Burden Of Meningococcal Disease Research Articles

Reducing inequalities with vaccines: New Zealand's MeNZB vaccine initiative to control an epidemic

Disadvantaged children of Māori and Pacific origin in New Zealand carry an inequitable burden of infectious diseases, many of which are preventable, some by vaccine. Immunisation is recognised in the developing world as a cheap, effective and efficient means of reducing inequalities. The MeNZB immunisation programme delivered in 2004-2006 towards the expected natural end of a projected 15-year epidemic appears to have had an effect (difficult to prove conclusively) on reducing the disproportionate burden of meningococcal disease carried by this group of children. It was delayed by the late engagement of the New Zealand Ministry of Health, fully briefed from 1996, leading to unnecessary and potentially avoidable deaths and sequelae, many lifelong. Further, failure to adequately assess vaccine effectiveness means that the contribution of MeNZB to the observed reduction in disease, particularly in those aged less than five years, will never be reliably known. However, the MeNZB campaign has at least left a legacy: the National Immunisation Register, which should enable New Zealand to minimise the 'vaccine inverse care law' and contribute to reducing ethnic inequity in the burden of vaccine preventable diseases.

Meningococcal disease in Asia: an under-recognized public health burden.

SUMMARYA literature search traced existing information on meningococcal disease in Asia. Reviewed data describing the epidemiology of meningococcal disease in Asia are incomplete, due in part to absence of surveillance in many countries, poor bacterial detection methods and social and healthcare barriers to disease reporting. This suggests that meningococcal disease in some Asian countries may be under-recognized, with a need to introduce/improve existing surveillance and case identification systems. Nevertheless, in some developing Asian countries, the disease burden may be significant. Serogroup A meningococcal epidemics are responsible for high morbidity and mortality in some countries and continue to be an ongoing threat, particularly in developing countries. There is an increasing role played by serogroups C, Y, and W-135 in invasive disease, indicating evolving meningococcal disease epidemiology in some countries. Multivalent meningococcal conjugate vaccines offer new opportunities in the region for reducing the meningococcal disease burden.

Cost of acute hospitalization and post-discharge follow-up care for meningococcal disease in the US

The combined costs of acute hospitalization and post-discharge follow-up care in patients with meningococcal disease have not been widely documented. In this study, data were retrospectively analyzed from three large databases of hospital discharge records and commercial insurance claims in the US. Cases of meningococcal disease were defined as admissions with an ICD-9-CM diagnosis code in the range of 036.x. From the 2005 HCUP Nationwide Inpatient Sample, 349 (weighted N=1,710) meningococcal-related hospitalizations were identified with a mean facility cost (in 2009 dollars) of $19,526 per admission. Similar estimates ($18,119 and $20,066, respectively) were obtained from 268 admissions identified in the LifeLink (formerly PharMetrics) database during 1999-2007 and from 1,058 hospitalizations in the Perspective Comparative Database (PCD) during 2000-2007. Using insurance claims from LifeLink, we estimated that payers incur an additional $26,178 in non-facility (professional and other ancillary) costs during the course of a meningococcal admission, as well as $22,230 in additional medical and pharmacy expenses for post-discharge care during the ensuing year. The majority of follow-up costs ($14,637) were attributed to repeat hospitalizations. Mean length of stay for meningococcal disease was consistently estimated across databases at 8 to 9 days. Data from the PCD further suggested that meningococcal disease carries, on average, nearly 2 days of intensive care unit utilization. In conclusion, hospital admissions for meningococcal disease are costly to payers. These costs are heightened when non-facility services and post-discharge care are also considered. Awareness of the full cost burden of meningococcal disease is needed when evaluating vaccination programs targeting the disease.

The epidemiology of meningococcal disease in India

To undertake a review of the literature on the epidemiology of meningococcal disease in India, with a view to informing future control policies. We searched the PUBMED, EMBASE, Global Health, IMSEAR and MedIND databases for observational studies relating to the burden of endemic meningococcal disease in India, the occurrence and epidemiological characteristics of epidemics, and the prevalence of individual meningococcal serogroups. The relatively few reports identified suggest that the incidence of endemic meningococcal disease in India is low, but that occasional epidemics of meningococcal disease have been recorded for at least 100 years. The larger epidemics have affected mainly the cities of northern India and have almost universally been caused by meningococci belonging to serogroup A. These epidemics have showed a few characteristics, including a marked seasonality, which are similar to those of epidemic meningococcal A disease in Africa. New serogroup A-containing meningococcal conjugate vaccines are now being developed and reaching the market, including an affordable monovalent serogroup A vaccine manufactured in India, but intended primarily for use in Africa. These new tools may have a role in containing future Indian epidemics, but their usefulness is dependent on early identification of epidemics. This will require a functional disease surveillance system with adequate laboratory support throughout India.

Epidemiology of meningococcal disease in Latin America: current situation and opportunities for prevention

Objective: Meningococcal disease continues to be a serious public health concern, being associated with high morbidity and mortality rates in many countries from Latin America. In addition to discussing recent changes in the epidemiology of meningococcal disease in the region, we also analyse the development and potential impact of new vaccines on the prevention of meningococcal disease.Methods: MEDLINE, SciELO, LILACS and websites of the national Ministries of Health databases were searched using the terms meningococcal disease, meningococcal epidemiology, Neisseria meningitidis, meningococcal vaccines and the name of Latin America countries, from 1998 to 2008, with emphasis on review articles, clinical trials and epidemiological studies.Results: Epidemiology of meningococcal disease in Latin America is characterized by marked differences from country to country. The overall incidence of meningococcal disease per year varied from less than 0·1 cases per 100,000 inhabitants in countries like Mexico to two cases per 100,000 inhabitants in Brazil. The highest age-specific incidence of meningococcal disease occurred in infants less than 1 year of age. Serogroups B and C were responsible for the majority of cases reported, but the emergence of serogroups W135 and Y was reported in some countries. Serogroup A disease is now rare in Latin America.Discussion: Although a few countries have established meningitis surveillance programs, the information is not uniform, and the quality of the reported data is poor in the majority of the region. The availability of new effective meningococcal conjugate vaccines and promising protein-based vaccine candidates against meningococcus B highlights the importance of a better understanding of the true burden of meningococcal disease in Latin America and also the need for cost-effectiveness studies before incorporating the new meningococcal vaccines to national immunization programs.

Challenges and progress in the development of a serogroup B meningococcal vaccine

Serogroup B meningococci cause the majority of the meningococcal disease burden in developed countries. Production of an effective and safe vaccine for serogroup B organisms has been hampered by the poor immunogenicity of the capsular polysaccharide that defines this group of bacteria. Previous efforts have focused on outer membrane vesicle vaccines, which have been implemented successfully during clonal outbreaks. However, the search for a universal vaccine against endemic polyclonal serogroup B meningococcal disease continues. In this review, we have highlighted recent development of outer membrane vesicle vaccines and progress in the evaluation of recombinant outer membrane protein vaccines.

Economics of an Adolescent Meningococcal Conjugate Vaccination Catch-up Campaign in the United States

In June 2005, the Advisory Committee on Immunization Practices recommended the newly licensed quadrivalent meningococcal conjugate vaccine for routine use among all US children aged 11 years. A 1-time catch-up vaccination campaign for children and adolescents aged 11-17 years, followed by routine annual immunization of each child aged 11 years, could generate immediate herd immunity benefits. The objective of our study was to analyze the cost-effectiveness of a catch-up vaccination campaign with quadrivalent meningococcal conjugate vaccine for children and adolescents aged 11-17 years. We built a probabilistic model of disease burden and economic impacts for a 10-year period with and without a program of adolescent catch-up meningococcal vaccination, followed by 9 years of routine immunization of children aged 11 years. We used US age- and serogroup-specific surveillance data on incidence and mortality. Assumptions related to the impact of herd immunity were drawn from experience with routine meningococcal vaccination in the United Kingdom. We estimated costs per case, deaths prevented, life-years saved, and quality-adjusted life-years saved. With herd immunity, the catch-up and routine vaccination program for adolescents would prevent 8251 cases of meningococcal disease in a 10-year period (a 48% decrease). Excluding program costs, this catch-up and routine vaccination program would save US$551 million in direct costs and $920 million in indirect costs, including costs associated with permanent disability and premature death. At $83 per vaccinee, the catch-up vaccination would cost society approximately $223,000 per case averted, approximately $2.6 million per death prevented, approximately $127,000 per life-year saved, and approximately $88,000 per quality-adjusted life-year saved. Targeting counties with a high incidence of disease decreased the cost per life-year saved by two-thirds. Although costly, catch-up and routine vaccination of adolescents can have a substantial impact on meningococcal disease burden. Because of herd immunity, catch-up and routine vaccination cost per life-year saved could be up to one-third less than that previously assessed for routine vaccination of children aged 11 years.

Epidemiology of meningococcal meningitis and changes in the surveillance system in Poland, 1970-2006

The objective of this study was to describe the general features of meningococcal meningitis epidemiology in 1970-2006 in Poland, in the context of changes made in surveillance system methods. Because of limited availability of case-based data, a more detailed analysis was performed only for the period 1994-2006 with special focus on case-fatality and diagnostic certainty. The reported annual number of meningococcal meningitis cases reached its peak of 416 (incidence 1.2 per 100,000) in 1981, after which it decreased to 76 cases in 2003 (incidence 0.2), and then increased to 151 cases in 2006 (incidence 0.4 per 100,000). The observed decrease was consistent with the decline in the number of live births and the drop in mortality from meningococcal disease observed using an independent reporting of death certificates. In 1994-2006, 1,677 cases of meningococcal meningitis were registered, with annual incidence varying between 0.2 and 0.5 per 100,000 inhabitants. Median age of patients was 4 years and 73% of cases were under 18 years of age. The majority of cases were caused by group B meningococci, but a trend towards increasing proportion of serogroup C has been identified. Meningococcal meningitis only was reported in 79% of cases, and meningitis with concomitant septicaemia in 21%. The overall case fatality was 3.7% - 4.5% in cases of meningitis only, and 7.1% in cases of meningitis with septicaemia. Based on the case definition introduced in 2005, 88.1% of the cases would be classified as confirmed and 4.8% as probable, whereas 7.1% would not fulfil the criteria of the case definition. Although diagnostic certainty of reported cases has improved in recent years, it is still problematic. Further efforts are needed to increase the proportion of serogrouped cases and assess the burden of meningococcal disease in Poland.

Clinical features and outcome of sporadic serogroup W135 disease Taiwan

BackgroundFew published reports have evaluated the clinical features and outcome of serogroup W135 meningococcal disease. In Taiwan, W135 is the second most prevalent meningococcal disease serogroup.MethodA nationwide study was conducted to retrospectively analyze epidemiologic data from 115 patients with laboratory confirmed meningococcal disease that occurred from 2001 through 2003.ResultsSerogroup W135 accounted for 26% of all cases and most (76.7%) were older than 20 years. There were no cases of serogroup W135 meningococcal disease associated with Hajj pilgrims, and all cases were sporadic. In 88 patients with complete case records, we compared the presenting symptoms, signs, laboratory data, and outcomes between W135 and non-W135 patients. There were no differences in presenting symptoms except for the higher prevalence of pneumonia found in W135 patients (23.8% vs. 1.5%; OR: 20.6; 95%CI: 2.3–189.0; p = 0.003). The distribution of inflammatory cells in CSF in patients with meningitis was also different between W135 and non-W135 patients. W135 patients had a trend toward more intubations and shock but it did not achieve statistical significance. In multivariate analysis of factors associated with death, three independent factors were found: bacteremia without meningitis, altered mental status, and petechiae or purpura on admission.ConclusionSporadic serogroup W135 meningococcal disease is an important component of the meningococcal disease burden in Taiwan, but it is not directly associated with Hajj pilgrims. Compared with patients infected by other serogroups of meningococci, patients with serogroup W135 were older and more likely to have extrameningeal involvement such as pneumonia.

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.

Vaccines for the prevention of meningococcal disease in children

Neisseria meningitidis is one of the most feared infections in pediatrics as the result of its rapid progression, high fatality rate, and frequent occurrence of sequelae. The 5 major meningococcal serogroups associated with disease are A, B, C, Y, and W-135. Currently available polysaccharide vaccines are effective in preventing disease caused by serogroups A, C, Y, and W-135 in older children and adults but do not elicit good long-term protection in young children. Vaccines that protect against serogroup B disease are still in development. As with the Haemophilus influenzae type b and pneumococcal polysaccharide vaccines, conjugation of the polysaccharide vaccine to a protein carrier dramatically changes vaccine characteristics, with resulting efficacy in infants. New meningococcal conjugate vaccines against serogroups A, C, Y, and W-135 are being developed. A serogroup C conjugate vaccine has been introduced successfully into the routine childhood schedule in the United Kingdom. New meningococcal conjugate vaccines are likely to have a dramatic effect on the burden of meningococcal disease within the next decade. Copyright 2002, Elsevier Science (USA). All rights reserved.

Early detection and response to meningococcal disease epidemics in sub-Saharan Africa: appraisal of the WHO strategy.

To assess the sensitivity, specificity and predictive value positive of the WHO threshold strategy for detecting meningococcal disease epidemics in sub-Saharan Africa and to estimate the impact of the strategy on an epidemic at district level. Data on meningitis cases at the district level were collected weekly from health ministries, WHO country and regional offices, and nongovernmental organizations in countries where there were epidemics of meningococcal disease in 1997. An epidemic was defined as a cumulative district attack rate of at least 100 cases per 100,000 population from January to May, the period of epidemic risk. The sensitivity, specificity and predictive value positive of the WHO threshold rate were calculated, and curves of sensitivity against (1 - specificity) were compared with alternatively defined threshold rates and epidemic sizes. The impact of the WHO strategy on a district epidemic was estimated by comparing the numbers of epidemic cases with cases estimated to have been prevented by vaccination. An analysis was made of 48 198 cases reported in 174 districts in Benin, Burkina Faso, the Gambia, Ghana, Mali, Niger, and Togo. These cases were 80.3% of those reported from Africa to WHO during the 1997 epidemic period. District populations ranged from 10,298 to 573,908. The threshold rate was crossed during two consecutive weeks in 69 districts (39.7%) and there were epidemics in 66 districts (37.9%). Overall, the sensitivity of the threshold rate for predicting epidemics was 97%, the specificity was 95%, and the predictive value positive was 93%. Taken together, these values were equivalent or better than the sensitivity, specificity and predictive value positive of alternatively defined threshold rates and epidemics, and remained high regardless of district size. The estimated number of potential epidemic cases decreased by nearly 60% in the age group targeted for vaccination in one district where the guidelines were followed in a timely manner. The use of the WHO strategy was sensitive and specific for the early detection of meningococcal disease epidemics in countries of sub-Saharan Africa during 1997 and had a substantial impact on a district epidemic. Nevertheless, the burden of meningococcal disease in these countries remains formidable and additional control measures are needed.