Complications and sequelae of meningococcal disease in Quebec, Canada, 1990-1994

Vaccinating first-year college students living in dormitories for Meningococcal disease: an economic analysis

BACKGROUND

Surveillance of meningococcal disease among U.S. college students found an elevated rate of this disease among first-year students living in dormitories.

OBJECTIVE

This study examines the economics of routinely vaccinating a cohort of 591,587 incoming first-year students who will live in dormitories for > or =1 years.

METHODS

A cost-benefit model (societal perspective) was constructed to measure the net present value (NPV) of various vaccination scenarios, as well as the cost/case and cost/death averted. Input values included hospitalization costs from $10,924 to $24,030 per hospitalization; immunization costs (vaccine plus administration costs) from $54 to $88 per vaccine; 30 nonfatal, vaccine-preventable cases over a 4-year period (includes 3 with sequelae); 3 premature deaths; value of human life from $1.2 million to $4.8 million; and long-run sequelae costs from $1298 to $14,600. Sensitivity analyses were also conducted on vaccine efficacy (80% to 90%); discount rate (0% to 5%); and coverage (60% to 100%).

RESULTS

The costs of vaccination outweighed the benefits gained with NPVs ranging from -$11 million to -$49 million. The net cost per case averted ranged from $0.6 million to $1.9 million. The net cost per death averted ranged from $7 million to $20 million. The break-even costs of vaccination (when NPV=$0) at 60% coverage ranged from $23 (90% vaccine efficacy) to $5 (80% efficacy).

CONCLUSIONS

The model showed that the vaccination program is not cost-saving. Key variables influencing the results were the low number of vaccine-preventable cases and the high cost of vaccination. However, from the perspective of students and parents, the cost of vaccination might be worth the real or perceived benefit of reducing the risk to an individual student of developing meningococcal disease.

Economic analysis of the 1992-1993 mass immunization campaign against serogroup C meningococcal disease in Quebec

The objective of the study was to evaluate the cost-effectiveness and utility of the mass immunization campaign performed in the province of Quebec in 1992-1993, following an outbreak of serogroup C meningococcal disease (CMD). Effectiveness data were extracted from a population-based cohort study, and cost estimates were obtained from surveys. Costs of the campaign to the health system were $ 26 million (1993 Canadian dollars). Between 48 and 74 CMD cases, and between 7 and 11 deaths were prevented in the following 5 years. Net societal costs were between $ 18 and 21 million (using a 3% discount rate), net costs per death averted were between $ 1.7 and 3.0 million, between $ 58,000 and 105,000 per life-year gained, and between $ 49,000 and 87,000 per quality-adjusted life-year gained. These economic indices are less favorable than those for current routine immunization programs in Canada, but within the range of those for other common health interventions.

Thoracic myelopathy complicating acute meningococcal meningitis: MRI findings

Spinal cord dysfunction is a rare complication of Neisseria meningitidis (meningococcal) meningitis. We report a 17-year-old patient who had a 3-day history of fever, headache and vomiting, agitation, and unresponsiveness. Cerebrospinal fluid showed a marked polymorphonuclear pleocytosis. Latex particle agglutination was positive for meningococci. The patient was given intravenous antibiotics and intravenous dexamethasone. Over the next 4 days, he developed weakness of the lower extremities, with areflexia and extensor plantar responses. MRI revealed contiguous hyperintensities on T2-weighted images involving the thoracic spinal cord from T4 to T9 and 4 brain abscesses. Five months later, he recovered brain function, but the paraparesis remained. This case illustrates that myelopathy may complicate acute meningococcal meningitis, possibly due to a vasculitis, stroke, autoimmune myelopathy, or direct infection of the spinal cord. Patients with myelopathy associated with acute meningitis should receive spinal MRI. In addition, meningitis should be considered in patients presenting with acute myelopathy.

Modelling cost effectiveness of meningococcal serogroup C conjugate vaccination campaign in England and Wales

OBJECTIVES

To assess the cost effectiveness of a meningococcal serogroup C conjugate vaccination campaign in 0-17 year olds.

DESIGN

Cost effectiveness analysis from the perspective of the healthcare provider.

SETTING

England and Wales.

MAIN OUTCOME MEASURE

Cost per life year saved.

RESULTS

In 1998-9, immediately before the introduction of meningococcal C vaccination, the burden of serogroup C disease was considerable, with an estimated 1137 cases in people aged 0-17 years and at least 72 deaths. The vaccination campaign is estimated to have cost between 126m pound sterling ($180m, 207m) and 241 pound sterling 3m, 395m), depending on the price of the vaccine. Under base case assumptions the cost per life year saved from the vaccination campaign is estimated to be 6259 pound sterling. School based vaccination was more cost effective than general practice based vaccination because of lower delivery costs. Immunisation of infants aged under 1 year was the least cost effective component of the campaign because, although this maximises the life years gained, the three dose schedule required is more expensive than other methods of delivery. Estimates of the cost per life year saved were sensitive to assumptions on the future incidence of disease and the case fatality ratio.

CONCLUSIONS

Meningococcal C vaccination is likely to be more cost effective in all age groups when the incidence of disease is high. It is also more cost effective when given to children aged 1-4 (by general practitioners) and to children and young people aged 5-17 years at school than when administered to infants under 12 months of age or young people aged 16-17 years who are not at school.

Neurodevelopmental outcome in meningococcal disease: a case-control study

AIMS

To determine long term neurodevelopmental outcome following the spectrum of meningococcal infection.

METHODS

Between 1988 and 1990, 152 cases of meningococcal disease were recruited; 139 survived. Between 1998 and 1999, 115 survivors (83%) were evaluated, together with 115 sex and age matched controls. Standard measures of neurological function, coordination, cognition, behaviour, and hearing were used to assess neurodevelopmental status.

RESULTS

One case has spastic quadriplegia. Gross neurological examination was normal in all other cases and all controls. Five cases and no controls have significant hearing loss. Cases performed at a lower level than controls on measures of coordination, cognition, and behaviour. Four cases and no controls had major impairments. The adjusted odds ratios for moderate and minor impairments were 3.6 (95% CI 1.3 to 10.3) and 1.6 (95% CI 0.8 to 3.4) respectively.

CONCLUSION

The majority of survivors from this cohort do not have gross neurological deficits. However, when objective measures of motor function, cognitive ability, and behaviour were applied significant detriments were found in meningococcal survivors.

Meningococcal disease prevention and control strategies for practice-based physicians (Addendum: recommendations for college students). Committee on Infectious Diseases

The numbers of reported cases of meningococcal disease in 15- to 24-year-olds and outbreaks of meningococcal serogroup C disease, including outbreaks in schools and other institutions, have increased during the past decade. In response to outbreaks on college campuses, the American College Health Association has taken an increasingly proactive role in alerting college students and their parents to the risk of this disease and informing them about the availability of an effective vaccine. Recent epidemiologic studies have demonstrated an increased risk of disease in college students living in dormitories, particularly among freshmen, compared with similarly aged persons in the general population. At least 60% of these cases are potentially preventable by vaccination with the quadrivalent meningococcal A, C, Y, and W-135 polysaccharide vaccine. These findings support immunization of college students, particularly freshmen living in dormitories. Hence, college students and their parents should be informed by health care professionals at routine prematriculation visits and during college matriculation of the risk of meningococcal disease and potential benefits of immunization. Vaccine should be made available to those requesting immunization. College and university health services also should facilitate implementation of educational programs concerning meningococcal disease and availability of immunization services.

Update on meningococcal disease with emphasis on pathogenesis and clinical management

The only natural reservoir of Neisseria meningitidis is the human nasopharyngeal mucosa. Depending on age, climate, country, socioeconomic status, and other factors, approximately 10% of the human population harbors meningococci in the nose. However, invasive disease is relatively rare, as it occurs only when the following conditions are fulfilled: (i) contact with a virulent strain, (ii) colonization by that strain, (iii) penetration of the bacterium through the mucosa, and (iv) survival and eventually outgrowth of the meningococcus in the bloodstream. When the meningococcus has reached the bloodstream and specific antibodies are absent, as is the case for young children or after introduction of a new strain in a population, the ultimate outgrowth depends on the efficacy of the innate immune response. Massive outgrowth leads within 12 h to fulminant meningococcal sepsis (FMS), characterized by high intravascular concentrations of endotoxin that set free high concentrations of proinflammatory mediators. These mediators belonging to the complement system, the contact system, the fibrinolytic system, and the cytokine system induce shock and diffuse intravascular coagulation. FMS can be fatal within 24 h, often before signs of meningitis have developed. In spite of the increasing possibilities for treatment in intensive care units, the mortality rate of FMS is still 30%. When the outgrowth of meningococci in the bloodstream is impeded, seeding of bacteria in the subarachnoidal compartment may lead to overt meningitis within 24 to 36 h. With appropriate antibiotics and good clinical surveillance, the mortality rate of this form of invasive disease is 1 to 2%. The overall mortality rate of meningococcal disease can only be reduced when patients without meningitis, i.e., those who may develop FMS, are recognized early. This means that the fundamental nature of the disease as a meningococcus septicemia deserves more attention.

Update on meningococcal disease with emphasis on pathogenesis and clinical management

The only natural reservoir of Neisseria meningitidis is the human nasopharyngeal mucosa. Depending on age, climate, country, socioeconomic status, and other factors, approximately 10% of the human population harbors meningococci in the nose. However, invasive disease is relatively rare, as it occurs only when the following conditions are fulfilled: (i) contact with a virulent strain, (ii) colonization by that strain, (iii) penetration of the bacterium through the mucosa, and (iv) survival and eventually outgrowth of the meningococcus in the bloodstream. When the meningococcus has reached the bloodstream and specific antibodies are absent, as is the case for young children or after introduction of a new strain in a population, the ultimate outgrowth depends on the efficacy of the innate immune response. Massive outgrowth leads within 12 h to fulminant meningococcal sepsis (FMS), characterized by high intravascular concentrations of endotoxin that set free high concentrations of proinflammatory mediators. These mediators belonging to the complement system, the contact system, the fibrinolytic system, and the cytokine system induce shock and diffuse intravascular coagulation. FMS can be fatal within 24 h, often before signs of meningitis have developed. In spite of the increasing possibilities for treatment in intensive care units, the mortality rate of FMS is still 30%. When the outgrowth of meningococci in the bloodstream is impeded, seeding of bacteria in the subarachnoidal compartment may lead to overt meningitis within 24 to 36 h. With appropriate antibiotics and good clinical surveillance, the mortality rate of this form of invasive disease is 1 to 2%. The overall mortality rate of meningococcal disease can only be reduced when patients without meningitis, i.e., those who may develop FMS, are recognized early. This means that the fundamental nature of the disease as a meningococcus septicemia deserves more attention.

Bacterial meningitis

In recent years, investigators have made significant advances in understanding the pathogenesis of bacterial meningitis, particularly with regard to understanding the cascade of biologic events that cause excessive inflammation within the central nervous system (CNS). Nevertheless, the most important event in the field of bacterial meningitis in the past decade is the dramatic decline in the incidence of Haemophilus influenzae meningitis in children as a result of the widespread use of the conjugated H. influenzae type b vaccine. Currently, the most important clinical challenge in this field is the emergence of the drug-resistant Streptococcus pneumoniae. This problem has significantly complicated initial management of patients with suspected bacterial meningitis. Preliminary data show promise with new conjugated S. pneumoniae vaccines.

Recognition, treatment and complications of meningococcal disease

Meningococcal disease remains a major cause of death in young children. A decrease in mortality requires recognition and treatment of the disease at a number of stages in the illness. Life-threatening meningococcal disease usually presents as septicaemia rather than meningitis. The cardinal feature of meningococcal septicaemia is the purpuric rash. Many parents recognise the rash and seek medical advice because of it. When primary care physicians recognise the rash, the administration of parenteral penicillin may decrease mortality. However, antibacterials are not given promptly if there is no rash or if the disease presents in an atypical form. In hospital, antibacterial therapy with a third-generation cephalosporin should be given. Disease severity needs to be assessed by a valid method, such as the Glasgow Meningococcal Septicaemia Prognostic Score (GMSPS). This can identify those patients who need intensive care and/or might benefit from new therapies. The 2 life-threatening complications are septic shock and meningoencephalitis with raised intracranial pressure. Despite numerous case reports of success with potential new treatments, none has been proven safe and/or effective by controlled trials. Although it is tempting to focus on new treatments, the early recognition of severe meningococcal disease by parents, primary care physicians and junior hospital doctors is equally, if not more, important as a potential means of decreasing mortality.