Invasive meningococcal disease: Timing and cause of death in England, 2008-2015

Forensic Microbiology: When, Where and How

Forensic microbiology is a relatively new discipline, born in part thanks to the development of advanced methodologies for the detection, identification and characterization of microorganisms, and also in relation to the growing impact of infectious diseases of iatrogenic origin. Indeed, the increased application of medical practices, such as transplants, which require immunosuppressive treatments, and the growing demand for prosthetic installations, associated with an increasing threat of antimicrobial resistance, have led to a rise in the number of infections of iatrogenic origin, which entails important medico-legal issues. On the other hand, the possibility of detecting minimal amounts of microorganisms, even in the form of residual traces (e.g., their nucleic acids), and of obtaining gene and genomic sequences at contained costs, has made it possible to ask new questions of whether cases of death or illness might have a microbiological origin, with the possibility of also tracing the origin of the microorganisms involved and reconstructing the chain of contagion. In addition to the more obvious applications, such as those mentioned above related to the origin of iatrogenic infections, or to possible cases of infections not properly diagnosed and treated, a less obvious application of forensic microbiology concerns its use in cases of violence or violent death, where the characterization of the microorganisms can contribute to the reconstruction of the case. Finally, paleomicrobiology, e.g., the reconstruction and characterization of microorganisms in historical or even archaeological remnants, can be considered as a sister discipline of forensic microbiology. In this article, we will review these different aspects and applications of forensic microbiology.

Invasive meningococcal disease in older adults: current perspectives and call for action

PURPOSE

Invasive meningococcal disease (IMD) is a devastating condition. While most attention is directed towards disease in children and adolescents, IMD poses an important cause of morbidity and mortality in adults ≥60 years. While immunization is a critical component of healthy ageing strategies, meningococcal immunization is not routinely offered to older adults. The aim of this review was to summarize clinical and epidemiological aspects of IMD and available immunization strategies, with a particular focus on disease in older individuals, to emphasize the importance of this rather neglected area.

METHODS

An expert working group was established to evaluate clinical and epidemiological data to raise awareness of IMD in older individuals, and develop suggestions to improve the existing burden.

RESULTS

Routine child and adolescent meningococcal immunization has substantially reduced IMD in these targeted populations. Consequently, prevalence and proportion of IMD among those ≥60 years, mostly unvaccinated, is increasing in developed countries (accounting for up to 25% of cases). IMD-related mortality is highest in this age-group, with substantial sequelae in survivors. IMD due to serogroups W and Y is more prevalent among older adults, often with atypical clinical features (pneumonia, gastrointestinal presentations) which may delay timely treatment.

CONCLUSIONS

IMD in older adults remains overlooked and greater awareness is required at clinical and societal levels. We encourage clinicians and immunization policy makers to reconsider IMD, with a call for action to remedy existing inequity in older adult access to protective meningococcal immunization.

Lifecycle model-based evaluation of infant 4CMenB vaccination in the UK

OBJECTIVES

Invasive meningococcal disease, an uncommon but severe disease, imposes catastrophic health and economic burdens. Cost-utility analysis (CUA) assumes separability in lifetime health and economic variables and cannot capture the full value of preventing such burdens. We overcome these limitations with a retrospective societal perspective cost-benefit analysis (CBA) of meningococcal serogroup B vaccination (4CMenB) of one infant cohort in the United Kingdom using a health-augmented lifecycle model (HALM) incorporating health's interactions with consumption, earnings, non-market time and financial risk.

METHODS

We used a static Markov model of vaccination's health impact and an HALM to estimate the private willingness to pay (PWTP) for the intrinsic and instrumental value of health under perfect capital markets, financial risk protection in the absence of insurance against permanent disability, parental spillovers, and acute phase disability. We estimated social WTP (SWTP) incorporating social severity preferences. We estimated rates of return that inform health payer reimbursement decisions, finance ministry budgeting decisions, and legislature taxation decisions. An expert Advisory Board investigated the validity of applying the HALM to infant 4CMenB.

RESULTS

The PWTP for a 2 + 1 vaccination schedule is £395, comprising £166 of disability insurance value, £79 of positive parental spillover value, £28 in the value of averting acute phase disability, and £122 in residual intrinsic and instrumental value of health. SWTP is £969.

CONCLUSIONS

HALM-based CBA provides an empirically richer, more utility-theoretically grounded approach to vaccine evaluation than CUA, demonstrating good value for money for legislatures (based on private values) and for all decision-makers (based on social values).

Accuracy of antigen tests for meningococcal meningitis in cerebrospinal fluid: A diagnostic meta-analysis

OBJECTIVES

Neisseria meningitidis is one of the major pathogens of meningitis in children worldwide and causes invasive meningococcal disease (IMD), which is a critical illness that mainly presents as meningitis and/or septicemia in children. Identification of N. meningitidis in cerebrospinal fluid (CSF) is the gold standard for the diagnosis of meningococcal meningitis, but antigen tests have advantages such as timely results, relatively low cost, and convenience. Yet, the diagnostic accuracy of antigen tests remains uncertain. Therefore, the aim of this meta-analysis was to evaluate the diagnostic accuracy of antigen tests for N. meningitidis in CSF.

METHODS

We searched the PubMed, Embase, and Cochrane Library databases for studies evaluating the diagnostic accuracy of antigen tests for N. meningitidis in CSF. We included studies that provided sufficient data to construct a 2 × 2 table on a per-sample basis. To determine the overall sensitivity and specificity of the antigen tests, we used polymerase chain reaction (PCR) as the reference standard and employed the hierarchical summary receiver operating characteristic model.

RESULTS

Nine studies with 4533 CSF samples were included. The meta-analysis yielded a pooled sensitivity of 91.2% (95% confidence interval [CI]: 80.0%-100.0%) and a pooled specificity of 93.8% (95% CI: 83.9%-100.0%). A subgroup analysis of 2 studies that reported the outcomes of MeningoSpeed yielded a pooled sensitivity of 93.4% (95% CI: 90.0%-95.8%) and a pooled specificity of 91.9% (95% CI: 88.6%-94.4%). Antigen testing for the N. meningitidis serogroup X had a pooled sensitivity of 92.4% (95% CI: 85.2%-96.2%) and a pooled specificity of 99.2% (95% CI: 78.7%-100.0%).

CONCLUSIONS

The studied antigen tests had high sensitivity and specificity for the diagnosis of meningococcal meningitis in CSF specimens. Antigen testing could serve as an accurate diagnostic method for assessing patients who have a suspected N. meningitidis infection.

Assessing the Role of Infant and Toddler MenACWY Immunisation in the UK: Does the Adolescent MenACWY Programme Provide Sufficient Protection?

A combined Haemophilus influenzae type b (Hib)/meningococcal serogroup C (MenC) vaccine will soon be unavailable in the UK immunisation schedule due to discontinuation by the manufacturer. An interim statement by the Joint Committee on Vaccination and Immunisation (JCVI) advises stopping MenC immunisation at 12 months of age when this occurs. We undertook an analysis of the public health impact of various potential meningococcal vaccination strategies in the UK in the absence of the Hib/MenC vaccine. A static population-cohort model was developed evaluating the burden of IMD (using 2005-2015 epidemiological data) and related health outcomes (e.g., cases, cases with long-term sequelae, deaths), which allows for the comparison of any two meningococcal immunisation strategies. We compared potential strategies that included different combinations of infant and/or toddler MenACWY immunisations with the anticipated future situation in which a 12-month MenC vaccine is not used, but the MenACWY vaccine is routinely given in adolescents. The most effective strategy is combining MenACWY immunisation at 2, 4, and 12 months of age with the incumbent adolescent MenACWY immunisation programme, resulting in the prevention of an additional 269 IMD cases and 13 fatalities over the modelling period; of these cases, 87 would be associated with long-term sequelae. Among the different vaccination strategies, it was observed that those with multiple doses and earlier doses provided the greatest protection. Our study provides evidence suggesting that the removal of the MenC toddler immunisation from the UK schedule would potentially increase the risk of unnecessary IMD cases and have a detrimental public health impact if not replaced by an alternate infant and/or toddler programme. This analysis supports that infant and toddler MenACWY immunisation can provide maximal protection while complementing both infant/toddler MenB and adolescent MenACWY immunisation programmes in the UK.

The burden of invasive meningococcal disease in the Netherlands, 2011-2020

INTRODUCTION

Representative information on disease course and outcome of invasive meningococcal disease (IMD) is important because of the shift in meningococcal epidemiology that recently occurred in the Netherlands. With this study, we update earlier research on the burden of IMD in the Netherlands.

MATERIAL AND METHODS

We performed a retrospective study using Dutch surveillance data on IMD from July 2011 to May 2020. Clinical information was collected from hospital records. The effect of age, serogroup, and clinical manifestation on disease course and outcome was assessed in multivariable logistic regression analyses. Grouping of infecting isolates was performed by Ouchterlony gel diffusion or by PCR.

RESULTS

Clinical information was collected for 278 IMD cases of which the majority had IMD-B (55%), followed by IMD-W (27%), IMD-Y (13%), and IMD-C (5%). Most patients presented with meningitis (32%) or sepsis (30%). Hospitalisation for ≥ 10 days was most frequent among 24-64 year olds (67%). ICU admission was highest among 24-64 year olds (60%), and in case of sepsis (70%), or sepsis plus meningitis (61%). Sequelae at discharge was lower for patients with mild meningococcaemia compared to patients with sepsis plus meningitis (OR: 0.19, 95% CI: 0.07-0.51). The overall case fatality rate was 7%, and was highest for IMD-Y (14%) and IMD-W (13%) patients.

CONCLUSIONS

IMD remains a disease with high morbidity and mortality. Sepsis (with or without meningitis) is associated with a more severe disease course and outcome compared to other clinical manifestations. The high disease burden can be partly prevented by meningococcal vaccination.

Outcomes of meningococcal serogroup B disease in children after implementation of routine infant 4CMenB vaccination in England: an active, prospective, national surveillance study

BACKGROUND

In 2015, the UK included 4CMenB, a multi-component, recombinant protein-based vaccine against meningococcal serogroup B (MenB) disease, in the national infant immunisation programme. We aimed to assess the effect of 4CMenB vaccination on the severity of MenB disease presentation and outcomes.

METHODS

In this active, prospective, national surveillance study, we used data from the UK Health Security Agency national surveillance of meningococcal disease. We included data from follow-up of children younger than 5 years with laboratory-confirmed MenB disease who were eligible for 4CMenB vaccination with general practice 3-6 months after disease onset. All invasive MenB isolates were tested using the Meningococcal Antigen Typing System to determine whether the isolate was potentially preventable by 4CMenB. Admission to intensive care, death, and, when possible, reported sequelae in survivors were reviewed alongside vaccine status. For the epidemiological analysis, we compared laboratory-confirmed MenB disease cases before 4CMenB implementation (Sept 1, 2010, to March 31, 2015) with those after implementation (Sept 1, 2015, to March 31, 2020). For clinical follow-up and outcomes, we included all children younger than 5 years with laboratory-confirmed MenB disease between Sept 1, 2015, and March 31, 2021.

FINDINGS

Between Sept 1, 2015, and March 31, 2021, there were 371 cases of MenB disease in children younger than 5 years, including 256 (69%) in those younger than 1 year and 128 (35%) in those younger than 3 months. After the introduction of 4CMenB, the peak age of patients with MenB disease shifted from 5-6 months to 1-3 months. Overall, 108 (29%) of 371 children were too young for vaccination, unvaccinated, or developed MenB disease within 14 days of the first dose. Of 110 meningococcal strains characterised, 11 (92%) of 12 were potentially preventable by 4CMenB in unvaccinated children compared with 53 (66%) of 80 in partly vaccinated and 11 (69%) of 16 in fully vaccinated children. 78 (21%) of 371 children required intensive care, and the case fatality ratio was 5% (17 of 371), with 11 of 17 deaths occurring before 1 year of age, including seven in infants who were too young (<8 weeks) for vaccination. Of 354 survivors, 57 (16%) had 74 sequelae reported; 45 (61%) of 74 were neurological, 17 (23%) were physical, two (3%) were behavioural or psychological, and ten (14%) were other complications. Prevalence of sequelae was similar in unvaccinated (15 [15%] of 98) and vaccinated (42 [16%] 256) children, as were composite outcomes of death or sequelae, and intensive care or death or sequelae.

INTERPRETATION

Cases of MenB disease in vaccine-eligible children declined after 4CMenB implementation, but morbidity in vaccinated and unvaccinated children remained unchanged, highlighting the importance of vaccination to prevent MenB disease. The lower peak age of infants with MenB disease after 4CMenB implementation, with a higher case fatality ratio in young infants, highlights the importance of timely vaccination.

FUNDING

UK Health Security Agency.

Estimation of the incidence of invasive meningococcal disease using a capture-recapture model based on two independent surveillance systems in Catalonia, Spain

OBJECTIVES

Invasive meningococcal disease (IMD) is an urgent notifiable disease and its early notification is essential to prevent cases. The objective of the study was to assess the sensitivity of two independent surveillance systems and to estimate the incidence of IMD.

DESIGN

We used capture-recapture model based on two independent surveillance systems, the statutory disease reporting (SDR) system and the microbiological reporting system (MRS) of the Public Health Agency of Catalonia, between 2011 and 2015. The capture-recapture analysis and 95% CIs were calculated using the Chapman formula. Multivariate vector generalised linear model was performed for adjusted estimation.

MEASURES

The variables collected were age, sex, year of report, size of municipality (<10 000 and ≥10 000), clinical form, death, serogroup, country of birth and type of reporting centre (private and public).

RESULTS

The sensitivity of the two combined surveillance systems was 88.5% (85.0-92.0). SDR had greater sensitivity than the MRS (67.9%; 62.7-73.1 vs 64.7%; 59.4-70.0). In 2014-2015, the sensitivity of both systems was higher (80.6%; 73.2-87.9 vs 73.4%; 65.2-81.6) than in 2011-2013 (59.3%; 52.6-66.0 vs 58.3%; 51.6-65.1). In private centres, the sensitivity was higher for SDR than for MRS (100%; 100-100 vs 4.8%; -4.4-13.9). The adjusted estimate of IMD cases was lower than that obtained using the Chapman formula (279; 266-296 vs 313; 295-330). The estimated adjusted incidence of IMD was 0.7/100 000 persons-year.

CONCLUSIONS

The sensitivity of enhanced surveillance through the combination of two complementary sources was higher than for the sources individually. Factors associated with under-reporting in different systems should be analysed to improve IMD surveillance.

Invasive meningococcal disease in older adults in North America and Europe: is this the time for action? A review of the literature

BACKGROUND

Neisseria meningitidis is an encapsulated Gram-negative diplococcus that asymptomatically colonises the upper respiratory tract in up to 25% of the population (mainly adolescents and young adults). Invasive meningococcal disease (IMD) caused by Neisseria meningitidis imposes a substantial public health burden,. The case fatality rate (CFR) of IMD remains high. IMD epidemiology varies markedly by region and over time, and there appears to be a shift in the epidemiology towards older adults. The objective of our review was to assess the published data on the epidemiology of IMD in older adults (those aged ≥ 55 years)in North America and Europe. Such information would assist decision-makers at national and international levels in developing future public health programmes for managing IMD.

METHODS

A comprehensive literature review was undertaken on 11 August 2020 across three databases: EMBASE, Medline and BIOSIS. Papers were included if they met the following criteria: full paper written in the English language; included patients aged ≥ 56 years; were published between 1/1/2009 11/9/2020 and included patients with either suspected or confirmed IMD or infection with N. meningitidis in North America or Europe. Case studies/reports/series were eligible for inclusion if they included persons in the age range of interest. Animal studies and letters to editors were excluded. In addition, the websites of international and national organisations and societies were also checked for relevant information.

RESULTS

There were 5,364 citations identified in total, of which 76 publications were included in this review. We identified that older adults with IMD were mainly affected by serogroups W and Y, which are generally not the predominant strains in circulation in most countries. Older adults had the highest CFRs, probably linked to underlying comorbidities and more atypical presentations hindering appropriate timely management. In addition, there was some evidence of a shift in the incidence of IMD from younger to older adults.

CONCLUSIONS

The use of meningococcal vaccines that include coverage against serogroups W and Y in immunization programs for older adults needs to be evaluated to inform health authorities' decisions of the relative benefits of vaccination and the utility of expanding national immunization programmes to this age group.

Nonspecific symptoms dominate at first contact to emergency healthcare services among cases with invasive meningococcal disease

BACKGROUND

An early appropriate response is the cornerstone of treatment for invasive meningococcal disease. Little evidence exists on how cases with invasive meningococcal disease present at first contact to emergency medical services.

METHODS

Retrospective observational study of cases presenting with invasive meningococcal disease from January 1st of 2016 to December 31st of 2020 in the Capital Region of Denmark with a catchment area population of 1,800,000. A single medical emergency center provides services to the region. Data was collected from emergency medical services' call audio files, data from the call receiver registrations, registrations from ambulance personal and electronic health record data from the hospitalization.

RESULTS

Of 1527 cases suspected of meningitis, 38 had invasive meningococcal disease and had been in contact with the emergency service. Most contacts were to the medical helpline rather than the emergency call center at initial contact to emergency medical services. All were hospitalized within 12 h. At initial contact, fever was present in 28 (74%) of 38 cases, while specific symptoms such as headache (n=12 (32%)), a rash or petechiae (n=9 (23%)) and stiffness of the neck (n=4 (11%)) varied and were infrequent. Cases younger than 18 years of age were more often male and more often presented with fever and rash/petechiae. Only 4 (11%) received prehospital antibiotic treatment.

CONCLUSIONS

Cases with invasive meningococcal disease presented with fever and unspecific symptoms. Although few were acutely ill at their initial contact, all were admitted within 12 h. We suggest that all feverish cases should be systematically asked about specific symptoms and should be wary of symptom progression to optimize the early management if cases with invasive meningococcal disease.

Long-Term Mortality and State Financial Support in Invasive Meningococcal Disease-Real-World Data Analysis Using the French National Claims Database (SNIIRAM)

OBJECTIVES

Invasive meningococcal disease (IMD) is an uncommon disease known for its acute phase mortality and long-term sequelae. The objective was to assess the impact of IMD on post-discharge mortality risk and dependence on the French state for financial aid.

METHODS

A 6-year retrospective analysis in the national insurance database (SNIIRAM) assessed mortality in IMD cases (both during acute phase and post-discharge) and matched controls as well as benefit claims (i.e., for salary loss compensation [SLC], long-term sickness [ALD] and complementary health insurance [CMUc]). Observed survival data were extrapolated to estimate lifetime life expectancy following IMD.

RESULTS

Between 2012 and 2017, 3532 incident IMD cases were hospitalised in France (peak in < 2 years and 15-24 year olds), of which 23.3% developed sequelae. With an average follow-up of 2.8 years, 12.9% of cases vs. 3.2% of controls died (p < 0.0001), with significantly more cases than controls dying both during the acute phase and post-discharge. Around a third of these deaths occurred post-discharge. Extrapolation to lifetime life expectancy estimated that having IMD at any age significantly reduces life expectancy in survivors of the acute disease phase, e.g., by around 16 years for cases aged 0-50 years. IMD cases in France were significantly more likely to receive state-funded SLC (relative risk [RR] 3.9, 95% confidence interval [95% CI] 2.3-6.4) and ALD benefits (RR 1.85, 95% CI 1.71-2.00).

CONCLUSIONS

IMD has a significant impact on mortality post-discharge, expected to persist over a lifetime. In addition to long-term sequelae, the financial burden extends beyond the healthcare sector. These results highlight the importance of IMD prevention (e.g., vaccination).