3. MENINGOCOCCAL DISEASE & PREVENTION Dr Deb Wilson Consultant in Communicable Disease Control 2001

4. Neisseria meningitidis l gram negative diplococci l throat carriage - varies with age l Neisseria lactamica carriage thought to be protective l systemic immunity or invasive disease usually develop within a week of acquisition l the length of carriage after acquiring meningococci varies l transmitted by prolonged person to person spread through droplets or respiratory secretions l serogroups - A, B, C, W135, Y l no environmental or animal reservoir

7. Meningococcal Disease Meningitis Septicaemia Conjunctivitis Septic Arthritis 10% mortality rate ?20% in septicaemia sequelae - amputations, deafness, brain damage, fits

8. Signs and symptoms MeningitisSepticaemia HeadacheRash Muscle & joint pains Nausea & vomiting FeverPhotophobia Neck stiffness Altered consciousness Cold hands & feet TachypnoeaTachycardia

9. Pre-admission penicillin l On suspicion of meningococcal disease give pre- admission benzyl penicillin - saves lives l preferably i.v. but i.m. if access is difficult V adults and children over 101.2 g V children aged 1 - 9 years600 mg V infants300 mg l alternatives if history of penicillin allergy are chloramphenicol or cefotaxime l pre-admission treatment pack V drugs V information

10. Diagnosis l Clinical l Microbiological V blood cultures V CSF microscopy & culture V throat swab V PCR on blood or CSF V serology V skin scrapings - microscopy & culture

11. Epidemiology l approximately 2500 cases and 250 deaths each year in England & Wales l seasonal variation l increase in disease 1995 onwards, especially C l incidence in County Durham & Darlington is V 10 per 100,000 per year l incidence highest in under 5s and teenagers l can occur at any age l serogroup B causes 70% deaths in under 5s l serogroup C causes 80% deaths in teenagers

13. Incidence in contacts of cases l Relative Risk in household contacts of cases 500- 1200 X population risk l RR in school contacts ?30 X population - highest RR in nursery schools, lowest RR in secondary schools l secondary cases mainly occur in 7 days following the index case

14. Roles and responsibilities CASE Recognise symptoms and seek help Make clinical diagnosis Confirm microbiological diagnosis Treat the case Deal with worries of: contacts public schools, colleges & nurseries workplace media Monitor who is getting disease, where, trends etc. Prevent linked cases

15. Confirmed, Probable or Possible l cannot wait for microbiology before contact tracing l Confirmed case V microbiological confirmation with clinical diagnosis l Probable case V signs and symptoms of meningococcal disease and this the most likely diagnosis l Possible cases V some signs and symptoms of meningococcal disease but another diagnosis is as likely or more likely

16. Contact Tracing l Defined by CCDC (or PHN) l Only contact trace confirmed or probable cases l Close contacts in 7 days before index case unwell V usual household members V stayed under same roof V boyfriend / girlfriend (intimate kissing) l Not V close contacts V sharing crockery V social kissing V contacts of contacts V healthcare workers (unless mouth to mouth)

17. Close contacts need…. l Information about signs and symptoms to increase vigilance l Antibiotic prophylaxis V a.s.a.p. V rifampicin or ciprofloxacin (unlicensed) l Vaccine V only if case is confirmed serogroup C (or A, W135 or Y) l Hospital & primary care roles re antibiotic prophylaxis

18. Clusters in schools, colleges l Single cases in school/college - offer information only to school, no prophylaxis l Two confirmed or probable cases that are due to the same organism (or could be due to the same organism) V offer information V offer antibiotic prophylaxis +/- vaccine to whole school - or relevant group

20. CONJUGATE VACCINES l conjugation - coupling of the polysaccharide antigen to a conjugate (e.g. protein) can overcomes the problem of lack of serological response to bacterial capsules l Hib vaccine was the first conjugate vaccine  dramatic reduction in invasive Hib disease in children l ?pneumococcal conjugate vaccine next

21. Bacterial Capsules l polysaccharide capsule V helps avoid ingestion of the bacteria by phagocytes V prevents complement system being activated V young children, the elderly and the immunocompromised are unable to mount a serological response to the capsule of bacteria - including pneumococci, meningococci and haemophilus influenzae l some capsule polysaccharides mimic host polysaccharides, thus protecting themselves V an issue with serogroup B meningococci l spleen is important with capsulate bacteria - intrasplenic phagocytosis