1,027 research outputs found
Detection of the United States Neisseria meningitidis urethritis clade in the United Kingdom, August and December 2019 - emergence of multiple antibiotic resistance calls for vigilance.
Since 2015 in the United States (US), the US Neisseria meningitidis urethritis clade (US_NmUC) has caused a large multistate outbreak of urethritis among heterosexual males. Its 'parent' strain caused numerous outbreaks of invasive meningococcal disease among men who have sex with men in Europe and North America. We highlight the arrival and dissemination of US_NmUC in the United Kingdom and the emergence of multiple antibiotic resistance. Surveillance systems should be developed that include anogenital meningococci
Characteristics and serotype distribution of childhood cases of invasive pneumococcal disease following pneumococcal conjugate vaccination in England and Wales, 2006-14
Background The 7-valent (PCV7) and 13-valent (PCV13) pneumococcal conjugate vaccines are
highly effective in preventing invasive pneumococcal disease (IPD) caused by vaccine serotypes.
Vaccine failure (vaccine-type IPD after age-appropriate immunisation) is rare. Little is known about
the risk, clinical characteristics or outcomes of PCV13 compared to PCV7 vaccine failure.
Methods Public Health England conducts IPD surveillance and provides a national reference
service for serotyping pneumococcal isolates in England and Wales. We compared the
epidemiology, rates, risk factors, serotype distribution, clinical characteristics, and outcomes of IPD
in children with PCV13 and PCV7 vaccine failure.
Results A total of 163 episodes of PCV failure were confirmed in 161 children over eight years (04
September 2006 to 03 September 2014) in ten birth cohorts. After three vaccine doses, PCV7 and
PCV13 failure rates were 0.19/100,000 (95% CI, 0.10-0.33; 57 cases) and 0.66/100,000 (95% CI,
0.44-0.99; 104 cases) vaccinated person-years, respectively. Children with PCV13 failure were
more likely to be healthy (87/105 [82.9%] vs. 37/56 [66.1%]; P=0.02), present with bacteremic lower
respiratory tract infection (61/105 [58.1%] vs. 11/56 [19.6%]; P<0.001) and develop empyema
(41/61 [67.2%] vs. 1/11 [9.1%]; P<0.001) compared to PCV7 failures. Serotypes 3 (n=38, 36.2%)
and 19A (n=30, 28.6%) were responsible for most PCV13 failures. Five children died (3.1%; 95%
CI, 1.0-7.1%), including four with co-morbidities.
Conclusions PCV failure is rare and, compared to PCV7 serotypes, the additional PCV13
serotypes are more likely to cause bacteremic lower respiratory tract infection and empyema in
healthy vaccinated children
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Suspected cluster of Neisseria meningitidis W invasive disease in an elderly care home: do new laboratory methods aid public health action? United Kingdom, 2015.
In 2015, a suspected cluster of two invasive meningococcal disease (IMD) cases of serogroup W Neisseria meningitidis (MenW) occurred in elderly care home residents in England over 7 months; case investigations followed United Kingdom guidance. An incident control team reviewed epidemiological information. Phenotyping of case specimens informed public health action, including vaccination and throat swabs to assess carriage. Whole genome sequencing (WGS) was conducted on case and carrier isolates. Conventional phenotyping did not exclude a microbiological link between cases (case 1 W:2a:P1.5,2 and case 2 W:2a:NT). After the second case, 33/40 residents and 13/32 staff were vaccinated and 19/40 residents and 13/32 staff submitted throat swabs. Two MenW carriers and two MenC carriers were detected. WGS showed that MenW case and carrier isolates were closely related and possibly constituted a locally circulating strain. Meningococcal carriage, transmission dynamics and influence of care settings on IMD in older adults are poorly understood. WGS analyses performed following public health action helped to confirm the close relatedness of the case and circulating isolates despite phenotypic differences and supported actions taken. WGS was not sufficiently timely to guide public health practice
Targeted DNA enrichment and whole genome sequencing of Neisseria meningitidis directly from clinical specimens
In England and Wales, approximately one half of all laboratory-confirmed meningococcal disease cases fail to yield a viable invasive isolate, primarily due to the use of antibiotics. Characterisation of non-culture meningococci has been restricted to the detection or sequencing of specific gene targets within clinical specimens. In this study we investigated the ability of the Agilent SureSelectXT kit to facilitate DNA enrichment and genome sequencing of meningococcal DNA within a small panel of blood and CSF specimens. A target-specific RNA oligonucleotide bait library was used to capture and enrich the bacterial DNA prior to next generation sequencing. A positive correlation between meningococcal DNA amount and genome coverage was observed with eight of the ten specimens producing genomes of acceptable quality. All commonly-used typing information derived from each acceptable non-culture genome matched those of an isolate from the same patient and the paired genomes showed a high level of congruence across indexed loci. We estimate that this technique could be used to perform whole genome sequencing on up to ∼45% of the positive specimens received by the Public Health England's Meningococcal Reference Unit. Further optimisation of the extraction and/or enrichment processes may, however, increase the proportion of non-culture cases from which quality genomes can be obtained
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Vaccination of Infants with Meningococcal Group B Vaccine (4CMenB) in England.
BACKGROUND: In September 2015, the United Kingdom introduced the multicomponent meningococcal group B vaccine (4CMenB, Bexsero) into its publicly funded national immunization program at a reduced two-dose priming schedule for infants, with a 12-month booster. METHODS: Using data from enhanced national surveillance of invasive meningococcal disease in England, we evaluated the effect of vaccination on the incidence of meningococcal group B disease during the first 3 years of the program. The effect of vaccination was assessed by comparing the observed incidence of disease with the expected incidence based on the incidence during the 4-year prevaccination period in equivalent cohorts and with the use of disease trends in cohorts of children younger than 5 years of age who were not eligible to receive the vaccine. Vaccine effectiveness was estimated with the use of the indirect screening method. RESULTS: 4CMenB uptake in England remained consistently high; data from the first 3 months of 2018 showed that 92.5% of children had completed the primary immunizations by their first birthday and 87.9% had received all three doses by 2 years. From September 2015 through August 2018, the incidence of meningococcal group B disease in England (average annual birth cohort, approximately 650,000 infants) was significantly lower in vaccine-eligible cohorts than the expected incidence (63 observed cases as compared with 253 expected cases; incidence rate ratio, 0.25; 95% confidence interval [CI], 0.19 to 0.36), with a 75% reduction in age groups that were fully eligible for vaccination. The adjusted vaccine effectiveness against meningococcal group B disease was 52.7% (95% CI, -33.5 to 83.2) with a two-dose priming schedule for infants and 59.1% (95% CI, -31.1 to 87.2) with a two-dose priming schedule plus a booster at 1 year). Over the 3-year period, there were 169 cases of meningococcal group B disease in the vaccine-eligible cohorts, and an estimated 277 cases (95% CI, 236 to 323) were prevented. CONCLUSIONS: The 4CMenB program was associated with continued positive effect against meningococcal group B disease in children in England, and protection after three doses of the vaccine was sustained for at least 2 years. (Funded by Public Health England.)
Understanding the reactogenicity of 4CMenB vaccine: Comparison of a novel and conventional method of assessing post-immunisation fever and correlation with pre-release in vitro pyrogen testing
BACKGROUND: Better understanding of vaccine reactogenicity is crucial given its potential impact upon vaccine safety and acceptance. Here we report a comparison between conventional and novel (continuous) methods of monitoring temperature and evaluate any association between reactogenicity and the monocyte activation test (MAT) employed for testing four-component capsular group B meningococcal vaccine (4CMenB) batches prior to release for clinical use in Europe. METHODS: Healthy 7-12-week-old infants were randomised in two groups: group PCV13 2 + 1 (received pneumococcal conjugate vaccine 13 valent (PCV13) at 2, 4 and 12 months) and group PCV13 1 + 1 (received reduced schedule at 3 and 12 months). In both, infants received the remaining immunisations as per UK national schedule (including 4CMenB at 2, 4 and 12 months of age). Fever was measured for the first 24 h after immunisations using an axillary thermometer and with a wireless continuous temperature monitoring device (iButton®). To measure the relative pyrogenicity of individual 4CMenB batches, MAT was performed according to Ph. Eu. chapter 2.6.30 method C using PBMCs with IL-6 readout. RESULTS: Fever rates detected by the iButton® ranged from 28.7% to 76.5% and from 46.6% to 71.1% in group PCV13 2 + 1 and PCV13 1 + 1 respectively, across all study visits. The iButton® recorded a higher number of fever episodes when compared with axillary measurements in both groups (range of axillary temperature fevers; group PCV13 2 + 1: 6.7%-38%; group PCV13 1 + 1: 11.4%-37.1%). An agreement between the two methods was between 0.39 and 0.36 (p < 0.001) at 8 h' time-point post primary immunisations. No correlation was found between MAT scores and fever rates, or other reported adverse events. CONCLUSIONS: It is likely that conventional, intermittent, fever measurements underestimates fever rates following immunisation. 4CMenB MAT scores didn't predict reactogenicity, providing reassurance that vaccine batches with the highest acceptable pyrogen level are not associated with an increase in adverse events. Clinicaltrials.gov identifier: NCT02482636
UKMenCar4: A cross-sectional survey of asymptomatic meningococcal carriage amongst UK adolescents at a period of low invasive meningococcal disease incidence.
Carriage of Neisseria meningitidis, the meningococcus, is a prerequisite for invasive meningococcal disease (IMD), a potentially devastating infection that disproportionately afflicts infants and children. Humans are the sole known reservoir for the meningococcus, and it is carried asymptomatically in the nasopharynx of ~10% of the population. Rates of carriage are dependent on age of the host and social and behavioural factors. In the UK, meningococcal carriage has been studied through large, multi-centre carriage surveys of adolescents in 1999, 2000, and 2001, demonstrating carriage can be affected by immunisation with the capsular group C meningococcal conjugate vaccine, inducing population immunity against carriage. Fifteen years after these surveys were carried out, invasive meningococcal disease incidence had declined from a peak in 1999. The UKMenCar4 study was conducted in 2014/15 to investigate rates of carriage amongst the adolescent population during a period of low disease incidence. The protocols and methodology used to perform UKMenCar4, a large carriage survey, are described here
Determinants of human immunodeficiency virus type 1 escape from the primary CD8+ cytotoxic T lymphocyte response
CD8+ cytotoxic T lymphocytes (CTLs) play an important role in containment of virus replication in primary human immunodeficiency virus (HIV) infection. HIV's ability to mutate to escape from CTL pressure is increasingly recognized; but comprehensive studies of escape from the CD8 T cell response in primary HIV infection are currently lacking. Here, we have fully characterized the primary CTL response to autologous virus Env, Gag, and Tat proteins in three patients, and investigated the extent, kinetics, and mechanisms of viral escape from epitope-specific components of the response. In all three individuals, we observed variation beginning within weeks of infection at epitope-containing sites in the viral quasispecies, which conferred escape by mechanisms including altered peptide presentation/recognition and altered antigen processing. The number of epitope-containing regions exhibiting evidence of early CTL escape ranged from 1 out of 21 in a subject who controlled viral replication effectively to 5 out of 7 in a subject who did not. Evaluation of the extent and kinetics of HIV-1 escape from >40 different epitope-specific CD8 T cell responses enabled analysis of factors determining escape and suggested that escape is restricted by costs to intrinsic viral fitness and by broad, codominant distribution of CTL-mediated pressure on viral replication
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