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10 years on - how has the world changed for our kids?
Infectious disease prevention in children: how far have we come in 10 years?
A/Professor Helen Marshall
How far have we come?
• Successes
– Reduction in serious life-threatening conditions in children
• Meningitis caused by Haemophilus influenzae, meningococcus,
pneumococcus
• Varicella (Chicken pox) and Herpes zoster (shingles)
• Rotavirus and all-cause Gastroenteritis
• Future challenges
– Current serious infectious diseases causing death and disability
in children
• Meningococcal B meningitis and septicaemia
• Pertussis (whooping cough)
• Optimising the dual benefit of immunisation programs
(direct and indirect protection) over the next 10 years
Infectious disease prevention in children
How far have we come?
1940 – Donald Hamilton (Sydney paediatrician)
In the previous 50 years pertussis had killed more children under 5 than
diphtheria. That year it destroyed 85 infants in our hospital out of 293
admitted. Very many of the infants stopped breathing in their spasms and
their colour blackened till a nurse rushed to revive them with
oxygen….pneumonia often developed and they lay there in their little cots,
emaciated and weak, wracked by their coughing spasms, losing their
nutrition by the vomiting or the very breath of life by the respiratory spasms
that their cough brought on.
When Director of Health was approached about campaigning for pertussis
immunisation his response was “a hospital was to treat illness not prevent it”
Adapted from Hamilton DG. The Medical Journal of Australia 1979; 2: 651
Haemophilus influenzae (Hib)
Haemophilus influenzae (Hib)
• A common cause of meningitis, epiglottitis and pneumonia prior to
introduction of Hib vaccine
• Meningitis and epiglottitis are almost invariably fatal without
treatment
• Most commonly affects children < 5 years, children < 2 years at
highest risk of infection
• 3% of children die from Hib meningitis and up to 30% have sequelae
including deafness and brain injury
• 3-5% of healthy school-aged children carry Hib bacteria in their
naso-pharynx ¹
Barbour ML. Emerg Inf Dis 1996;2(3):176-82.
Impact of Hib vaccine on Hib disease
Hib vaccine
introduced
July 1993
• Introduced into the Australian Immunisation Program in July 1993
• Schedule 2,4,6 months with a booster vaccination at 12 months
• 549 cases in 1992 – 11 cases in 2013 (< 5 year olds)
95% reduction in notifications of Hib disease in the past decade
www9.health.gov.au/cda/source/rpt$cfm
Reduction in Hib disease in both developed
and developing countries
Morris SK, Moss WJ, Halsey N. The Lancet infectious diseases. 2008;8(7):435-43.
Indirect (herd immunity) effects of Hib
vaccination
proportion of children immunised
carriage of Hib
transmission of Hib
Hib disease in
unimmunised individuals
Ladhani SN. Clin Ther. 2012 Feb; 34(2):385-99.
Hib notifications in the UK
Meningococcal disease
Meningitis and septicaemia
•
•
•
•
•
Caused by serogroups A,B,C,W,X,Y
Approx. 240 cases per year in Australia
Case fatality rate of 5-10%
Bimodal pattern of disease
- Children < 5 years of age, particularly infants < 6 months of age
- Adolescents, 15-24 years of age
Complications (sequelae)
– Limb amputation due to limb ischaemia/gangrene, deafness, skin
scarring ¹
Carriage
- 5 -11% of adults (up to 25% in teenagers)
- invasive strains generally <1 - 2%
Approximately 1/3 of cases of meningococcal disease were due to serogroup C
prior to introduction of the Men C vaccine
Wang B, Marshall H et al. PIDJ 2014;33(3):316-318.
Meningococcal vaccination
• Meningococcal C immunisation introduced in 2003
• One dose of Men C vaccine is provided to children at 1 year of age
• Vaccines against Meningococcal A, C, W and Y strains are also
available for private purchase but not part of a funded program
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No.cases
Meningococcal disease by month and serotype South Australia
2000-2008
Year/month
Gp B
Courtesy of CDCB, SA Health
Gp C
Gp Y
Gp W135
No Gp
Impact of Men C vaccine on Meningococcal C disease
Meningococcal serogroup C disease notification rates, Australia, 1999 to 2007,
by age group and year of diagnosis in age groups offered vaccination
Direct protection
Chiu C et al. Communicable Diseases Intelligence. 2010;34(Supplement):S53.
Impact of Men C vaccine on all age groups
(vaccinated and unvaccinated)
•
Meningococcal serogroup C disease notification rates, Australia, 1999 to
2007, by age group and year of diagnosis, in all age groups
Indirect protection
Chiu C et al. Communicable Diseases Intelligence. 2010;34(Supplement):S53.
Reduction in varicella (chicken pox) and Herpes
zoster (shingles) since varicella vaccine introduction
•
•
Since introduction of varicella vaccine in a funded immunisation program,
there has been a 68% reduction in varicella related hospitalizations
80% of the children who were hospitalized were not immunized, including
three previously healthy children children who needed intensive care
Marshall H et al. PIDJ 2013; 32(5):530-537.
Direct and indirect benefits of rotavirus
vaccine introduction
Age-specific RVGE and ACGE hospitalisation rates per 100,000 children; pre and
post rotavirus vaccine introduction
Clarke M, Marshall H. Vaccine 2011;29(29-30):4663-4667.
Meningococcal B disease
Pertussis (whooping cough)
Future challenges
Meningococcal B Disease
• Serogroup B is now the cause of 85% of cases of meningococcal
disease in Australia
• Incidence 1:100 000, but up to 12/100,000 in infants < 12 months
• Case fatality rate is high despite antibiotic treatment (5-10%)
–Sequelae in up to 57% of survivors
(major sequelae include amputations, hearing loss, skin scarring)
• Bimodal pattern of disease
–Peak incidence in infants < 6 months of age; CFR 8%
–2nd peak incidence in adolescents; CFR~10%
CDI 2007;31(1):63
Men B vaccine
• Recently licensed in Australia, Canada and the EU
• Currently available in Australia for private purchase
• UK Joint Committee on Vaccines and Immunisation, UK
has recommended the Men B vaccine be included in the
national immunisation program
• Inclusion of the Men B vaccine in the funded Australian
immunisation program is currently under review by the
PBAC
Infectious disease prevention in children
Challenge: Pertussis (whooping cough) still causes deaths
in babies < 6 months of age
• Pertussis
– bacterial respiratory infection (Bordetella pertussis)
– highly infectious (spreads to 90% susceptible household contacts)
– affects all ages, strictly human
• Complications
–
–
–
–
pneumonia
seizures
hypoxic encephalopathy
cardiomyopathy
• Case fatality 0.03%
(< 6 months 0.8%)
Australian Immunisation Handbook, 10th Edition 2013 (updated January 2014) Chapter 4.12; available at
www.immunise.health.gov.au/internet/immunise/publishing.nsf/Content/handbook10-4-12 (accessed 24 Jan
2014)
Epidemics in Australia
Removal 18 mth
DTPa
Sept 2003
Yr 9 DTPa
Jan 2004
Disease Surveillance & Investigation Section, Communicable Disease Control Branch, South Australia Health.
www.health.sa.gov.au/pehs/notifiable-diseases-summary/pertussis.png Accessed 24 Jan 2014
Challenge: pertussis epidemics still occur
Mertsola 20103
Elliot 20044
1. Mattoo S, Cherry JD. Clin Microbiol Rev 2005; 18: 326–38; 2 Zhang et al. Cochrane Database
of Systematic Reviews 2011; 1: CD001478; 3. Mertsola J, et al. Clinical Infectious Diseases 2010; 51: 656–62;
4. Elliot et al. Pediatr Infect Dis J 2004; 23: 246–52; 5. Herald Sun News 2011
http://www.heraldsun.com.au/archive/news/doctors-warn-parents-to-keep-newborns-at-home-as-whoopingcough-epidemic-escalates/story-e6frf7l6-1226056035514; 6. Cherry JD. N Engl J Med 2012; 367:785-7
VAC/VAB/0016e/13
Challenge: Preventing pertussis in newborn
infants who are at highest risk of dying
Infant pertussis
immunisation schedule
• 2,4,6 months, boosters at
4 years and 13 years of
age
Strategies to protect the
most vulnerable infants
• Cocooning
• Neonatal vaccination
• Maternal vaccination
Wood N, Marshall H, PIDJ. 2014;33(5):511-7
Antibody responses to pertussis toxin (anti-PT) when
pertussis vaccine is administered at birth
In conclusion
• Immunisation has contributed significantly to preventing death and
disability from serious infections in children over the past decade
• We need to improve uptake of vaccines in the community to
optimise the dual benefit of direct and indirect protection
• There is the potential to improve reduction in disease even further
over the next decade with new vaccines becoming available against
life-threatening infections
• We need to continue to provide evidence on the significant benefits
vaccines have delivered and ensure parents continue to feel
confident in their decision to have their children immunised
Infectious disease prevention in children