Etiology of Pediatric Meningitis in West Africa Using Molecular Methods in the Era of Conjugate Vaccines against Pneumococcus, Meningococcus, and Haemophilus influenzae Type b.

Despite the implementation of effective conjugate vaccines against the three main bacterial pathogens that cause meningitis, Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and Neisseria meningitidis serogroup A, the burden of meningitis in West Africa remains high. The relative importance of other bacterial, viral, and parasitic pathogens in central nervous system infections is poorly characterized. Cerebrospinal fluid (CSF) specimens were collected from children younger than 5 years with suspected meningitis, presenting at pediatric teaching hospitals across West Africa in five countries including Senegal, Ghana, Togo, Nigeria, and Niger. Cerebrospinal fluid specimens were initially tested using bacteriologic culture and a triplex real-time polymerase chain reaction (PCR) assay for N. meningitidis, S. pneumoniae, and H. influenzae used in routine meningitis surveillance. A custom TaqMan Array Card (TAC) assay was later used to detect 35 pathogens including 15 bacteria, 17 viruses, one fungus, and two protozoans. Among 711 CSF specimens tested, the pathogen positivity rates were 2% and 20% by the triplex real-time PCR (three pathogens) and TAC (35 pathogens), respectively. TAC detected 10 bacterial pathogens, eight viral pathogens, and Plasmodium. Overall, Escherichia coli was the most prevalent (4.8%), followed by S. pneumoniae (3.5%) and Plasmodium (3.5%). Multiple pathogens were detected in 4.4% of the specimens. Children with human immunodeficiency virus (HIV) and Plasmodium detected in CSF had high mortality. Among 220 neonates, 17% had at least one pathogen detected, dominated by gram-negative bacteria. The meningitis TAC enhanced the detection of pathogens in children with meningitis and may be useful for case-based meningitis surveillance.

Causes of Pediatric Meningitis in Botswana: Results From a 16-Year National Meningitis Audit.

BACKGROUND: Central nervous system infections are an important cause of childhood morbidity and mortality in high HIV-prevalence settings of Africa. We evaluated the epidemiology of pediatric meningitis in Botswana during the rollout of antiretroviral therapy, pneumococcal conjugate vaccine and Haemophilus influenzae type B (HiB) vaccine. METHODS: We performed a cross-sectional study of children (<15 years old) evaluated for meningitis by cerebrospinal fluid (CSF) examination from 2000 to 2015, with complete national records for 2013-2014. Clinical and laboratory characteristics of microbiologically confirmed and culture-negative meningitis were described and incidence of Streptococcus pneumoniae, H. influenzae and cryptococcal meningitis was estimated for 2013-2014. RESULTS: A total of 6796 unique cases were identified. Median age was 1 year [interquartile range 0-3]; 10.4% (435/4186) of children with available HIV-related records were known HIV-infected. Overall, 30.4% (2067/6796) had abnormal CSF findings (positive microbiologic testing or CSF pleocytosis). Ten percent (651/6796) had a confirmed microbiologic diagnosis; including 26.9% (175/651) Cryptococcus, 18.9% (123/651) S. pneumoniae, 20.3% (132/651) H. influenzae and 1.1% (7/651) Mycobacterium tuberculosis. During 2013-2014, national cryptococcal meningitis incidence was 1.3 cases per 100,000 person-years (95% confidence interval, 0.8-2.1) and pneumococcal meningitis incidence 0.7 per 100,000 person-years (95% confidence interval, 0.3-1.3), with no HiB meningitis diagnosed. CONCLUSIONS: Following HiB vaccination, a marked decline in microbiologically confirmed cases of H. influenzae meningitis occurred. Cryptococcal meningitis remains the most common confirmed etiology, demonstrating gaps in prevention-of-mother-to-child transmission and early HIV diagnosis. The high proportion of abnormal CSF samples with no microbiologic diagnosis highlights limitation in available diagnostics.

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.

ASSESSMENT OF THE DIAGNOSTIC AND PROGNOSTIC ROLE OF CEREBEROSPINAL FLUID INTERLEUKIN-8 LEVEL IN ADULT PATIENTS WITH MENINGITIS.

Meningitis necessitates immediate diagnosis and therapy. It is important to distingu- ish bacterial from aseptic meningitis, as this help to avoid complications and unnece- ssary antibiotic use. This work assessed the diagnostic and prognostic role of cerebro-spinal fluid interleukin-8 (IL-8) level in adult patients with meningitis. Ninety adult patients with meningitis were studied. They were divided into 3 groups: bacterial, tuberculous and aseptic meningitis. Full clinical examination and laboratory workup of meningitis were done. Cerebrospinal fluid (CSF) IL-8 levels were assessed. Patients were followed up till discharge or death. CSF IL-8 level was significantly higher in bacterial and tuberculous meningitis in comparison to aseptic meningitis. At cut off value 121.77 pg/ml, the area under ROC curve was 0.774 with efficacy 69% for differentiating viral from non-viral meningitis. The test efficacy is low in differentiating tuberculous from bactedal meningitis. There is no correlation of CSF IL-8 levels and disease severity or prognosis.

[Concentration of tazobactam/piperacillin in the cerebrospinal fluid of patients with Haemophilus influenzae type B meningitis].

While the incidence of Haemophilus influenzae type b (Hib) meningitis is expected to decrease with the widespread use of the Hib vaccine, the resistance of Hib has actually increased. Therefore, selection of the initial antibiotics used for treatment must be performed with resistant bacteria, including beta-lactamase negative ampicillin resistant H. influenzae (BLNAR), in mind. Tazobactam/piperacillin (TAZ/PIPC) has a satisfactory minimum inhibitory concentration (MIC) against BLNAR and is a beta-lactamase inhibitor. Although there is no insurance coverage for its use in patients with meningitis, the penetration of TAZ/PIPC into cerebrospinal fluid (CSF) in animal experiments promises a satisfactory result, and we have been using a combination of ceftriaxone (CTRX) and TAZ/PIPC as an initial treatment and a resistant bacteria countermeasure in patients with Hib meningitis at our hospital since 2008. We examined the concentration of TAZ/PIPC in CSF to further investigate the possibility of using TAZ/PIPC as an antibiotic treatment against bacterial meningitis. In cases treated with a 1: 8 drug formulation of TAZ/PIPC against Hib meningitis at our hospital, we used the remaining portion of a CSF sample collected after the initiation of TAZ/PIPC administration and then measured the concentrations of TAZ and PIPC in the CSF. Six specimens from 5 patients between the ages of 6 and 59 months were examined. The dosage of TAZ/PIPC was 95.7-113.6 mg/kg/dose x 3 times/day, and the CSF concentrations at 0-105 minutes after the completion of the administration were 0.319-1.32 microg/mL for TAZ and 2.54-7.74 microg/mL for PIPC. With the approved dosage, the peak concentration level during the acute period indicated a sufficient CSF concentration level for the antibacterial and beta-lactamase inhibition effects against Hib. As an antibiotic treatment for H. influenzae meningitis, the combined usage of TAZ/PIPC is likely to be effective as a resistant bacteria countermeasure, in addition to third-generation cephem drugs and meropenem.

The causative pathogen determines the inflammatory profile in cerebrospinal fluid and outcome in patients with bacterial meningitis.

BACKGROUND: The brain's inflammatory response to the infecting pathogen determines the outcome of bacterial meningitis (BM), for example, the associated mortality and the extent of brain injury. The inflammatory cascade is initiated by the presence of bacteria in the cerebrospinal fluid (CSF) activating resident immune cells and leading to the influx of blood derived leukocytes. To elucidate the pathomechanisms behind the observed difference in outcome between different pathogens, we compared the inflammatory profile in the CSF of patients with BM caused by Streptococcus pneumonia (n = 14), Neisseria meningitidis (n = 22), and Haemophilus influenza (n = 9). METHODS: CSF inflammatory parameters, including cytokines and chemokines, MMP-9, and nitric oxide synthase activity, were assessed in a cohort of patients with BM from Burkina Faso. RESULTS: Pneumococcal meningitis was associated with significantly higher CSF concentrations of IFN-γ , MCP-1, and the matrix-metalloproteinase (MMP-) 9. In patients with a fatal outcome, levels of TNF-α, IL-1 ß, IL-1RA, IL-6, and TGF-α were significantly higher. CONCLUSION: The signature of pro- and anti-inflammatory mediators and the intensity of inflammatory processes in CSF are determined by the bacterial pathogen causing bacterial meningitis with pneumococcal meningitis being associated with a higher case fatality rate than meningitis caused by N. meningitidis or H. influenzae.

Bacterial isolates from cerebrospinal fluid of children with suspected acute meningitis in a Nigerian tertiary hospital.

AIMS AND OBJECTIVES: To determine the common aetiolog of acute bacterial meningitis in children and their antibiotic susceptibility pattern. MATERIALS AND METHODS: A retrospective study with a review of cerebrospinal fluid culture reports of paediatric patients aged 0-15 years, suspected of acute meningitis in the Medical Microbiology Department of Aminu Kano Teaching Hospital, Kano, Nigeria from October 2006 to October 2009 from October 2006 to October 2009. RESULTS: A positive culture bacterial isolation rate of 3.3% (n=50/1500) with prevalence of Streptococcus pneumoniae (24%), Neisseria meningitidis (22%), Escherichia coli (16%), Haemophilus influenzae (14%), Group B streptococci (8%) and Enterococci (8%) which were susceptible to ceftriaxone (96%), cefotaxime (95%) and ciprofloxacin (93%) across the bacterial isolates. Neonates were 55% (n=6.8/12.4) most at risk. CONCLUSION: Neonates are the most at risk of acute bacterial meningitis. In the absence of antibiotic susceptibility report, ceftriaxone should be considered as a first choice reliable antibiotic for empirical treatment of meningitis in children, in this environment.

Prospective multi-centre sentinel surveillance for Haemophilus influenzae type b & other bacterial meningitis in Indian children.

BACKGROUND & OBJECTIVES: Haemophilus influenzae type b (Hib) is one of the leading bacterial causes of invasive disease in populations without access to Hib conjugate vaccines (Hib-CV). India has recently decided to introduce Hib-CV into the routine immunization programme in selected States. Longitudinal data quantifying the burden of bacterial meningitis and the proportion of disease caused by various bacteria are needed to track the impact of Hib-CV once introduced. A hospital-based sentinel surveillance network was established at four places in the country and this study reports the results of this ongoing surveillance. METHODS: Children aged 1 to 23 months with suspected bacterial meningitis were enrolled in Chennai, Lucknow, New Delhi, and Vellore between July 2008 and June 2010. All cerebrospinal fluid (CSF) samples were tested using cytological, biochemical, and culture methods. Samples with abnormal CSF (≥10 WBC per µl) were tested by latex agglutination test for common paediatric bacterial meningitis pathogens. RESULTS: A total of 708 patients with abnormal CSF were identified, 89 of whom had a bacterial pathogen confirmed. Hib accounted for the majority of bacteriologically confirmed cases, 62 (70%), while Streptococcus pneumoniae and group B Streptococcus were identified in 12 (13%) and seven (8%) cases, respectively. The other eight cases were a mix of other bacteria. The proportion of abnormal CSF and probable bacterial meningitis that was caused by Hib was 74 and 58 per cent lower at Christian Medical College (CMC), Vellore, which had a 41 per cent coverage of Hib-CV among all suspected meningitis cases, compared to the combined average proportion at the other three centres where a coverage between 1 and 8 per cent was seen (P<0.001 and P= 0.05, respectively). INTERPRETATION & CONCLUSIONS: Hib was found to be the predominant cause of bacterial meningitis in young children in diverse geographic locations in India. Possible indications of herd immunity was seen at CMC compared to sites with low immunization coverage with Hib-CV. As Hib is the most common pathogen in bacterial meningitis, Hib-CV would have a large impact on bacterial meningitis in Indian children.

Acute meningitis prognosis using cerebrospinal fluid interleukin-6 levels.

BACKGROUND: Improved diagnostic tests would aid in diagnosing and treating community-acquired meningitis. OBJECTIVE: To analyze the diagnostic value of interleukin-6 (IL-6) in the cerebrospinal fluid (CSF) of patients presenting with symptoms of acute meningitis. MATERIAL AND METHODS: In a 6-month prospective, observational, cross-sectional emergency department (ED) study, serum and CSF samples were obtained from all patients with a headache and fever in whom the physician suspected meningitis. Patients were excluded if computed tomography findings contraindicated a lumbar puncture, if they had bleeding disorders, or if their serum indicated bleeding. IL-6 levels were measured and compared in patients with (Group A) and without (Group B) bacterial meningitis. RESULTS: Samples were obtained from 53 patients, of whom 40 were ultimately found to have meningitis. These 40 patients averaged 49.6 ± 21.9 years, with number of men 18 (45%), hospitalizations 21 (52%), mortality 3 (.07%), and IL-6 average rating 491 (median: 14.5; range 0000-6000). Findings in the two groups were: Group A (with meningitis): n = 13, average IL-6 level: 1495 (median: 604; 25/75 percentiles: 232.5-2030; 95% confidence interval [CI] 371.7-2618.6; range 64-6000). Group B (with aseptic meningitis): n = 27, average IL-6 level: 7.34 (median: 5; 25/75 percentiles: 0.0/15.1; 95% CI 3.94-10.73; range 0-23.6). Mann-Whitney rank sum test: p < 0.0001. CONCLUSIONS: In patients with acute bacterial meningitis, CSF cytokine concentrations are elevated. Measuring CSF inflammatory cytokine levels in patients with acute meningitis could be a valuable ED diagnostic tool. Using this tool could improve the prognosis of patients with bacterial meningitis by allowing more rapid initiation of antibiotic treatment.

Changes in serotype distribution of Haemophilus influenzae meningitis isolates identified through laboratory-based surveillance following routine childhood vaccination against H. influenzae type b in Brazil.

Following routine childhood vaccination against Haemophilus influenzae type b (Hib) disease in Brazil in 1999, passive laboratory surveillance reported increasing numbers of non-b serotypes and nontypeable H. influenzae (NTHi) from meningitis cases. To characterize this increase, we analyzed data on 3910 H. influenzae isolated from cerebrospinal fluid or blood from meningitis cases that were sent to the national reference laboratory for serotyping from 1990 to 2008. Hib accounted for 98% of H. influenzae meningitis isolates received during 1990-1999 versus 59% during 2000-2008, while non-b serotypes increased from 1% to 19% and NTHi increased from 2% to 22% of H. influenzae isolates received during the two periods. Higher proportions of non-b serotypes and NTHi than Hib were isolated from blood rather than cerebrospinal fluid. Estimated incidence rates for H. influenzae meningitis for Sao Paulo state remained below 1 case per million population during 2000-2008, although annual incidence of NTHi meningitis (mean, 0.03 cases per 100,000 population) increased in several age groups. Changes in surveillance for H. influenzae following introduction of Hib conjugate vaccine likely contributed to increased numbers of non-b and nontypeable H. influenzae meningitis isolates received at the national reference laboratory.

Meningitis and septicemia caused by nontypeable Haemophilus influenzae in a previously healthy 2-year-old girl.

Nontypeable Haemophilus influenzae (NTHi) commonly colonizes the upper respiratory tract of children and causes otitis media, sinusitis, and bronchitis. Invasive NTHi diseases such as meningitis and septicemia have rarely been reported, especially in children with underlying predisposing conditions such as head trauma and immune compromise. However, we report a previously healthy 2-year-old girl who developed meningitis and septicemia caused by NTHi biotype ΙΙΙ. She was treated with dexamethasone, meropenem, and ceftriaxone, and recovered uneventfully. We wish to emphasize that NTHi should be borne in mind as a potential pathogen that can cause meningitis and septicemia, even in previously healthy children.

Incidence of childhood Haemophilus influenzae type b meningitis in Sri Lanka.

OBJECTIVE: To demonstrate the burden of Haemophilus influenzae type b (Hib) disease in Sri Lanka and provide information for decision-making in public health planning and vaccine introduction. METHODS: This was a prospective, population-based study carried out in 2004, to describe the epidemiology and calculate the incidence of meningitis caused by Hib in children <5 years of age in the district of Colombo, Sri Lanka. Hib was identified in cerebrospinal fluid (CSF) specimens by culture and antigen detection (latex agglutination test; LAT). RESULTS: The lumbar puncture rate in children <5 years of age was 1.9%. A causative bacterial organism was identified in 108 meningitis cases, and in 54 (50%) this was Hib. The LAT increased the Hib detection rate in CSF four-fold. In 2004, the annual incidence of Hib meningitis in Colombo was 20.1 cases per 100000 children aged <5 years. CONCLUSIONS: This study is the first from Sri Lanka reporting the Hib meningitis incidence rate pre-vaccine introduction. The reported incidence rate is one of the highest from the Asian region, but is likely an underestimation considering the difficulties in the laboratory identification of Hib.

Haemophilus influenzae serotype a meningitis.

This work describes a case of Haemophilus influenzae serotype a meningitis in Brazil, after almost a decade since the introduction of Haemophilus influenzae serotype b conjugate vaccine. Uncertainty about the replacement of H. influenzae serotypes as a cause of invasive diseases justifies continuous surveillance, coupled with investigations of carriage rates and requirements of chemoprophylaxis in contact persons.

Bacterial meningitis incidence in Thai children estimated by a rapid assessment tool (RAT).

Acute bacterial meningitis is an important cause of morbidity and mortality in children. To estimate the incidence of meningitis caused by all types of bacteria in Thai children under five years of age, data were collected using a rapid assessment tool (RAT) and analyzed. Clinical and laboratory data from suspected meningitis cases for a one-year period were retrospectively collected from 5 selected catchment areas located in the 4 regions of the country. Adjusted incidences of confirmed bacterial meningitis were calculated based on laboratory quality and lumbar puncture rates. Seventy-five suspected meningitis cases were identified among 305,023 children under age five in the catchment areas, with an unadjusted incidence of 24.6 per 100,000. Of these, 66.2, 55.9, and 33.8% were unconfirmed bacterial, purulent, and confirmed bacterial meningitis cases, respectively. Among the confirmed bacterial meningitis cases, 39.1, 26.1, 21.7 and 13.0% were caused by Haemophilus influenzae type B, gram-positive cocci, gram-negative bacilli, and Neisseria meningitidis, respectively. After adjusting based on the RAT application, the incidence of confirmed bacterial meningitis was about double that of the unadjusted incidence. This study gives an interval of possible incidences of bacterial meningitis in children under age five, which is between the unadjusted (low estimate) and adjusted (high estimate) incidences.

Pediatric bacterial meningitis surveillance - African region, 2002--2008.

Sub-Saharan Africa has one of the world's greatest disease burdens of Haemophilus influenzae type b (Hib), Streptococcus pneumoniae, and Neisseria meningitidis infections. In 2000, Hib and S. pneumoniae infections accounted for approximately 500,000 deaths in the region; during the past 10 years, N. meningitidis has been responsible for recurring epidemics resulting in approximately 700,000 cases of meningitis. Introduction of vaccines against bacterial pathogens in Africa has been constrained by competing public health priorities, limited availability of Hib and S. pneumoniae vaccines, suboptimal N. meningitidis vaccine, inadequate funding, and limited information regarding the disease burden associated with these infections. The World Health Organization (WHO) and CDC analyzed data for 2002--2008 from the Pediatric Bacterial Meningitis (PBM) Surveillance Network, which collects information on laboratory-confirmed bacterial meningitis cases among children aged <5 years at sentinel hospitals in countries throughout the WHO African Region. The results of that analysis determined that, during 2002-2008, a total of 74,515 suspected cases of meningitis were reported. Among the 69,208 suspected cases with known laboratory results, 4,674 (7%) samples were culture-positive for the three bacterial infections under surveillance: 2,192 (47%) were positive for S. pneumoniae, 1,575 (34%) for Haemophilus influenzae, and 907 (19%) for N. meningitidis. The majority of the remaining culture results were negative. These and other PBM network findings will help guide strategies for strengthening laboratory and data management capacity at existing sentinel hospitals and for planning future network expansion in the WHO African Region.

Serial cerebrospinal fluid neurofilament concentrations in bacterial meningitis.

Neurofilament (NF) is one of the major cytoskeleton proteins of neurons. We investigated the concentrations of the heavy subunit of NF (NF-H) in cerebrospinal fluid (CSF) as biomarkers of neuronal injury in bacterial meningitis. Concentrations of NF-H in CSF of 26 children with bacterial meningitis and in 16 control subjects were measured by ELISA. The CSF NF-H levels were elevated in 22 of the 26 children (85%) with bacterial meningitis. The peak CSF NF-H level occurred at a median period of 10.5 days after onset of illness (range, 1 to 35 days). The peak CSF NF-H levels of the patients with neurological sequelae (n=4) were significantly higher than those without sequelae (n=22) (7.06 vs. 2.46 ng/mL as median, p=0.048). There was no significant difference in CSF NF-H levels between patients with and without severe neurological sequelae up to day 14 of illness, but the CSF NF-H levels in patients with sequelae were significantly higher than in those without sequelae after day 14 of illness (2.04 vs. 1.19 ng/mL as median, p=0.024). We suggest that neuronal injury occurs in bacterial meningitis regardless of the presence or absence of neurological sequelae.

Microbial genome count in cerebrospinal fluid compared with clinical characteristics in pneumococcal and Haemophilus influenzae type b meningitis in children.

Cerebrospinal fluid genome counts were determined by quantitative real-time polymerase chain reaction from 121 children: 36 with Streptococcus pneumoniae and 85 with Haemophilus influenzae meningitis. To examine the interactions of genome count and to determine its prognostic importance, we projected the results against findings on admission and different outcomes. The genome count varied vastly in both meningitides ranging from 0 to 9,250,000/microL. The genome quantity was weakly associated with only some of the patient findings on admission. High counts predicted neurologic (odds ratio [OR]=1.36; 95% confidence interval [CI], 1.09-1.69; P=0.006 for 1 log increase) but not audiologic sequelae. They also predicted death in S .pneumoniae (OR=2.05; 95% CI, 1.08-3.87; P=0.03) but not in H. influenzae meningitis.

[Multiplex PCR assay in spinal fluid to identify simultaneously bacterial pathogens associated to acute bacterial meningitis in Chilean children]. / Diseño y evaluación de una reacción de polimerasa en cadena (RPC) múltiple, para la identificación de bacterias causantes de meningitis aguda en líquido cefalorraquídeo de niños chilenos.

BACKGROUND: Acute bacterial meningitis (ABM) is a serious disease that needs rapid diagnosis for an accurate treatment. The most important etiological agents are: Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b. Overall pathogen detection rate in patients with ABM in Chile is 83%. AIM: To evaluate a Polymerase Chain Reaction (PCR) protocol for simultaneous detection of several pathogens in patients with ABM. MATERIAL AND METHODS: We designed and evaluated a multiplex PCR protocol for simultaneous specific genes identifications of S pneumoniae ( inverted exclamation markytA and ply genes), N meningitidis (ctrA, crgA) and H influenzae (bexA) in cerebrospinal fluid (CSF) samples from pediatric patients with suspected diagnosis of ABM. Sensitivity, specificity and minimum detection levels of DNA were determined. Amplifications ofrDNA 16S gene was done to confirm extraction of bacterial DNA. RESULTS: Ninety nine CSF samples were studied, 90 from children with fever and negative CSF culture, and 9 from ABM and positive culture patients. The PCR protocol had a sensitivity of 89%, specificity of 100%, positive predictive value 100% and negative predictive value 99%. CONCLUSIONS: We observed a high concordance (89%) between bacteriological cultures and the PCR protocol results. This diagnostic tool could increase identification of agents in specific settings such as patients previously treated with antibiotics.

Diseño y evaluación de una reacción de polimerasa en cadena (RPC) múltiple, para la identificación de bacterias causantes de meningitis aguda en líquido cefalorraquídeo de niños chilenos / Multiplex PCR assay in spinal fluid to identify simultaneously bacterial pathogens associated to acute bacterial meningitis in Chilean children

Background: Acute bacterial meningitis (ABM) is a serious disease that needs rapid diagnosis for an accurate treatment. The most important etiological agents are: Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b. Overall pathogen detection rate in patients with ABM in Chile is 83 percent. Aim: To evaluate a Polymerase Chain Reaction (PCR) protocol for simultaneous detection of several pathogens in patients with ABM. Material and methods: We designed and evaluated a multiplex PCR protocol for simultaneous specific genes identifications of S pneumoniae (¡ytA and ply genes), N meningitidis (ctrA, crgA) and H influenzae (bexA) in cerebrospinal fluid (CSF) samples from pediatric patients with suspected diagnosis of ABM. Sensitivity, specificity and minimum detection levels of DNA were determined. Amplifications ofrDNA 16S gene was done to confirm extraction of bacterial DNA. Results: Ninety nine CSF samples were studied, 90 from children with fever and negative CSF culture, and 9 from ABM and positive culture patients. The PCR protocol had a sensitivity of 89 percent, specificity of 100 percent, positive predictive value 100 percent and negative predictive value 99 percent. Conclusions: We observed a high concordance (89 percent) between bacteriological cultures and the PCR protocol results. This diagnostic tool could increase identification of agents in specific settings such as patients previously treated with antibiotics.