Trends in malaria in Australia,1991-1997

This report published in Communicable Diseases Intelligence Volume 22, No 11, 29 October 1998 contains an analysis of the malaria cases in the current NNDSS dataset was undertaken for cases with onset dates in 1991 to 1997.

Page last updated: 04 November 1998

A print friendly PDF version is available from this Communicable Diseases Intelligence issue's table of contents.


Bronwen Harvey


An analysis of the malaria cases in the current NNDSS dataset was undertaken for cases with onset dates in 1991 to 1997. To allow for reporting delays, the analysis for each year included cases with onset dates in that year which were reported up to and including 30 June in each subsequent calendar year. Data were downloaded from EpiInfo version 6 and analysed using SPSS for Windows version 8.0 Time series data for the period 1917- 1991 were downloaded from the NNDSS historic data collection in Microsoft Excel.

The number of malaria cases notified each year varied between a low of 622 in 1995 and a high of 866 in 1996. Each year, the state reporting the highest number of cases was Queensland (Table 1). Males have predominated with a M:F ratio varying between 2.3 and 2.5. The highest number of cases has been in the young adult age groups, with peaks in the 20-24 years age group in 1991, 1993, 1994 and 1997 and in the 25-29 years age group in 1992, 1995 and 1996 (Table 2).

Table 1. Malaria notifications, Australia, 1991-1997, by State or Territory

State/ Territory
Year of onset
1991 1992 1993 1994 1995 1996 1997
ACT
22
26
18
24
21
27
17
NSW
139
125
174
185
98
213
162
NT
46
31
29
40
37
26
34
Qld
391
338
291
298
277
412
376
SA
40
35
25
30
24
21
22
Tas
10
14
11
14
1
5
5
Vic
79
132
81
83
127
107
83
WA
38
40
40
30
37
55
34
Total
765
741
669
704
622
866
733

Source: National Notifiable Diseases Surveillance System

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Table 2. Malaria notifications, Australia, 1991-1997, by age group and sex

Age group (years)
Sex1
1991 1992 1993 1994 1995 1996 1997
M F M F M F M F M F M F M F
0-4
10
9
8
8
10
13
9
5
4
4
13
12
16
13
5-9
13
13
19
13
14
7
13
10
10
3
18
18
15
10
10-14
39
22
24
15
20
13
15
8
20
11
27
12
17
13
15-19
68
30
53
34
54
28
59
31
33
35
74
37
55
31
20-24
87
26
68
17
79
26
89
30
59
25
85
45
73
31
25-29
85
24
100
34
71
20
71
34
76
22
96
37
68
29
30-34
47
24
62
16
46
21
58
20
50
14
58
32
63
27
35-39
46
17
57
19
39
15
41
18
42
15
60
20
50
17
40-44
49
11
37
16
39
15
50
16
38
21
46
14
38
11
45-49
36
11
29
10
38
12
30
8
45
7
56
10
43
12
50-54
9
8
18
3
17
6
32
12
24
9
19
7
34
10
55-59
12
1
11
7
16
6
12
1
17
2
20
7
15
3
60-64
10
4
12
5
8
2
4
3
7
1
7
4
8
3
65-69
3
1
4
2
5
4
3
4
7
3
13
2
10
2
70-74
3
0
8
0
4
1
2
0
3
4
2
2
2
75-79
1
0
1
0
1
0
2
0
1
1
2
0
2
2
80-84
1
0
0
1
0
0
1
0
1
1
0
0
0
1
85+
2
0
1
1
0
0
0
0
1
0
0
0
0
NS
16
17
17
5
10
2
8
4
5
2
5
1
0
2
Total
537
218
529
206
471
191
499
204
442
177
603
260
509
219

Source: National Notifiable Diseases Surveillance System
1. Excludes the following cases or whom sex was not stated: 1991 = 10, 1992 = 6, 1993 = 7, 1994 = 1, 1995 = 3, 1996 = 3, 1997 = 5.


Data on malaria species have been included in the NNDSS since 1995. Although reporting was initially poor, with no species recorded for over 70% of cases in 1995, there has been a gradual improvement since then. Species data were recorded for 65% of cases in 1996 and 87% of cases in 1997. In each of these years, the predominant species was Plasmodium vivax, accounting for between 64% and 69% of the cases for whom species was reported. P. falciparum accounted for between 29% and 32% of cases for whom species was reported. Mixed falciparum/vivax infections occurred in a small proportion of cases (<1% to 2.3%) each year.

Data on Aboriginality are poorly reported in the NNDSS and, in most years, aboriginality is not recorded for over half of the cases. Where status has been recorded, the number of cases reported as occurring in Aboriginal and Torres Strait Islander persons has varied from 0 (1995) to 12 (1997).

While the number of cases has fluctuated from year to year, there appears to have been a plateauing of the upward trend in cases that was seen in the 1970s and 1980s (Figure 1). There have also been no significant trends in the age, sex, geographic and seasonal distribution of cases. The proportions of cases due to P. falciparum in the 1995 - 1997 period are similar to those reported by the AMR for 1992 and 1993 (Commun Dis Intell 1998;22:237-244).

Figure 1. Malaria notifications, Australia, 1991-1997, by State or Territory

Figure 1. Malaria notifications, Australia, 1991-1997, by State or Territory


This article was published in Communicable Diseases Intelligence Volume 22, No 11, 29 October 1998.

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