Search

Background This retrospective hospital-based surveillance aimed to assess the epidemiology, causative pathogens trend, and serotypes distribution of pneumococcal meningitis among children aged under five years with bacterial meningitis in southern Vietnam after the introduction of pentavalent vaccine in the Expanded Program on Immunization (EPI). Methods From 2012 to 2021, cerebrospinal fluid samples were collected from children aged under five years with suspected bacterial meningitis at Children's Hospitals 1 and 2 in Ho Chi Minh City. Probable bacterial meningitis (PBM) cases were identified using biochemistry and cytology. Real-time Polymerase Chain Reaction was used to confirm cases of confirmed bacterial meningitis (CBM) caused by Streptococcus pneumoniae, Haemophilus influenzae, or Neisseria meningitidis. S. pneumoniae serotyping was performed. Results Of the 2,560 PBM cases, 158 (6.2%) were laboratory-confirmed. The CBM proportion decreased during the 10-year study and was associated with age, seasonality, and permanent residence. S. pneumoniae was the most common pathogen causing bacterial meningitis (86.1%), followed by H. influenzae (7.6%) and N. meningitidis (6.3%). The case fatality rate was 8.2% (95% confidence interval: 4.2%-12.2%). Pneumococcal serotypes 6A/B, 19F, 14, and 23F were the most prevalent, and the proportion of pneumococcal meningitis cases caused by the 10-valent pneumococcal conjugate vaccine (PCV) serotypes decreased from 96.2% to 57.1% during the PCV eras. Conclusions S. pneumoniae is the most frequent causative agent of bacterial meningitis in children aged under five years in southern Vietnam over the last decade. Policymakers may need to consider introducing PCVs into the EPI to effectively prevent and control bacterial meningitis.

Objectives: Southern Vietnam experienced a large measles outbreak of over 26,0 0 0 cases during 20182020. We aimed to understand and quantify the measles spread in space-time dependence and the transmissibility during the outbreak.Methods: Measles surveillance reported cases between January 2018 and June 2020, vaccination coverage, and population data at provinicial level were used. To illustrate the spatio-temporal pattern of disease spread, we employed the endemic-epidemic multivariate time series model decomposing measles risk additively into autoregressive, spatio-temporal, and endemic components. Likelihood-based estimation procedures were performed to determine the time-varying reproductive number R e of measles. Results: Our analysis showed that the incidence of measles was associated with vaccination coverage heterogeneity and spatial interaction between provincial units. The risk of infections was dominated by between-province transmission (36.1% to 78.8%), followed by local endogenous transmission (4.1% to 61.5%). In contrast, the endemic behavior had a relatively small contribution (2.4% to 33.4%) across provinces. In the exponential phase of the epidemic, R e was above the threshold with a maximum value of 2.34 (95% CI: 2.20-2.46).Conclusion: Local vaccination coverage and human mobility are important factors contributing to the measles dynamics in Southern Vietnam, and the high risk of inter-provincial transmission is of most concern. Strengthening the disease surveillance is recommended, and further research is essential to understand the relative contribution of population immunity and control measures in measles epidemics. (c) 2022 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. We would like to thank the VLIR-UOS for awarding T.H.T.N. a scholarship to study the Master of Epidemiology at the University of Antwerp, Belgium. We are pleased to acknowledge the Pasteur Institute in Ho Chi Minh City including the Board of Directors for supporting the research endeavor in terms of data use, colleagues of the Outbreak Control Unit (Pham Duy Quang, Nguyen Thi Phuong Thuy, Tran Cong Kha, Doan Ngoc Minh Quan, Nguyen Quoc Kien, Tran Anh Tuan, Phan Thi Ngoc Uyen, Nguyen Viet Thinh, Hoang Thi Lien, and Phan Cong Hung), and the EPI Unit (Hoang Anh Thang, Chau Van Luom, Truong Cong Hieu, Vo Ngoc Quang, Nguyen Dieu Thuy, Nguyen Thi Huyen, Phan Thi Quynh Tram, Vien Dang Khanh Linh, Nguyen Thi Thu Trang, Nguyen Van Hoang, Tran Quang Trung, Trinh Trung Truc, Tran Thanh Hai) for their huge efforts and enthusiasm in case monitoring, surveillance and contact tracing, outbreak investigation, and launching the supplementary immunization activities during the measles outbreak. We would also like to acknowledge the large contribution of 20 Provincial Centers for Disease Control and Prevention in two cities and 18 provinces in Southern Vietnam in the EPI National Project.

Background In 2016-2017, 68 women in Southern Vietnam had RT-PCR confirmed Zika virus (ZIKV) infection during pregnancy. We report here the outcomes of the pregnancies and the virological analyses related to this outbreak. Methods We collected clinical and epidemiological information from the women who were enrolled in the study. Medical records related to the pregnancy in 2016–2017 were retrieved for those who were not able to be enrolled in the study. Children born to women with ZIKV infection during pregnancy were also enrolled. Serum samples were evaluated for presence of ZIKV antibodies. Phylogenetic analyses were performed on Zika virus genomes sequenced from the 2016–2017 serum samples. Findings Of the 68 pregnancies, 58 were livebirths and 10 were medically terminated. Four of the medical records from cases of fetal demise were able to be retrieved, of which one was consistent with congenital ZIKV infection. Of the 58 women with a livebirth, 21 participated in the follow-up investigation. All but two women had serologic evidence of ZIKV infection. Of the 21 children included in the study (mean age: 30.3 months), 3 had microcephaly at birth. No other clinical abnormalities were reported and no differences in neurodevelopment were observed compared to a control group. Phylogenetic analysis revealed a clade within the ZIKV Asian lineage and branch at the root of samples from the 2013–2014 French Polynesian outbreak. The prM S139N mutation was not observed. Interpretation We have been able to demonstrate a clade within the ZIKV Asian lineage implicated in adverse pregnancy outcomes in Southern Vietnam. Funding INCEPTION project (PIA/ANR-16-CONV-0005) and a grant received from BNP Paribas Simplidon.

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

Objectives: Rotavirus (RV) genotypes vary geographically, and this can affect vaccine effectiveness (VE). This study investigated the genotype distribution of RV and explored VE before introducing the RV vaccine to the national immunization programme in Vietnam. Methods: This hospital-based surveillance study was conducted at Children’s Hospital 1, Ho Chi Minh City in 2013–2018. Stool samples and relevant data, including vaccination history, were collected from children aged