Meningococcal pneumonia: characterization and review of cases seen over the past 25 years

A Double Whammy Pneumonia: The First Reported Case of Concurrent Neisseria meningitidis and SARS-CoV-2 Pneumonia

Meningococcal pneumonia (MP) is a rare manifestation of meningococcal disease. The MP was first described in 1907 when Neisseria meningitidis (NM) isolates were identified in sputum samples obtained from soldiers with pneumonia. Preceding and concurrent viral infections constitute a major risk for MP. During the 1918-1919 influenza pandemic, a significant increase in MP cases were reported in patients with preceding influenza infection. Despite the end of the last H1N1 influenza pandemic in 2010, seasonal influenza infections still pose a risk for simultaneous MP. History appears to be repeating itself with concomitant bacterial and viral coinfection amid the current SARS-CoV-2 pandemic. Herein presented is a unique case of an elderly woman who presented with, to the best of our knowledge, the first reported case of possible concurrent SARS-CoV-2 and MP infections.

Risk factors for invasive meningococcal disease: a retrospective analysis of the French national public health insurance database

Vaccination of at-risk populations against Neisseria meningitidis is an important strategy to prevent invasive meningococcal disease (IMD). The objective of this study was to characterize preexisting risk factors in patients with IMD and to compare their relative importance. This case-control analysis was performed in the French national public health insurance database (SNDS). Cases consisted of all people hospitalized for IMD in France over a six-year period (2012–2017). Controls were matched by age, gender, and district of residence. Medical risk factors were identified from ICD-10 codes in the SNDS. Socioeconomic risk factors studied were low household income and social deprivation of the municipality of residence. Associations of these risk factors with hospitalization for IMD were quantified as odds ratios (ORs) between cases and controls with their 95% confidence intervals (95%CI). The medical risk factors showing the most robust associations were congenital immunodeficiency (OR: 39.1 [95%CI: 5.1–299], acquired immunodeficiency (10.3 [4.5–24.0]) and asplenia/hyposplenia (6.7 [3.7–14.7]). In addition, certain chronic medical conditions, such as autoimmune disorders (5.4 [2.5–11.8]), hemophilia (4.7 [1.8–12.2]) and severe chronic respiratory disorders (4.3 [3.1–6.2]) were also strongly associated, as was low household income (1.68 [1.49–1.80]). In conclusion, this study has documented potential risk factors associated with hospitalization for IMD in a large and comprehensive sample of individuals with IMD in France. Several of the risk factors identified may help identify groups who could benefit from targeted prevention measures (such as vaccination) in order to reduce the burden of IMD.

A Comprehensive Review of Meningococcal Disease Burden in India

INTRODUCTION

Meningococcal disease caused by Neisseria meningitidis has a high case fatality rate. Of 12 distinct serogroups, A, B, C, W-135 (W) and Y cause the majority of infections. The meningococcal disease burden and epidemiology in India are not reliably known. Hence, we performed a narrative review with a systematically conducted search to summarize information on meningococcal disease burden and epidemiology and vaccination recommendations for meningococcal disease in India.

METHODS

A search of Medline and Embase databases was undertaken to identify relevant publications published in the last 25 years.

RESULTS

Results from 32 original publications, 11 of which were case reports, suggest a significant burden of meningococcal disease and related complications. Meningococcal disease is increasingly reported among adolescents and adults, and large outbreaks have been reported in this population. Meningococcal disease in India is caused almost exclusively by serogroup A; serogroups B, C, W and Y have also been documented. Meningococcal disease burden data remain unreliable because of limited disease surveillance, insufficient laboratory capacity, misdiagnosis and prevalence of extensive antibiotic use in India. Lack of access to healthcare also increases under-reporting, thus bringing the reliability of the data into question. Conjugate meningococcal vaccines are being used for disease prevention by national governments and immunization programs globally. In India, meningococcal vaccination is recommended only for certain high-risk groups, during outbreaks and for international travelers such as Hajj pilgrims and students pursuing studies abroad.

CONCLUSION

Meningococcal disease is prevalent in India but remains grossly underestimated and under-reported. Available literature largely presents outbreak data related to serogroup A disease; however, non-A serogroup disease cases have been reported. Reliable epidemiologic data are urgently needed to inform the true burden of endemic disease. Further research into the significance of meningococcal disease burden can be used to improve public health policy in India. Fig. 1 Plain language summary.

Neisseria meningitidis pneumonia with bacteremia without meningitis: An atypical presentation

Neisseria meningitidis remains the most important cause of bacterial meningitis worldwide. The second most common and potentially severe end-organ manifestation of invasive meningococcal disease is meningococcal pneumonia. It occurs between 5 % and 15 % of all patients with invasive meningococcal disease. N. meningitidis sepsis and meningitis continue to be associated with high morbidity and mortality, however, meningococcal pneumonia is uncommon and often underreported. We describe a case of sepsis secondary to pneumonia with N. meningitidis bacteremia, without any evidence of meningitis. This case reports aims at highlighting pneumonia as a presentation of N. meningitidis bacteremia, and the need for a high level of clinical suspicion to establish the diagnosis.

Complete genome and methylome analysis of Neisseria meningitidis associated with increased serogroup Y disease

Invasive meningococcal disease (IMD) due to serogroup Y Neisseria meningitidis emerged in Europe during the 2000s. Draft genomes of serogroup Y isolates in Sweden revealed that although the population structure of these isolates was similar to other serogroup Y isolates internationally, a distinct strain (YI) and more specifically a sublineage (1) of this strain was responsible for the increase of serogroup Y IMD in Sweden. We performed single molecule real-time (SMRT) sequencing on eight serogroup Y isolates from different sublineages to unravel the genetic and epigenetic factors delineating them, in order to understand the serogroup Y emergence. Extensive comparisons between the serogroup Y sublineages of all coding sequences, complex genomic regions, intergenic regions, and methylation motifs revealed small point mutations in genes mainly encoding hypothetical and metabolic proteins, and non-synonymous variants in genes involved in adhesion, iron acquisition, and endotoxin production. The methylation motif CACNNNNNTAC was only found in isolates of sublineage 2. Only seven genes were putatively differentially expressed, and another two genes encoding hypothetical proteins were only present in sublineage 2. These data suggest that the serogroup Y IMD increase in Sweden was most probably due to small changes in genes important for colonization and transmission.

Variable clinical presentation by the main capsular groups causing invasive meningococcal disease in England

BACKGROUND

Invasive meningococcal disease (IMD) typically presents as meningitis, septicaemia or both. Atypical clinical presentations are rare but well-described. We aimed to assess the relationship between meningococcal capsular group, age, clinical presentation, diagnosis and outcome among IMD cases diagnosed in England during 2014.

METHODS

Public Health England conducts enhanced national surveillance of IMD in England. Clinical data for laboratory-confirmed MenB, MenW and MenY cases in ≥5 year-olds were used to classify presenting symptoms, diagnosis and outcomes. Multivariable logistic regression was used to assess independent associations between meningococcal capsular group, clinical presentation, gender, age and death.

RESULTS

In 2014, there were 340 laboratory-confirmed IMD cases caused by MenB (n = 179), MenW (n = 95) and MenY (n = 66). Clinical presentation with meningitis alone was more prevalent among MenB cases (28%) and among 15-24 year-olds (20%), whilst bacteraemic pneumonia was most prevalent among MenY cases (26%) and among ≥65 year-olds (24%). Gastrointestinal symptoms were recorded preceding or during presentation in 15% (40/269) cases with available information, including 5% (7/140) MenB, 17% (8/47) MenY and 30% (25/82) MenW cases. Upper respiratory tract symptoms were reported in 16% (22/141) MenB, 23% (11/47) MenY and 31% (26/84) MenW cases. Increasing age was also independently associated with bacteraemic meningococcal pneumonia, with no cases among 5-14 year-olds compared to 24% in ≥65 year-olds. Case fatality rates increased with age but no significant associations with death were identified.

CONCLUSIONS

Healthcare professionals should be aware of the atypical clinical presentations associated with the less prevalent meningococcal capsular groups in different age-groups.

Meningococcal pneumonia: a review

Background

Although Neisseria meningitidis is one of the major causes of meningitis, meningococcal pneumonia is the most common non-neurological organ disease caused by this pathogen.

Methods

We conducted a review of the literature to describe the risk factors, pathogenesis, clinical features, diagnosis, treatment and prevention of meningococcal pneumonia.

Results

Meningococcal pneumonia was first described in 1907 and during the 1918–1919 influenza pandemic large numbers of cases of meningococcal pneumonia occurred in patients following the initial viral infection. A number of publications, mainly case series or case reports, has subsequently appeared in the literature. Meningococcal pneumonia occurs mainly with serogroups Y, W-135 and B. Risk factors for meningococcal pneumonia have not been well characterised, but appear to include older age, smoking, people living in close contact (e.g. military recruits and students at university), preceding viral and bacterial infections, haematological malignancies, chronic respiratory conditions and various other non-communicable and primary and secondary immunodeficiency diseases. Primary meningococcal pneumonia occurs in 5–10% of patients with meningococcal infection and is indistinguishable clinically from pneumonia caused by other common pathogens. Fever, chills and pleuritic chest pain are the most common symptoms, occurring in > 50% of cases. Productive sputum and dyspnoea are less common. Diagnosis of meningococcal pneumonia may be made by the isolation of the organism in sputum, blood, or normally sterile site cultures, but is likely to underestimate the frequency of meningococcal pneumonia. If validated, PCR-based techniques may be of value for diagnosis in the future. While penicillin was the treatment of choice for meningococcal infection, including pneumonia, prior to 1991, a third generation cephalosporin has been more commonly used thereafter, because of concerns of penicillin resistance. Chemoprophylaxis, using one of a number of antibiotics, has been recommended for close contacts of patients with meningococcal meningitis, and similar benefits may be seen in contacts of patients with meningococcal pneumonia. Effective vaccines are available for the prevention of infection with certain meningococcal serogroups, but this field is still evolving.

Conclusion

Meningococcal pneumonia occurs fairly frequently and should be considered as a possible cause of pneumonia, particularly in patients with specific risk factors.

Meningococcal Pneumonia in a Young Healthy Male

A 23-year-old male presented to the emergency department with one-day history of right-sided pleuritic chest pain, haemoptysis, and fever. In the emergency department, the blood pressure was 140/60 mmHg, heart rate 89/min, body temperature 40°C, respiratory rates 20 breaths/min, and oxygen saturation 98% in room air. Physical examination revealed rales and bronchial breathing in the right infrascapular region. Laboratory analysis showed raised white blood cell counts and elevated inflammation markers. Chest X-ray showed right lower lobe consolidation. Intravenous(IV) ceftriaxone and doxycycline were started for the management of community-acquired pneumonia as per the local guideline. Later, on admission, blood culture was positive for Neisseria meningitidis (N. meningitidis). Ceftriaxone was continued for 4 days, and the patient was discharged while being on oral amoxicillin (1 gm TDS) for another 3 days. He remained well during the outpatient follow-up.

The CRISPR/Cas system in Neisseria meningitidis affects bacterial adhesion to human nasopharyngeal epithelial cells

Neisseria meningitidis, a commensal β-proteobacterium of the human nasopharynx, constitutes a worldwide leading cause of sepsis and epidemic meningitis. A recent genome-wide association study suggested an association of its type II-C CRISPR/Cas system with carriage and thus less invasive lineages. Here, we show that knock-out strains lacking the Cas9 protein are impaired in the adhesion to human nasopharyngeal cells which constitutes a central step in the pathogenesis of invasive meningococcal disease. Transcriptome sequencing data further suggest that meningococcal Cas9 does not affect the expression of surface adhesins but rather exerts its effect on cell adhesion in an indirect manner. Consequently, we speculate that the meningococcal CRISPR/Cas system exerts novel functions beyond its established role in defence against foreign DNA.

Invasive meningococcal disease without meningitis: a forgotten diagnosis

Neisseria meningitidis, a Gram-negative diplococcus, is an uncommon cause of pneumonia. There have been only about 344 cases reported worldwide from 1906 to 2015. To our knowledge, there have been only 3 cases reported in the USA in the past 2 decades. We present a case of a 72-year-old male with a past medical history of severe COPD, obstructive sleep apnea, and stage I lung cancer status post-stereotactic body radiation therapy 1 year ago, who was admitted with a 6-day history of productive cough with yellowish sputum, shortness of breath, extreme myalgias, and fatigue. Chest X-ray revealed an infiltrative process in the left lower lung field and left-sided pleural effusion. Blood cultures grew beta-lactamase-negative N. meningitidis after 24 hours. Our patient was initially treated with broad-spectrum antibiotics, which were later switched to amoxicillin to complete a total of 14 days of antibiotics. Diagnosing meningococcal pneumonia requires a high level of suspicion, as sputum cultures may be falsely positive due to asymptomatic carriage of the organism in the upper respiratory tract in up to 10% of outpatient population. We highlight this case as early recognition and treatment is critical. The case fatality rate for N. meningitidis pneumonia has been reported to be higher compared with meningococcal meningitis.

Increase in Meningococcal Serogroup W Disease, Victoria, Australia, 2013-2015

In Victoria, Australia, invasive meningococcal disease caused by Neisseria meningitidis serogroup W increased from 4% of all cases in 2013 to 30% in 2015. This increase resulted largely from strains similar to those in the serogroup W sequence type 11 clonal complex, previously described in the United Kingdom and South America.

A 58-Year-Old Woman With Pneumonia and Gram-Negative Diplococci

CASE PRESENTATION

A 58-year-old woman with COPD, cor pulmonale, diabetes, and hypertension had a productive cough of greenish and purulent sputum, low-grade fever, and shortness of breath. Medications were metformin, losartan, cholecalciferol, folic acid, a multivitamin, fluticasone by inhalation, and, as needed, ipratropium by inhalation. She lived alone and worked as a physician, had received that year's seasonal influenza vaccine, was a heavy smoker, did not drink alcohol or use illicit drugs, and had no personal or family history of allergy and autoimmunity.

Clinical presentation of invasive disease caused by Neisseria meningitidis serogroup Y in Sweden, 1995 to 2012

Over the period 1995–2012, the incidence of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup Y (NmY) increased significantly in Sweden. This is mainly due to the emergence of a predominant cluster named strain type YI subtype 1, belonging to the ST-23 clonal complex (cc). The aim of this study was to examine the clinical picture of patients with invasive disease caused by NmY and to analyse whether the predominant cluster exhibits certain clinical characteristics that might explain the increased incidence. In this retrospective observational study, the medical records available from patients with IMD caused by Nm serogroup Y in Sweden between 1995 and 2012 were systematically reviewed. Patient characteristics, in-hospital findings and outcome were studied and differences between the dominating cluster and other isolates were analysed. Medical records from 175 of 191 patients were retrieved. The median age was 62 years. The all-cause mortality within 30 days of admission was 9% (15/175) in the whole material; 4% (2/54) in the cohort with strain type YI subtype 1 and 11% (12/121) among patients with other isolates. Thirty-three per cent of the patients were diagnosed with meningitis, 19% with pneumonia, 10% with arthritis and 35% were found to have bacteraemia but no apparent organ manifestation. This survey included cases with an aggressive clinical course as well as cases with a relatively mild clinical presentation. There was a trend towards lower mortality and less-severe disease in the cohort with strain type YI subtype 1 compared with the group with other isolates.

Fulminant invasive meningococcal disease due to serogroup Y infection: a highly unusual case reflecting worrying increases in carriage and incidence

A young man presented to accident and emergency with a short history of diarrhoea and vomiting, with no medical history. He deteriorated rapidly during triage and never regained consciousness. He was pronounced dead after hours of attempted resuscitation. He was found to have organisms suggestive of diplococci on his blood film and subsequently had MenY found via PCR testing. This case illustrates a highly unusual presentation of invasive meningococcal disease caused by MenY which is quietly and dangerously increasing in incidence in the UK, particularly in young healthy patients. All clinicians are reminded to be vigilant in order to diagnose and treat this often fatal disease as well as to promote uptake of the quadrivalent MenACWY vaccine.

Meningococcal pneumonia in Japan: A case report and literature review

Neisseria meningitidis often causes meningitis and meningococcemia; however, meningococcal pneumonia is quite rare. Herein, we report a case of non-invasive meningococcal pneumonia initially misdiagnosed as pneumonia due to Moraxella catarrhalis on the basis of a Gram stain in a 43-year-old woman with asthma, type 2 diabetes mellitus, and schizophrenia. She visited our hospital following a 3-day history of fever, productive cough, and shortness of breath. Since her sputum smear revealed Gram-negative diplococcus and the chest radiograph showed infiltration in the lower right lung field, her initial diagnosis was pneumonia caused by M. catarrhalis. However, the next day, the sputum culture colonies were unlike those of M. catarrhalis, and matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis revealed the pathogen to be N. meningitidis. As a result, we administered the appropriate treatment and ensured adequate infection prevention and control measures including, droplet precautions and prophylaxis provided to close contacts. Secondary infection did not occur. Although meningococcal pneumonia is not common, physicians should consider N. meningitidis when Gram-negative diplococci are observed in respiratory specimens, as N. meningitidis cannot be distinguished from M. catarrhalis with Gram staining alone. Moreover, it is also important to monitor the appearance of the pathogenic colonies and to closely coordinate with laboratory technicians to determine appropriate treatments. In this article, we review the previous case reports of meningococcal pneumonia reported in 1984-2015 in Japan, summarizing the clinical characteristics and comparing previous reviews of the literature.

Meningococcal pneumonia

Neisseria meningitidis remains the most important cause of bacterial meningitis worldwide, particularly in children and young adults. The second most common and a potentially severe end-organ manifestation of invasive meningococcal disease (excluding systemic sepsis) is meningococcal pneumonia. It occurs in between 5% and 15% of all patients with invasive meningococcal disease and is thus the second most common non-systemic end-organ manifestation. To establish the diagnosis requires a high level of clinical awareness - the incidence is therefore very likely underreported and underestimated. This review of 344 meningococcal pneumonia cases reported in the Americas, Europe, Australia, and Asia between 1906 and 2015 presents risk factors, pathogenesis, clinical manifestations, diagnostic approaches, treatment, and prognosis of meningococcal pneumonia.

Invasive meningococcal disease in England: assessing disease burden through linkage of multiple national data sources

BACKGROUND

In England, Public Health England conducts enhanced surveillance of invasive meningococcal disease (IMD). The continuing decline in reported IMD cases has raised concerns that the MRU may be underestimating true IMD incidence.

METHODS

We linked five national datasets to estimate disease burden over five years, including PHE Meningococcal Reference Unit (MRU) confirmations, hospital episode statistics (HES), electronic reports of significant infections by National Health Service (NHS) Hospitals, death registrations and private laboratory reports.

RESULTS

During 2007-11, MRU confirmed 5115 IMD cases and 4275 (84%) matched to HES, including 3935 (92%) with A39* (meningococcal disease) and 340 (8%) with G00* (bacterial meningo-encephalitis) ICD-10 codes. An additional 2792 hospitalised cases with an A39* code were identified in HES. Of these, 1465 (52%) matched to one of 53,806 samples tested PCR-negative for IMD by MRU and only 73 of the remaining 1327 hospitalised A39* cases were confirmed locally or by a private laboratory. The characteristics of hospitalised cases without laboratory confirmation were similar to PCR-negative than PCR-positive IMD cases.

CONCLUSIONS

Interrogation of multiple national data sources identified very few laboratory confirmations in addition to the MRU-confirmed cases. The large number of unconfirmed and PCR-negative cases in HES suggests increased awareness among clinicians with low thresholds for hospitalising patients with suspected IMD.

Meningococcal disease: clinical presentation and sequelae

The clinical spectrum of invasive meningococcal disease is diverse with meningitis and/or septicaemia being the commonest modes of presentation. The severity of manifestations of meningococcal infection ranges from bacteraemia, associated with mild non-specific symptoms, to fulminant sepsis with multiorgan failure and death in approximately 10-15% of cases. Localised infections (such as conjunctivitis or septic arthritis) as well as chronic disease may be the sole clinical manifestations but can also lead to disseminated fulminant disease. Among survivors, disabling long-term sequelae can complicate meningococcal disease and result in potentially devastating effects on the quality of life of survivors, most of whom are infants, children and adolescents. The only rational approach to the prevention of meningococcal disease and the associated human suffering is through vaccination.

Importance of circulating antibodies in protection against meningococcal disease

Neisseria meningitidis infection results in life-threatening illnesses, including bacteremia, sepsis and meningitis. Early diagnosis and treatment are a challenge due to rapid disease progression, resulting in high mortality and morbidity in survivors. Disease can occur in healthy individuals, however, risk of infection is higher in patients with certain risk factors. N meningitidis carriage and case-fatality rates are high in adolescents and young adults. The absolute incidence of meningococcal disease has decreased partially due to increasing meningococcal vaccination rates. Maintaining protective levels of circulating antibodies by vaccination is necessary for clinical protection against disease. The Centers for Disease Control and Prevention Advisory Committee on Immunization Practices guidelines recommend vaccination for all individuals aged 11 through 12 years, followed by a booster dose at age 16 years for maintenance of protective antibody levels throughout the high-risk years. Despite these guidelines, many adolescents remain unvaccinated and susceptible to infection and disease. 

Invasive meningococcal capsular group Y disease, England and Wales, 2007-2009

Increases may result from mutations that allow the organism to evade the immune system.

Enhanced national surveillance for invasive meningococcal disease in England and Wales identified an increase in laboratory-confirmed capsular group Y (MenY) disease from 34 cases in 2007 to 44 in 2008 and 65 in 2009. For cases diagnosed in 2009, patient median age at disease onset was 60 years; 39% of patients had underlying medical conditions, and 19% died. MenY isolates causing invasive disease during 2007–2009 belonged mainly to 1 of 4 clonal complexes (cc), cc23 (56% of isolates), cc174 (21%), cc167 (11%), and cc22 (8%). The 2009 increase resulted primarily from sequence type 1655 (cc23) (22 cases in 2009, compared with 4 cases each in 2007 and 2008). cc23 was associated with lpxL1 mutations and meningitis in younger age groups (<25 years); cc174 was associated with nonmeningitis, particularly pneumonia, in older age groups (>65 years). The increase in MenY disease requires careful epidemiologic and molecular monitoring.

Bacteraemic pneumonia caused by Neisseria meningitidis serogroup Y

In this article, we describe a case of bacteraemic pneumonia caused by Neisseria meningitidis serogroup Y.

Meningococcal group A sepsis associated with rare manifestations and complicated by Kawasaki-like disease

Neisseria meningitidis serogroup A septicemia and the development of Kawasaki disease in a 10-month-old male infant are described. The patient also experienced a number of primary/septic manifestations as consequences of the direct infectious assault and secondary/hypersensitivity immune-mediated complications. The present observation indicates an etiological relationship between invasive meningococcal infection group A and Kawasaki disease, an association in favor of superantigen-induced theory for the latter occurrence.

Microbiological aspects of bacterial lower respiratory tract illness in children: typical pathogens

Whilst childhood immunization programmes have had an impact on the spectrum of pneumonic diseases seen in children, bacteria remain an important cause of lower respiratory tract infection (LRTI), particularly in younger and debilitated children. Because of the difficulty in obtaining lower respiratory tract specimens in children, specific diagnosis has often been difficult, although advances in diagnostic techniques have provided a much greater range of tools for the clinician. The challenge is to understand the application and limitation of these tests in the diagnosis of LRTI. This review examines the microbiological and diagnostic issues around Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, Neisseria meningitidis and enteric Gram negative pathogens.

Genetic and antigenic analysis of invasive serogroup Y Neisseria meningitidis isolates collected from 1999 to 2003 in Canada

One hundred forty serogroup Y Neisseria meningitidis isolates recovered from patients with invasive meningococcal disease (IMD) in Canada from 1999 to 2003 were analyzed by genetic and serological methods. Seventy-four isolates (52.9%) belonged to serotype 2c, and most have serosubtype antigen P1.5,2 (37 isolates, 26%) or P1.5 (31 isolates, 22%). Forty-eight isolates (34.3%) belonged to serotype 14 and have serosubtype antigen P1.5,2 (13 isolates, 9%) or P1.5 (7 isolates, 5%) or were nonserosubtypeable (27 isolates, 19%). Thirteen isolates (9.3%) were nonserotypeable. Multilocus sequence typing identified two unrelated clonal populations of serogroup Y meningococci causing invasive disease in Canada: ST-23 and ST-167 clonal complexes. Almost all ST-167-related isolates were typed as 2c:P1.5, while strains of the ST-23 clonal complex were either serotype 14 or 2c but with the serosubtype antigen P1.5,2. In contrast to previous reports that patients with serogroup Y disease are usually older, 26% of the Canadian serogroup Y cases were found in the 10-to-19-year-old age group and another 11% were in the 20-to-39-year-old age group.

Pneumonia and empyema caused by penicillin-resistant Neisseria meningitidis: a case report and literature review

Pneumonia is an uncommon manifestation of Neisseria meningitidis infection, and empyema is rarely reported. Uniform penicillin susceptibility has been assumed for meningococcal infections for many years, but decreased penicillin susceptibility has been recognized recently with increasing frequency. Breakpoints to define different categories of susceptibility were published recently by the Clinical and Laboratory Standards Institute. We report the case of a teenage girl with sepsis and extensive bilateral pneumonia with empyema caused by an N meningitidis isolate that was resistant to penicillin. Her protracted clinical course suggested that penicillin resistance contributed to her delayed recovery. Our experience with this patient suggests that susceptibility testing should be performed in every case of N meningitidis isolation, and treatment with a third-generation cephalosporin should be provided until the susceptibility results are known. Clinical suspicion of N meningitidis as a possible cause of respiratory symptoms accompanied by hypotension, even in the absence of a rash, may aid in diagnosis and therefore in the treatment and provision of prophylaxis to contacts of patients with meningococcal disease.

Prospects for vaccine prevention of meningococcal infection

Neisseria meningitidis is the leading cause of bacterial meningitis in the United States and worldwide. A serogroup A/C/W-135/Y polysaccharide meningococcal vaccine has been licensed in the United States since 1981 but has not been used universally outside of the military. On 14 January 2005, a polysaccharide conjugate vaccine that covers meningococcal serogroups A, C, W-135, and Y was licensed in the United States for 11- to 55-year-olds and is now recommended for the routine immunization of adolescents and other high-risk groups. This review covers the changing epidemiology of meningococcal disease in the United States, issues related to vaccine prevention, and recommendations on the use of the new vaccine.

Meningococcal vaccines

Meningococcal disease is one of the most feared and serious infections in the young and its prevention by vaccination is an important goal. The high degree of antigenic variability of the organism makes the meningococcus a challenging target for vaccine prevention. Meningococcal polysaccharide vaccines against serogroup A and C are efficacious and have been widely used, often in combination with serogroup Y and W135 components. Their relative lack of immunogenicity in young children and infants can be overcome by conjugation to a protein carrier. The effectiveness of serogroup C glycoconjugate vaccines in children of all ages has been demonstrated and they have now been introduced into routine vaccination schedules. Conjugate vaccines against other serogroups, including A, Y, and W135 will soon be available and it is hoped they may emulate this success. Prevention of serogroup B disease has proven more elusive. Several serogroup B vaccines based on outer membrane vesicles have been shown to be immunogenic and reasonably effective in adults and older children, but the protection offered by them is chiefly strain-specific. Multivalent recombinant PorA vaccines have been developed to broaden the protective effect, but no efficacy data are available as yet. Intensive efforts have been directed at other outer membrane protein vaccine candidates and lipopolysaccharide, and some of these have been shown to offer protection in experimental animal models. Nonpathogenic Neisseriae spp. such as Neisseria lactamica are also possible vaccine candidates. Previously unknown proteins have been identified from in silico analysis of the meningococcal genome and their vaccine potential explored. However, none of these has yet been presented as the 'universal' protective antigen and work in this field continues to be held back by our limited knowledge concerning the mechanisms of natural protection against serogroup B meningococci.

[Extra-meningeal meningococcal infection: report of 14 cases]

INTRODUCTION AND METHOD

Fifty-five patients (17 adults, 38 children) with meningococcal infection were admitted between 1986 and 2002 in a university hospital (500 beds). Fourteen of them (nine adults, five children) presented with an extra-meningeal infection. We compared adults and children presentations.

RESULTS

All adults had immunodeficiency. Septic locations were various (three bacteriemia, four pneumoniae, one infected ascitis, one cutaneous abscess). All patients received amoxicillin or third generation cephalosporin. Hospitalisation was prolonged (mean: 47 days). Seven patients required intensive care unit admission, and two of them died. All children (all were less than 36-month-old) presented with fever. Only one was immunodeficient (infected by human immunodeficiency virus). Neisseria meningitidis grew from blood in four, and in the throat for the remaining one. Hospitalisation was of short duration (mean: 4 days) and none of the children required intensive care unit. All the children recovered rapidly with antibiotics.

CONCLUSION

Outcome of extra-meningeal infection with N. meningitidis is different in adults and children. Adults present with immunodeficiency, infection is severe and patients present with various clinical features; children have a more homogeneous clinical presentation (fever) and outcome is excellent.

Opportunities for Control of Meningococcal Disease in the United States

The United States currently has relatively low rates of meningococcal disease caused by Neisseria meningitidis. Serogroups Y, C, and B are most common. Although most cases are sporadic, a minority are associated with outbreaks. Pediatric populations have disproportionately higher rates of disease, but nearly two thirds of all cases occur in persons aged 15 years and older. The major challenge to control of domestic meningococcal disease is the absence of a vaccine to prevent sporadic cases spanning many age groups. The quadrivalent A/C/Y/W-135 meningococcal polysaccharide vaccine is licensed in the United States, but because of its limited efficacy in children under two years of age, it is recommended for high-risk groups and outbreak response rather than routine childhood immunization. New conjugate meningococcal vaccines have successfully reduced endemic disease in the United Kingdom, and similar vaccines promise to have a dramatic impact on the burden of meningococcal disease in the United States.

The role of particular strains of Neisseria meningitidis in meningococcal arthritis, pericarditis, and pneumonia

The clinical presentations of meningococcal diseases other than meningitis or meningococcemia may lead to erroneous diagnosis. Although several reports have described unusual meningococcal diseases, the Neisseria meningitidis strains involved in these forms have been poorly characterized. In this study, meningococcal arthritis and pericarditis were confirmed by isolation of N. meningitidis and/or detection of meningococcal DNA in synovial or pericardial fluid, respectively, and meningococcal pneumonia was detected by isolation of N. meningitidis from blood. From 1999 through 2002, meningococcal disease was bacteriologically confirmed in 26 cases of arthritis, 6 cases of pericarditis, and 33 cases of pneumonia by the National Reference Center for the Meningococci in Paris. We found a statistically significant association between strains of serogroup W135, mostly of the clonal complex ET-37, and arthritis. Pneumonia was most frequently diagnosed in patients aged >70 years, and 54.5% of the strains belonged to serogroup W135, although these strains had heterogeneous phenotypes. Bacteremia is a key step in the pathophysiology of meningococcal disease and precedes any form of invasive infection.

Gram-negative Diplococcal Respiratory Infections

Human respiratory tract infections caused by gram- negative diplococci continue to remain significant issues in health care. Although not addressed as frequently as the classical diplococcal pneumonia, the gram-positive Streptococcus pneumoniae (the pneumococcus), infections due to Neisseria meningitidis (the meningococcus), and Moraxella catarrhalis (formerly called both Neisseria catarrhalis and Branhamella catarrhalis) are addressed here including their microbiology, respiratory tract manifestations, antimicrobial treatment, and potential prevention with immunization.

Meningococcal disease among children who live in a large metropolitan area, 1981-1996

Neisseria meningitidis is an important cause of serious bacterial infections in children. We undertook a study to identify meningococcal infections of the blood, cerebrospinal fluid, or both of children in a defined geographic area to describe the burden of disease and the spectrum of illness. We reviewed the medical records of all children aged <18 years who had meningococcal infections at the 4 pediatric referral hospitals in Boston, Massachusetts, from 1981 through 1996. We identified 231 patients with meningococcal disease; of these 231 patients, 194 (84%) had overt disease and 37 (16%) had unsuspected disease. Clinical manifestations included meningitis in 150 patients, hypotension in 26, and purpura in 17. Sixteen patients (7%) died. Although meningococcal disease is devastating to a small number of children, we found that the burden of pediatric disease that it caused at the 4 pediatric referral centers in this geographic region was limited; that patients with overt meningococcal disease are most likely to have meningitis; and that individual practitioners are unlikely to encounter a patient with unsuspected meningococcal disease.