĩa, thách thức chính thuộc hệ thống TCDV với kết quả định tính ghi nhận đa mã tiêm chủngvà thiếu dữ liệu TCDV trên NIIS. Để nâng tỷ lệ tiêm chủng và thu hẹp khoảng trống miễn dịch, cần chiếnlược can thiệp đa dạng, phù hợp văn hóa từng vùng, ưu tiên nhóm khó tiếp cận, kết hợp cải thiện quản lýthông tin, tăng cường rà soát và tiêm bù tại trường học.

Hepatitis B remains a major public health issue in Vietnam. Mandatory reporting to the national electronic communicable disease surveillance system (eCDS) has been required since July 2016. We conducted an evaluation of the hepatitis B surveillance system in Ninh Binh, the province with the highest reported burden of hepatitis B in Northern Vietnam, between 2017 and 2022. Using the CDC’s guidelines for evaluating public health surveillance systems, we assessed four key attributes: simplicity, timeliness, data quality, and acceptability. This retrospective evaluation included document reviews, analysis of hepatitis B data, and in-depth interviews with provincial-level healthcare staff involved in the reporting of hepatitis B cases. The results showed that the eCDS improved reporting frequency, provided more detailed case information, and enhanced data accessibility compared to the previous paper-based system. However, the system faced several challenges, including unclear objectives, difficulties in distinguishing acute from chronic cases, insufficient training for staff, lack of supervision for data quality, and technical software issues. Despite these challenges, stakeholders found the system acceptable but emphasized the need for improvements, including revising the system’s objectives, automating case classification, enhancing training, securing funding for maintenance, and implementing regular data review processes.

Background/Objectives: In Vietnam, COVID-19 vaccination campaigns for children have encountered numerous challenges due to acceptance issues among parents. This study aimed to assess parental decision-making and identify factors influencing their decision to vaccinate their children against COVID-19. Methods: This was a cross-sectional online survey conducted between April and May 2023 among parents of children aged 6–17 years enrolled in urban and rural schools in Thai Nguyen province, Vietnam. Data on parental and child demographics, vaccination decision-making, COVID-19 experiences, and health beliefs based on the Health Belief Model were collected and analyzed, using univariate and multivariable multinomial regression analyses. Results: Among 4235 respondents (median age 41 years, 80.4% female), 81.3% had accepted all vaccine doses for their children, 9.7% had accepted some doses, 4.6% had rejected all doses, and 4.5% had not vaccinated their children for reasons unrelated to vaccine acceptance. Factors influencing parental decision-making included parental age, educational status, area of residence, health beliefs, prior experience with COVID-19 vaccination, and their child’s age and health status. Conclusions: We found overall high levels of parental acceptance for COVID-19 vaccination for children in Thai Nguyen province. To enhance COVID-19 vaccination acceptance, targeted communication strategies should focus on younger parents, those living in urban areas, parents with higher educational levels, and those with children who are younger or have underlying medical conditions. Trusted sources such as healthcare workers, teachers, and official health websites are essential for disseminating accurate information and fostering trust in vaccination programs.

Measles remains a major public health burden worldwide. Parents often hesitate to vaccinate children with chronic diseases. We investigated the association between the percentage of vaccination and chronic diseases and explore hospital infections’ role in the 2017–2019 measles outbreak across northern Vietnam provinces. A total of 2,064 children aged 0–15 years old admitted for measles to the National Children’s Hospital during the outbreak were included in the study. Demographic information, clinical characteristics, vaccination statuses and laboratory examination were extracted from electronic medical records, vaccination records, or interviews with parents when other sources were unavailable. The incidence rate that provincial hospitals sent to the National Children’s Hospital was proportional to the population density of their provinces of residence. Early nosocomial transmission of measles was observed before community-acquired cases emerged in many provinces. Among patients aged over 18 months, those with chronic diseases had a proportion of vaccination of 9.4%, lower than patients without chronic diseases at 32.4%. Unvaccinated patients had a higher proportion of hospital-acquired infections with aOR = 2.42 (1.65–3.65), p < 0.001 relative to vaccinated patients. The proportion of hospital-acquired infections was higher among children with chronic diseases compared to those without, with aOR = 3.81 (2.90–5.02), p < 0.001. Measles spread in healthcare settings prior to community cases that occurred in several provinces. We recommend enhancing hospital infection control by increasing staff training and improving early detection and isolation during non-outbreak periods. Measles patients with chronic diseases exhibited lower proportions of vaccination and faced a higher risk of hospital-acquired infections. It is crucial to establish comprehensive vaccination guidelines and enhance parental awareness regarding the significance and safety of measles vaccination to protect these vulnerable individuals.

Background: The COVID-19 pandemic has revealed significant challenges in disease forecasting and in developing a public health response, emphasizing the need to manage missing data from various sources in making accurate forecasts. Objective: We aimed to show how handling missing data can affect estimates of the COVID-19 incidence rate (CIR) in different pandemic situations. Methods: This study used data from the COVID-19/SARS-CoV-2 surveillance system at the National Institute of Hygiene and Epidemiology, Vietnam. We separated the available data set into 3 distinct periods: zero COVID-19, transition, and new normal. We randomly removed 5% to 30% of data that were missing completely at random, with a break of 5% at each time point in the variable daily caseload of COVID-19. We selected 7 analytical methods to assess the effects of handling missing data and calculated statistical and epidemiological indices to measure the effectiveness of each method. Results: Our study examined missing data imputation performance across 3 study time periods: zero COVID-19 (n=3149), transition (n=1290), and new normal (n=9288). Imputation analyses showed that K-nearest neighbor (KNN) had the lowest mean absolute percentage change (APC) in CIR across the range (5% to 30%) of missing data. For instance, with 15% missing data, KNN resulted in 10.6%, 10.6%, and 9.7% average bias across the zero COVID-19, transition, and new normal periods, compared to 39.9%, 51.9%, and 289.7% with the maximum likelihood method. The autoregressive integrated moving average model showed the greatest mean APC in the mean number of confirmed cases of COVID-19 during each COVID-19 containment cycle (CCC) when we imputed the missing data in the zero COVID-19 period, rising from 226.3% at the 5% missing level to 6955.7% at the 30% missing level. Imputing missing data with median imputation methods had the lowest bias in the average number of confirmed cases in each CCC at all levels of missing data. In detail, in the 20% missing scenario, while median imputation had an average bias of 16.3% for confirmed cases in each CCC, which was lower than the KNN figure, maximum likelihood imputation showed a bias on average of 92.4% for confirmed cases in each CCC, which was the highest figure. During the new normal period in the 25% and 30% missing data scenarios, KNN imputation had average biases for CIR and confirmed cases in each CCC ranging from 21% to 32% for both, while maximum likelihood and moving average imputation showed biases on average above 250% for both CIR and confirmed cases in each CCC. Conclusions: Our study emphasizes the importance of understanding that the specific imputation method used by investigators should be tailored to the specific epidemiological context and data collection environment to ensure reliable estimates of the CIR.