The Australian Immunisation Handbook 10th Edition 2013

4.10.3 Epidemiology
Meningococci cause both sporadic and epidemic disease throughout the world.
Serogroup A disease occurs predominantly in low-income countries, such as
those in Africa and Asia, while serogroup B is the major cause of sporadic
meningococcal disease in most developed countries, including Australia.
Serogroup C meningococci have been occasionally associated with small
clusters of meningococcal disease cases in schools, universities and nightclubs in
Australia in the past. 5-7 Rarely, there are clusters of meningococcal disease cases
associated with serogroup B. 8
As in other temperate climates, meningococcal disease cases occurring in
Australia tend to follow a seasonal trend, with a large proportion of cases
reported during late winter and early spring. The overall notification rate for
invasive meningococcal disease to the National Notifiable Diseases Surveillance
System reached a peak of 3.5 per 100 000 in 2001, but declined to 1 case per
100 000 in 2010. 9,10 There have been considerable differences noted in the
incidence of meningococcal disease between Australian states and territories in
the past. Notifications include meningococcal disease cases that were diagnosed
on clinical grounds alone, and those cases that were confirmed by laboratory
methods such as culture, serology or nucleic acid testing of clinical material.
In 2009, 259 cases were reported nationally, of which 194 were laboratoryconfirmed.
9,10 The majority of laboratory-confirmed meningococcal cases were
serogroup B (83%) and serogroup C (5.6%). 10 There has been a sustained decline
in serogroup C meningococcal disease among the 1–19 years age group, as
well as other age groups not targeted in the vaccine program, since the 2003
introduction of routine serogroup C vaccination and catch-up programs. 9-11 In
other countries that introduced a meningococcal C vaccination program, this
herd immunity effect has also resulted in a reduction in incidence in age groups
not targeted by the program. 12-14
Meningococcal disease can occur in any age group, but a large proportion of
cases occur in those