lecture on bacterial meningitis for all medical personnel by Dr. khalid Al-Harby , consultant family physician , Al- madinah , KSA

1. 1 BACTERIAL MENINGITIS INTRODUCTION EPIDEMIOLOGICAL TRENDS DIAGNOSTIC EVALUATION INITIAL APPROACH TO MANAGEMENT PATHOGEN-SPECIFIC THERAPY DURATION OF ANTIMICROBIAL Rx ADJUVANT THERAPY

2. 2 Bacterial meningitis Dr / Khalid Al-Harby

3. 3 INTODUCTION High morbidity and mortality 60% of infant who survive G-ve bacillary meningitis have developmental disabilities and/or neurological sequelae 25% was the case-fatality rate in a review of 493 episodes of bact.meningitis in adults. It is a life-threatening medical emergency cases of meningitis are a leading cause of malpractice suits against emergency doctors

4. 4 Cont. introduction Meningitis is characterized by inflammation of the pia-arachnoid and surrounding CSF. Nasopharyngeal mucosal colonization by potentially pathogenic bacteria is the usual first step, although the organism may be included by trauma or at the time of a neurosurgical or diagnostic procedure. Individuals who are especially susceptible include: -

5. 5 Cont.introduction Those who are asplenic ( sicklers, or splenectomized) who congenitally lack terminal complement components. Who have poor anti-body response to bacterial polysaccharides ( young children or persons with multiple myeloma ).

6. 6 Epidemiological trends The frequency of meningitis due to H. influenzae in children has declined dramatically because of widespread use of H. influenzae type b vaccines ( 95% reduction in incidence in the past decade). Lasker Award in 1996. H. influenzae meningitis has almost disappeared from U.S.A.

7. 7 Diagnostic evaluation It should be considered as a medical emergency and promptly evaluated. Typical CSF finding but -ve gram stain: - latex agglutination test: -specific c-reactive protein in CSF : sensitive petechial scraping :- diagnostic in 70% of cases. A CT scan is rarely needed (? Delay diagn.)

8. 8 Diagnostic evaluation Prior oral antibiotics can decrease the positive yield of CSF culturs by 4-33% and of Gram’s stain 7-41%. Cell count, glucose, and protein usually are not affected. C&S obtained 24h after initial antibiotic administration are +ve only in 20% of cases lymphocyte predominance in a patient who otherwise appears to have bact.meningitis.

9. 9 Empirical treatment When lumpar puncture is delayed or Gram’s stain of the CSF is nondiagnostic. Ceftriaxone is avoided in neonate because of concerns regarding protein binding and displacement of bilirubin. Many antibiotics penetrate BBB poorly under normal circumstances (penetration improves if meninges are inflamed). Patients with bacterial meningitis must

10. 10 cont always be admitted to a hospital ward for I.V antibiotics, observation, and supportive care (no role for oral or I.M. treatment)

11. 11 Adjuvant therapy Inflammatory potential of G+ve cell wall and G-ve lipopolysaccharide. Dexamethasone 0.15mg per kg every 6 h. for 2-4 days is recommended in children over 2m of age suspected to have bact.meningitis. It should be initiated I.V. with or slightly before the antibiotics if delayed 3-4h after 1st dose of antibiotics

12. 12 Cont. Do not give sever sepsis, suspected or documented is a contra-indication.

13. 13 Meningococcal meningitis Sudden onset of fever, intense headache, nausea, and often vomiting, stiff neck and, a petechial rash with pink macules. Case fatality rate (10-50%) in fulminant meningococcemia, the death rate remains high despite prompt antibacterial treatment. Neisseria meningitidis groups(A,B,C,X,Y,W135,Z)

14. 14 cont It occurs in winter and springs mainly preliminarily a disease of very small children*(m>f). Irregular epidemics man is the only reservoir. Transmitted by direct contact, including respiratory droplets during epidemics, over half of the men in

15. 15 cont In a military unit may be healthy carriers of pathogenic meningococci. I.P = 2-10 days C.P = Until eradicated from the nose and mouth. Susceptibility decrease with age group-specific immunity of unknown duration follows even subclinical infections

16. 16 Preventive measures Health education reduce overcrowding quadrivalent vaccine (A,C.Y.W135) is effective in adults and is only used vaccine in U.S.A. since 1971. Duration of protection is limited in children 1-3 y. of age.(poor immunogenicity especially C) no vaccine against B

17. 17 Control Report to local health authority. Respiratory isolation for 24h. After starting antibiotics concurrent disinfection of discharge close contacts (share utensils) need obsevat- Ion for early signs of the disease. Rifampicine 600mg BID for 2 d. (10mg/kg for children , 5mg/kg for neonate) ceftriaxone 250mg IM stat, 125mg if under 15 y. of age. Ciprofloxacin 500mg

18. 18 Cont. P.o stat for adults health care personnel :- only intimate exposure to nasopharyngeal secretions (e.g.mouth to mouth resuscitation) warrant prophylaxis.?? Vaccination of close Contact is of no practical use. The pt. should be given rifampicine prior to discharge from the hospital* the goal of prophylaxis is to eliminate the carrier state from naso-pharynx