PDF file - Department of Health and Ageing

National Notifiable Diseases Surveillance System, 2004
Annual report
Trends in incident hepatitis B infection by year and
age group are shown in Figure 7.
Figure 7. Trends in notification rates of
incident hepatitis B infections, Australia, 1995 to
2004, by age group
Rate per 100,000 population
8
7
6
5
4
3
2
1
0
0-14
15-19
20-29
30-39
40+
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
In the past fi ve years, rates of incident hepatitis B
notifi cations fell by 75 per cent among cases in the
15–19 year age group and by 38 per cent among
cases in the 20–24 year age group. The reported
source of exposure for cases of incident hepatitis B
infection in 2004 was reported from South Australia,
Tasmania and Victoria (Table 5).
The proportion of newly acquired hepatitis B infections
associated with injecting drug use increased
from 44 per cent in 2002 to 53 per cent in 2004. By
contrast, the proportion of newly acquired hepatitis
B infections associated with sexual contact declined
from 26 per cent in 2002 to 22 per cent in 2004. 2
Table 5. Incident hepatitis B infection,
Australia,* 2004, by exposure category
Exposure category Number Percentage
Injecting drug use 74 52.8
Sexual contact 31 22.2
Male homosexual contact 1
Heterosexual contact 30
Blood/tissue recipient 0
Skin penetration procedure 0
Healthcare exposure 0
Household contact 1 0.7
Other 1 0.7
Undetermined 33 23.6
Total 140 100.0
* Data from South Australia, Tasmania and Victoria
only, (National Centre in HIV Epidemiology and
Clinical Research, 2005 2 ).
Hepatitis B (unspecified) notifications
Case defi nition – Hepatitis B – unspecifi ed
Only confirmed cases are reported.
Confirmed case: Detection of hepatitis B
surface antigen or hepatitis B virus by nucleic
acid testing in a case who does not meet any
of the criteria for a newly acquired case.
In 2004, 5,861 cases of hepatitis B (unspecified)
infection were notified to NNDSS, giving a rate of
29.1 cases per 100,000 population. New South Wales
(42.4 cases per 100,000 population) and Victoria
(29.8 cases per 100,000 population) recorded the
highest notification rates. The male to female ratio
was 1.3:1. Among males, the highest notification rate
was in the 35–39 year age group (63.3 cases per
100,000 population), whereas among females, the
highest notification rate was in the 25–29 year age
group (63.4 cases per 100,000 population, (Figure 8).
The rate of notification of hepatitis B (unspecified)
infection increased from 19.4 in 1996 to 42.8 in 2000
and declined to 29.1 cases per 100,000 population in
2004 (Figure 8).
Figure 8. Notification rate for hepatitis B
(unspecified) infections, Australia, 2004, by age
group and sex*
Rate per 100,000 population
70
60
50
40
30
20
10
0
0-4
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75-79
80-84
85+
Age group (years)
Male
Female
Trends in hepatitis B (unspecifi ed) infection by age
group and year are shown in Figure 9.
Rates of hepatitis B (unspecifi ed) notifi cations in
2000–2004 fell by 49 per cent among cases in the
15–19 year age group, 27 per cent in the 20–29 year
age range and 22 per cent in the 30–39 year age
range. Rates in other age groups remained relatively
stable.
CDI Vol 30 No 1 2006 23