Influence of socio-economic inequality measured by the Gini coefficient on meningitis incidence caused by Mycobacterium tuberculosis and Haemophilus influenzae in Colombia, 2008-2011.

Bacterial meningitis is an important cause of infectious neurological morbidity and mortality. Its incidence has decreased with the introduction of vaccination programmes against preventable agents. However, low-income and middle-income countries with poor access to health care still have a significant burden of the disease. Thus, the relationship between the Gini coefficient and H. influenzae and M. tuberculosis meningitis incidence in Colombia, during 2008-2011, was assessed. In this ecological study, the Gini coefficient was obtained from the Colombian Department of Statistics, incidence rates were calculated (cases/1,000,000 pop) and linear regressions were performed using the Gini coefficient, to assess the relationship between the latter and the incidence of meningitis. It was observed that when inequality increases in the Colombian departments, the incidence of meningitis also increases, with a significant association in the models (p<0.01) for both M. tuberculosis (r²=0.2382; p<0.001) and H. influenzae (r²=0.2509; p<0.001). This research suggests that high Gini coefficient values influence the incidence of Mycobacterium tuberculosis and Haemophilus influenzae meningitis, showing that social inequality is critical to disease occurrence. Early detection, supervised treatment, vaccination coverage, access to health care are efficient control strategies.

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.

Burden of Haemophilus influenzae type b disease in Pakistani children.

Estimates of the burden of Haemophilus influenzae type b (Hib) in children in Pakistan are limited. A prospective surveillance was set up in 8 sentinel sites in Karachi and Hyderabad in January 2004. A total of 1481 children aged < 5 years underwent lumbar puncture for suspected acute bacterial meningitis. Specimens from 237 (16.0%) children met the criteria for probable bacterial meningitis, and Hib was detected in 45 of them (19.0%). The minimum detected incidence of Hib meningitis in the Hyderabad area was 7.6 per 100 000 in children < 5 years of age, and 38.1 per 100 000 children < 1 year. Hib vaccination is justified for inclusion in Pakistan's expanded programme of immunization.

[Epidemiology of Haemophilus influenzae meningitis in Tunisia]. / Epidémiologie des méningites à Haemophilus influenzae en Tunisie.

The incidence of Haemophilus influenzae b meningitis (Hib) in children < 5 years in Tunisia was studied through a surveillance system set up in June 2000 and followed for 14 months. Population-based surveillance began in 3 governorates and sentinel surveillance in 2. Children < 5 years suspected of meningitis had lumbar puncture, macroscopic exam, blood count, chemical analysis and culture carried out. In the 14 months, 80 cases of meningitis were recorded. From the population-based surveillance most cases were children < 1 year (73.6%) and boys (64%). H. influenzae was isolated in 38% of cases, pneumococci in 13% and meningococci in 7%. The incidence of confirmed Hib was 14.4/100 000 children. The estimated cost of identifying and treating Hib meningitis and its complications was greater than the cost of vaccine introduction. Based this study, the Ministry of Health has decided to introduce Hib vaccination.

Rapid assessment tool for Haemophilus influenzae type b disease in developing countries.

Haemophilus influenzae type b (Hib) still causes a substantial number of deaths among children in developing countries, despite the availability of effective conjugate vaccines. A major obstacle in developing a Hib vaccine has been limited awareness about the impact of Hib disease. A tool was developed to estimate the national rates of Hib meningitis and pneumonia by assessing retrospective local data over 7 to 10 days. Data from 11 countries in Africa, the Middle East, and Asia were studied and showed rates of Hib meningitis from >50 cases per 100,000 children >5 years in Ghana and Uganda to <15 per 100,000 in Iran, Jordan, and Uzbekistan. Results were affected by the quality of available data. The Hib rapid assessment tool can be useful to countries that desire a timely assessment of Hib disease rates.

Global reduction of Hib disease: what are the next steps? Proceedings of the meeting Scottsdale, Arizona, September 22-25, 2002.

On September 22 to 25, 2002, a group of infectious disease specialists, public health officials, and vaccine experts from 33 countries gathered in Scottsdale, Arizona, to discuss the epidemiology and control of disease caused by Haemophilus influenzae type b (Hib) in the era of Hib conjugate vaccines. This supplement is a synthesis of the major themes and key lessons identified at the meeting. The objectives of the conference were to review the 10-year experience with Hib conjugate vaccines, discuss strategies to reduce Hib disease rates to lowest possible levels in industrialized countries, review impediments to the introduction of Hib vaccine in developing countries, and discuss strategies for disseminating lessons learned from countries using to those not using Hib conjugate vaccines. Over 10 years of international experience with Hib conjugate vaccines has demonstrated that they are safe and effective. Routine use of Hib conjugate vaccine has consistently led to decreases in the incidence of invasive Hib disease of 90% or more across a wide range of epidemiologic situations in industrialized countries. In some countries, the vaccine has caused a near-disappearance of invasive Hib disease through a combination of direct protection and herd immunity. Developing countries that have implemented routine vaccination (eg, The Gambia, Chile) have also had substantial disease reduction. In countries where Hib conjugate vaccine is being used, reducing Hib disease incidence to the lowest possible level will depend on maintaining high vaccine coverage levels, conducting surveillance for Hib disease, and investigating Hib disease cases. The optimal Hib vaccination strategy will depend on many factors, including local epidemiology and programmatic considerations. In countries that are not using Hib conjugate vaccine, information on the local burden of Hib disease will be essential for leaders considering vaccine introduction. Where disease burden is high, a multifaceted approach is urgently needed to evaluate and overcome barriers to vaccine introduction. In areas where Hib disease burden is not well characterized, additional work will be needed to understand the epidemiology of Hib disease and to communicate the value of Hib conjugate vaccine.

National Surveillance System and Hib meningitis incidence in Italy.

In 1994, the Italian Ministry of Health implemented a National Surveillance System to obtain data on the incidence of bacterial meningitis and its causative agents, including Haemophilus influenzae type b (Hib). As a consequence, case reporting of Hib meningitis is increasing year by year; in 1996, there were 126 notifications, of which 73% were in children under 2 years of age. Although underreporting still exists, parallel prospective or retrospective epidemiological surveys conducted in some Italian Regions allowed for partial correction of the incidence of Hib meningitis (up to 18.5/100,000 population in 1994).

[Evaluation of the polymerase chain reaction technique for the diagnosis of meningitis caused by Neisseria meningitidis and Haemophilus influenzae]. / Valoración de la técnica de reacción en cadena de la polimerasa para el diagnóstico de las meningitis causadas por N. meningitidis y H. influenzae. Grupo de Trabajo de la Enfermedad Invasiva por H. influenzae.

BACKGROUND: Bacterial meningitis is a severe infection of the central nervous system (CNS), most frequently caused by Neisseria meningitidis in our setting. Microbiologic diagnosis of bacterial meningitis is not enough sensitive because its efficiency can be affected by the therapeutic regimen given to the patient. Polymerase chain reaction (PCR) can provide a more sensitive diagnosis and allow us to get an earlier result. OBJECTIVES: To assess the sensitivity and specificity of a PCR technique for the diagnosis of meningitis caused by N. meningitidis and Haemophilus influenzae. MATERIAL AND METHODS: Ninety-six patients who were attended because of suspected bacterial meningitis on the Hospital de Sant Joan de Déu, Corporació Sanitària Parc Taulí and Hospital de la Santa Creu i Sant Pau, and had negative results by conventional laboratory methods, were selected for the study. A total of 99 cerebrospinal fluid samples (CSF) were obtained and evaluated for PCR. DNA extracts of the CSF samples were amplified by universal primers. Amplification products were hybridized with specific probes for Haemophilus genus and N. meningitidis. Positive and negative controls were included to asses the reliability of PCR. RESULTS: Eight of the 99 CSF samples (8%) were positive by PCR and subsequent hybridization with the specific probe of N. meningitidis. None of the amplicons hybridized with the probe of Haemophilus genus. Thirteen percent of the patients (8/59) with clinical suspicious of non-neonatal sepsis or meningitis were diagnosed by PCR, amongst them, 36% of the cases (4/11) with initial diagnosis of meningococcal sepsis or meningitis. CONCLUSIONS: The sensitivity and the specificity of the PCR technique afford a complementary method to conventional ones, in special for the diagnosis of meningococcal meningitis in the group of pediatric patients.

Use of the Limulus amebocyte lysate test as a cost-effective screen for gram-negative agents of meningitis.

A retrospective review of data from two institutions demonstrated that the Limulus amebocyte lysate test was a simple and cost-effective means to screen cerebrospinal fluids (CSF) for Gram-negative agents of meningitis. Results of either gelation Limulus amebocyte lysate (LAL) or chromogenic Limulus amebocyte lysate (CLAL) tests on 1504 CSF were evaluated along with results of antigen detection tests [ADT; either latex agglutination (LA) or counterimmunoelectrophoresis (CIE)], cultures, and Gram-stains. All 127 CSF positive for Haemophilus or Neisseria by culture and/or ADT were also positive by Limulus test (100%). The sensitivities of Gram stain examination, culture, LA, and CIE for these two pathogens were 81%, 91%, 86%, and 63%, respectively. The Limulus test on lumbar CSF was positive in 67% of cases with other Gram-negative bacillary meningitis, in 33% of cases with Gram-negative bacillary abscess or ventriculitis, in none of the cases with Gram-positive, mycobacterial, treponemal, fungal, or viral meningitis, and in 1% of cases with either normal or otherwise negative bacteriologic findings. Overall, sensitivity and specificity of the Limulus test were 97% and 99%, respectively. The cost of either version of the Limulus test was less than 15% of the cost of ADT batteries for Haemophilus and Neisseria. Based on its sensitivity for Haemophilus and Neisseria in CSF, we propose its use as a cost-effective screen to minimize the need for the more expensive ADT batteries.

Use of rapidly generated results in patient management.

The usefulness of a rapid diagnostic test in patient management depends on the sensitivity of the test, the clinical consequences of false-negative or false-positive results, the ease and cost of performance, and the timely availability of results. A test that is sensitive, specific, inexpensive, and rapid is presumed to be useful clinically. However, there has been surprisingly little effort to measure the actual impact of the results on patient care. Since antigen detection for Haemophilus influenzae type b disease has been available for more than a decade, it will be used as a model to illustrate several factors that help determine the benefits, limitations, and pitfalls of antigen detection in the management of patients with serious bacterial infections. Herein we will compare the use of antigen detection in meningitis with that in other Haemophilus influenzae type b diseases. We also will review our experience with the impact of rapid diagnosis on the treatment of bacterial meningitis. Finally, other factors that influence the usefulness of antigen detection on patient care will be explored by comparing the potential consequences of laboratory error on the management of patients with Haemophilus influenzae type b infections with that of management of other kinds of infections, such as streptococcal pharyngitis, sexually transmitted diseases, and viral respiratory infections.