Burden of meningitis and other severe bacterial infections of children in africa: implications for prevention

Determinants of mortality among pediatric patients admitted to Wolaita Sodo University Comprehensive Specialized Hospital with acute bacterial meningitis, Southern Ethiopia: an unmatched case-control study

BACKGROUND

People of all ages suffer from acute bacterial meningitis, but children are the most vulnerable, accounting for over 50% of all cases and deaths in children under the age of five. It is the leading cause of morbidity, mortality, and long-term suffering worldwide. Children are at great risk of disease and mortality due to a lack of specific immunity associated with their young age. As a result, determinants of death were found among pediatric patients treated with acute bacterial meningitis at Wolaita Sodo University Comprehensive Specialized Hospital in Southern Ethiopia.

METHODS

A facility-based unmatched case-control study was conducted on pediatric patients admitted with acute bacterial meningitis at Wolaita Sodo University Comprehensive Specialized Hospital from July 1, 2019, to June 30, 2022. A total of 355 (71 cases and 284 controls) pediatric medical charts were used for data extraction using a preestablished checklist. Data were checked for completeness and consistency, entered into Epi-Data version 4.6 software, and transported to SPSS version 25 for analysis. Multivariable logistic regression analysis was performed to identify the independent determinants of acute bacterial meningitis mortality at a P value of < 0.05 along with a 95% confidence interval (CI).

RESULTS

Age between 2 months and 5 years (adjusted odds ratio (AOR) = 3.19, 95% CI = 1.15-8.88), admission in the summer season (AOR = 0.27, 95% CI = 0.15-0.49), and family size greater than or equal to six (AOR = 3.13, 95% CI = 1.76-5.56), initial antibiotic change (AOR = 10.81, 95% CI = 2.10-55.7), clinical features at presentation such as loss of consciousness (AOR = 16.90, 95% CI = 4.70-60.4), abnormal body movements (seizures) (AOR = 6.51, 95% CI = 1.82-23.4), increased intracranial pressure (AOR = 3.63, 95% CI = 1.78-7.4), malnutrition (AOR = 2.98, 95% CI = 1.34-6.59) and presence of more than one comorbidity (AOR = 3.03, 95% CI = 1.03-9.03) were found to be determinants of acute bacterial meningitis mortality.

CONCLUSIONS

In summary, children aged 2 months to 5 years from large families ( > = 6) with a history of initial antibiotic change, malnutrition, more than one comorbidity, and worse clinical characteristics were related to greater death due to acute bacterial mortality in this study.

Comparison of bacterial culture with BioFire® FilmArray® multiplex PCR screening of archived cerebrospinal fluid specimens from children with suspected bacterial meningitis in Nigeria

BACKGROUND

Diagnosis of bacterial meningitis remains a challenge in most developing countries due to low yield from bacterial culture, widespread use of non-prescription antibiotics, and weak microbiology laboratories. The objective of this study was to compare the yield from standard bacterial culture with the multiplex nested PCR platform, the BioFire® FilmArray® Meningitis/Encephalitis Panel (BioFire ME Panel), for cases with suspected acute bacterial meningitis.

METHODS

Following Gram stain and bacterial culture on cerebrospinal fluid (CSF) collected from children aged less than 5 years with a clinical suspicion of acute bacterial meningitis (ABM) as defined by the WHO guidelines, residual CSF specimens were frozen and later tested by BioFire ME Panel.

RESULTS

A total of 400 samples were analyzed. Thirty-two [32/400 (8%)] of the specimens were culture positive, consisting of; three Salmonella spp. (2 Typhi and 1 non-typhi), three alpha hemolytic Streptococcus, one Staphylococcus aureus, six Neisseria meningitidis, seven Hemophilus influenzae, 11 Streptococcus pneumoniae and 368 were culture negative. Of the 368 culture-negative specimens, the BioFire ME Panel detected at least one bacterial pathogen in 90 (24.5%) samples, consisting of S. pneumoniae, N. meningitidis and H. influenzae, predominantly. All culture positive specimens for H. influenzae, N. meningitidis and S. pneumoniae also tested positive with the BioFire ME Panel. In addition, 12 specimens had mixed bacterial pathogens identified. For the first time in this setting, we have data on the viral agents associated with meningitis. Single viral agents were detected in 11 (2.8%) samples while co-detections with bacterial agents or other viruses occurred in 23 (5.8%) of the samples.

CONCLUSIONS

The BioFire® ME Panel was more sensitive and rapid than culture for detecting bacterial pathogens in CSF. The BioFire® ME Panel also provided for the first time, the diagnosis of viral etiologic agents that are associated with meningoencephalitis in this setting. Institution of PCR diagnostics is recommended as a routine test for suspected cases of ABM to enhance early diagnosis and optimal treatment.

Evaluation of Laboratories Supporting Invasive Bacterial Vaccine-Preventable Disease (IB-VPD) Surveillance in the World Health Organization African Region, through the Performance of Coordinated External Quality Assessment

(1) Background: Laboratories supporting the invasive bacteria preventable disease (IB-VPD) network are expected to demonstrate the capacity to identify the main etiological agents of pediatric bacterial meningitis (PBM) (Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae) on Gram stains and in phenotypic identification. Individual reports of sentinel site (SSL), national (NL) and regional reference (RRL) laboratories participating in the World Health Organization (WHO)-coordinated external quality assessment, distributed by the United Kingdom National External Quality Assessment (EQA) Services (UK NEQAS) for Microbiology between 2014 and 2019 were analyzed. (2) Methods: The panels consisted of (1) unstained bacterial smears for Gram staining, (2) viable isolates for identification and serotyping/serogrouping (ST/SG) and (3) simulated cerebral spinal fluid (CSF) samples for species detection and ST/SG using polymerase chain reaction (PCR). SSLs and NLs tested for Gram staining and species identification (partial panel). RRLs, plus any SSLs and NLs (optionally) also analyzed the simulated CSF samples (full panel). The passing score was ≥75% for NLs and SSLs, and ≥90% for RRLs and NLs/SSLs testing the full panel. (3) Results: Overall, 63% (5/8) of the SSLs and NLs were able to correctly identify the targeted pathogens, in 2019; but there were challenges to identify Haemophilus influenzae either on Gram stains (35% of the labs failed 2014), or in culture. Individual performance showed inconsistent capacity, with only 39% (13/33) of the SSLs/NLs passing the EQA exercise throughout all surveys in which they participated. RRLs performed well over the study period, but one of the two failed to reach the minimal passing score in 2016 and 2018; while the SSLs/NLs that optionally tested the full panel scored between 75% and 90% (intermediate pass category). (4) Conclusions: We identified a need for implementing a robust quality management system for timely identification of the gaps and then implementing corrective and preventive actions, in addition to continuous refresher training in the SSLs and NLs supporting the IB-VPD surveillance in the World Health Organization, Regional Office for Africa (WHO AFRO).

Global Burden and Its Association with Socioeconomic Development Status of Meningitis Caused by Specific Pathogens over the Past 30 years: A Population-Based Study

BACKGROUND

Meningitis is a severe and fatal neurological disease and causes lots of disease burden. The purpose of this study was to assess the global, regional, and national burdens and trends of meningitis by age, sex, and etiology.

METHODS

Data on the burden of meningitis were collected from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019. R and Joinpoint were used for statistical analysis and charting.

RESULTS

In 2019, meningitis caused 236,222 deaths and 15,649,865 years of life lost (YLL) worldwide. The age-standardized death rate and age-standardized YLL rate of meningitis were 3.29 and 225, which decreased steadily. Burden change was mainly driven by epidemiological changes. Regionally, meningitis burden was the highest in Sub-Saharan Africa. Burden of disease increasingly concentrated in low sociodemographic index countries, and this was most pronounced in meningitis caused by N. meningitidis. Countries such as Mali, Nigeria, Sierra Leone, etc., especially need to enhance the rational allocation of public health resources to reduce the disease burden. Children and men were more likely to be affected by meningitis. PM2.5 was found to be an important risk factor.

CONCLUSIONS

This study provides the first comprehensive understanding of the global disease burden of meningitis caused by specific pathogens and highlights policy priorities to protect human health worldwide, with particular attention to vulnerable regions, susceptible populations, environmental factors, and specific pathogens.

Diagnosis of Pediatric Stroke in Resource Limited Settings

Global awareness of stroke as a significant cause of neurologic sequelae and death in children has increased over the years as more data in this field becomes available. However, most published literature on pediatric stroke have limited geographic representation. Data on childhood stroke from developing countries remains limited. Thus, this paper reviewed geographic/ethnic differences in pediatric stroke risk factors highlighting those reported in low- and middle-income countries, and proposes a childhood arterial ischemic stroke diagnostic algorithm for resource limited settings. Stroke risk factors include cardiac disorders, infectious diseases, cerebral arteriopathies, hematologic disorders, inflammatory diseases, thrombophilia and genetic conditions. Infection of the central nervous system particularly tuberculous meningitis, is a leading cause of pediatric arterial ischemic stroke in developing countries. Stroke should be considered in children with acute focal neurologic deficit especially in the presence of aforementioned risk factors. Cranial magnetic resonance imaging with angiography is the neuroimaging modality of choice but if unavailable, cranial computed tomography with angiography may be performed as an alternative. If both are not available, transcranial doppler together with neurologic exam may be used to screen children for arterial ischemic stroke. Etiological diagnosis follows with the aid of appropriate laboratory tests that are available in each level of care. International collaborative research on stroke risk factors that are prevalent in low and middle income countries will provide information for drafting of stroke care guidelines that are universal yet inclusive taking into consideration regional differences in available resources with the goal of reducing global stroke burden.

Viral meningitis in Sudanese children: Differentiation, etiology and review of literature

Diagnosis of viral meningitis (VM) is uncommon practice in Sudan and there is no local viral etiological map. We therefore intended to differentiate VM using standardized clinical codes and determine the involvement of herpes simplex virus types-1 and 2 (HSV-1/2), varicella zoster virus, non-polio human enteroviruses (HEVs), and human parechoviruses in meningeal infections in children in Sudan. This is a cross-sectional hospital-based study. Viral meningitis was differentiated in 503 suspected febrile attendee of Omdurman Hospital for Children following the criteria listed in the Clinical Case Definition for Aseptic/Viral Meningitis. Patients were children age 0 to 15 years. Viral nucleic acids (DNA/RNA) were extracted from cerebrospinal fluid (CSF) specimens using QIAamp® UltraSens Virus Technology. Complementary DNA was prepared from viral RNA using GoScriptTM Reverse Transcription System. Viral nucleic acids were amplified and detected using quantitative TaqMan® Real-Time and conventional polymerase chain reactions (PCRs). Hospital diagnosis of VM was assigned to 0%, when clinical codes were applied; we considered 3.2% as having VM among the total study population and as 40% among those with proven infectious meningitis. Two (0.4%) out of total 503 CSF specimens were positive for HSV-1; Ct values were 37.05 and 39.10 and virus copies were 652/PCR run (261 × 103/mL CSF) and 123/PCR run (49.3 × 103/mL CSF), respectively. Other 2 (0.4%) CSF specimens were positive for non-polio HEVs; Ct values were 37.70 and 38.30, and the approximate virus copies were 5E2/PCR run (~2E5/mL CSF) and 2E2/PCR run (~8E4/mL CSF), respectively. No genetic materials were detected for HSV-2, varicella zoster virus, and human parechoviruses. The diagnosis of VM was never assigned by the hospital despite fulfilling the clinical case definition. Virus detection rate was 10% among cases with proven infectious meningitis. Detected viruses were HSV-1 and non-polio HEVs. Positive virus PCRs in CSFs with normal cellular counts were seen.

Caging Cationic Polymer Brush-Coated Plasmonic Nanostructures for Traceable Selective Antimicrobial Activities

Cationic polymers are under intense research to achieve prominent antimicrobial activity. However, the cellular and in vivo toxicity caused by nonspecific electrostatic interaction has become a major challenge for their practical applications. Here, the development of a "caging" strategy based on the use of a block copolymer consisting of a stealth block and an anionic block that undergoes degradation in presence of enzymes secreted by selective bacterial pathogens of interest is reported. The results have shown that antimicrobial cationic polymer brushes-coated gold nanorods (AuNRs) can be caged by the block polymer of poly(ethylene glycol) and anionic, lipase-degradable block of ε-caprolactone and methacrylic acid copolymer to afford neutrally charged surfaces. The caged AuNRs are activated by lipase released by bacteria of interest to endow an excellent bactericidal effect but show minimal binding and toxicity against mammalian cells and nonspecific bacteria that do not produce lipase. In this design, AuNRs play multifunctional roles as the scaffolds for polymer brushes, photothermal transducers, and imaging probes for traceable delivery of the activation and delivery of bactericidal cationic polymer brushes. The caging strategy opens new opportunities for the safe delivery of antimicrobial materials for the treatment of bacterial infections.

Outcome of childhood bacterial meningitis on three continents

Our objective was to quantify the differences in the outcomes from childhood bacterial meningitis (BM) and to describe the factors associated with them in different parts of the world. This study is a secondary analysis of prospectively collected data from five clinical BM trials conducted in Finland, Latin America (LatAm), and Angola between 1984 and 2017. As all data were collected uniformly, direct comparison of the series was possible. Associations between patient characteristics and death or dismal outcome—the triad of death, severe neurological sequelae, or deafness—were explored. In all, data on 2123 children with BM were analyzed. Etiology was confirmed in 95%, 83%, and 64%, in Finland, LatAm and Angola, respectively. The leading agents were Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis. Dismal outcome was the end result for 54%, 31%, and 5% of children in Angola, LatAm, and Finland, respectively. Although underweight, anemia, and tardy arrival worsened prognoses in Angola and LatAm, it was the presenting condition that was central in terms of outcome. In multivariate analysis, the factors independently associated with dismal outcome were the study site (Angola vs. Finland, OR 11.91, 95% CI 5.54–25.63, p < 0.0001 or LatAm vs. Finland, OR 9.46, 95% CI 4.35–20.61, p < 0.0001), Glasgow Coma Score < 13 (OR 4.58, 95% CI 3.31–6.32, p < 0.0001), seizures (OR 1.96, 95% CI 1.43–2.69), age < 1 year (OR 1.55, 95% CI 1.13–2.14, p = 0.007), and pneumococcal etiology (OR 1.49, 95% CI 1.08–2.06, p = 0.015). Greatly dissimilar outcomes from BM reflected the findings on admission on all three continents. Optimizing growth, preventing anemia, and prompt treatment may improve outcomes in resource poor areas.

Epidemiology of Pediatric Meningitis in South Korea From 2010 to 2018: A Population-based Retrospective Cohort Study

BACKGROUND

Studies evaluating the epidemiology of pediatric meningitis are limited in our region. This study aimed to describe recent trends in the incidence of pediatric meningitis.

METHODS

We estimated national trends in hospitalization rates for pediatric meningitis (<18 years) by analyzing data from the Health Insurance Review and Assessment database between 2010 and 2018. Meningitis cases were identified based on International Classification of Diseases, Tenth Revision (ICD-10) codes and hospitalization rates were calculated.

RESULTS

In this national population-based study, a total of 119,644 hospitalizations and 58 deaths due to pediatric meningitis were identified. The hospitalization rates of pediatric bacterial meningitis have declined by 50.0%, from 3.4 per 100,000 in 2010 to 1.7 per 100,000 in 2018. The mortality rates for bacterial and viral meningitis were 2.0% and 0.002%, respectively. Despite the decreased annual incidence of bacterial meningitis, its mortality rate did not change significantly during the study period. The only risk factor identified for mortality in bacterial meningitis patients among age group, sex, region of residence, and season was age below 1 year (P < 0.001). As children under 1 year have a high-mortality rate (4.2%), patients in this age group require close monitoring. The reasons behind indistinct seasonal patterns of bacterial meningitis warrant further investigation.

CONCLUSIONS

Childhood bacterial meningitis has shown a significant decline in incidence from 2010 to 2018. In contrast, viral meningitis has not shown a trend over time. Knowledge of these changes may aid clinicians in the decision-making process and management of meningitis patients.

An overview of bacterial meningitis epidemics in Africa from 1928 to 2018 with a focus on epidemics "outside-the-belt"

Background

Bacterial meningitis occurs worldwide but Africa remains the most affected continent, especially in the "Meningitis belt" that extends from Senegal to Ethiopia. Three main bacteria are responsible for causing bacterial meningitis, i.e., N. meningitidis (Nm), S. pneumoniae and H. influenzae type b. Among Nm, serogroup A used to be responsible for up to 80 to 85% of meningococcal meningitis cases in Africa. Since 2000, other Nm serogroups including W, X and C have also been responsible for causing epidemics. This overview aims to describe the main patterns of meningitis disease cases and pathogens from 1928 to 2018 in Africa with a special focus on disease conditions “out-of-the-belt” area that is still usually unexplored. Based on basic spatio-temporal methods, and a 90-years database of reported suspected meningitis cases and death from the World Health Organization, we used both geographic information system and spatio-temporal statistics to identify the major localizations of meningitis epidemics over this period in Africa.

Results

Bacterial meningitis extends today outside its historical limits of the meningitis belt. Since the introduction of MenAfrivac vaccine in 2010, there has been a dramatic decrease in NmA cases while other pathogen species and Nm variants including NmW, NmC and Streptococcus pneumoniae have become more prevalent reflecting a greater diversity of bacterial strains causing meningitis epidemics in Africa today.

Conclusion

Bacterial meningitis remains a major public health problem in Africa today. Formerly concentrated in the region of the meningitis belt with Sub-Saharan and Sudanian environmental conditions, the disease extends now outside these historical limits to reach more forested regions in the central parts of the continent. With global environmental changes and massive vaccination targeting a unique serogroup, an epidemiological transition of bacterial meningitis is ongoing, requiring both a better consideration of the etiological nature of the responsible agents and of their proximal and distal determinants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06724-1.

Prevalence and characteristics of children with otitis media with effusion in Vietnam

PURPOSE

Otitis media with effusion (OME) commonly occurs and persists in young children. It can cause hearing impairment and damage to the tympanic membrane without treatment. We aimed to determine the prevalence and association of Streptococcus pneumoniae in the nasopharynx of healthy children before the introduction of a pneumococcal conjugate vaccine.

METHODS

In October 2016, nasopharyngeal swabs collection and otoscope examinations by an otolaryngologist were conducted in children aged less than 24 months in Nha Trang, Vietnam. OME was diagnosed as the presence of middle ear fluid using a digital otoscope equipped with a pneumatic otoscope. Quantitative PCR targeting pneumococci-specific lytA (the major autolysis gene) and bacterial culture were performed to detect S. pneumoniae. The point prevalence of OME in the study area was estimated. The association between OME and S. pneumoniae in the nasopharynx was evaluated using a multivariable logistic regression model.

RESULTS

Among the 274 children who underwent bilateral ear examinations and nasopharyngeal swab collections, 47 had OME (17.2%, 95% confidence interval [CI] 12.9-22.1%) and 96 were colonized with S. pneumoniae (35.0%, 29.4-41.0%). OME and nasopharyngeal S. pneumoniae carriage were positively associated in children aged less than 12  months (adjusted odds ratio [aOR] 3.83, 1.40-10.51). Day-care attendance and living in a rural area were independently associated with OME (aOR 5.87, 2.31-14.91, and aOR 3.77, 1.58-8.99, respectively).

CONCLUSIONS

The nasopharyngeal pneumococcal carriage was associated with OME among children aged  <12 months. A further study after introducing a pneumococcal conjugate vaccine (PCV) is required to better understand the effect of PCV and S. pneumoniae carriage on OME in young children.

Prevalence of Streptococcus pneumoniae in conjunctival flora and association with nasopharyngeal carriage among children in a Vietnamese community

Conjunctival pneumococcal serotypes among members of a community have not been investigated well. We determined the prevalence and association of Streptococcus pneumoniae in the nasopharynx and conjunctiva among children in a community before pneumococcal conjugate vaccine introduction. In October 2016, conjunctival and nasopharyngeal swabs were collected from children (< 24 months old) and nasopharyngeal swabs from mothers in Nha Trang, Vietnam. Quantitative lytA PCR and DNA microarray were performed to detect and serotype S. pneumoniae. The association between S. pneumoniae in the nasopharynx and conjunctiva was evaluated using multivariable logistic regression model. Among 698 children, 62 (8.9%, 95% CI 6.9-11.2%) were positive for S. pneumoniae in the conjunctiva. Non-encapsulated S. pneumoniae were most commonly identified, followed by serotypes 6A, 6B, and 14. Nasopharyngeal and conjunctival detection were positively associated (aOR 47.30, 95% CI 24.07-92.97). Low birth-weight, day-care attendance, and recent eye symptoms were independently associated with S. pneumoniae detection in the conjunctiva (aOR 11.14, 95% CI 3.76-32.98, aOR 2.19, 95% CI 1.45-3.31, and aOR 3.59, 95% CI 2.21-5.84, respectively). Serotypes and genotypes in the conjunctiva and nasopharynx matched in 87% of the children. Three mothers' nasopharyngeal pneumococcal samples had matched serotype and genotype with their child's in the conjunctiva and nasopharynx. S. pneumoniae presence in nasopharynx and conjunctiva were strongly associated. The high concordance of serotypes suggests nasopharyngeal carriage may be a source of transmission to the conjunctiva.

Declines in Pediatric Bacterial Meningitis in the Republic of Benin Following Introduction of Pneumococcal Conjugate Vaccine: Epidemiological and Etiological Findings, 2011-2016

BACKGROUND

Pediatric bacterial meningitis (PBM) remains an important cause of disease in children in Africa. We describe findings from sentinel site bacterial meningitis surveillance in children <5 years of age in the Republic of Benin, 2011-2016.

METHODS

Cerebrospinal fluid (CSF) was collected from children admitted to Parakou, Natitingou, and Tanguieta sentinel hospitals with suspected meningitis. Identification of Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, and Neisseria meningitidis (meningococcus) was performed by rapid diagnostic tests, microbiological culture, and/or polymerase chain reaction; where possible, serotyping/grouping was performed.

RESULTS

A total of 10 919 suspected cases of meningitis were admitted to the sentinel hospitals. Most patients were 0-11 months old (4863 [44.5%]) and there were 542 (5.0%) in-hospital deaths. Overall, 4168 CSF samples were screened for pathogens and a total of 194 (4.7%) PBM cases were confirmed, predominantly caused by pneumococcus (98 [50.5%]). Following pneumococcal conjugate vaccine (PCV) introduction in 2011, annual suspected meningitis cases and deaths (case fatality rate) progressively declined from 2534 to 1359 and from 164 (6.5%) to 14 (1.0%) in 2012 and 2016, respectively (P < .001). Additionally, there was a gradual decline in the proportion of meningitis cases caused by pneumococcus, from 77.3% (17/22) in 2011 to 32.4% (11/34) in 2016 (odds ratio, 7.11 [95% confidence interval, 2.08-24.30]). Haemophilus influenzae meningitis fluctuated over the surveillance period and was the predominant pathogen (16/34 [47.1%]) by 2016.

CONCLUSIONS

The observed decrease in pneumococcal meningitis after PCV introduction may be indicative of changing patterns of PBM etiology in Benin. Maintaining vigilant and effective surveillance is critical for understanding these changes and their wider public health implications.

Otitis Media-associated Bacterial Meningitis in Children in a Low-income Country

BACKGROUND

Otitis media (OM) is a common childhood infection that may result in bacterial meningitis (BM). However, OM-associated BM remains poorly characterized. We aimed to study the occurrence, clinical presentation and outcome of this type of childhood BM in Luanda, Angola.

METHODS

Five hundred twelve children from our previous clinical BM trial, with the ear meticulously examined, were analyzed whether they had or not OM, and according to their age, ≤12 month old and >12 month old. Prospectively collected clinical data, laboratory test results and outcome for these groups were assessed.

RESULTS

Sixty-two children (12%) had OM-associated BM, of whom 39 had otorrhea. Ear discharge was more common in older children (median age 45 months old vs. 12 months old; P < 0.001). Children with OM often showed an additional infectious focus (n = 20, 32% vs. n = 82, 18%; P = 0.016), were dehydrated (n = 16, 26% vs. n = 66, 15%; P = 0.04), and showed higher odds of complicated clinical course or death (odds ratios 2.27, 95% CI: 1.004-5.15, P = 0.049) compared with children without OM. The >12-month-old children with OM often arrived in poor clinical condition with coma and/or ptosis. Otorrhea was associated with HIV positivity. Infants with otorrhea frequently lived under poor socioeconomic conditions.

CONCLUSIONS

Children with OM-associated BM were prone to many problems, such as being especially ill at presentation, undergoing a difficult clinical course and showing a higher risk of complicated or fatal outcome. HIV infection and malnutrition were common in children with otorrhea, which was also associated with low socioeconomic status.

Diagnosis of bacterial meningitis in Ghana: Polymerase chain reaction versus latex agglutination methods

Bacterial meningitis is a public health crisis in the northern part of Ghana, where it contributes to very high mortality and morbidity rates. Early detection of the causative organism will lead to better management and effective treatment. Our aim was to evaluate the diagnostic accuracy of Pastorex and Wellcogen latex agglutination tests for the detection of bacterial meningitis in a resource-limited setting. CSF samples from 330 suspected meningitis patients within the northern zone of Ghana were analysed for bacterial agents at the zonal Public Health Reference Laboratory in Tamale using polymerase chain reaction (PCR) and two latex agglutination test kits; Pastorex and Wellcogen. The overall positivity rate of samples tested for bacterial meningitis was 46.4%. Streptococcus pneumoniae was the most common cause of bacterial meningitis within the sub-region, with positivity rate of 25.2%, 28.2% and 28.8% when diagnosed using Wellcogen, Pastorex and PCR respectively. The Pastorex method was 97.4% sensitive while the Wellcogen technique was 87.6% sensitive. Both techniques however produced the same specificity of 99.4%. Our study revealed that the Pastorex method has a better diagnostic value for bacterial meningitis than the Wellcogen method and should be the method of choice in the absence of PCR.

Goal directed therapy for suspected acute bacterial meningitis in adults and adolescents in sub-Saharan Africa

Background

Mortality from acute bacterial meningitis (ABM) in sub-Saharan African adults and adolescents exceeds 50%. We tested if Goal Directed Therapy (GDT) was feasible for adults and adolescents with clinically suspected ABM in Malawi.

Materials and methods

Sequential patient cohorts of adults and adolescents with clinically suspected ABM were recruited in the emergency department of a teaching hospital in Malawi using a before/after design. Routine care was monitored in year one (P1). In year two (P2), nurses delivered protocolised GDT (rapid antibiotics, airway support, oxygenation, seizure control and fluid resuscitation) to a second cohort. The primary endpoint was composite mean number of clinical goals attained. Secondary endpoints were individual goals attained and death or disability from proven or probable ABM at day 40.

Results

563 patients with suspected ABM were enrolled in the study; 273 were monitored in P1; 290 patients with suspected ABM received GDT in P2. 61% were male, median age 33 years and 90% were HIV co-infected. ABM was proven or probable in 132 (23%) patients. GDT attained more clinical goals compared to routine care: composite mean number of goals in P1 was 0·55 vs. 1·57 in P2 GDT (p<0·001); Death or disability by day 40 from proven or probable ABM occurred in 29/57 (51%) in P1 and 38/60 (63%) in P2 (p = 0·19).

Conclusion

Nurse-led GDT in a resource-constrained setting was associated with improved delivery of protocolised care. Outcome was unaffected.

Trial registration

www.isrctn.comISRCTN96218197

Prevalence, causes, and behavioral and emotional comorbidities of acute symptomatic seizures in Africa: A critical review

Seizures with fever includes both febrile seizures (due to nonneurological febrile infections) and acute symptomatic seizures (due to neurological febrile infections). The cumulative incidence (lifetime prevalence) of febrile seizures in children aged ≤6 years is 2-5% in American and European studies, but there are no community-based data on acute symptomatic seizures in Africa. The incidence of acute symptomatic seizures in sub-Saharan Africa is more than twice that in high-income countries. However, most studies of acute symptomatic seizures from Africa are based on hospital samples or do not conduct surveys in demographic surveillance systems, which underestimates the burden. It is difficult to differentiate between febrile seizures and acute symptomatic seizures in Africa, especially in malaria-endemic areas where malaria parasites can sequester in the brain microvasculature; but this challenge can be addressed by robust identification of underlying causes. The proportion of complex acute symptomatic seizures (i.e., seizures that are focal, repetitive, or prolonged) in Africa are twice that reported in other parts of the world (>60% vs. ∼30%), which is often attributed to falciparum malaria. These complex phenotypes of acute symptomatic seizures can be associated with behavioral and emotional problems in high-income countries, and outcomes may be even worse in Africa. One Kenyan study reported behavioral and emotional problems in approximately 10% of children admitted with acute symptomatic seizures, but it is not clear whether the behavioral and emotional problems were due to the seizures, shared genetic susceptibility, etiology, or underlying neurological damage. The underlying neurological damage in acute symptomatic seizures can lead not only to behavioral and emotional problems but also to neurocognitive impairment and epilepsy. Electroencephalography may have a prognostic role in African children with acute symptomatic seizures. There are significant knowledge gaps regarding acute symptomatic seizures in Africa, which results in lack of reliable estimates for planning interventions. Future epidemiological studies of acute symptomatic seizures should be set up in Africa.

A dynamic relationship between mucosal T helper type 17 and regulatory T-cell populations in nasopharynx evolves with age and associates with the clearance of pneumococcal carriage in humans

Pneumococcal carriage is common in young children, which may account for the high incidence of disease in this age group. Host factors determining the clearance of carriage in humans remain unclear. We aimed to study the relationships between T helper type 17 (Th17) and Foxp3(+) regulatory T (Treg) cells in nasopharynx-associated lymphoid tissue (NALT) and carriage in children and adults. Frequencies of Th17 and Treg cells in NALT were analysed by flow cytometry in association with age and pneumococcal carriage status. Cytokine responses following pneumococcal stimulation were analysed by cytometric beads array. The frequencies of Th17 and Treg cells in NALT were inversely correlated (R -0.60). Whereas Treg cell frequency decreased with age (R -0.63), both Th17 and the Th17: Treg ratio increased with age (R 0.62 and R 0.64, respectively). Also, the Th17: Treg ratio was higher in carriage-negative than in carriage-positive children (p <0.01). Pneumococcal stimulation of tonsillar cells increased both Th17 and Treg cell numbers, but the Th17: Treg ratio and pattern of cytokine responses differed between carriage-negative and carriage-positive children. The former showed markedly higher Th17: Treg and interleukin-17A: interleukin-10 ratios than in the latter (p <0.01). Pneumococcal stimulation also induces Th17, although the capacity of this Th17 differentiation from naive T cells of young children was low, but increased with age. We demonstrated a dynamic relationship between Th17 and Treg cells in human nasopharynx that evolves with age. The balance between Th17 and Treg cells in NALT appears to be a major host factor closely associated with the clearance of Streptococcus pneumoniae from the nasopharynx.

Understanding Bacterial Isolates in Blood Culture and Approaches Used to Define Bacteria as Contaminants: A Literature Review

BACKGROUND

Interpretation of blood culture isolates is challenging due to a lack of standard methodologies for identifying contaminants. This problem becomes more complex when the specimens are from sick young infants, as a wide range of bacteria can cause illness among this group.

METHODS

We used 43 key words to find articles published between 1970 and 2011 on blood culture isolates and possible contaminants in the PubMed database. Experts were also consulted to obtain other relevant articles. Selection of articles followed systematic methods considering opinions from more than 1 reviewer.

RESULTS

After reviewing the titles of 3869 articles extracted from the database, we found 307 relevant to our objective. Based on the abstracts, 42 articles were selected for the literature review. In addition, we included 7 more articles based on cross-references and expert advice. The most common methods for differentiating blood culture isolates were multiple blood cultures from the same subject, antibiograms and molecular testing. Streptococcus pneumoniae, Hemophilus influenzae, Neisseria meningitidis and group A and B streptococcus were always considered as pathogens, whereas Bacillus sp., Diphtheroids, Propionibacterium and Micrococcus were commonly regarded as contaminants. Coagulase-negative staphylococci were the most frequent isolates and usually reported as contaminants unless the patient had a specific condition, such as long-term hospitalization or use of invasive devices (catheters).

CONCLUSIONS

Inaccurate interpretation of blood culture may falsely guide treatment and also has long-term policy implications. The combination of clinical and microbiological knowledge, patient's clinical history and laboratory findings are essential for appropriate interpretation of blood culture.

Trend, features and outcome of meningitis in the Communicable Diseases hospital, Alexandria, Egypt, 1997-2006

BACKGROUND

Following vaccine introduction, long-term epidemiological changes have been occurred in meningitis. Studying these changes is of practical importance for both public health planning and clinical management.

OBJECTIVES

To study trend in meningitis in Alexandria, Egypt (1997-2006) as well patients' characteristics and outcome.

MATERIALS AND METHODS

The descriptive epidemiologic approach was adopted. Study population was all discharge records and computer files of meningitis admissions to the Communicable Diseases Hospital in Alexandria, Egypt, 1997-2006. Outcome measures were age, number and percentage of patients, organisms proportions and case fatality.

RESULTS

The study included 1210 recorded meningitis cases. Patients had a mean age of 22.26 years and a male to female ratio of 1.8 : 1. Study started with a sharp descent of yearly admissions (1997-1999) and ended by a sharp increase (2004-2006). Cases insignificantly increased during autumn through spring. Neisseria meningitidis was the dominant pathogen (28.9%) in all years. Mycobacterium tuberculosis (MTB) was the second common agent (11.6%) with a decreasing frequency till 2000. Streptococcus pneumoniae was responsible for 8.9% of cases. Group B Streptococci and Haemophilus influenzae type b caused 2.8% and 2.4% of cases respectively. Both had a declining trend. Other bacteria (gram negative bacteria, non specific streptococci and staphylococci) was isolated in 2.7% whereas no organism could be identified in 45.6% of specimens. All agent differences were statistically significant where P<0.001. The mean hospital stay was 14.95 days. Overall case fatality was 17.6%. The most lethal was other bacteria [Odds Ratio=6.0, 95% Confidence interval=3.0-12.2]. Fatal outcome was predicted by short hospital stay (regression coefficient(r)=-0.17, P<0.001), diagnosis of other bacterial (r=1.75, P<0.001), pneumococcal (r=0.66, P=0.02) or tuberculous meningitis (r=0.59, P=0.04) and being an elderly (r=1.80, P<0.001) or an adult (r=1.03, P<0.001).

CONCLUSION

Neisseria remained the main etiologic agent of meningitis. TB emerged as the second pathogen. Rate of bacterial un-detection was high. Mean age of meningitis had shifted to adult age. Other bacteria, pneumococci, MTB and advanced age were important predictors for mortality.

Frequency of Pathogenic Paediatric Bacterial Meningitis in Mozambique: The Critical Role of Multiplex Real-Time Polymerase Chain Reaction to Estimate the Burden of Disease

BACKGROUND

In Sub-Saharan Africa, including Mozambique, acute bacterial meningitis (ABM) represents a main cause of childhood mortality. The burden of ABM is seriously underestimated because of the poor performance of culture sampling, the primary method of ABM surveillance in the region. Low quality cerebrospinal fluid (CSF) samples and frequent consumption of antibiotics prior to sample collection lead to a high rate of false-negative results. To our knowledge, this study is the first to determine the frequency of ABM in Mozambique using real-time polymerase chain reaction (qPCR) and to compare results to those of culture sampling.

METHOD

Between March 2013 and March 2014, CSF samples were collected at 3 regional hospitals from patients under 5 years of age, who met World Health Organization case definition criteria for ABM. Macroscopic examination, cytochemical study, culture, and qPCR were performed on all samples.

RESULTS

A total of 369 CSF samples were collected from children clinically suspected of ABM. qPCR showed a significantly higher detection rate of ABM-causing pathogens when compared to culture (52.3% [193/369] versus 7.3% [27/369], p = 0.000). The frequency of Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococci, and Neisseria meningitidis were 32.8% (121⁄369), 12.2%, (45⁄369), 3.0% (16⁄369) and 4.3% (11⁄369), respectively, significantly higher compared to that obtained on culture (p < 0.001 for each).

CONCLUSION

Our findings demonstrate that culture is less effective for the diagnosis of ABM than qPCR. The common use of culture rather than qPCR to identify ABM results in serious underestimation of the burden of the disease, and our findings strongly suggest that qPCR should be incorporated into surveillance activities for ABM. In addition, our data showed that S. pneumoniae represents the most common cause of ABM in children under 5 years of age.

In vivo efficacy and molecular docking of designed peptide that exhibits potent antipneumococcal activity and synergises in combination with penicillin

We have previously designed a series of antimicrobial peptides (AMPs) and in the current study, the in vivo therapeutic efficacy and toxicity were investigated. Among all the peptides, DM3 conferred protection to a substantial proportion of the lethally infected mice caused by a strain of penicillin-resistant Streptococcus pneumoniae. Synergism was reported and therapeutic efficacy was significantly enhanced when DM3 was formulated in combination with penicillin (PEN). No toxicity was observed in mice receiving these treatments. The in silico molecular docking study results showed that, DM3 has a strong affinity towards three protein targets; autolysin and pneumococcal surface protein A (pspA). Thus AMPs could serve as supporting therapeutics in combination with conventional antibiotics to enhance treatment outcome.

Accuracy of cerebrospinal leucocyte count, protein and culture for the diagnosis of acute bacterial meningitis: a comparative study using Bayesian latent class analysis

OBJECTIVE

To examine the utility of laboratory methods other than bacterial culture in diagnosing acute bacterial meningitis (ABM).

METHODS

Bayesian latent class analysis was used to estimate diagnostic precision of cerebrospinal fluid (CSF) culture, leucocyte counts and protein concentrations for ABM in Melanesian children.

RESULTS

With a cut-off of ≥20 leucocytes/mm(3) , the area under the receiver operating characteristic curve (AUC ROC) was >97.5% for leucocyte counts. A lower (93%) AUC ROC was observed for CSF protein concentrations ≥1 g/l. CSF culture had poor sensitivity and high specificity.

CONCLUSION

Leucocyte counts provide sufficient diagnostic precision to aid clinical decision-making in ABM.

Accuracy of initial clinical diagnosis of acute bacterial meningitis in children from a malaria-endemic area of Papua New Guinea

BACKGROUND

The diagnosis of acute bacterial meningitis (ABM) is challenging in resource-limited settings where cerebral malaria and viral encephalitis are also common.

METHODS

To assess the accuracy of an initial clinical diagnosis of ABM in a malaria-endemic area of Papua New Guinea (PNG), a retrospective chart review of hospitalized children aged 2 months to 10 years was conducted.

RESULTS

Of the 481 eligible children, 240 had an initial clinical diagnosis of ABM that was confirmed independently by trained research staff under standardized conditions, with laboratory support in only 84 (17.5%; 84/481). When compared with the final laboratory-confirmed diagnosis, an initial diagnosis of ABM had a sensitivity, specificity, positive predictive value and negative predictive value of 76% (95% CI 66-85%), 56% (95% CI 51-61%), 27% (95% CI 21-33) and 92% (95% CI 87-95%), respectively. There was discordance between initial and final diagnosis of ABM in 196 children; 176 initially considered to have ABM had an alternative diagnosis, while 20 without an initial diagnosis of ABM were confirmed to have ABM.

CONCLUSION

These data show that initial misdiagnosis of ABM is common in a malaria-endemic area of PNG. A diagnostic algorithm using standardized assessment for meningeal irritation, coma and malaria parasitological testing needs further evaluation in this setting.

Bacterial meningitis in Malawian adults, adolescents, and children during the era of antiretroviral scale-up and Haemophilus influenzae type b vaccination, 2000-2012

BACKGROUND

We documented bacterial meningitis trends among adults and children presenting to a large teaching hospital in Malawi during introduction of Haemophilus influenzae type b (Hib) vaccination and the rollout of antiretroviral therapy (ART).

METHODS

We analyzed data from 51 000 consecutive cerebrospinal fluid (CSF) samples obtained from adults, adolescents, and children with suspected meningitis admitted to the Queen Elizabeth Central Hospital, Blantyre, Malawi, between 2000 and 2012.

RESULTS

There was a significant decline in the total number of CSF isolates over 12 years (incident rate ratio [IRR], 0.93; 95% CI, .92-.94; P < .001). This decline was entirely in children aged <5 years (IRR, 0.87; 95% CI, .85-.88; P < .001) and coincided with the introduction of Hib vaccination. The number of adult isolates has remained unchanged (IRR, 0.99; 95% CI, .97-1.0; P = .135) despite rapid scale-up of ART provision. In children aged <5 years, Streptococcus pneumoniae, nontyphoidal salmonellae (NTS), and Hib were the most frequently isolated pathogens, and have declined over this time period. Streptococcus pneumoniae was the most frequently isolated pathogen in older children and adults. Estimated incidence of bacterial meningitis in 2012 was 20 per 100,000 cases in children aged <14 years, 6 per 100,000 adolescents, and 10 per 100,000 adults.

CONCLUSIONS

Rates of bacterial meningitis have declined in children, but not adults, coinciding with the introduction of Hib vaccination. The highly successful rollout of ART has not yet resulted in a reduction in the incidence in adults where the burden remains high. Long-term surveillance of bacterial meningitis outside of the epidemic "meningitis belt" in Africa is essential.

Activation of memory Th17 cells by domain 4 pneumolysin in human nasopharynx-associated lymphoid tissue and its association with pneumococcal carriage

Pneumococcal carriage is common in children that may account for the high incidence of disease in this age group. Recent studies in animals suggest an important role for CD4+ T cells, T helper type 17 (Th17) cells in particular, in pneumococcal clearance. Whether this Th17-mediated mechanism operates in humans and what pneumococcal components activate Th17 are unknown. We investigated the ability of domain 4 pneumolysin (D4Ply) to activate CD4+ T cells including Th17 in human nasopharynx-associated lymphoid tissue (NALT) and peripheral blood. We show that D4Ply elicited a prominent CD4+ T-cell proliferative response. More importantly, D4Ply elicited a significant memory Th17 response in NALT, and a moderate response in peripheral blood mononuclear cells (PBMCs). This D4Ply-elicited memory Th17 response was more marked in carriage- than in carriage+ children in both NALT and PBMCs. In contrast, no difference was shown in D4Ply-induced Th1 response between the two groups. We also show D4Ply activated human monocytes and murine macrophages that was in part dependent on Toll-like receptor 4 (TLR-4). Our results support a protective role of Th17 against pneumococcal carriage in human nasopharynx, and identify a novel property of D4Ply to activate Th17 in NALT that may offer an attractive vaccine candidate in intranasal immunization against pneumococcal infection.

Role of Clinical Presentations and Routine CSF Analysis in the Rapid Diagnosis of Acute Bacterial Meningitis in Cases of Negative Gram Stained Smears

Background and Aim. Bacterial meningitis is a lethal, disabling endemic disease needing prompt antibiotic management. Gram stained smears is rapid accurate method for diagnosis of bacterial meningitis. In cases of negative gram stained smears diagnosis is delayed till culture results. We aim to assess the role of clinical presentations and routine CSF analysis in the cost-effective rapid diagnosis of negative gram stained smears bacterial meningitis. Methods. Cross sectional study including 623 acute meningitis patients divided into two groups: bacterial meningitis and nonbacterial meningitis groups. The clinical presentations, systemic inflammatory parameters, and CSF analysis were evaluated and compared in both groups. Results. Altered conscious level, localizing neurological signs, Kernig's and Brudzinski's signs together with peripheral leucocytosis (>10.000/mm(3)), high CRP (>6) together with high CSF protein (>50 gl/dL), CSF neutrophilic count (≥50% of total CSF leucocytic count), and low CSF glucose level (<45 gm/dL) and CSF/serum glucose ≤0.6 were significantly diagnostic in bacterial meningitis patients. From the significant CSF analysis variables CSF protein carried the higher accuracy of diagnosis 78% with sensitivity 88% and specificity 72%. Conclusions. High CSF protein (>50 mg/dL) together with plasma inflammatory markers and CSF cytochemical parameters can diagnose bacterial meningitis in gram stain negative smear till culture results.

The economic burden of meningitis to households in Kassena-Nankana district of Northern Ghana

OBJECTIVE

To estimate the direct and indirect costs of meningitis to households in the Kassena-Nankana District of Ghana.

METHODS

A Cost of illness (COI) survey was conducted between 2010 and 2011. The COI was computed from a retrospective review of 80 meningitis cases answers to questions about direct medical costs, direct non-medical costs incurred and productivity losses due to recent meningitis incident.

RESULTS

The average direct and indirect costs of treating meningitis in the district was GH¢152.55 (US$101.7) per household. This is equivalent to about two months minimum wage earned by Ghanaians in unskilled paid jobs in 2009. Households lost 29 days of work per meningitis case and thus those in minimum wage paid jobs lost a monthly minimum wage of GH¢76.85 (US$51.23) due to the illness. Patients who were insured spent an average of GH¢38.5 (US$25.67) in direct medical costs whiles the uninsured patients spent as much as GH¢177.9 (US$118.6) per case. Patients with sequelae incurred additional costs of GH¢22.63 (US$15.08) per case. The least poor were more exposed to meningitis than the poorest.

CONCLUSION

Meningitis is a debilitating but preventable disease that affects people living in the Sahel and in poorer conditions. The cost of meningitis treatment may further lead to impoverishment for these households. Widespread mass vaccination will save households' an equivalent of GH¢175.18 (US$117) and impairment due to meningitis.

Clinical features, proximate causes, and consequences of active convulsive epilepsy in Africa

PURPOSE

Epilepsy is common in sub-Saharan Africa (SSA), but the clinical features and consequences are poorly characterized. Most studies are hospital-based, and few studies have compared different ecological sites in SSA. We described active convulsive epilepsy (ACE) identified in cross-sectional community-based surveys in SSA, to understand the proximate causes, features, and consequences.

METHODS

We performed a detailed clinical and neurophysiologic description of ACE cases identified from a community survey of 584,586 people using medical history, neurologic examination, and electroencephalography (EEG) data from five sites in Africa: South Africa; Tanzania; Uganda; Kenya; and Ghana. The cases were examined by clinicians to discover risk factors, clinical features, and consequences of epilepsy. We used logistic regression to determine the epilepsy factors associated with medical comorbidities.

KEY FINDINGS

Half (51%) of the 2,170 people with ACE were children and 69% of seizures began in childhood. Focal features (EEG, seizure types, and neurologic deficits) were present in 58% of ACE cases, and these varied significantly with site. Status epilepticus occurred in 25% of people with ACE. Only 36% received antiepileptic drugs (phenobarbital was the most common drug [95%]), and the proportion varied significantly with the site. Proximate causes of ACE were adverse perinatal events (11%) for onset of seizures before 18 years; and acute encephalopathy (10%) and head injury prior to seizure onset (3%). Important comorbidities were malnutrition (15%), cognitive impairment (23%), and neurologic deficits (15%). The consequences of ACE were burns (16%), head injuries (postseizure) (1%), lack of education (43%), and being unmarried (67%) or unemployed (57%) in adults, all significantly more common than in those without epilepsy.

SIGNIFICANCE

There were significant differences in the comorbidities across sites. Focal features are common in ACE, suggesting identifiable and preventable causes. Malnutrition and cognitive and neurologic deficits are common in people with ACE and should be integrated into the management of epilepsy in this region. Consequences of epilepsy such as burns, lack of education, poor marriage prospects, and unemployment need to be addressed.

Risk factors for death and severe sequelae in Malawian children with bacterial meningitis, 1997-2010

BACKGROUND

Acute bacterial meningitis (ABM) causes significant death and disability in children worldwide, with HIV recognized as an established risk factor for infection and negative outcomes. However, additional major risk factors for death and disability in pediatric ABM remain unclear.

METHODS

We conducted a retrospective analysis of case data from 3 departmental studies of ABM involving 1784 children <15 years old who attended Queen Elizabeth Central Hospital in Blantyre, Malawi during 1997 to 2010. Univariate and multivariate logistic regression models were used to estimate the effects of HIV seropositivity, impaired consciousness and causative organism on death and severe sequelae.

RESULTS

Impaired consciousness or coma at the time of admission was strongly associated with death (coma: odds ratio [OR] = 14.4, 95% confidence interval [CI]: 9.42, 22.1) and severe sequelae (Coma: OR = 3.27, 95% CI: 2.02, 5.29) in multivariate logistic regression models. HIV seropositivity was significantly associated with increased odds of death (OR = 1.65, 95% CI: 1.20, 2.26) but not with developing severe sequelae (OR = 0.88, 95% CI: 0.56, 1.38). After adjustment, infection with Salmonella spp. was associated with increased odds of death (OR = 2.11, 95% CI: 1.06, 4.08) and pneumococcal meningitis was associated with increased odds of severe sequelae (OR = 1.84, 95% CI: 1.03, 3.29).

CONCLUSIONS

Impaired consciousness and HIV infection increased the odds of death from ABM in Malawian children. Use of pneumococcal conjugate vaccine could greatly reduce the burden of ABM in Malawi.

The changing profile of pediatric meningitis at a referral centre in Cape Town, South Africa

BACKGROUND

Pediatric meningitis remains a common cause of childhood morbidity and mortality in developing countries. Knowledge of the causative organisms in a region is of importance in guiding empiric antibiotic regimes and immunization schedules assisting decisions on primary health-care interventions.

METHODS

This retrospective review of 557 meningitis cases represents a third pediatric survey conducted over a 3-year period (January 2007 to December 2009) at the same institution and after an interval of 14 years. Cases were identified using cerebrospinal fluid results. Demographic and laboratory variables were collected and meningitis was classified as aseptic/viral, bacterial, septic, tuberculous meningitis (TBM) or fungal.

RESULTS

The commonest form of bacterial meningitis was TBM diagnosed in 22% (n = 126) of children. Streptococcus pneumoniae 4% (n = 23) and Klebsiella pneumoniae 3% (n = 17) were the next commonest causes of bacterial meningitis diagnosed. Haemophilus influenzae meningitis occurred in <1% (n = 3) of cases with a median age of 3 months. Aseptic meningitis remains the commonest category. Human immunodeficiency virus (HIV) testing was requested in 43% (n = 241) of cases; 8% (n = 46) were positive.

CONCLUSION

TBM remains the commonest cause of pediatric bacterial meningitis in the Western Cape. It is concerning that the percentage of TBM cases out of the total study population has more than doubled compared with that in previous surveys. The low prevalence and young age of H. influenzae meningitis cases confirm the benefits derived from H. influenzae type b (Hib) vaccination.

Naturally acquired and conjugate vaccine-induced antibody to Haemophilus influenzae type b (Hib) polysaccharide in Malian children: serological assessment of the Hib immunization program in Mali

Haemophilus influenzae type b (Hib) conjugate vaccine for infants (6, 10, and 14 weeks of age) was introduced into the Malian Expanded Program on Immunization in July 2005, to diminish invasive Hib disease in young children. Antibodies to Hib capsular polysaccharide (PRP) were measured in infants and toddlers from an area already served by the Hib immunization program (Bamako) and in unimmunized children of the same age in a district (Kangaba) where Hib immunization had not yet begun. Among vaccinated Bamako children 6-23 months of age, 77-93% exhibited PRP titers ≥ 1.0 μg/mL, indicating long-term protection, versus only 10-23% of Kangaba children of that age. High PRP antibody titers in immunized children persisted through 2 years of age. Moreover, ∼50% of Bamako children exhibited anti-PRP titers ≥ 5.0 μg/mL; a level that impedes Hib upper respiratory carriage, and may thereby diminish the Hib transmission to the unimmunized susceptible population (i.e., providing indirect protection).

Bacterial meningitis among children under the age of 2 years in a high human immunodeficiency virus prevalence area after Haemophilus influenzae type b vaccine introduction

AIM

The aim of this study was to describe bacterial causes of meningitis among children < 2 years in a high human immunodeficiency virus (HIV) prevalence area after introduction of routine Haemophilus influenzae type b vaccination.

METHODS

Data collected between April 2003 and December 2008 were extracted from a surveillance database and medical records of children < 2 years admitted in Mbarara Hospital, Uganda with suspected bacterial meningitis. HIV infection was confirmed using rapid tests and polymerase chain reaction and bacterial meningitis by using cerebrospinal fluid culture.

RESULTS

Between April 2003 and December 2008, 1464 children under 5 years were admitted with suspected bacterial meningitis of which 1235 (84.4%) had cerebrospinal fluid collected; 894 (72.4%) of these samples were from children < 2 years. Of the 894 samples, 64 (7.2%) grew an organism including Streptococcus pneumoniae (26; 41%), Salmonella species (20; 31%), H. influenzae (6; 9%) and coliforms (7; 11%), and five (8%) grew contaminants that are all coagulase negative Staphylococcus. Of the 894 children, 468 (52.3%) were tested for HIV; 16.7% were positive. Fifty-one children had a pathogenic isolate and a treatment outcome, and 23 (45%) died; 13 (56.6%) deaths were due to S. pneumoniae, eight (34.8%) were due to Salmonella spp., one (4.3%) was due to H. influenzae and one (4.3%) was due to coliforms. HIV infection was associated with a threefold increase in mortality, increased likelihood of a bacterial isolate and decreased likelihood of malaria parasitaemia.

CONCLUSION

Following H. influenzae type b vaccine introduction, S. pneumoniae and Salmonella spp. are the major causes of bacterial meningitis among children < 2 years in Uganda. Pneumococcal conjugate vaccines and reduction in mother to child transmission of HIV could reduce the observed mortality.

Predictors of acute bacterial meningitis in children from a malaria-endemic area of Papua New Guinea

Predictors of acute bacterial meningitis (ABM) were assessed in 554 children in Papua New Guinea 0.2-10 years of age who were hospitalized with culture-proven meningitis, probable meningitis, or non-meningitic illness investigated by lumbar puncture. Forty-seven (8.5%) had proven meningitis and 36 (6.5%) had probable meningitis. Neck stiffness, Kernig's and Brudzinski's signs and, in children < 18 months of age, a bulging fontanel had positive likelihood ratios (LRs) ≥ 4.3 for proven/probable ABM. Multiple seizures and deep coma were less predictive (LR = 1.5-2.1). Single seizures and malaria parasitemia had low LRs (≤ 0.5). In logistic regression including clinical variables, Kernig's sign and deep coma were positively associated with ABM, and a single seizure was negatively associated (P ≤ 0.01). In models including microscopy, neck stiffness and deep coma were positively associated with ABM and parasitemia was negatively associated with ABM (P ≤ 0.04). In young children, a bulging fontanel added to the model (P < 0.001). Simple clinical features predict ABM in children in Papua New Guinea but malaria microscopy augments diagnostic precision.

Prognostic accuracy of five simple scales in childhood bacterial meningitis

BACKGROUND

In childhood acute bacterial meningitis, the level of consciousness, measured with the Glasgow coma scale (GCS) or the Blantyre coma scale (BCS), is the most important predictor of outcome. The Herson-Todd scale (HTS) was developed for Haemophilus influenzae meningitis. Our objective was to identify prognostic factors, to form a simple scale, and to compare the predictive accuracy of these scales.

METHODS

Seven hundred and twenty-three children with bacterial meningitis in Luanda were scored by GCS, BCS, and HTS. The simple Luanda scale (SLS), based on our entire database, comprised domestic electricity, days of illness, convulsions, consciousness, and dyspnoea at presentation. The Bayesian Luanda scale (BLS) added blood glucose concentration. The accuracy of the 5 scales was determined for 491 children without an underlying condition, against the outcomes of death, severe neurological sequelae or death, or a poor outcome (severe neurological sequelae, death, or deafness), at hospital discharge.

RESULTS

The highest accuracy was achieved with the BLS, whose area under the curve (AUC) for death was 0.83, for severe neurological sequelae or death was 0.84, and for poor outcome was 0.82. Overall, the AUCs for SLS were ≥0.79, for GCS were ≥0.76, for BCS were ≥0.74, and for HTS were ≥0.68.

CONCLUSIONS

Adding laboratory parameters to a simple scoring system, such as the SLS, improves the prognostic accuracy only little in bacterial meningitis.

Pathogen Genomics and the Potential for Understanding Diseases in the Developing World

Approximately 46% and 32% of deaths among children under five globally occur in sub-Saharan Africa and South Asia, respectively. Over 80% of the 4.2 million child deaths in Africa are caused by infectious diseases, sharply contrasted to Europe where 39% of the 0.15 million child deaths are attributable to infectious diseases (Fig. 5.1) (Black et al. 2010). Hence, despite the remarkable public health advancements in hygiene, sanitation, antimicrobial drugs and vaccine strategies of the twenty-first century, the burden of infectious diseases remains unacceptably high in the developing world.

Increased risk of death in human immunodeficiency virus-infected children with pneumococcal meningitis in South Africa, 2003-2005

BACKGROUND

Pneumococcal disease is a major global cause of morbidity and mortality. This study evaluated risk factors for mortality in children with pneumococcal meningitis and other invasive pneumococcal diseases (IPD).

METHODS

The study population included patients <15 years of age with laboratory-confirmed IPD and available outcome data between January 1, 2003 and December 31, 2005 as reported to a national laboratory-based surveillance program. Meningitis was defined by having pneumococcus identified from cerebrospinal fluid culture, while other IPD included patients with pneumococci identified from other normally sterile site specimens. Risk factors for mortality were evaluated using multivariable logistic regression.

RESULTS

A total of 2251 patients with IPD were reported from sentinel sites: 581 with laboratory-confirmed meningitis and 1670 with other IPD. The case-fatality ratio was 35% (205/581) among meningitis cases and 18% (300/1670) among other IPD cases (P < 0.001). Among individuals with available human immunodeficiency virus (HIV) status data, HIV coinfection was less likely among patients with meningitis compared with other IPD (74% [244/328] vs. 82% [880/1067] P < 0.001). On multivariable analysis, HIV-infected status (odds ratio [OR]: 5.34, 95% confidence interval [CI]: 2.32-12.29), Pitt bacteremia score ≥4 (OR: 3.08, 95% CI: 1.21-7.83) and age group <1 year (OR: 2.58, 95% CI: 1.21-5.51) were independent predictors of death among patients with meningitis. Among children with other IPD, malnutrition was an independent predictor of death while HIV infection was not independently associated with increased risk of death.

CONCLUSIONS

Pneumococcal meningitis is associated with a high case-fatality ratio among South African children and this is increased by HIV coinfection. Increasing access to antiretroviral therapy and a catch-up program for pneumococcal conjugate vaccine among HIV-infected and malnourished children could reduce this excess mortality.

Predictors of bacterial meningitis in resource-limited contexts: an Angolan case

Background

Despite the great morbidity and mortality that childhood bacterial meningitis (BM) is experiencing in Africa, diagnosis of BM in resource-limited contexts is still a challenge. Several algorithms and clinical predictors have been proposed to help physicians in decision-making but a lot of these markers used variables that are calculable only in well-equipped laboratories. Predictors or algorithm based on parameters that can be easily performed in basic laboratories can help significantly in BM diagnosis, even in resource-limited settings, rural hospitals or health centers.

Results

This retrospective study examined 145 cerebral-spinal fluid (CSF) specimens from children from 2 months to 14 years. CSF specimens were divided into two groups, according to the presence or not of a clinical diagnosis of BM. For each specimen, CSF aspect, CSF white blood cells (WBC) count, CSF glucose and protein concentration were analyzed and statistical analysis were performed. CSF WBC count ≥10/µl is no more a valuable predictor of BM. CSF protein concentration ≥50 mg/dl has a better sensitivity for BM diagnosis and when used with CSF glucose concentration ≤40 mg/dl, can help to diagnose correctly almost all the BM cases. An algorithm including CSF protein concentration, glucose concentration and WBC count has been proposed to rule out BM and to correctly diagnose it.

Conclusions

In resource-limited health centers, the availability of a combination of easy-to-obtain parameters can significantly help physicians in BM diagnosis. The prompt identification of a BM case can be rapid treated or transferred to adequate structures and can modify the outcome in the patient.

Hyporesponsiveness and its clinical implications after vaccination with polysaccharide or glycoconjugate vaccines

Hyporesponsiveness (immune tolerance) follows vaccination with meningococcal polysaccharide and many pneumococcal polysaccharide serotypes. Hyporesponsiveness after Haemophilus influenzae type b polysaccharide vaccination has not been directly observed, but may follow exposure during disease in some individuals. Use of currently licensed conjugate vaccines has not been associated with hyporesponsiveness to date, with the possible exception of pneumococcal serotype 3. Introduction of polysaccharide vaccines anywhere into a conjugate vaccination schedule may result in reduced immune responses on subsequent exposure. This review of vaccine-induced hyporesponsiveness and its potential clinical implications considers recent evidence suggesting that hyporesponsiveness may occur for specific components of combined conjugate vaccines, such as pneumococcal serotype 3. These data have implications for the development of new multivalent vaccines.

Bacterial meningitis and Haemophilus influenzae type b conjugate vaccine, Malawi

A retrospective database review showed that Haemophilus influenzae type b conjugate vaccine decreased the annual number of cases of H. influenzae type b meningitis in children in Blantyre, Malawi. Among young bacterial meningitis patients, HIV prevalence was high (36.7% during 1997–2009), and pneumococcus was the most common etiologic agent (57% in 2009).

Etiology of meningitis among patients admitted to a tertiary referral hospital in Botswana

This retrospective review evaluated records of cerebrospinal fluid samples between 2000 and 2008 at Princess Marina Hospital in Gaborone, Botswana. Of the 7501 cerebrospinal fluid samples reviewed, Streptococcus pneumoniae (n = 125) and Haemophilus influenzae (n = 60) were the most common bacteria cultured. There were also 1018 cryptococcal and 44 tuberculous meningitis cases. Antimicrobial susceptibilities are described. Public health interventions could decrease the burden of meningitis in Botswana.

Epidemiology, molecular characterization and antibiotic resistance of Neisseria meningitidis from patients ≤15 years in Manhiça, rural Mozambique

Background

The epidemiology of meningococcal disease in Mozambique and other African countries located outside the “meningitis belt” remains widely unknown. With the event of upcoming vaccines microbiological and epidemiological information is urgently needed.

Methods

Prospective surveillance for invasive bacterial infections was conducted at the Manhiça District hospital (rural Mozambique) among hospitalized children below 15 years of age. Available Neisseria meningitidis isolates were serogrouped and characterized by Multilocus Sequence Typing (MLST). Antibiotic resistance was also determined.

Results

Between 1998 and 2008, sixty-three cases of confirmed meningococcal disease (36 meningitis, 26 sepsis and 1 conjunctivitis) were identified among hospitalized children. The average incidence rate of meningococcal disease was 11.6/100,000 (8/100,000 for meningitis and 3.7/100,000 for meningococcemia, respectively). There was a significant rise on the number of meningococcal disease cases in 2005–2006 that was sustained till the end of the surveillance period. Serogroup was determined for 43 of the 63 meningococcal disease cases: 38 serogroup W-135, 3 serogroup A and 2 serogroup Y. ST-11 was the most predominant sequence type and strongly associated with serogroup W-135. Two of the three serogroup A isolates were ST-1, and both serogroup Y isolates were ST-175. N. meningitidis remained highly susceptible to all antibiotics used for treatment in the country, although the presence of isolates presenting intermediate resistance to penicillin advocates for continued surveillance.

Conclusions

Our data show a high rate of meningococcal disease in Manhiça, Mozambique, mainly caused by serogroup W-135 ST-11 strains, and advocates for the implementation of a vaccination strategy covering serogroup W-135 meningococci in the country.

The dynamics of nasopharyngeal streptococcus pneumoniae carriage among rural Gambian mother-infant pairs

Background

Streptococcus pneumoniae is an important cause of community acquired pneumonia, sepsis, meningitis and otitis media globally and has been incriminated as a major cause of serious childhood bacterial infections in The Gambia. Better understanding of the dynamics of transmission and carriage will inform control strategies.

Methods

This study was conducted among 196 mother-infant pairs recruited at birth from six villages in the West Kiang region of The Gambia. Nasopharyngeal swabs were collected from mother-infant pairs at birth (within 12 hours of delivery), 2, 5 and 12 months. Standard techniques of culture were used to identify carriage and serotype S. pneumoniae.

Results

Of 46 serotypes identified, the 6 most common, 6A, 6B, 14, 15, 19F and 23F, accounted for 67.3% of the isolates from infants. Carriage of any serotype among infants rose from 1.5% at birth to plateau at approximately 80% by 2 m (prevalence at 2 m = 77%; 5 m = 86%; 12 m = 78%). Likewise, maternal carriage almost doubled in the first 2 months post-partum and remained elevated for the next 10 m (prevalence at birth = 13%; 2 m = 24%; 5 m = 22%; 12 m = 21%). Carriage was significantly seasonal in both infants and mothers with a peak in December and lowest transmission in August. The total number of different serotypes we isolated from each infant varied and less than would be expected had the serotypes assorted independently. In contrast, this variability was much as expected among mothers. The half-life of a serotype colony was estimated to be 1.90 m (CI_95%: 1.66-2.21) in infants and 0.75 m (CI_95%: 0.55-1.19) in mothers. While the odds for a serotype to be isolated from an infant increased by 9-fold if it had also been isolated from the mother, the population attributable fraction (PAF) of pneumococcal carriage in infants due to maternal carriage was only 9.5%. Some marked differences in dynamics were observed between vaccine and non-vaccine serotypes.

Conclusions

Colonisation of the nasopharynx in Gambian infants by S. pneumoniae is rapid and highly dynamic. Immunity or inter-serotype competition may play a role in the dynamics. Reducing mother-infant transmission would have a minimal effect on infant carriage.

Pneumococcal conjugate vaccines in the prevention of childhood pneumonia

Lower respiratory tract infections are among the most important causes of childhood mortality worldwide, more than 2 million children die due to pneumonia every year. A number of infections caused by the main pathogens related to pneumonia can be prevented through vaccination ( S. pneumoniae, H. influenzae type-b, morbilli, pertussis, influenza). In the last decade, after the introduction of the 7-valent pneumococcal conjugated vaccine (PCV), the epidemiological background of childhood pneumonia has changed. Recently, several studies have been performed to collect data and evidences about the efficacy of PCV against noninvasive pneumococcal diseases (e.g. pneumonia, otitis media). These investigations showed 10-50% decrease of all pneumonia cases, 10-30% decrease of radiologically diagnosed pneumonia, and 50-70% decrease of the incidence of pneumococcal pneumonia in children. The aim of this review was to determine the role of the PCV in the prevention of childhood pneumonia according to the medical literature, and to summarize the efforts of global organizations (WHO, UNICEF, GAVI) in the fight against pneumonia in children.

Diagnosis of Streptococcus pneumoniae and Haemophilus influenzae type b meningitis by identifying DNA from cerebrospinal fluid-impregnated filter paper strips

BACKGROUND

Bacterial meningitis remains often etiologically unconfirmed, especially in resource-poor settings. We tested the potential of real-time polymerase chain reaction to identify Streptococcus pneumoniae (Pnc) and Haemophilus influenzae type b (Hib) from cerebrospinal fluid impregnated on filter paper strips.

METHODS

Pnc and Hib genome equivalents were blindly quantified by polymerase chain reaction from 129 liquid cerebrospinal fluid (CSF) samples-the standard-and strips stored at room temperature for months. Genome counts were compared by simple regression.

RESULTS

The strips showed a sensitivity and specificity of 92% and 99% for Pnc, and of 70% and 100% for Hib, respectively. The positive and negative predictive values were 94% and 97% for Pnc, and 100% and 89% for Hib, respectively. For Pnc, the positive and negative likelihood ratio was 92 and 0.08, and the overall accuracy 98%, whereas for Hib they were 70 and 0.30, and 91%, respectively. Genome counting showed good correlation between the filter paper and liquid CSF samples, r(2) being 0.87 for Pnc and 0.68 for Hib (P < 0.0001 for both).

CONCLUSION

Although not replacing bacterial culture, filter paper strips offer an easy way to collect and store CSF samples for later bacteriology. They can also be transported in standard envelops by regular mail.

Do helminths cause epilepsy?

Both helminthiases and epilepsy occur globally, and are particularly prevalent in developing regions of the world. Studies have suggested an association between epilepsy and helminth infection, but a causal relationship is not established in many helminths, except perhaps with neurocysticercosis. We review the available literature on the global burden of helminths, and the epidemiological evidence linking helminths to epilepsy. We discuss possible routes that helminths affect the central nervous system (CNS) of humans and the immunological response to helminth infection in the CNS, looking at possible mechanisms of epileptogenesis. Finally, we discuss the current gaps in knowledge about the interaction between helminths and epilepsy.

Sequelae due to bacterial meningitis among African children: a systematic literature review

BACKGROUND

African children have some of the highest rates of bacterial meningitis in the world. Bacterial meningitis in Africa is associated with high case fatality and frequent neuropsychological sequelae. The objective of this study is to present a comprehensive review of data on bacterial meningitis sequelae in children from the African continent.

METHODS

We conducted a systematic literature search to identify studies from Africa focusing on children aged between 1 month to 15 years with laboratory-confirmed bacterial meningitis. We extracted data on neuropsychological sequelae (hearing loss, vision loss, cognitive delay, speech/language disorder, behavioural problems, motor delay/impairment, and seizures) and mortality, by pathogen.

RESULTS

A total of 37 articles were included in the final analysis representing 21 African countries and 6,029 children with confirmed meningitis. In these studies, nearly one fifth of bacterial meningitis survivors experienced in-hospital sequelae (median = 18%, interquartile range (IQR) = 13% to 27%). About a quarter of children surviving pneumococcal meningitis and Haemophilus influenzae type b (Hib) meningitis had neuropsychological sequelae by the time of hospital discharge, a risk higher than in meningococcal meningitis cases (median = 7%). The highest in-hospital case fatality ratios observed were for pneumococcal meningitis (median = 35%) and Hib meningitis (median = 25%) compared to meningococcal meningitis (median = 4%). The 10 post-discharge studies of children surviving bacterial meningitis were of varying quality. In these studies, 10% of children followed-up post discharge died (range = 0% to 18%) and a quarter of survivors had neuropsychological sequelae (range = 3% to 47%) during an average follow-up period of 3 to 60 months.

CONCLUSION

Bacterial meningitis in Africa is associated with high mortality and risk of neuropsychological sequelae. Pneumococcal and Hib meningitis kill approximately one third of affected children and cause clinically evident sequelae in a quarter of survivors prior to hospital discharge. The three leading causes of bacterial meningitis are vaccine preventable, and routine use of conjugate vaccines could provide substantial health and economic benefits through the prevention of childhood meningitis cases, deaths and disability.