Neisseria meningitidis Pratthana Srisangthong

What should be known about N. meningitidis? Gram negative diplococci Capsular polysaccharides Thirteen serogroup : A, B, C, D, X, Y, Z, E, W-135, H, I, K and L Outer membrane Lipo-oligosaccharide Serogroup specific antibodies arise during carrier state Serological cross reactivity

What should be known about N. meningitidis? Colonization or carrier state V.S. disease Carrier state : chronic, intermittent and transient Transmission from carrier to carrier : via respiratory route ( droplet ) Disease epidermic is associated with rapid rate of spreading of the carrier state Invasive disease occurs in seronegative persons with a newly acquired, virulence meningococcus in the presence of appropiate factors.

Pathogenesis Nasopharyngeal attach and colonization Preexisting condition smoking, prior URI, crowdy, household contact Nasopharyngeal attach and colonization Disease causing strain Entering into the epithelial cell Intracellular survive and transportation Deficiency of antimeningococcal antibody invasion Survival in blood stream

Risk factors for invasive meningococcal infection Factor associated colonization Patients with anatomical or functional splenectomy Complement deficiency Microbiologists routinely exposed to N. meningitidis Travelers to epidermic region

Meningococcemia in Thailand The majority of cases are caused by serogroup B. The incidence is rare.

Epidermiology Saharan africa has greastest percents. Most case arise in children Menigococcal disease occurs more commonly among household contacts Most secondary cases occur within 2 weeks of the primary case

Clinical manifestations Bacteremia without sepsis Meningococcemia without meningitis Meningitis with / without meningococcemia meningoencephalitis

Generalized malaised Weakness Headache Sepsis Leucocytosis Rash Myocarditis Shock DIC Massive hemorrhagic pulmonary edema Subendocardial hemorrhage Adrenal hemorrhage

Uncommon manifestations Arthritis Pericarditis immunologic reaction Conus medullaris syndrome CN dysfunction ( VI, VII, VIII ) Pneumonia Urethritis

Poor prognotic factors Extremes of age A short period between onset of disease and admission The absence of meningitis Wide spread skin leision ( purpura fulminans) Shock and / or MODS including DIC The absence of leukocytosis High concentration of cytokines eg IL-10

Laboratory diagnosis Bacterial isolation from sterile sites Bacterial antigen in CSF : CIE, latex agglutination PCR in blood and CSF

The number of deaths can be reduced by Early recognition and correct management Prompt chemoprophylaxis of close contacts Rapid mass vaccine vaccination

Treatment Early therapy Antibiotic therapy ceftriaxone 2 g/d PGs 18 – 24 mU/d chloramphenical 4 g/d Early therapy

Non antibiotic therapy Supportive care Role of corticosteroid ??? Heparin not indicated New therapy -activated protein C in severe sepsis -recombinant protein composed of the N terminal fragment of human bactericidal/ permeability – increasing protein ???

Chemoprophylaxis Rifampicin 1,200 mg/d 2 d Ciprofloxacin 500 mg/d 1 d Ceftriaxone 259 mg im 1 dose Start within 2 week 90 – 95 % efficacy In eradication of nasopharyngeal carrier and absence of secondary case

Who should recieve? The household contact during epidermic and endermic situation ( direct and indirect contact ) Close population : college dormitories, long term care hospitals, nursery schools, day care center and military barracks Medical personnels who have exposure : > 8 hr contact while in close proximity ( 3 feet ) , direct exposed the patients’ oral secretion eg ETT , mouth to mouth resusutation

Immunoprophylaxis Vaccine derived from capsular polysaccharide of group A and C Quarivalent product containing capsular polysaccharidecof group A, C, Y, W-135 No vaccine in group B The protection lasts 2- 4 yr Poor immunogenic in infants and short protection in children < 2 yr

Immunization is recommended in High risks eg complement deficiency,persons with splenectomy Military recruits Freshmen living in dormitories Microbiologists routined exposed to N. meningitidis Travelers to hyperendemic , epidermic area Thank you