Rise in Group W Meningococcal Carriage in University Students, United Kingdom.
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SUBMITTER: Oldfield NJ
PROVIDER: S-EPMC5443439 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:In January and February 2015, Neisseria meningitidis serogroup B (NmB) outbreaks occurred at two universities in the United States, and mass vaccination campaigns using MenB vaccines were initiated as part of a public health response. Meningococcal carriage evaluations were conducted concurrently with vaccination campaigns at these two universities and at a third university, where no NmB outbreak occurred. Meningococcal isolates (N = 1,514) obtained from these evaluations were characterized for capsule biosynthesis by whole-genome sequencing (WGS). Functional capsule polysaccharide synthesis (cps) loci belonging to one of seven capsule genogroups (B, C, E, W, X, Y, and Z) were identified in 122 isolates (8.1%). Approximately half [732 (48.4%)] of isolates could not be genogrouped because of the lack of any serogroup-specific genes. The remaining 660 isolates (43.5%) contained serogroup-specific genes for genogroup B, C, E, W, X, Y, or Z, but had mutations in the cps loci. Identified mutations included frameshift or point mutations resulting in premature stop codons, missing or fragmented genes, or disruptions due to insertion elements. Despite these mutations, 49/660 isolates expressed capsule as observed with slide agglutination, whereas 45/122 isolates with functional cps loci did not express capsule. Neither the variable capsule expression nor the genetic variation in the cps locus was limited to a certain clonal complex, except for capsule null isolates (predominantly clonal complex 198). Most of the meningococcal carriage isolates collected from student populations at three US universities were non-groupable as a result of either being capsule null or containing mutations within the capsule locus. Several mutations inhibiting expression of the genes involved with the synthesis and transport of the capsule may be reversible, allowing the bacteria to switch between an encapsulated and non-encapsulated state. These findings are particularly important as carriage is an important component of the transmission cycle of the pathogen, and understanding the impact of genetic variations on the synthesis of capsule, a meningococcal vaccine target and an important virulence factor, may ultimately inform strategies for control and prevention of disease caused by this pathogen.
| S-EPMC8893959 | biostudies-literature
Project description:In the 1997-98 academic year, we conducted a longitudinal study of meningococcal carriage and acquisition among first-year students at Nottingham University, Nottingham, United Kingdom. We examined the dynamics of long-term meningococcal carriage with detailed characterization of the isolates. Pharyngeal swabs were obtained from 2,453 first-year students at the start of the academic year (October), later on during the autumn term, and again in March. Swabs were immediately cultured on selective media, and meningococci were identified and serologically characterized. Nongroupable strains were genetically grouped using a PCR-based assay. Pulsed-field gel electrophoresis was used to determine the link between sequential isolates. Of the carriers initially identified in October, 44.1% (98 of 222) were still positive later on in the autumn (November or December); 57.1% of these remained persistent carriers at 6 months. Of the index carriers who lost carriage during the autumn, 16% were recolonized at 6 months. Of 344 index noncarriers followed up, 22.1% acquired carriage during the autumn term and another 13.7% acquired carriage by March. Overall, 43.9% (397 of 904) of the isolates were noncapsulated (serologically nongroupable); by PCR-based genogrouping, a quarter of these belonged to the capsular groups B and C. The ratio of capsulated to noncapsulated forms for group B and C strains was 2.9 and 0.95, respectively. Sequential isolates of persistent carriers revealed that individuals may carry the same or entirely different organisms at different times. We identified three strains that clearly switched their capsular expression on and off at different times in vivo. One student developed invasive meningococcal disease after carrying the same organism for over 7 weeks. The study revealed a high rate of turnover of meningococcal carriage among students. Noncapsulated organisms are capable of switching their capsular expression on and off (both ways) in the nasopharynx, and group C strains are more likely to be noncapsulated than group B strains. Carriage of a particular meningococcal strain does not necessarily protect against colonization or invasion by a homologous or heterologous strain.
| S-EPMC86789 | biostudies-literature
Project description:BackgroundIn the United Kingdom, rising levels of disease due to Neisseria meningitidis serogroup W clonal complex (cc) sequence type (ST) 11 (MenW:cc11) strains led to introduction of meningococcal conjugate vaccine (MenACWY) for teenagers. We investigated the impact of immunization on carriage of meningococci targeted by the vaccine, using whole-genome sequencing of isolates recovered from a cohort of vaccinated university students.MethodsStrain designation data were extracted from whole-genome sequencing data. Genomes from carried and invasive MenW:cc11 strains were compared using a gene-by-gene approach. Serogrouping identified isolates expressing capsule antigens targeted by the vaccine.ResultsIsolates with a W: P1.5,2: F1-1: ST-11 (cc11) designation and belonging to the emerging 2013-strain of the South American-United Kingdom MenW:cc11 sublineage were responsible for an increase in carried group W strains. A multifocal expansion was evident, with close transmission networks extending beyond individual dormitories. Carried group Y isolates were predominantly from cc23 but showed significant heterogeneity, and individual strain designations were only sporadically recovered. No shifts toward acapsulate phenotypes were detected in targeted meningococcal populations.ConclusionsIn a setting with high levels of MenACWY use, expansion of capsule-expressing isolates from the 2013-strain of MenW:cc11 but not MenY:cc23 isolates is indicative of differential susceptibilities to vaccine-induced immunity.
| S-EPMC5853931 | biostudies-literature
Project description:PurposeThe aim of the study was to estimate the meningococcal carriage rate and to identify the genotypic characteristics of the strains isolated from healthy military recruits and university students in order to provide data that might increase our understanding on the epidemiology of meningococcus and obtain information which helps to evaluate the potential effects on control programs such as vaccination.MethodsA total of 1420 oropharyngeal single swab samples were collected from military recruits and university students on voluntary basis, aged 18-26 years. New York City Medium was used for culture and the suspected N. meningitidis colonies were identified by Gram stain, oxidase and rapid carbohydrate utilization tests. Further characterisation was carried out by molecular methods (multiplex PCR, MLST, WGS).ResultsThe overall carriage rate was of 12.7%; 15% and 10.4% for recruits and university students respectively. MenB (39.4%) was the most prevalent followed by MenY (12.8%) and MenW (4.4%). Among the initial 76 Non Groupable (NG) isolates, Whole Genome Sequence Analysis (WGS) revealed that 8.3% belonged to MenE, 3.3% to MenX and 1.1% to MenZ, while, 53 strains (29.4%) were finally identified as capsule null. Genetic diversity was found among the MenB isolates, with 41/44 cc and 35 cc predominating.ConclusionMeningococcal carriage rate in both groups was lower compared to our previous studies (25% and 18% respectively) with predominance of MenB isolates. These findings, help to further our understanding on the epidemiology of meningococcal disease in Greece. Although the prevalence of carriage seems to have declined compared to our earlier studies, the predominant MenB clonal complexes (including 41/44cc and 35cc) are associated with invasive meningococcal disease.
| S-EPMC5131982 | biostudies-literature
Project description:BACKGROUND:Meningococcal disease incidence in the United States is at an all-time low. In a previous study of Georgia high school students, meningococcal carriage prevalence was 7%. The purpose of this study was to measure the impact of a meningococcal conjugate vaccine on serogroup Y meningococcal carriage and to define the dynamics of carriage in high school students. METHODS:This was a prospective cohort study at 8 high schools, 4 each in Maryland and Georgia, during a school year. Students at participating schools received quadrivalent meningococcal conjugate vaccine that uses diphtheria toxoid as the protein carrier (MCV4-DT). In each state, 2 high schools were randomly assigned for MCV4-DT receipt by students at the beginning of the study, and 2 were randomly assigned for MCV4-DT receipt at the end. Oropharyngeal swab cultures for meningococcal carriage were performed 3 times during the school year. RESULTS:Among 3311 students, the prevalence of meningococcal carriage was 3.21%-4.01%. Phenotypically nongroupable strains accounted for 88% of carriage isolates. There were only 5 observed acquisitions of serogroup Y strains during the study; therefore, the impact of MCV4-DT on meningococcal carriage could not be determined. CONCLUSIONS:Meningococcal carriage rates in US high school students were lower than expected, and the vast majority of strains did not express capsule. These findings may help explain the historically low incidence of meningococcal disease in the United States.
| S-EPMC5783552 | biostudies-literature
Project description: Not available
| S-EPMC2874357 | biostudies-literature
Project description:Swedish meningococcal carriage study performed in 2018-2019.
| PRJEB41190 | ENA
Project description:IntroductionDespite cigarette-like adverse health outcomes associated with waterpipe tobacco smoking and increase in its use among youth, it is a much underexplored research area. We aimed to measure the prevalence and patterns of waterpipe tobacco use and evaluate tobacco control policy with respect to waterpipe tobacco, in several universities across the UK. We also aimed to measure stop smoking practitioners' encounter of waterpipe tobacco smoking.MethodsWe distributed an online survey to six UK universities, asking detailed questions on waterpipe tobacco. Multivariable logistic regression models, adjusted for age, gender, ethnicity, graduate status, university and socioeconomic status (SES) assessed associations between waterpipe tobacco smoking (single use and dual use with cigarettes) and sociodemographic variables. SES was ascertained by average weekly self-spend on non-essentials. We also descriptively analysed data from a 2012 survey of stop smoking practitioners to assess the proportion of clients that used waterpipe regularly.Resultsf 2217 student responses, 66.0% (95% CI 63.9-68.0%) had tried waterpipe tobacco smoking; 14.3% (95% CI 12.8-15.8%) reported past-30 day use, and 8.7% (95% CI 7.6-9.9%) reported at least monthly users. Past-30 day waterpipe-only use was associated with being younger (AOR 0.95, 95% CI 0.91-0.99), male (AOR 1.44, 95% CI 1.08-1.94), higher SES (AOR 1.16, 95% CI 1.06-1.28) and belonging to non-white ethnicities (vs. white, AOR 2.24, 95% CI 1.66-3.04). Compared to less than monthly users, monthly users were significantly more likely to have urges to smoke waterpipe (28.1% vs. 3.1%, p<0.001) report difficulty in quitting (15.5% vs. 0.8%, p<0.001), report feeling guilty, and annoyed when criticised about waterpipe smoking (19.2% vs. 9.2%, p<0.001). Nearly a third (32.5%) of respondents who had tried waterpipe had violated the UK smokefree law and a quarter (24.5%) reporting seeing health warnings on waterpipe tobacco packaging or apparatuses. Of 1,282 smoking cessation practitioners, a quarter (23.4%, 95% CI 21.5-26.1%) reported having some clients who regularly use waterpipes, but 69.5% (95% CI 67.0-72.0%) never ask clients about waterpipe use. Three quarters (74.8%, 95% CI 72.4-77.1%) want more information about waterpipe tobacco smoking.ConclusionsWhile two thirds of university students have ever tried waterpipe tobacco, at least monthly use is less common. Regular users display features of waterpipe tobacco dependence, and a substantial minority of SSS practitioners encounter clients who regularly use waterpipe. The lack of training on waterpipe for SSS practitioners and reported violations of smokefree laws for waterpipe highlight the need for regular surveillance of and a coordinated tobacco control strategy for waterpipe use.
| S-EPMC4706414 | biostudies-literature
Project description:ObjectivesThe focus of this review was to systematically review and meta-analyse the prevalence of ACEs among university students in the UK.MethodThe systematic searching of six electronic databases (conducted February 2024) identified ten relevant articles (peer-reviewed articles of a quantitative nature that included ACE prevalence). PROSPERO reference: CRD42022364799.ResultsPooled prevalence for number of ACEs endured was 55.4% (95% CI: 32.4% - 78.4%; I2 > 99.5%) for one or more, and 31.6% (7.5% - 55.6%; I2 > 99.5%) for three or more. Pooled prevalence was: 15.9% (7.0% - 24.7%; I2 > 94.5%) for physical abuse; 27.0% (18.1% - 35.9%; I2 > 94.5%) for emotional abuse; 12.1% (5.2% - 19.0%; I2 > 94.5%) for sexual abuse; 8.4% (1.7% - 15.1%; I2 > 95.4%) for physical neglect, and 30.0% (21.5% - 38.5%; I2 > 95.4%) for emotional neglect. Pooled prevalence for household dysfunction categories were: 34.4% (22.8% - 46.0%) for parental separation; 18.4% (10.1% - 26.8%) for domestic violence; 35.2% (23.6% - 46.8%) for mental health difficulties; 21.4% (12.9% - 29.9%) for substance use; and 5.7% (2.3% - 9.1%) for incarceration (I2 > 88.8% for all household dysfunction items). Significant heterogeneity was observed between studies for most categories of adversity, and it was not possible to explain/reduce this variance by removing small numbers of influential/discrepant studies. Further analyses suggested potential influences of measurement tool used, country of data collection, and age and sex of participants.ConclusionResults demonstrate considerable, largely unaccounted-for, heterogeneity in estimates of the prevalence of ACEs, impeding confidence in any summary statistics. Conclusions must be tentative due to analyses being underpowered given small numbers of papers, as well as potential confounds, meaning results may not be truly representative. However, results do suggest high prevalence rates which warrant further investigation, with appropriate support offered to students.
| S-EPMC11356454 | biostudies-literature