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National Notifiable Diseases Surveillance System, 2004
Annual report
Leptospirosis
Case defi nition – Leptospirosis
Only confirmed cases are reported.
Confirmed case: Requires isolation of
pathogenic Leptospira species, OR a fourfold
or greater rise in Leptospira agglutination
titre between acute and convalescent phase
sera obtained at least two weeks apart and
preferably conducted at the same laboratory,
OR a single Leptospira micro agglutination titre
greater than or equal to 400 supported by a
positive enzyme-linked immunosorbent assay
IgM result.
1.0 cases per 100,000 population) and New South
Wales (40 notifications, 0.6 cases per 100,000 population).
Forty per cent of all notifications were from
Far North Queensland (Map 10); the notification rate
in this Statistical Division of residence was 28.8 cases
per 100,000 population.
Most cases were male (n=151, male to female
ratio 10.1:1). There was little evidence that rates of
notifi cation varied between age groups.
Figure 57. Trends in notification rates of
leptospirosis, Australia and Queensland, 1991 to
2004
7
Leptospirosis is caused by the spirochaete, Leptospira.
Nationally, 166 notifications of leptospirosis
were received during 2004 (0.9 cases per 100,000
population). This rate is relatively low compared to
the previous years but is 31 per cent higher than the
national rate in 2003 (Figure 57).
In 2004, the notification rate was highest in
Queensland (110 notifications, 2.8 cases per 100,000
population), the Northern Territory (1 notification,
Rate per 100,000 population
6
5
4
3
2
1
0
Queensland
Australia
1991 1993 1995 1997 1999 2001 2003
Year of notification
Map 10.
Notification rates of leptospirosis, Australia, 2004, by Statistical Division of residence
CDI Vol 30 No 1 2006 65