Title : Prevalence and characteristics of neisseria meningitidis carriage among high school students from the Vilnius region, Lithuania
Abstract:
Neisseria meningitidis causes invasive meningococcal disease (IMD), which is associated with significant mortality and long-term consequences, especially among young children. The incidence of IMD in Lithuania was among the highest in European countries during the past two decades reaching 2.9 cases/105 population in 2017. The worst disease-affected region was the Vilnius region, accounting for the majority of disease cases across all age groups. In 2020-2022, the incidence of IMD decreased in Lithuania accounting for approx. 0.36 cases/105 population. The drop is presumably related to COVID-19 restriction measures and vaccination against serogroup B meningococci. Oropharyngeal carriage of N. meningitidis is thought to be a prerequisite for the development of IMD. In industrialized countries, meningococcal carriage reaches a peak in young adults, however no data exist on N.meningitidis carriage among Lithuanians of 18-25-years-old. For the current study, oropharyngeal swabs were collected in 2022 from 300 students. N.meningitidis was detected and identified by culture and quantitative real-time PCR by targeting ctrA and porA genes. The genogroup and the MLST profile of isolates were determined by conventional PCR. Carriage prevalence was 4.33% (13/300). Most carriage isolates were genogroup B (30%) and capsule null (53.8%). Two isolates possessed the ctrA gene, however they were non-genogroupable in genotypic assays. The dominant genogroup B was compatible with that implicated in IMD in Lithuania, however the majority of clonal complexes (cc) of carriage isolates were not similar to invasive ones: the most common clonal complex was cnl cc198, cc269, and cnl cc1136. Noticeably, cnl cc198 was also dominant among Swedish, Dutch and Italian young adults. One isolate of ST-213 (cc213) has the same genotype as that causing IMD in Lithuania. Circulating isolates of genogroup B cc269 have invasive potential as cc269 is among the IMD-causing isolates in many countries.
Audience take away:
• Oropharyngeal carriage of N. meningitidis is thought to be a prerequisite for the development of invasive meningococcal disease (IMD)
• This study provides new data on the meningococcal carriage in Lithuania, a country with high IMD incidence • The epidemiology of carriage revealedN. meningitidis isolates having an invasive potential
• The understanding of meningococcal epidemiology in countries with high IMD incidence is crucial for the development of future public health and vaccination policy.
• The faculty could use the results of the current study to expand their research or teaching to address public health interventions.
