Communicable Diseases Surveillance - Additional reports

This report published in Communicable Diseases Intelligence Volume 24, No 7, July 2000 contains an analysis and tables of monthly notifiable diseases and laboratory data, and quarterly surveillance reports.

Page last updated: 08 August 2000

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




Sentinel Chicken Surveillance Programme

Sentinel chicken flocks are used to monitor flavivirus activity in Australia. The main viruses of concern are Murray Valley encephalitis (MVE) and Kunjin which cause the potentially fatal disease Australian encephalitis in humans. Currently 28 flocks are maintained in the north of Western Australia, seven in the Northern Territory, nine in New South Wales and ten in Victoria. The flocks in Western Australia and the Northern Territory are tested year round but those in New South Wales and Victoria are tested only from November to March, during the main risk season.

Results are coordinated by the Arbovirus Laboratory in Perth and reported bimonthly. For more information see Commun Dis Intell 2000;24:8-9.

AK Broom,1 JS Mackenzie,2 L Melville,3 DW Smith,4 PI Whelan5

1. Department of Microbiology, The University of Western Australia
2. Department of Microbiology, The University of Queensland
3. Berrimah Agricultural Research Centre, Northern Territory
4. PathCentre, Western Australia
5. Department of Health and Community Services, Northern Territory


Sentinel chicken serology was carried out for 23 of the 28   flocks in Western Australia in May and June 2000. A new flock was established at the Bidyadanga Aboriginal community, approximately 150km south of Broome and was bled for the first time in June 2000. Widespread MVE was still detected in the Kimberley, Pilbara, Gascoyne and Midwest regions in May. however, the number of seroconversions declined in June, except for some areas of the Pilbara, particularly those sites near permanent water (Harding and Ophthalmia dams). The number of chickens positive for flavivirus antibodies by ELISA at each site and the identity of the infecting virus(es) are shown in Table 6. A number of the later seroconversions have not yet been confirmed. Top of page

Table 6. Flavivirus seroconversions in Western Australian sentinel chicken flocks in May and June 2000

Location
May 2000 June 2000
MVE MVE/KUN KUN MVE MVE/KUN KUN
Kimberley
Wyndham
1
1
1
 
 
 
Kununurra
1
 
 
 
 
 
Halls Creek
2
 
 
 
 
 
Fitzroy Crossing
1
 
 
 
 
1
Derby*
3
 
1
 
 
 
Curtain Air Base
4
 
 
 
 
 
Lombadina
 
 
 
2
 
 
Broome*
8#
 
 
 
 
 
Pilbara
South Hedland
1
1
 
 
 
1
Karratha
 
 
 
4#
 
 
Harding Dam*
 
 
 
4
1
 
Nullagine
1
 
1
 
 
 
Tom Price
 
 
 
1
 
 
Paraburdoo
2
 
1
4
 
 
Ophthalmia Dam
6
1
 
2
 
 
Newman
1
 
 
 
 
 
Exmouth
4
2
 
1
 
1
Gascoyne
Carnarvon
3
 
 
 
 
 
Mid-West
Dongara
4
 
 
 
 
 

* 2 flocks of 12 chickens at these sites
# These results have not yet been confirmed.
MVE Antibodies to Murray Valley encephalitis virus detected by ELISA.
KUN Antibodies to Kunjin virus detected by ELISA.


High levels of MVE virus activity occurred in 2000 as a result of high wet season rainfall in the Kimberley region and high cyclonic rains and extensive flooding in the Pilbara, Gascoyne, Murchison and Midwest regions. MVE virus antibodies have been detected in chickens in the Murchison and Midwest regions for the first time this year. This is the furthest south the virus has ever been detected. A survey to determine MVE antibody levels in domestic chickens located in this region and areas further south and east is being carried out to determine the limit of MVE virus activity in Western Australia this year. A number of news media warnings have been issued by the Health Department of Western Australia to alert residents living in the northern areas of Western Australia to the increased risk of disease. Additional warnings were also sent out by the Regional Public Health Units to Aboriginal communities in the regions. To date eleven cases of Australian encephalitis caused by MVE virus have been confirmed from Western Australia. In addition there have been several cases of non-encephalitic disease caused by Kunjin virus reported from Western Australia.

Serum samples from all seven of the Northern Territory sentinel chicken flocks were tested in our laboratory in May 2000 and from six flocks in June 2000. There were a number of seroconversions to flaviviruses in the flocks located at Alice Springs, Leanyer, Katherine, Tennant Creek and Gove in May and at Alice Springs, Howard Springs, and Gove in June. The number of chickens positive for flavivirus antibodies by ELISA at each site and the identity of the infecting virus(es) are shown in Table 7. A number of news media warnings have been issued by the Northern Territory Health Department and to date there have been four cases of Australian encephalitis confirmed from central Australia.

The MVE surveillance programs using sentinel chickens in New South Wales and Victoria finished in April 2000.

Table 7. Flavivirus seroconversions in Northern Territory sentinel chicken flocks in May and June 2000

Location
May 2000 June 2000
MVE MVE/KUN KUN MVE MVE/KUN KUN
Alice Springs
1
 
 
 
1#
 
Howard Springs
 
 
 
1#
 
 
Leanyer
2
 
 
 
 
 
Gove
1
 
 
3#
 
 
Tennant Creek
6#
 
 
 
 
 
Katherine
1
 
 
 
 
 

# These results have not yet been confirmed.
MVE Antibodies to Murray Valley encephalitis virus detected by ELISA.
KUN Antibodies to Kunjin virus detected by ELISA.


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HIV and AIDS Surveillance

National surveillance for HIV disease is coordinated by the National Centre in HIV Epidemiology and Clinical Research (NCHECR), in collaboration with State and Territory health authorities and the Commonwealth of Australia. Cases of HIV infection are notified to the National HIV Database on the first occasion of diagnosis in Australia, by either the diagnosing laboratory (Australian Capital Territory, New South Wales, Tasmania, Victoria) or by a combination of laboratory and doctor sources (Northern Territory, Queensland, South Australia, Western Australia). Cases of AIDS are notified through the State and Territory health authorities to the National AIDS Registry. Diagnoses of both HIV infection and AIDS are notified with the person's date of birth and name code, to minimise duplicate notifications while maintaining confidentiality.

Tabulations of diagnoses of HIV infection and AIDS are based on data available three months after the end of the reporting interval indicated, to allow for reporting delay and to incorporate newly available information. More detailed information on diagnoses of HIV infection and AIDS is published in the quarterly Australian HIV Surveillance Report, and annually in HIV/AIDS and related diseases in Australia Annual Surveillance Report. The reports are available from the National Centre in HIV Epidemiology and Clinical Research, 376 Victoria Street, Darlinghurst NSW 2010. Telephone: (02) 9332 4648; Facsimile: (02)   9332 1837; http://www.med.unsw.edu.au/nchecr.

HIV and AIDS diagnoses and deaths following AIDS reported for 1 to 29 February 2000, as reported to 31 May 2000, are included in this issue of Communicable Diseases Intelligence (Tables 8 and 9).

Table 8. New diagnoses of HIV infection, new diagnoses of AIDS and deaths following AIDS occurring in the period 1 to 29 February 2000, by sex and State or Territory of diagnosis

  ACT NSW NT Qld SA Tas Vic WA Totals for Australia
This period 2000 This period 1999 Year to date 2000 Year to date 1999
HIV diagnoses Female
0
1
0
2
0
0
0
1
4
7
13
10
Male
0
20
0
12
1
0
5
4
42
39
111
85
Sex not reported
0
0
0
0
0
0
0
0
0
0
1
0
Total1
0
21
0
14
1
0
5
5
46
46
126
95
AIDS diagnoses Female
0
2
0
1
0
0
0
0
3
1
7
1
Male
0
3
0
2
1
0
4
1
11
12
30
22
Total1
0
5
0
3
1
0
4
1
14
13
37
23
AIDS deaths Female
0
0
0
0
0
0
0
0
0
0
3
0
Male
1
3
0
3
1
0
2
0
10
6
13
27
Total1
1
3
0
3
1
0
2
0
10
6
16
28

1. Persons whose sex was reported as transgender are included in the totals.


Table 9. Cumulative diagnoses of HIV infection, AIDS and deaths following AIDS since the introduction of HIV antibody testing to 29 February 2000, by sex and State or Territory

  State or Territory Australia
ACT NSW NT Qld SA Tas Vic WA
HIV diagnoses Female
26
604
11
153
61
5
212
116
1,188
Male
223
10,901
109
1,990
674
79
3,892
918
18,786
Sex not reported
0
252
0
0
0
0
24
0
276
Total1
249
11,775
120
2,150
735
84
4,142
1,038
20,293
AIDS diagnoses Female
9
188
0
48
25
3
69
26
368
Male
86
4,644
36
823
346
44
1,616
350
7,945
Total1
95
4,844
36
873
371
47
1,692
378
8,336
AIDS deaths Female
4
113
0
32
15
2
49
16
231
Male
66
3,171
24
567
231
29
1,270
248
5,606
Total1
70
3,292
24
601
246
31
1,325
265
5,854

1. Persons whose sex was reported as transgender are included in the totals.


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Childhood immunisation coverage

Tables 10 and 11 provide the latest quarterly report on childhood immunisation coverage from the Australian Childhood Immunisation Register (ACIR).

The data show the percentage of children fully immunised at age 12 months for the cohort born between 1 January and 31 March 1999 and at 24 months of age for the cohort born between 1 January and 31 March 1998, according to the Australian Standard Vaccination Schedule.

A full description of the methodology used can be found in Commun Dis Intell 1998;22:36-37.

Acceptance of a report does not imply a causal relationship between administration of the vaccine and the medical outcome, or that the report has been verified as to the accuracy of its contents. It is estimated that 250,000 doses of vaccines are administered every month to Australian children under the age of six years.

Table 10. Percentage of children immunised at 1 year of age, preliminary results by disease and State for the birth cohort 1 January to 31 March 1999; assessment date 30 June 2000

Vaccine
State or Territory Australia
ACT NSW NT Qld SA Tas Vic WA
Total number of children
1,068
21,412
941
12,332
4,509
1,541
15,102
6,225
63,130
Diphtheria, Tetanus, Pertussis (%)
91.5
88.2
84.2
90.4
91.9
92.8
91.2
88.8
89.8
Poliomyelitis (%)
91.2
88.4
84.6
90.3
91.8
92.6
91.3
88.8
89.8
Haemophilus influenzae type b (%)
91.3
87.6
88.7
90.4
90.7
91.7
90.8
88.0
89.3
Fully immunised (%)
91.1
86.5
82.7
89.7
90.2
91.1
90.0
86.9
88.4
Change in fully immunised since last quarter (%)
-0.7
-0.1
-0.3
0.0
+1.1
+2.8
+0.6
+1.1
+0.3


Table 11. Proportion of children immunised at 2 years of age, preliminary results by disease and State for the birth cohort 1 January to 31 March 1998; assessment date 30 June 20001

Vaccine
State or Territory Australia
ACT NSW NT Qld SA Tas Vic WA
Total number of children
1,102
21,148
956
12,392
4,579
1,517
14,842
6,196
62,732
Diphtheria, Tetanus, Pertussis (%)
90.0
85.6
79.4
90.1
89.4
87.2
88.3
86.4
87.5
Poliomyelitis (%)
93.6
90.1
90.0
92.7
94.0
93.4
93.2
91.0
91.9
Haemophilus influenzae type b (%)
89.0
84.8
86.3
90.1
88.8
86.4
88.3
85.6
87.2
Measles, Mumps, Rubella (%)
92.5
89.3
89.7
92.1
92.4
92.9
92.1
90.2
91.0
Fully immunised (%)2
87.0
78.0
74.6
86.2
84.2
82.7
83.4
79.5
81.7
Change in fully immunised since last quarter (%)
+4.4
+4.2
+1.6
+4.7
+6.3
+4.0
+5.7
+6.2
+5.0

1. The 12 months age data for this cohort was published in Commun Dis Intell 1999;23:232.
2. These data relating to 2 year old children should be considered as preliminary. The proportions shown as 'fully immunised' appear low when compared with the proportions for individual vaccines. This is at least partly due to poor identification of children on immunisation encounter forms.
Acknowledgment: These figures were provided by the Health Insurance Commission (HIC), to specifications provided by the Commonwealth Department of Health and Aged Care. For further information on these figures or data on the Australian Childhood Immunisation Register please contact the Immunisation Section of the HIC: Telephone 02 6124 6607.


This article was published in Communicable Diseases Intelligence Volume 24, No 7, July 2000.

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