Epidemic Meningococcal Meningitis Research Articles

Trends in Neisseria meningitidis serogroups amongst patients with suspected cerebrospinal meningitis in the meningitis belt of Ghana: a 5-year retrospective study

BackgroundSerogroup A Neisseria meningitidis was the major cause of meningococcal meningitis epidemics in the African meningitis belt before 2010 when the monovalent meningococcal A conjugate vaccine (MenAfriVac) was introduced in the region. Therefore, this study aimed to establish the trends in N. meningitidis serogroups from 2016 to 2020 in Ghana’s meningitis belt.MethodsPolymerase chain reaction (PCR) confirmed laboratory results of suspected cases of cerebrospinal meningitis from January, 2016 to March, 2020 were obtained from the Tamale Public Health Laboratory. The data were subjected to trend analysis using Statistical Package for the Social Sciences version 25. Differences between discrete variables were analyzed using the Cochran–Armitage trend test.ResultsOf the 2,426 suspected cases, 395 (16.3%) were confirmed positive for N. meningitidis using PCR. Serogroup X showed a significant upward trend (P < 0.01), and serogroup W showed a downward trend (P < 0.01). However, no significant trend was observed for any other serogroup.ConclusionThis study showed the emergence of serogroup X, a non-vaccine type, as the predominant N. meningitidis serogroup in the wake of a declining serogroup W in Ghana’s meningitis belt.

Prevalence and factors influencing cerebro-spinal meningitis, in Kano Metropolis, Nigeria

Meningococcal disease is a contagious disease caused by the meningococcus (Neisseria meningitidis), a Gram-negative bacterium. Today epidemic meningococcal meningitis is a major public health problem affecting tropical countries, particularly in sub-Saharan Africa, it causes considerable morbidity and mortality. Frequent epidemics and control measures have met with limited success. This study analyzes the incidence, and influencing factors of meningitis in Kano metropolis, Nigeria. The study made use of both primary and secondary data. Primary data was collected using questionnaire while secondary data was obtained from hospital records. The study adopted systematic sampling to select four Local Government Areas. Purposive sampling technique was employed to select houses for the administration of 384 copies of questionnaire. Data was analyzed using both descriptive and inferential statistics as well as GIS-mapping such as: line graph, percentages, kernel density estimation and regression. The result showed that out of the 8724 cases of meningitis recorded from 2008 – 2017, LGA recorded the highest incidences (37.3%), where population is high and estimated density shows very high cluster. Also, incidence of meningitis, though with fluctuating pattern, appeared to be increasing from 2014 to 2017. Factors like overcrowding of people sleeping in the same room (0.0674) and increase in temperature (0.0641) were the most significant factors of meningitis in the study area. Awareness should be made on the need for a ventilated housing especially during the high temperature season (March to April) in the area

Meningococcal Meningitis and Coal Mining in Provincial England: Geographical Perspectives on a Major Epidemic, 1929–33

This article presents the first systematic study of the spatial transmission of the 1929–33 epidemic of meningococcal meningitis and its association with local coal mining communities in three adjacent high incidence counties of England; Nottinghamshire, Derbyshire, and the West Riding of Yorkshire. Drawing on a robust method of spatial epidemiological analysis (swash‐backwash model), we demonstrate a gradient response with local levels of employment in coal mining for each of three key parameters of the epidemic wave: spatial velocity of transmission; duration of infectivity; and spatial reach. Partial least squares regression analysis identifies the relatively young and fertile demographic of local mining communities as the principal determinant of the resulting epidemic burden. Other sociodemographic parameters, including established risk factors for invasive meningococcal disease (low social class, high residential density, and overcrowding) are found to play little, or no, role in the spatial distribution of the disease. Our findings have importance for understanding the historic links between the coal mining industry and epidemic meningococcal meningitis, and point to possible present‐day opportunities for intervention through the designation of coal mining communities as defined risk groups for meningococcal vaccines.

Mathematical modeling and analysis of meningococcal meningitis transmission dynamics

Meningococcal meningitis (MCM) is one of the serious public health threats in the tropical and sub-tropical regions. In this paper, we propose an epidemic model to study the transmission dynamics of MCM with high- and low-risk susceptible populations. The model considers two different groups of susceptible individuals depending on the availability of medical resources (MR, including hospitals, health workers, etc.), which varies the infection risk. We find that the model exhibits the phenomenon of backward bifurcation (BB), which increases the difficulty of MCM control since the dynamics are not merely relying on the basic reproduction number, [Formula: see text]. This study explores the effects of MR on the MCM epidemics by mathematical analysis and shows the existence of BB on MCM disease. Our findings suggest that providing adequate MR in a community is crucial in mitigating MCM incidences and deaths, especially, in the MCM endemic regions.

Elimination of Epidemic Meningitis in the African Region: Progress and Challenges:2010-2016

Epidemics of meningococcal disease constitute a major public health challenge in Africa, affecting mostly the 24 countries of the meningitis belt. These epidemics led to a call for a call for a safe, effective and affordable conjugate vaccine against the major serogroup responsible for recent epidemics by leaders of the region. This paper documents experiences with efforts at eliminating epidemic meningitis in the African Region. The meningoccocal serogroup A conjugate vaccine was developed, licensed and offered to more than 235 million people through mass vaccination campaigns in 16 countries since 2010. Future plans include providing the vaccine to the remaining countries in the African Meningitis Belt and, to implement the vaccine into routine national infant immunization programme and to organise catch-up immunization campaigns every 5 years for unvaccinated <5 year-olds who had missed their routine vaccinations. The success of the project is evidenced by the large declines in cases of group A meningococcal disease since 2010, with no cases reported in vaccinated persons across the 16 countries, reflecting the highly effective nature of the vaccine. The successful control of serogroup A meningococcal disease has highlighted the need to tackle other meningococcal serogroups through development of polyvalent conjugate vaccines with the aim of eliminating epidemics of meningococcal meningitis in the African region.

Epidemics of meningococcal meningitis in Northern Nigeria focus on preventive measures.

Throughout the past 200 years, epidemics of meningococcal infection have been noted in Northern Nigeria. Consequently, control of meningococcal meningitis is one of the major priorities in infection control in the region. The proportions of cases of invasive meningococcal disease (IMD) caused by the five common serotypes (A, B, C, Y, and W135) vary among different regions and within specific geographic locations. Hence, effective and comprehensive disease control can only be achieved with the use of vaccines that target all of these disease-causing serotypes. Vaccines for the majority of meningococcal serogroups implicated in causing IMD are available in developed countries and have proven effective in reducing the disease incidence. However, the overall success of a vaccine depends on its coverage of the at-risk population as well as safety and effectiveness of the vaccine at preventing disease. Therefore, maximizing the global impact of these vaccines requires having them made available in regions with the high incidence of the disease, like Northern Nigeria, where rates of meningococcal disease are several times higher than in industrialized nations, and the reported mortality is usually high.

Successful African introduction of a new Group A meningococcal conjugate vaccine: Future challenges and next steps

ABSTRACTThe introduction of a new Group A meningococcal conjugate vaccine, MenAfriVacR, has been a important public health success. Group A meningococcal meningitis has disappeared in all countries where the new Men A conjugate vaccine has been used at public health scale. However, continued control of Group A disease in sub-Saharan Africa will require that community immunity against Group A meningococci be maintained. Modeling studies have shown that unless herd immunity is maintained Group A meningococcal disease will return.To ensure that African populations remain protected birth cohorts must be protected with an EPI formulation of MenAfriVacR (5 mcg) given at 9 months with Measles 1. In addition, populations born after the initial 1-29 year old campaigns and consequently not yet immunized with the new Men A conjugate vaccine, will have to be immunized in country-specific catch-up campaigns. Countries with poor EPI coverage (Measles 1 coverage < 60%) will likely need quinquennial vaccination campaigns aimed at covering 1-4 year olds. Implementing these strategies is the only sure way of ensuring that Group A meningococcal meningitis epidemics will not recur.A second problem that requires urgent attention is the challenge of dealing with Non-A meningococcal meningitis epidemics in sub-Saharan Africa. Groups C, W and X meningococci are well-established circulating strains in sub-Saharan Africa and are responsible for yearly focal meningitis epidemics that vary in severity and remain unpredictable as to size and geographic distribution. For this reason, polyvalent meningococcal conjugate vaccines that are affordable and appropriate for the African context must be developed and introduced. These new meningococcal vaccines when combined with more affordable pneumococcal conjugate vaccines offer the promise of a meningitis-free Sub-Saharan Africa.

The association between respiratory tract infection incidence and localised meningitis epidemics: an analysis of high-resolution surveillance data from Burkina Faso

Meningococcal meningitis epidemics in the African meningitis belt consist of localised meningitis epidemics (LME) that reach attack proportions of 1% within a few weeks. A meningococcal serogroup A conjugate vaccine was introduced in meningitis belt countries from 2010 on, but LME due to other serogroups continue to occur. The mechanisms underlying LME are poorly understood, but an association with respiratory pathogens has been hypothesised. We analysed national routine surveillance data in high spatial resolution (health centre level) from 13 districts in Burkina Faso, 2004–2014. We defined LME as a weekly incidence rate of suspected meningitis ≥75 per 100,000 during ≥2 weeks; and high incidence episodes of respiratory tract infections (RTI) as the 5th quintile of monthly incidences. We included 10,334 health centre month observations during the meningitis season (January-May), including 85 with LME, and 1891 (1820) high-incidence episodes of upper (lower) RTI. In mixed effects logistic regression accounting for spatial structure, and controlling for dust conditions, relative air humidity and month, the occurrence of LME was strongly associated with high incidence episodes of upper (odds ratio 23.9, 95%-confidence interval 3.1–185.3), but not lower RTI. In the African meningitis belt, meningitis epidemics may be triggered by outbreaks of upper RTI.

Novel anti-infective potential of salvianolic acid B against human serious pathogen Neisseria meningitidis.

BackgroundEpidemics of meningococcal meningitis cause significant health problems especially in Sub-Saharan Africa. Novel anti-infective candidates are needed. In modern anti-adhesion therapy initial attachment of bacteria to host cells is prevented. Our unique studies have revealed anti-adhesive candidates from natural products, namely milk and berries, against Neisseria meningitidis adhesion. In the present study against N. meningitidis adhesion, a novel binding inhibitor was found; salvianolic acid B (SA-B), a polyphenol from the radix Salviae miltiorrhizae, an important part of Chinese folk medicine.MethodsIn order to test inhibition of meningococcal pili binding and anti-adhesion activity of SA-B, bovine thyroglobulin, a reference glycoprotein for meningococcal receptor was used in a microtiter plate assay. Inhibitory activity was tested by using serial dilutions of SA-B extracts of 98 and 70 % purity. Results were confirmed in a HEC-1B cell dot assay and antimicrobial activity was measured by using a microbroth dilution assay.ResultsAlmost total (93 %) inhibition of pili binding, anti-adhesion, was achieved with the 70 % extract of SA-B at the concentration of 0.3 mg/mL in the bovine thyroglobulin reference model. 50 % binding inhibition activity was achieved with 0.6 µg/mL of the SA-B extract. Total inhibition of the pili binding to HEC-1B cells was found at the tested concentration of 0.5 mg/mL. The 98 % pure SA-B resulted in weaker inhibition. At the concentration of 0.3 mg/mL 78 % inhibition was achieved in the thyroglobulin model. For 50 % inhibition 2.4 μg/mL of pure SA-B was needed. The difference between the binding inhibition activities (70 and 98 % pure SA-B) was statistically significant (P = 0.03). Antimicrobial activity of 70 % SA-B, when investigated against N. meningitidis, was detected only in relatively high concentrations.ConclusionsOur results indicate that plant SA-B may prevent meningococcal infections by inhibiting meningococcal binding and may thus have an impact on the amount of nasopharyngeal carriers of N. meningitidis. This may prevent the spreading of meningococcal infections between humans. One could conclude that SA-B and its source dried radix S. miltiorrhizae, which is an important part of Chinese folk medicine, could be valuable candidates for further research in meningococcal disease prevention.

Pattern of the meningococcal meningitis outbreak in Northern Nigeria, 2009.

Despite the availability of vaccines, children are the people most often affected by epidemic meningococcal meningitis. The pattern of the epidemic meningococcal meningitis outbreak in Northern Nigeria in 2009 and the Neisseria meningitidis strains responsible for this epidemic are described here. A retrospective cross-sectional study was conducted in 16 states, involving 48 local government areas (LGAs), 91 health facilities, and 96 communities. Data collection involved in-depth interviews with key informants from the federal to the community level, a review of records, and a solution-oriented national workshop with participants from all states of the Federation. Cerebrospinal fluid (CSF) samples were collected from some of the suspected cases at the start of the outbreak and were tested using the rapid Pastorex latex agglutination kit. Kastina (11153, 20.4%), Jigawa (8643, 15.8%), Bauchi (8463, 15.5%), Kano (6811, 12.4%), and Gombe (6110, 11.2%) were the states with the highest prevalence of meningitis. The states of Nasarawa (11.0%), Adamawa (8.0%), and Borno (7.6%) recorded the highest percentage of deaths, while the Shongom (Gombe State 12.5%), Illela (Sokoto State 9.8%), and Ikara (Kaduna State 9.1%) LGAs recorded the most deaths amongst cases seen. The testing of CSF samples during meningitis outbreaks is recommended in order to monitor the occurrence of the multiple meningitis serotypes during these outbreaks and to direct serotype-specific vaccination response activities.

From Epidemic Meningitis Vaccines for Africa to the Meningitis Vaccine Project.

Background. Polysaccharide vaccines had been used to control African meningitis epidemics for >30 years but with little or modest success, largely because of logistical problems in the implementation of reactive vaccination campaigns that are begun after epidemics are under way. After the major group A meningococcal meningitis epidemics in 1996–1997 (250 000 cases and 25 000 deaths), African ministers of health declared the prevention of meningitis a high priority and asked the World Health Organization (WHO) for help in developing better immunization strategies to eliminate meningitis epidemics in Africa.Methods. WHO accepted the challenge and created a project called Epidemic Meningitis Vaccines for Africa (EVA) that served as an organizational framework for external consultants, PATH, the US Centers for Disease Control and Prevention (CDC), and the Bill & Melinda Gates Foundation (BMGF). Consultations were initiated with major vaccine manufacturers. EVA commissioned a costing study/business plan for the development of new group A or A/C conjugate vaccines and explored the feasibility of developing these products as a public–private partnership. Representatives from African countries were consulted. They confirmed that the development of conjugate vaccines was a priority and provided information on preferred product characteristics. In parallel, a strategy for successful introduction was also anticipated and discussed.Results. The expert consultations recommended that a group A meningococcal conjugate vaccine be developed and introduced into the African meningitis belt. The results of the costing study indicated that the “cost of goods” to develop a group A – containing conjugate vaccine in the United States would be in the range of US$0.35–$1.35 per dose, depending on composition (A vs A/C), number of doses/vials, and presentation. Following an invitation from BMGF, a proposal was submitted in the spring of 2001.Conclusions. In June 2001, BMGF awarded a grant of US$70 million to create the Meningitis Vaccine Project (MVP) as a partnership between PATH and WHO, with the specific goal of developing an affordable MenA conjugate vaccine to eliminate MenA meningitis epidemics in Africa. EVA is an example of the use of WHO as an important convening instrument to facilitate new approaches to address major public health problems.

Climate Regimes, El Niño-Southern Oscillation, and Meningococcal Meningitis Epidemics.

Meningococcal meningitis is a major public health problem that kills thousands annually in Africa, Europe, North, and South America. Occurrence is, however, highest during the dry seasons in Sahel Africa. Interannual changes in precipitation correlate with interannual changes in El Niño-Southern Oscillation (ENSO), while interdecadal changes in precipitation correlate with Pacific Decadal Oscillation (PDO). The objective of the study was to determine if there is spectral coherence of seasonal, interannual, and interdecadal changes in occurrence of meningococcal meningitis in Sahel, Central, and East Africa with interannual and interdecadal changes of PDO and ENSO. Time series were fitted to occurrence of meningococcal meningitis in Sahel, Central, and East Africa, to indices of precipitation anomalies in the Sahel, and to indices of ENSO and PDO anomalies. Morlet wavelet was used to transform the time series to frequency-time domain. Wavelet spectra and coherence analyses were performed. Occurrence of meningococcal meningitis showed seasonal, interannual, and interdecadal changes. The magnitude of occurrence was higher during warm climate regime, and strong El Niños. Spectra coherence of interannual and interdecadal changes of ENSO and PDO with occurrence of meningococcal meningitis in Sahel, Central, and East Africa were significant at p < 0.0001. Precipitation in Sahel was low during warm climate regimes. Spectra coherence of changes in precipitation in Sahel with ENSO was significant at p < 0.0001. ENSO and PDO are determinants of the seasonal, interannual, and interdecadal changes in occurrence of meningococcal meningitis. Public health management of epidemics of meningococcal meningitis should include forecast models of changes in ENSO to predict periods of low precipitation, which initiate occurrence.

Meningococcal meningitis: vaccination outbreak response and epidemiological changes in the African meningitis belt.

The main approach to controlling epidemics of meningococcal meningitis in the African meningitis belt has been reactive vaccination campaigns with serogroup A polysaccharide vaccine once the outbreak reached an incidence threshold. Early reactive vaccination is effective in reducing morbidity and mortality. A recent paper in International Health has shown that earlier reactive vaccination campaigns may be even more effective than increasing the coverage area of vaccination. Monovalent serogroup A conjugate vaccine programs have recently been launched to prevent transmission in endemic areas in the African meningitis belt. Conjugate vaccines can induce immunological memory and have impact on pharyngeal carriage. However, reactive vaccination still has a role to play taking into account the dynamic changes in the epidemiology of meningitis in this area.

Soil dust aerosols and wind as predictors of seasonal meningitis incidence in Niger.

Background: Epidemics of meningococcal meningitis are concentrated in sub-Saharan Africa during the dry season, a period when the region is affected by the Harmattan, a dry and dusty northeasterly trade wind blowing from the Sahara into the Gulf of Guinea.Objectives: We examined the potential of climate-based statistical forecasting models to predict seasonal incidence of meningitis in Niger at both the national and district levels.Data and methods: We used time series of meningitis incidence from 1986 through 2006 for 38 districts in Niger. We tested models based on data that would be readily available in an operational framework, such as climate and dust, population, and the incidence of early cases before the onset of the meningitis season in January–May. Incidence was used as a proxy for immunological state, susceptibility, and carriage in the population. We compared a range of negative binomial generalized linear models fitted to the meningitis data.Results: At the national level, a model using early incidence in December and averaged November–December zonal wind provided the best fit (pseudo-R2 = 0.57), with zonal wind having the greatest impact. A model with surface dust concentration as a predictive variable performed indistinguishably well. At the district level, the best spatiotemporal model included zonal wind, dust concentration, early incidence in December, and population density (pseudo-R2 = 0.41).Conclusions: We showed that wind and dust information and incidence in the early dry season predict part of the year-to-year variability of the seasonal incidence of meningitis at both national and district levels in Niger. Models of this form could provide an early-season alert that wind, dust, and other conditions are potentially conducive to an epidemic.Citation: Pérez García-Pando C, Stanton MC, Diggle PJ, Trzaska S, Miller RL, Perlwitz JP, Baldasano JM, Cuevas E, Ceccato P, Yaka P, Thomson MC. 2014. Soil dust aerosols and wind as predictors of seasonal meningitis incidence in Niger. Environ Health Perspect 122:679–686; http://dx.doi.org/10.1289/ehp.1306640

Towards Realtime Spatiotemporal Prediction of District Level Meningitis Incidence in Sub-Saharan Africa

Summary Within an area of sub-Saharan Africa termed ‘the meningitis belt’, meningococcal meningitis epidemics are a major public health concern. The epidemic control strategy that is currently utilized is reactive, such that a vaccination programme is initiated in a district once a predefined weekly incidence threshold has been exceeded. We report progress towards the development of an early warning system based on statistical modelling of district level weekly incidence data. Four modelling approaches are considered and their forecasting performances are compared by using weekly epidemiological data from Niger for the period 1986–2007. We conclude that the models under consideration are advantageous in different situations. The three-state Markov model described in which observed incidence is categorized according to policy-defined thresholds gives the most reliable short-term forecasts, whereas the dynamic linear model proposed, using log-transformed weekly incidence as the response variable, gives more reliable predictions of annual epidemics.

Meningococcal Conjugate Vaccine Effective in Chad

Regions of Africa have large, seasonal epidemics of meningococcal meningitis, usually serogroup A. In Chad, epidemics have persisted despite the use of polysaccharide vaccine given in response to outbreaks. Conjugate vaccines offer potential advantages — immunogenicity in young children, induction of immunologic memory, and prevention of pharyngeal carriage. An affordable, monovalent serogroup A polysaccharide–tetanus toxoid conjugate vaccine (PsA-TT) was developed through the Meningitis Vaccine Project, a public–private partnership. Based …

Laboratory evaluation of a rapid diagnostic test for Neisseria meningitidis serogroup A

Epidemics of meningococcal meningitis occur periodically in the African 'meningitis belt' and are mainly, but not only, due to serogroup A. We tested a dipstick as a rapid detection test (RDT) to detect serogroup A using 401 cerebrospinal fluid (CSF) samples. The detection limits were 10(5) CFU/ml with sensitivity and specificity for detecting serogroup A in CSF samples of 88% and 99%, respectively. The new RDT can be used in field surveillance of meningococcal meningitis to help characterize meningitis cases particularly after introduction of the conjugate vaccine against serogroup A.

Epidemic cerebrospinal meningitis in children at Federal Medical Centre, Gusau, Zamfara state, Nigeria

Epidemic meningococcal meningitis is a major public health problem still affecting tropical countries, particularly in Sub-Saharan Africa, which lieswithin African meningitis belt. Repeated large scale epidemics of CSM have been reported in northern Nigeria for the past four decades. It is one of the important causes of morbidity and mortality in these regions. Mortality from the CSM remains high despite advances in treatment modalities. Neisseria meningitidis serogroup A have been the major cause of large scale epidemics in tropical countries, while serogroups B, C, Y and W-135 are responsible for most of invasive disease in America and other developed countries.Objective: To determine the pattern of epidemic CSM in children atFederal Medical Centre, Gusau.Method: The study was a retrospective one carried out in children agedsix months to 12 years admitted into Emergency Paediatrics Unit (EPU) with a diagnosis of CSM within the period January to May, 2009.Results: Seventy- seven children with epidemic CSM were admittedand managed in EPU from January-May 2009.Conclusion: Neisseria meningitidis serogroup A CSM is becoming thedisease of young infants, and stresses the need for inclusion ofCSM vaccine in early infancy in routine immunization policy, in areas within the meningitis belt in Sub-Saharan Africa.

BiotecVisions 2013, February

BiotecVisions 2013, February

Lack of antigenic diversification of major outer membrane proteins during clonal waves ofNeisseria meningitidisserogroup A colonization and disease

In particular in the 'meningitis belt' of sub-Saharan Africa, epidemic meningococcal meningitis is a severe public health problem. In the past decades, serogroup A lineages have been the dominant etiologic agents, but also other serogroups have caused outbreaks. A comprehensive vaccine based on subcapsular outer membrane proteins (OMPs) is not available. Here, we have investigated whether meningococcal populations overcome herd immunity by changing antigenic properties of their OMPs. Meningococcal isolates were collected in the context of longitudinal studies in Ghana between 2002 and 2008 and in Burkina Faso between 2006 and 2007. Serogroup A strains isolated during two clonal waves of colonization and disease showed no diversification in the genes encoding their PorA, PorB, and FetA proteins. However, we detected occasional allelic exchange of opa genes, as well as wide variation in the number of intragenic tandem repeats, showing that phase variation of Opa protein expression is a frequent event. Altogether we observed a remarkable antigenic stability of the PorA, PorB and FetA proteins over years. Our results indicate that while herd immunity may be responsible for the disappearance of meningococcal clones over time, it is not a strong driving force for antigenic diversification of the major OMPs analyzed here.