Invasive Meningococcal Disease Remains a Health Threat in Vietnam People's Army.

OBJECTIVE: Despite strict surveillance, Neisseria meningitidis still causes life-threatening invasive meningococcal disease (IMD). The study aimed to describe the prevalence, clinical and subclinical features, and treatment outcomes of IMD among young soldiers of the Vietnam People's Army. METHODS: A prospective, population-based surveillance study was conducted in all Vietnamese military hospitals from January 2014 to June 2021. The presence of Neisseria meningitidis was confirmed by PCR or culture from blood or/and CSF. Epidemiological indices (incidence, serogroups, and distribution of cases by length of service), medical history, clinical and sub-clinical features, and treatment outcomes were documented and analyzed. RESULTS: There were 69 IMD cases (91% serogroup B) documented, mainly in conscripts (91%). The highest annual incidence was 3.33/100,000 soldiers per year. Of these cases, 44% were meningitis (n=30), 19% septicemia (n=13), and 38% meningococcemia (n=26). The most common clinical symptoms were neck stiffness (61 cases, 88%), petechial rash (51%), and shock (20 cases, 29%). Laboratory findings showed leukocytosis in 96% of IMD cases, PCT >0.05 (ng/mL) in 100%, elevated leukocyte count (>1,000/mm3) in 71%, and high protein >1 g/L in 70%. The overall mortality rate was 9%. Two cases were found to be resistant to ceftriaxone. Prognostic factors of severity included petechial rash (OR = 9.82, p < 0.001), septicemia (OR = 5.83, p < 0.001), meningococcemia (OR = 6.22, p < 0.001), low platelet count, prolonged prothrombin time; high PCT (AUC = 0.84, p < 0.001), and increased creatinine (AUC = 0.86, p < 0.001). CONCLUSION: IMD remains a health threat in the armed forces in Vietnam, especially among new recruits. To the best of our knowledge, this is the first study in Vietnam describing ceftriaxone resistance in Neisseria meningitidis and suggests the need to reconsider standard empiric therapy for IMD.

Protein A-conjugated iron oxide nanoparticles for separation of Vibrio cholerae from water samples.

Pathogen separation is of great significance for precise detection and prevention of disease outbreaks. For the first time, protein A conjugated with chitosan-coated iron oxide nanoparticles was prepared for pathogen separation at low concentrations from liquid samples. Vibrio cholerae O1 (VO1) bacteria were used for testing the effectiveness of this conjugate. Transmission electron microscopy (TEM) was used to confirm the presence of captured VO1. The results showed that, after binding with a specific antibody, the conjugate allows separation of VO1 bacteria from water samples at a concentration as low as 10 cfu mL(-1). Moreover, the conjugate can be used in parallel with conventional or modern diagnostic tests for quick and accurate detection of pathogens.