MENINGOCOCCAL MENINGOCOCCAL DISEASE & PREVENTIONDISEASE & PREVENTION

Dr Deb WilsonDr Deb Wilson

Consultant in Communicable Disease ControlConsultant in Communicable Disease Control

20012001

Neisseria meningitidis gram negative diplococci throat carriage - varies with age Neisseria lactamica carriage thought to be protective systemic immunity or invasive disease usually develop within

a week of acquisition the length of carriage after acquiring meningococci varies transmitted by prolonged person to person spread through

droplets or respiratory secretions serogroups - A, B, C, W135, Y no environmental or animal reservoir

Meningococcal Disease

•Meningitis

•Septicaemia

•Conjunctivitis

•Septic Arthritis

•10% mortality rate ?20% in septicaemia

• sequelae - amputations, deafness, brain damage, fits

Signs and symptoms

Meningitis Septicaemia

Headache

Rash

Muscle & joint pains

Nausea & vomiting

Fever

Photophobia

Neck stiffness

Altered consciousness

Cold hands & feet

Tachypnoea

Tachycardia

Pre-admission penicillin On suspicion of meningococcal disease give pre-

admission benzyl penicillin - saves lives preferably i.v. but i.m. if access is difficult

adults and children over 10 1.2 g children aged 1 - 9 years 600 mg infants 300 mg

alternatives if history of penicillin allergy are chloramphenicol or cefotaxime

pre-admission treatment pack drugs information

Diagnosis

Clinical Microbiological

blood cultures CSF microscopy & culture throat swab PCR on blood or CSF serology skin scrapings - microscopy & culture

Epidemiology approximately 2500 cases and 250 deaths each year in England &

Wales seasonal variation increase in disease 1995 onwards, especially C

incidence in County Durham & Darlington is 10 per 100,000 per year

incidence highest in under 5s and teenagers

can occur at any age

serogroup B causes 70% deaths in under 5s

serogroup C causes 80% deaths in teenagers

Incidence in contacts of cases

Relative Risk in household contacts of cases 500-1200 X population risk

RR in school contacts ?30 X population - highest RR in nursery schools, lowest RR in secondary schools

secondary cases mainly occur in 7 days following the index case

Roles and responsibilities

CASE

Recognise symptoms and seek help

Make clinical diagnosis

Confirm microbiological diagnosis

Treat the case

Deal with worries of: contactspublicschools, colleges & nurseriesworkplacemedia

Monitor who is getting disease, where, trends etc.

Prevent linked cases

Confirmed, Probable or Possible

cannot wait for microbiology before contact tracing

Confirmed case microbiological confirmation with clinical diagnosis

Probable case signs and symptoms of meningococcal disease and this the

most likely diagnosis

Possible cases some signs and symptoms of meningococcal disease but

another diagnosis is as likely or more likely

Contact Tracing Defined by CCDC (or PHN) Only contact trace confirmed or probable cases Close contacts in 7 days before index case unwell

usual household members stayed under same roof boyfriend / girlfriend (intimate kissing)

Not close contacts sharing crockery social kissing contacts of contacts healthcare workers (unless mouth to mouth)

Close contacts need…. Information about signs and symptoms to increase

vigilance

Antibiotic prophylaxis a.s.a.p. rifampicin or ciprofloxacin (unlicensed)

Vaccine only if case is confirmed serogroup C (or A, W135 or Y)

Hospital & primary care roles re antibiotic prophylaxis

Clusters in schools, colleges

Single cases in school/college - offer information only to school, no prophylaxis

Two confirmed or probable cases that are due to the same organism (or could be due to the same organism) offer information offer antibiotic prophylaxis +/- vaccine to whole

school - or relevant group

Laboratory Confirmed Cases of Serogroup C Meningococcal DiseaseEngland & Wales - Cumulative Cases aged 15 to 17 years old

0

20

40

60

80

100

120

140

1601 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53

week no (totals from mid-year)

no

of

case

s

Cumulative Cases 1998/1999

Cumulative Cases 1999/2000

Cumulative Cases 2000/2001 (to week2000/51)

Immunisation with serogroup C conjugate vaccine in 15 - 17 yr olds began on 1 November 1999

CONJUGATE VACCINES conjugation - coupling of the polysaccharide antigen to a

conjugate (e.g. protein) can overcomes the problem of lack of serological response to bacterial capsules

Hib vaccine was the first conjugate vaccine dramatic reduction in invasive Hib disease in children

?pneumococcal conjugate vaccine next

Bacterial Capsules polysaccharide capsule

helps avoid ingestion of the bacteria by phagocytes prevents complement system being activated 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

some capsule polysaccharides mimic host polysaccharides, thus protecting themselves an issue with serogroup B meningococci

spleen is important with capsulate bacteria - intrasplenic phagocytosis