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Communicable Diseases Surveillance consists of data from various sources. The National Notifiable Diseases Surveillance System (NNDSS) is conducted under the auspices of the Communicable Diseases Network Australia New Zealand. The Virology and Serology Laboratory Reporting Scheme (LabVISE) is a sentinel surveillance scheme. The Australian Sentinel Practice Research Network (ASPREN) is a general practitioner-based sentinel surveillance scheme. In this report, data from the NNDSS are referred to as 'notifications' or 'cases', whereas those from ASPREN are referred to as 'consultations' or 'encounters' while data from the LabVISE scheme are referred to as 'laboratory reports'.
Vaccine preventable diseasesA total of 297 notifications were received with a notification date in February. Notification numbers for the different VPDs overall remained stable and as noted in previous reports, most were the result of continuing pertussis activity in most States and Territories. There were no cases of diphtheria or Haemophilus influenzae type b. The number of mumps and rubella cases were stable. Most rubella cases occurred in males aged 20-24 years (Figure 1).
Figure 1. Notifications of rubella, February 2000, by age group and sex
Pertussis cases in this period (255) had decreased when compared with January cases (380) and the five year mean (468), but was similar to February 1999 (260). The decrease in the number of cases was in New South Wales, Queensland and Tasmania. Cases of pertussis occurred in all age groups with peaks in those aged 10-14 years and those aged 40-44 years (Figure 2). There was a male to female ratio of 0.8:1. Immunisation status information was mostly provided for those aged 0-4 years. The majority of cases aged 0-4 years were described as partly immunised (Figure 2). For cases in the 10-14 year age group and 40-44 year age group immunisation status was mostly not provided. Of note amongst those aged 10-14 years, a small proportion of cases occurred in those fully immunised and a slightly greater proportion in those partly immunised.
Figure 2. Notifications of pertussis, February 2000, by age group and immunisation status
A total of 24 reports of meningococcal disease were received with a notification date in February; similar to numbers from February last year (18) and the 5 year mean (22), but showing a decrease when compared with January (45). Most cases occurred in those under 30 years with a predominance in those aged 0-4 and 15-19 years. Overall the ratio of males to females was 1.2:1. Serotype information was provided for 63% (15/24) of cases. Of the 15 notifications for which serotype information was provided, the following was found: serotype B (n=6, 40%), serogroup C (n=7, 46%), serogroup Y (n=1, 7%) and serogroup W (n=1, 7%).
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Bloodborne diseasesThere were 1,949 notifications of hepatitis C diagnosed in February 2000 that were not already on the State and Territory notifiable diseases systems. This was an increase from January 2000 (1,520), February last year (1,862) and for the mean of the last 5 years (1,329). Of these, 25 were identified to be incident cases. The majority of the incident notifications were in the 15-29 year old age group (72%) and the male to female ratio was 1.3:1.
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Gastrointestinal diseasesThere were 609 notifications of salmonellosis with a notification month of February 2000. This was a decrease from January 2000 (666), February last year (917) and for the mean of the last 5 years (834) (Figure 3). Thirty-two percent (226 cases) were in the 0-5 year age group with an overall male to female ratio of 1:1.
Figure 3. Notifications of salmonellosis, January 1991 to February 2000, by date of notification
There were 5 notifications of typhoid with a notification month of February 2000. Of the four States reporting SLTEC/VTEC there were 5 cases, all from South Australia. There was also 1 case of HUS in New South Wales.
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Quarantinable diseasesFrom 1 January 1998 to 29 February 2000, a total of 8 cases of cholera have been reported to NNDSS (Box 1). There were 3 cases from New South Wales, 3 from Victoria, and 1 each from Queensland and South Australia. Cases were aged from 2 to 66 years with a male to female ratio of 1.3:1. One case of cholera was confirmed as a locally transmitted case, and the source of infection was unknown for another case in Victoria. The remainder of cases were acquired overseas. The detail of the source of infection and serotype are shown in Box 1.
There were no cases of plague, rabies, yellow fever or viral haemorrhagic fever with a notification month of February 2000.
Box 1. Notifications of cholera, January 1998 to February 2000, by source of infection and serotype
Date of notification
Date of report
Source of infection
|NSW||66||M||29/01/98||9/02/98||Bali||01 - el tor - ogawa|
|Qld||25||F||2/03/98||10/03/98||Bali||01 - El tor - ogawa|
|Vic||41||M||13/05/98||15/05/98||Bali||01 - El tor - ogawa|
|NSW||14||M||29/01/99||3/02/99||NSW||01 - El tor - ogawa|
|NSW||2||F||3/04/99||8/04/99||India||01 - El tor - ogawa|
|Vic||66||M||23/08/99||23/08/99||Jakarta||01 - ogawa|
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Sexually transmissible diseasesThere were 1,728 notifications of sexually transmissible diseases with a notification month of February 2000, which is similar to January 2000 (1,793) and February last year (1,804) but is less than the mean for the last 5 years (1,363) (Figure 4). The notifications were in all age groups with a male to female ratio of 2.5:1. The increase in notifications of sexually transmitted diseases is mainly due to the increased notifications for chlamydial infection. This, however, may only be a reflection of increased testing rather than disease incidence.
Figure 4. Notifications of sexually transmissible diseases, January 1991 to February 2000, by date of notification, and disease
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Vectorborne diseasesThere were 49 notifications of dengue with a notification month of February 2000. This was the same as for January 2000 (49), but an increase from February last year (21) and for the mean for the last 5 years (25) (Figures 5 and 6). The notifications were in all age groups with a male to female ratio of 1:1. The increase was mainly in Queensland (31) and Northern Territory (14) due to both imported cases and local transmission in Queensland, and elsewhere from imported cases mainly from East Timor.
Figure 5. Notifications of dengue, January 1991 to February 2000, by date of notification
Figure 6. Notifications of dengue, January 1999 to February 2000, by date of notification
There were 548 notifications of Ross River virus infection with a notification month of February 2000, which was an increase from January 2000 (536) but was less than for February last year (668) and for the mean for the last 5 years (887). The majority of notifications were in Queensland and Western Australia (70%) and mainly in the 25-49 year age group (64%), with a male to female ratio of 0.8:1
There were 88 notifications of malaria with a notification month of February 2000, which was an increase from January 2000 (71) and for the mean for the last 5 years (82), but was less than for February last year (91) (Figures 7 and 8). Of the cases, there were 55 from P. vivax, 22 P. falciparum, 2 P. ovale and 2 P. malariae. The majority of notifications were in Queensland (53) from returning service personnel from East Timor and from PNG students. The majority of notifications were in the 15-29 year age group (53%) with a male to female ratio of 3.3:1.
Figure 7. Notifications of malaria, January 1991 to February 2000, by date of notification
Figure 8. Notifications of malaria, January 1999 to February 2000, by date of notification
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Other bacterial diseasesThere were 33 notifications of legionellosis with a notification month of February 2000; the majority being in Victoria (60%). This was more than the notifications for January 2000 (17), and for the mean for the last 5 years (20) but was similar to February last year (38). The age for the notifications ranged from 25-79 years and the male to female ratio was 1.8:1. These cases were associated with an outbreak in Victoria.
This article was published in Communicable Diseases Intelligence Volume 24, Supplement, March 2000.