Meningococcal carriage in Norwegian teenagers: strain characterisation and assessment of risk factors

• Published in: Epidemiology and infection Vol. 148; p. e80
• Main Authors: Watle, S V, Caugant, D A, Tunheim, G, Bekkevold, T, Laake, I, Brynildsrud, O B, Næss, L M
• Format: Journal Article
• Language: English; Norwegian
• Published: England Cambridge University Press 01.01.2020
• Subjects: Adolescent; Age; Antibiotics; Carrier State - epidemiology; Carrier State - microbiology; Child; Cigarette smoking; Cross-Sectional Studies; Female; Gene sequencing; Genomes; Health risks; Humans; Immunization; Invasive meningococcal disease; Laboratories; Male; Meningococcal disease; Meningococcal Infections - epidemiology; Meningococcal Infections - microbiology; Neisseria meningitidis - genetics; Neisseria meningitidis - isolation & purification; Norway - epidemiology; Original Paper; Phylogenetics; Phylogeny; Population studies; Public health; Questionnaires; Risk analysis; Risk assessment; Risk Factors; Risk taking; Secondary schools; Smoking; Students; Teenagers; Tobacco; Vaccination; Vaccines; Whole genome sequencing; Young Adult; Norway; United States > US; whole genome sequencing; smokeless tobacco; Neisseria meningitidis; Swedish snus; Carriage; meningococcal vaccines; teenager
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268820000734

Teenagers have a higher risk of invasive meningococcal disease (IMD) than the general population. This cross-sectional study aimed to characterise strains of Neisseria meningitidis circulating among Norwegian teenagers and to assess risk factors for meningococcal carriage. Oropharyngeal swabs were collected from secondary-school students in southeastern Norway in 2018-2019. Meningococcal isolates were characterised using whole genome sequencing. Risk factors for meningococcal carriage were assessed from questionnaire data. Samples were obtained from 2296 12-24-year-olds (majority 13-19-year-olds). N. meningitidis was identified in 167 (7.3%) individuals. The highest carriage rate was found among 18-year-olds (16.4%). Most carriage isolates were capsule null (40.1%) or genogroup Y (33.5%). Clonal complexes cc23 (35.9%) and cc198 (32.3%) dominated and 38.9% of carriage strains were similar to invasive strains currently causing IMD in Norway. Use of Swedish snus (smokeless tobacco) (OR 1.56, 95% CI 1.07-2.27), kissing >two persons/month (OR 2.76, 95% CI 1.49-5.10) and partying >10 times/3months (OR 3.50, 95% CI 1.45-8.48) were associated with carriage, while age, cigarette smoking, sharing of drinking bottles and meningococcal vaccination were not. The high meningococcal carriage rate among 18-year-olds is probably due to risk-related behaviour. Use of Swedish snus is possibly a new risk factor for meningococcal carriage. Almost 40% of circulating carriage strains have invasive potential.