Evaluation and validation of a commercial ELISA versus the toxin neutralization assay for determination of diphtheria anti-toxin in human serum.

Diphtheria is a potentially life-threatening infection and remains endemic in many low- and middle-income countries (LMICs). A reliable, low-cost method for serosurveys in LMICs is warranted to estimate the accurate population immunity to control diphtheria. The correlation between the ELISA results against diphtheria toxoid and the gold standard diphtheria toxin neutralization test (TNT) values is poor when ELISA values are <0.

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.

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.

Simple clinical and laboratory predictors to improve empirical treatment strategies in areas of high scrub typhus and dengue endemicity, central Vietnam.

Background: Dengue fever is highly endemic in Vietnam, but scrub typhus-although recognized as an endemic disease-remains underappreciated. These diseases together are likely to account for more than half of the acute undifferentiated fever burden in Vietnam. Scrub typhus (ST) is a bacterial disease requiring antimicrobial treatment, while dengue fever (DF) is of viral etiology and does not.

Genome-wide analysis of SARS-CoV-2 strains circulating in Vietnam: Understanding the nature of the epidemic and role of the D614G mutation.

Genome-wide analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains is essential to better understand infectivity and virulence and to track coronavirus disease 2019 (COVID-19) cases and outbreaks. We performed whole-genome sequencing of 27 SARS-CoV-2 strains isolated between January 2020 and April 2020. A total of 54 mutations in different genomic regions was found.

Zika preparedness and response in Viet Nam.

The findings and conclusions in this article are those of the authors and do not necessarily represent the official positions of the United States Centers for Disease Control and Prevention.

Expanding severe acute respiratory infection (SARI) surveillance beyond influenza: The process and data from 1 year of implementation in Vietnam.

Background: In 2016, as a component of the Global Health Security Agenda, the Vietnam Ministry of Health expanded its existing influenza sentinel surveillance for severe acute respiratory infections (SARI) to include testing for 7 additional viral respiratory pathogens. This article describes the steps taken to implement expanded SARI surveillance in Vietnam and reports data from 1 year of expanded surveillance.

Methods: The process of expanding the suite of pathogens for routine testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) included laboratory trainings, procurement/distribution of reagents, and strengthening and aligning SARI surveillance epidemiology practices at sentinel sites and regional institutes (RI).