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