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

Presentation of NNDSS data

In the March 2000 issue an additional summary table was introduced. Table 1 presents 'date of notification' data, which is a composite of three components: (i) the true onset date from a clinician, if available, (ii) the date the laboratory test was ordered, or (iii) the date reported to the public health unit. Table 2 presents the crude incidence of diseases by State or Territory for the current reporting month. Table 3 presents data by report date for information only. In Table 3 the report date is the date the public health unit received the report.

Table 1 now includes the following summary columns: total current month 2000 data; the totals for previous month 2000 and corresponding month 1999; a 5 year mean which is calculated using previous, corresponding and following month data for the previous 5 years (Morb Mortal Wkly Rep, 2000:49;139-146); year to date (YTD) figures; the mean for the year to date figures for the previous 5 years; and the ratio of the current month to the mean of the last 5 years.

Highlights for August, 2000

Communicable Disease Surveillance Highlights report on data from various sources, including the National Notifiable Diseases Surveillance System (NNDSS) and several disease specific surveillance systems that provide regular reports to Communicable Diseases Intelligence. These national data collections are complemented by intelligence provided by State and Territory communicable disease epidemiologists and/or data managers who have recently formed a Data Management Network. This additional information has enabled the reporting of more informative highlights each month.

The NNDSS is conducted under the auspices of the Communicable Diseases Network Australia New Zealand and the CDI Virology and Serology Laboratory Reporting Scheme (LabVISE) is a 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'.

Three types of data are included in National Influenza Surveillance, 2000. These are sentinel general practitioner surveillance conducted by the Australian Sentinel Practice Research Network (ASPREN), the Department of Human Services (Victoria), the Department of Health (New South Wales) and the Tropical Influenza Surveillance Scheme, Territory Health Services (Northern Territory); laboratory surveillance data from the Communicable Diseases Intelligence Virology and Serology Laboratory Reporting Scheme (LabVISE); and the World Health Organization Collaborating Centre for Influenza Reference and Research; and absenteeism surveillance conducted by Australia Post. Data from ASPREN are referred to as 'consultations' or 'encounters'. For further information about these schemes, see Commun Dis Intell 2000;24:9-10.

In August 2000 the number of reports of some diseases has increased compared with their 5 year mean; these include incident hepatitis B (1.6), incident hepatitis C (2.2), chlamydial infection (1.5), malaria (1.5), legionellosis (1.5) and meningococcal infection (1.3).

Typhoid

There were four notifications of typhoid in August 2000 with three cases in New South Wales (29 year-old male, 29 year old female and a 36 year old male) and one case in Victoria (15 year old male).

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Vaccine preventable diseases

All vaccine preventable diseases except mumps and pertussis had fewer reports this month than for the 5 year mean. The increase in the notification rate (1.1/100,000 population) for mumps was due to an increase in Western Australia (2.6/100,000 population) and New South Wales (1.9/100,000 population). The increase in the notification rate (34.6/100,000 population) (Figure 1) for pertussis was, as last month, due to an increase in the Australian Capital Territory (130.2/100,000 population) and New South Wales (64.6/100,000 population). Measles cases continued to be at their lowest level since the national notification system began (Figure 2). Of the two cases in August 2000, one each was reported in New South Wales (28 year-old male) and Western Australia (1 year-old female).

Figure 1. Notification rate of pertussis, New South Wales, Australian Capital Territory and Australia, 1 January 1991 to 31 August 2000, by month of notification



Figure 2. Notification rate of measles, Australia, 1 January 1991 to 31 August 2000, by month of notification

Malaria

There were 83 notifications of malaria in August 2000. The increase in the notification rate (5.3/100,000 population) (Figure 3) was due to an increase in the Northern Territory (56/100,000 population) and Queensland (14/100,000 population). Most cases were in the 15-34 age range (69%) and were mainly returning service personnel and students; all were imported.

Figure 3. Notification rate of malaria, Australia, 1 January 1991 to 31 August 2000, by month of notification

Legionellosis

There were 18 notifications of legionellosis in August 2000. The increase in the notification rate (1.1/100,000 population) was due to an increase in South Australia (6.4/100,000 population).

Meningococcal infections

There were 74 notifications of meningococcal infection in August 2000 - a notification rate of 4.7/100,000 population (Figure 4). Of these cases, 34 per cent were under 5 years of age, 15 per cent were in the 5-14 year age range and 30 per cent were in the 15-24 age range. The serogroups were available for 40 cases; of these 53 per cent, 43 per cent and 5 per cent were serogroup B, C and Y respectively.

Figure 4. Notification rate of meningococcal infection, Australia, 1 January 1991 to 31 August 2000, by month of notification



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Influenza

There were 107 laboratory reports of influenza for August 2000, a decrease from 647 in August 1999, and a decrease from 185 in July 2000 (Figure 5). Of the laboratory reports received in August 2000 for weeks 31-35, 91 were influenza A and 29 were influenza B, with the weekly proportion of influenza B varying from 18 per cent to 38 per cent (Figure   6). The weekly percentage of influenza B has increased from the same period last year when it varied between 6 per cent and 16 per cent.

Figure 5. Laboratory reports of influenza, 1999 to 2000, by month of specimen collection



Figure 6. Laboratory reports of influenza, Australia, week 36 1999 to week 35 2000, by week of specimen collection



The percentages of Australia Post employees absent in August 2000 (weeks 31-35) for 3 or more consecutive days remained similar to last year and to the previous month, although there were some weekly fluctuations (Figure 7). All of the influenza surveillance schemes reported an increase in the rate of influenza-like illness consultations with the New South Wales Influenza Surveillance Scheme reporting the highest rate (32/1,000 consultations) in August 2000 (weeks 31-35; Figure 8).

Figure 7. Absenteeism rates in Australia Post, 1999 and 2000 to 31 August



Figure 8. Sentinel general practitioner influenza consultation rates, week 36 1999 to week 35 2000, by scheme




This article was published in Communicable Diseases Intelligence Volume 24, No 9, September 2000.