Bacterial meningitis (BM) is a severe disease caused by various bacterial pathogens. Toll-like receptors (TLRs) protect humans from invading pathogens. In this study, we determined whether single nucleotide polymorphisms (SNPs) of TLR4 and TLR9 are associated with susceptibility to and outcome of BM in Angolan children. Samples were taken from 241 patients and 265 age-matched ethnic controls. The SNPs TLR4 rs4986790 (896A > G) and TLR9 rs187084 (−1486T > C) were determined by high-resolution melting analysis (HRMA). The frequency of variant genotypes in TLR4 was significantly higher in patients with Haemophilus influenzae meningitis than controls (odds ratio (OR), 2.5; 95% confidence interval (CI), 1.2–5.4; p = 0.021), whereas the frequency of variant genotypes in TLR9 was significantly lower in patients with H. influenzae meningitis than controls (OR, 0.4; 95% CI, 0.2–0.9; p = 0.036). No such differences were found with other causative pathogens, such as Streptococcus pneumoniae and Neisseria meningitidis. At the time of discharge, patients with meningitis caused by Gram-negative bacteria who were carriers of variant TLR4 genotypes had a higher risk of ataxia (OR, 12.91; 95% CI, 1.52–109.80; p = 0.019) and other neurological sequelae (OR, 11.85; 95% CI, 1.07–131.49; p = 0.044) than those with the wild-type TLR4 genotype. Our study suggests an association between H. influenzae meningitis and genetic variation between TLR4 and TLR9 in Angolan children.

The immunological response in bacterial meningitis (BM) causes the formation of reactive oxygen and nitrogen species (ROS, RNS) and activates myeloperoxidase (MPO), an inflammatory enzyme. Thus, structural oxidative and nitrosative damage to proteins and DNA occurs. We aimed to asses these events in the cerebrospinal fluid (CSF) of pediatric BM patients. Phenylalanine (Phe), para-tyrosine (p-Tyr), nucleoside 2′-deoxiguanosine (2dG), and biomarkers of ROS/RNS-induced protein and DNA oxidation: ortho-tyrosine (o-Tyr), 3-chlorotyrosine (3Cl-Tyr), 3-nitrotyrosine (3NO₂-Tyr) and 8-oxo-2′-deoxyguanosine (8OHdG), concentrations were measured by liquid chromatography coupled to tandem mass spectrometry in the initial CSF of 79 children with BM and 10 without BM. All biomarkers, normalized with their corresponding precursors, showed higher median concentrations (p < 0.0001) in BM compared with controls, except 8OHdG/2dG. The ratios o-Tyr/Phe, 3Cl-Tyr/p-Tyr and 3NO₂-Tyr/p-Tyr were 570, 20 and 4.5 times as high, respectively. A significantly higher 3Cl-Tyr/p-Tyr ratio was found in BM caused by Streptococcus pneumoniae, than by Haemophilus influenzae type b, or Neisseria meningitidis (p = 0.002 for both). In conclusion, biomarkers indicating oxidative damage to proteins distinguished BM patients from non-BM, most clearly the o-Tyr/Phe ratio. The high 3Cl-Tyr/p-Tyr ratio in pneumococcal meningitis suggests robust inflammation because 3Cl-Tyr is a marker of MPO activation and, indirectly, of inflammation.

Background: Streptococcus pneumoniae meningitis (SpM) remains a major health burden worldwide, particularly in low- and middle-income countries. Identifying the patients at highest risk for mortality and disabling sequelae may reveal potentially avoidable predisposing factors and identify patients most in need of intensive care. We searched for factors that do not require laboratory facilities. Methods: This study was a secondary analysis of prospectively collected data from 5 clinical trials of childhood bacterial meningitis on 3 continents between 1984 and 2017. SpM cases were analyzed by study site and predictors for poor outcome (death or severe sequelae) were identified from the whole series, Latin America and Angola. Results: Among a total of 1575 children (age range: 2 months to 15 years), 505 cases were due to pneumococci. Compared to other etiologies, SpM doubled the death rate (33% vs. 17%) and tripled poor outcome (15% vs. 6%). In SpM, Glasgow Coma Score <13 [odds ratio (OR): 4.73] and previous antibiotics in Angola (OR: 1.70) were independent predictors for death. Predictors for poor outcome were age <1 year (OR: 2.41) and Glasgow Coma Score <13 (OR: 6.39) in the whole series, seizures in Latin America (OR: 3.98) and previous antibiotics in Angola (OR: 1.91). Angolan children had a 17-fold increased risk for poor outcome when compared with Finnish children (P = 0.011). Conclusions: Our study proved the severity of SpM when compared with other etiologies. The outcome was especially poor in Angola. Most patients at risk for poor outcome are easily identified by clinical factors on admission.

: In areas with suboptimal resources, blood transfusion may not be feasible even when mandatory for severely anemic children with a life-threatening disease. We evaluated how much not having received a transfusion affected the survival in 171 children with an admission blood hemoglobin level of < 6 g/dL and bacterial meningitis in Luanda, Angola. Of these children, 75% (128 of 171) had received a blood transfusion during hospitalization, but 25% (43 of 171) had not. Within the first week, 33% of patients (40 of 121) with transfusion and 50% (25 of 50) without a transfusion died ( P = 0.04). Early transfusion (days 1–2 of hospitalization) prolonged the time of survival from a median of 132 hours [interquartile range (IQR), 15–168] to 168 hours (IQR, 69–168; P = 0.004), and had odds of 0.49 (95% CI, 0.25–0.97; P = 0.040) for death compared with no transfusion. The effect of transfusion/no transfusion at any time during hospitalization on mortality within 30 days, and prolongation of the time of survival were similar to early transfusion but showed even clearer benefits. Our results emphasize the value of timely transfusion in facilities that care for severely anemic children with severe infections to maximize their chances of survival.

Neuronal damage in bacterial meningitis (BM) partly stems from the host´s inflammatory response and induced oxidative stress (OS). We studied the association of cerebrospinal fluid (CSF) biomarkers indicating oxidative damage to proteins with course of illness and outcome in childhood BM in Angola. Ortho-tyrosine/phenylalanine (o-Tyr/Phe), 3-chlorotyrosine/para-tyrosine (3Cl-Tyr/p-Tyr), and 3-nitrotyrosine/para-tyrosine (3NO₂-Tyr/p-Tyr) concentration ratios were measured in 79 BM admission CSF samples, employing liquid chromatography coupled to tandem mass spectrometry. Besides death, disease outcomes were registered on Day 7 of treatment and one month after discharge (control visit). The outcome was graded according to the modified Glasgow Outcome Scale (GOS), which considers neurological and audiological sequelae. Children with a o-Tyr/Phe ratio below the median were more likely to present focal convulsions and secondary fever during recovery and suboptimal outcome (GOS < 5) on Day 7 and at control visit (odds ratio (OR) 2.85; 95% CI 1.14–7.14 and OR 5.23; 95% CI 1.66–16.52, respectively). Their most common sequela was ataxia on Day 7 and at control visit (OR 8.55; 95% CI 2.27–32.22 and OR 5.83; 95% CI 1.12–30.4, respectively). The association of a higher admission CSF o-Tyr/Phe ratio with a better course and outcome for pediatric BM points to a beneficial effect of OS.

Background/Objectives: Bacterial meningitis is a severe disease with a fatality rate of 5–50%. It is mainly caused by Streptococcus pneumoniae or Neisseria meningitidis, which can also cause simultaneous infections outside the central nervous system. Toll-like receptors (TLRs) have an important role in the innate immune system. The TLR2 subfamily comprises the four highly homologous members TLR1, TLR2, TLR6, and TLR10, which also have an important immunomodulatory role in infectious diseases. Methods: The study cohort consists of 190 bacterial meningitis patients aged 1 to 147 months from randomized clinical trials and 268 controls from Luanda, Angola. Polymorphisms of TLR2 (rs111200466) and TLR10 (rs10856837 and rs11096956) were determined using PCR-based methods and Sanger sequencing. The genotyping results were analyzed together with clinical data to determine whether gene polymorphisms of TLR2 and TLR10 are associated with susceptibility and outcome of bacterial meningitis in Angolan children. Results: At admission and during hospitalization, patients with pneumococcal meningitis carrying a variant (ins/del or del/del) of TLR2 rs111200466 had a significantly lower risk of coexisting infections (OR 0.27; 95% CI 0.11–0.65; p = 0.004), particularly pneumonia (OR 0.18; 95% CI 0.06–0.49; p = 0.001). In addition, haplotype analysis demonstrated that a variant genotype of TLR2 rs111200466 together with a wildtype of TLR10 SNPs (rs10856837 and rs11096956) may protect against coexisting pneumonia (OR 0.2; 95% CI 0.06–0.6; p = 0.007). Conclusions: This study suggests an association between coexisting infection and genetic variation in TLR2 and TLR10 of bacterial meningitis in Angolan children.