Objective: To examine the magnitude of isolated anti-HBc and other HBV serological patterns and associated predictors among adults seeking general health check-up at a large health center in Vietnam. Methods: All 564 outpatients seeking general health checkup between January 2016 and December 2016 were asked to undertake HBV surface antigen, surface antibody, IgG and IgM core antibody (anti-HBc total), platelet counts, and liver function testing. An administered questionnaire was used to collect information regarding demography, in-house sources of infection, lifestyle, health condition and treatment, and HBV vaccination. Results: Male gender (P=0.043), age (P=0.000), living in urban areas (P=0.040), HBV vaccination status (P=0.033), and ALT (P=0.040) were associated with isolated anti-HBc. HBV infection was associated with HBV vaccination status (P=0.001), ALT levels (P=0.010), AST levels (P=0.020), and platelet counts (P=0.007). Past/resolved HBV infection was associated with AST levels (P=0.005), ALT levels (P=0.014), and age (P=0.000). Conclusions: Isolated anti-HBc is quite prevalent. Predictors of isolated anti-HBc include male gender, living in rural areas, and HBV non-vaccination. The prevalence of isolated anti-HBc also increases with age. To timely detect occult HBV infection and prevent transmission, anti-HBc testing should be included in the health check-up for high risk individuals and screening program where HBV nucleic acid test is not available. To prevent transmission, clinicians need to pay more attention on those who are at risk of having isolated anti-HBc and closely follow-up patients with isolated anti-HBc and educate them about the prevention of HBV infection.

Introduction: Hospitals are a key source of information for the early identification of emerging disease outbreaks and acute public health events for risk assessment, decision-making and public health response. The objective of this study was to identify potential facilitators and barriers for event reporting from the curative sector to the preventive medicine sector in Viet Nam. Methods: In 2016, we conducted 18 semi-structured, in-depth interviews, as well as nine focus group discussions, with representatives from the curative and preventive medicine sectors in four provinces. We transcribed the interviews and focus group discussions and used thematic analysis to identify the factors that appeared to affect public health event reporting. Results: We identified five major themes. First, the lack of a legal framework to guide reporting meant hospital staff relied on internal procedures that varied from hospital to hospital, which sometimes delayed reporting. Second, participants stated the importance of an enabling environment, such as leadership support and having focal points for reporting, to facilitate reporting. Third, participants described the potential benefits of reporting, such as support provided during outbreaks and information received about local outbreaks. Fourth, some challenges prohibited timely reporting such as not perceiving reporting to be the task of the curative sector and hesitancy to report without laboratory confirmation. Finally, limited resources and specialist capacities in remote areas hindered timely detection and reporting of unusual events. Discussion: This study identified potential opportunities to promote the detection and reporting of unusual events from health-care workers to the public health sector, and thus to improve the overall health security system in Viet Nam.The influenza virus is a respiratory pathogen that is transmitted through respiratory droplets.1 During seasonal influenza epidemics, high attack rates cause a significant public health burden.2 The infection is usually self-limited in young adults but can lead to severe infections in people in high-risk groups, including elderly people (> 65 years old), pregnant women, children aged 6–59 months and adults with chronic illnesses.3