An Assessment of the Relationship between Built Environment and Socioeconomic Factors with the Incidence of Meningococcal Meningitis in Kaduna Urban Area, Nigeria

Meningococcal meningitis is an airborne disease that has been a threat to human life in many regions of the world, especially in West Africa. The disease has caused permanent physical impairment to some of its victims and many lives have been lost due to the disease. Factors that are associated with the incidence of the disease which are geographically referenced include built environment, geographical location and climatic conditions. Others are socioeconomic and demographic factors. This study established the relationship between built environment and socioeconomic factors with the incidence of the disease. Data that were used include the incidences of the disease from 2007 to 2011, housing conditions, population density, number of house ownership, employment, income level, and the number of hospitals, schools and refuse dumps. Neighborhoods were used as the unit of analysis in the study. The method of analyzing the data includes factor analysis and some statistical techniques in Geographical Information System such as the Ordinary Least Square (OLS). The findings of the study reveal the spatial variations of the incidence of Meningococcal meningitis in Kaduna Urban Area (KUA). The study recommends that there should be strict observance of the development control regulations especially at the high density residential neighborhood. The model can also be used for other communicable disease to ensure the health of the public.

Meningococcal disease, a clinical and epidemiological review

Meningococcal disease is the acute infection caused by Neisseria meningitidis, which has humans as the only natural host. The disease is widespread around the globe and is known for its epidemical potential and high rates of lethality and morbidity. The highest number of cases of the disease is registered in the semi-arid regions of sub-Saharan Africa. In Brazil, it is endemic with occasional outbreaks, epidemics and sporadic cases occurring throughout the year, especially in the winter. The major epidemics of the disease occurred in Brazil in the 70's caused by serogroups A and C. Serogroups B, C and Y represent the majority of cases in Europe, the Americas and Australia. However, there has been a growing increase in serogroup W in some areas. The pathogen transmission happens for respiratory route(droplets) and clinically can lead to meningitis and sepsis(meningococcemia). The treatment is made with antimicrobial and supportive care. For successful prevention, we have some measures like vaccination, chemoprophylaxis and droplets' precautions. In this review, we have described and clarify clinical features of the disease caused by N. meningitidis regarding its relevance for healthcare professionals.

Fatal meningococcal meningitis in a 2-year-old child:A case report

BACKGROUND In fatal cases of meningococcal septicemia, bacteriological diagnosis may not be straightforward due to postmortem replication and relocation of endogenic microflora. In medicolegal practice, aside from routine autopsy and histopathology, also other diagnostic methods, such as microbiological tests,immunohistochemistry and polymerase chain reaction(PCR), are used to examine body fluids and tissues.CASE SUMMARY We present the case of sudden death in a 2-year-old child. The patient died approximately 30 min after hospital admission before any routine diagnostic procedures were undertaken. Presence of whole-body rash and fulminant course of the disease raised suspicion of meningococcal septicemia. An autopsy was performed seven days after death when the body showed the signs of late postmortem decomposition. No etiological factor of septicemia could be identified based on macro-and microscopic findings. However, PCR demonstrated the presence of genetic material of group W Neisseria meningitidis in patient's cerebrospinal fluid and blood.CONCLUSION Microbiological PCR should be conducted postmortem whenever a specific etiological factor could not be identified with conventional methods.

Mandatory meningococcal vaccine, and other recommended immunisations: Uptake, barriers, and facilitators among health care workers and trainees at Hajj

AIM To evaluate the uptake of a mandatory meningococcal, a highly recommended influenza, and an optional pneumococcal vaccine, and to explore the key factors affecting vaccination rate among health care workers(HCWs) during the Hajj.METHODS An anonymous cross-sectional online survey was distributed among HCWs and trainees who worked or volunteered at the Hajj 2015-2017 through their line managers, or by visiting their hospitals and healthcare centres in Makkah and Mina. Overseas HCWs who accompanied the pilgrims or those who work in foreign Hajj medical missions were excluded. Pearson's χ2 test was used to compare categorical variables and odds ratio(OR) was calculated by "risk estimate" statistics along with 95% confidence interval(95%CI).RESULTS A total of 138 respondents aged 20 to 59(median 25.6) years with a male to female ratio of 2.5:1 participated in the survey. Only 11.6%(16/138) participants reported receiving all three vaccines, 15.2%(21/138) did not receive any vaccine, 76.1%(105/138) received meningococcal, 68.1%(94/138) influenza and 13.8%(19/138) pneumococcal vaccine. Females were more likely to receive a vaccine than males(OR 3.6, 95%CI: 1.0-12.7, P < 0.05). Willingness to follow health authority's recommendation was the main reason for receipt of vaccine(78.8%) while believing that they were up-to-date with vaccination(39.8%) was the prime reason for non-receipt. CONCLUSION Some HCWs at Hajj miss out the compulsory and highly recommended vaccines; lack of awareness is a key barrier and authority's advice is an important motivator. Health education followed by stringent measures may be required to improve their vaccination rate.

Antibiotics for eradicating meningococcal carriages:Network meta-analysis and investigation of evidence inconsistency

AIM To compare different antibiotics for eradicating the carriage of Neisseria meningitidis(N.meningitidis),and to investigate heterogeneity and evidence inconsistency.METHODS From a search of Pub Med and published systematic reviews,we identified 23 trials evaluating 15 antibiotics that could be connected in a trial network.The outcome of interest is the eradication of N.meningitidis.We used Win BUGS to conduct random-effects,mixed treatment comparisons.Heterogeneity and evidence inconsistency was investigated by meta-regression modelling and examining characteristics of trial participants and interventions evaluated.RESULTS Rifampin,ciprofloxacin,minocycline,ceftriaxone,and azythromycin were statistically significantly(P<0.05)more effective than placebo.The probability of being the best was 67.0%for a combination of rifampin and minocycline,25.0%for ceftriaxone,1.7%for azythromycin,and below 1%for the remaining regimens.Significant inconsistency between the direct and indirect estimates was observed for the comparison of rifampin and ciprofloxacin(P<0.01),which may becaused by different types of carriers and different doses of ciprofloxacin.CONCLUSION A range of prophylactic antibiotic regimens are effective for eradicating meningococcal carriages,and treatment choice will depend on the individual priorities of the patients and physicians.In clinical situations where complete eradication is considered to be of the utmost importance,a combination of rifampin and minocycline seems to offer the highest likelihood of success.Ceftriaxone as a single intramuscular injection is also likely to be more effective as compared with the other two antibiotics(ciprofloxacin or rifampin)recommended by the current guidelines.

Proteoliposome and Polysaccharide-Based Meningococcal Vaccine Are Immunogenic in Infants and Toddlers and Primes for Memory against Serogroup C Polysaccharide

Neisseria meningitidis capsular polysaccharides are the main target of the protective immune response against bacterial meningitis. They are thymus-independent type 2 (TI-2) antigens that are poorly immunogenic and not protective in young children, and their administration may impair subsequent challenge with the same polysaccharide. These problems have been addressed using three different vaccines consisting of 1) polysaccharide alone, 2) polysaccharide covalently conjugated to a carrier protein, and 3) polysaccharide with Proteoliposome (PL) adsorbed onto Al(OH)3. VA-MENGOC-BC? is one of the third types of vaccine. It contains PL (detergent-extracted external membrane proteins forming vesicles) and polysaccharide (Ps) from N. meningitidis serogroups B and C (PsC), respectively. Nevertheless, there is a concern that to overcome the TI-2 nature of Ps the covalently conjugation to a carrier is mandatory. Therefore, we evaluated the immune response induced by VA-MENGOC-BC? in infants and toddlers in order to determine whether it stimulates the response against the PsC. High IgG anti PsC and anti PL responses were seen following the administration of two doses in infants and toddlers, after a 3rd dose in pre-teenagers, and after confirmed carrier stages in young adults. The anti PL IgG response persisted longer than anti PsC IgG response and IgM response against both antigens was maintained. An IgG1 anti PL response predominated, as well as IgG4 > IgG3 > IgG1 anti PsC responses. These results suggest that non-covalent incorporation of PsC onto Al(OH)3 containing?PL as adjuvant is immunogenic, primes for memory, and induces long-lasting specific antibody response. The improved PsC immunogenicity of this vaccine may be due to the preferential and potent Th1 response induced in mice and human by the PL as adjuvant.

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,TZo.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.

Optimization of the Process for Preparing Bivalent Polysaccharide Conjugates to Develop Multivalent Conjugate Vaccines against Streptococcus pneumoniae or Neisseria meningitidis and Comparison with the Corresponding Licensed Vaccines in Animal Models

Objective:This study aimed to describe,optimize and evaluate a method for preparing multivalent conjugate vaccines by simultaneous conjugation of two different bacterial capsular polysaccharides(CPs)with tetanus toxoid(TT)as bivalent conjugates.Methods:Different molecular weights(MWs)of polysaccharides,activating agents and capsular polysaccharide/protein(CP/Pro)ratio that may influence conjugation and immunogenicity were investigated and optimized to prepare the bivalent conjugate bulk.Using the described method and optimized parameters,a 20-valent pneumococcal conjugate vaccine and a bivalent meningococcal vaccine were developed and their effectiveness was compared to that of corresponding licensed vaccines in rabbit or mouse models.Results:The immunogenicity test revealed that polysaccharides with lower MWs were better for Pn1-TT-Pn3 and MenA-TT-MenC,while higher MWs were superior for Pn4-TT-Pn14,Pn6A-TT-Pn6B,Pn7F-TT-Pn23F and Pn8-TT-Pn11A.For activating polysaccharides,1-cyano-4-dimethylaminopyridinium tetrafluoroborate(CDAP)was superior to cyanogen bromide(CNBr),but for Pn1,Pn3 and MenC,N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride(EDAC)was the most suitable option.For Pn6A-TT-Pn6B and Pn8-TT-Pn11A,rabbits immunized with bivalent conjugates with lower CP/Pro ratios showed significantly stronger CP-specific antibody responses,while for Pn4-TT-Pn14,higher CP/Pro ratio was better.Instead of interfering with the respective immunological activity,our bivalent conjugates usually induced higher IgG titers than their monovalent counterparts.Conclusion:The result indicated that the described conjugation technique was feasible and efficacious to prepare glycoconjugate vaccines,laying a solid foundation for developing extended-valent multivalent or combined conjugate vaccines without potentially decreased immune function.

Vaccinations against respiratory infections in Arabian Gulf countries: Barriers and motivators

AIM To study the uptake, barriers and motivators of influen-za, pneumococcal, meningococcal and pertussis vaccines among members of public in Arabian Gulf countries.METHODS A cross-sectional survey among the Gulf Cooperation Council(GCC) countries' residents. Data collected electronically through a smartphone app. The survey variables aimed to investigate the respondents' awareness about vaccines against influenza, pneumococcal, meningococcal and pertussis infections. Collected data concerning the respondents' socio-demographic characteristics, their perception toward vaccine uptake and the factors that motivate or demotivate them from taking influenza vaccine. The data were analysed statistically using the SPSS v.23.0. Differences in the characteristics of users from different countries were quantified through bivariate analysis. Other important variables and controlling factors were studied using logistic regression. RESULTS A total of 1812 respondents participated in the study. Their mean age was 27 years, 82% were male and 24% had ≥ 1 chronic diseases. The overall uptake of influenza vaccine was 17%(21% among "at risk" people) and ranged from 15% in Saudi Arabia to 24% in Qatar. Doctor's advice(23%) and a perception of having low body immunity(21%) were the main cited reasons for being vaccinated, whereas unawareness about the vaccine(43%) was the main barrier. The overall uptake of pneumococcal vaccine in the preceding three years was 22%(25% among "at risk" individuals) and ranged from 0% in Bahrain to 79% in Kuwait. The overall uptake of pertussis vaccine was 16%(31% among "vulnerable" people), and ranged from 7% in Saudi Arabia to 75% in Oman. The overall uptake of meningococcal vaccine was 20%(29% among the "at risk" people) and ranged from 3% in Oman to 50% in Bahrain.CONCLUSION The vaccination uptake across GCC countries is suboptimal and varies widely across the countries. Further research is needed to unearth the reasons and formulate action plan.

Chronic Meningococcemia

Neisseria meningitidis is a gram-negative diplococcus which causes invasive disease. The most frequent clinical manifestations caused by infection with this pathogen, are meningitis and fulminant septic shock. More benign forms with a subacute or chronic pattern are rare but still can evolve to meningitis and have a fatal outcome. This entity is difficult to recognize, as febrile erythema with otherwise good general condition may simulate other diseases, namely viral infections. The authors reported the cases of two healthy young adults who were misdiagnosed with a viral infection. What they really had was a meningococcemia without meningitis presenting with mild and unspecific symptoms, such as, intermittent fever and a discrete macular rash. We pretend to highlight this rare, unspecific and heterogeneous symptoms which can provoke negligence of a potentially life threatening condition.

Theoretical assessment of the impact of desert aerosols on the dynamical transmission of meningitidis serogroup A

This paper has been motivated by the following biological question: how influential me desert uerosols in the transmission of meningitidis serogroup A (MenA)? A mathematical model for the dynamical transmission of MenA is considered,with the aim of investigating the impact of desert aerosols.Sensitivity analysis of the model has been performed in order to determine the impact of related parameters on meningitis outbreak.We derive the basic reproduction number R0.We prove that there exists a threshold parameter ζ such that when R0 <ζ< 1,the disease-free equilibrium is globally asymptotically stable (GAS).However,when ζ< R0 < 1,the model exhibits the phenomenon of backward bifurcation.At the endemic level,we show that the number of infectious individuals in the presence of desert aerosols is larger than the correspond-ing number without the presence of desert aerosols.In conjunction with the inequality R0^0< R0 where R0^0 is the basic reproduction number without desert aerosols,we found that the ingestion of aerosols by carriers will increase the endemic level,and the severity of the outbreak.This suggests that the control of MenA passes through a combination of a large coverage vaccination of young susceptible individuals and the production of a vaccine with a high level of efficacy as well as respecting the hygienic rules to avoid the inhalation of desert aerosols.Theoretical results are supported by numerical simulations.