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2000: The year in review

In 2000, there were continuing challenges to and advances in communicable disease control in Australia. Important initiatives were taken which will have impacts on communicable diseases surveillance and control well into the future.

In September 2000, Sydney hosted the Olympic games. This event drew around 300,000 domestic and international visitors as well as 15,000 athletes and officials from 200 countries. Media attention was intense with around 15,000 media personnel attending the games. The size of this event necessitated active health surveillance covering notifiable diseases as well as surveillance of presentations to emergency departments and medical centres, and environmental and food safety inspections.¹ Data from all these sources were entered into a special database and reviewed daily by medical epidemiologists. High priority diseases for surveillance included foodborne diseases, pneumonia, influenza, pertussis, meningitis, measles and hepatitis. The Games were completed without any major public health incidents.

In April 2000, a large outbreak of legionellosis occurred in Melbourne, with 113 cases notified in Victoria and another 12 cases elsewhere in Australia and New Zealand. The outbreak was associated with visits to the Melbourne aquarium and resulted in 4 deaths. A contaminated water-cooling tower was implicated.

The deployment of 5,500 Australian Defence Forces (ADF) to East Timor in late 1999 resulted in increased exposure to malaria and dengue. Two hundred and sixty-seven ADF personnel contracted malaria, with 64 developing clinical symptoms in East Timor and 212 being diagnosed on return to Australia. A further 26 ADF personnel contracted dengue.

A milestone in communicable disease control was passed in October 2000, when Australia, along with all other countries in the Western Pacific Region (WPR) was declared polio-free by the World Health Organization (WHO). Australia's last case of polio was reported in 1977 and all cases since then have been vaccine associated.²

A special issue of the Medical Journal of Australia in October 2000 focussed attention on the burden of pneumococcal disease in Australia and future use of pneumococcal vaccines. The incidence of pneumococcal disease among Aboriginal children in central Australia is among the highest in the world.³ To date, vaccines composed of pneumococcal polysaccharides were the only available and these were not effective in preventing infections in children. In 2000, the first efficacy trial of a new multivalent conjugate vaccine against Streptococcus pneumoniae showed a very high protective efficacy against invasive pneumococcal disease in children.⁴ The vaccine was licensed for use in Australia in December 2000 and recommendations for a vaccination program in Australian children were published in March 2001. It is hoped that this vaccination program, focussing on groups of children at highest risk of disease, will have a major impact on pneumococcal disease in Australia.

An important new initiative in the control of foodborne disease in Australia was launched in 2000. The Commonwealth Department of Health and Ageing (DoHA) established and funded a collaborative network, called 'OzFoodNet' to enhance the existing surveillance mechanisms for foodborne disease across Australia. OzFoodNet aims to estimate the incidence of foodborne disease in Australia, to learn more about causes and determinants of foodborne disease, to identify risky practices associated with food handling and preparation and to train foodborne disease epidemiologists.⁵ Specific studies include a national survey of diarrhoeal disease prevalence, case control studies on risk factors for infections with Campylobacter, Salmonella Enteriditis, Listeria and Shiga-like toxin producing Escherichia coli (SLTEC) and developing a register to record foodborne disease outbreaks.

In August 2000, the Commonwealth published an implementation plan in response to the report by the Joint Expert Advisory Committee on Antibiotic Resistance (JETACAR) The use of antibiotics in food-producing animals: antibiotic resistant bacteria in animals and humans. An interdepartmental implementation group guided by an expert advisory committee is working on developing surveillance systems to monitor the prevalence of antibiotic resistance and other measures to control the prevalence of antibiotic resistance in Australia.

As international concern over variant Creutzfeldt-Jakob disease (vCJD) increased in 2000, Australian Health Ministers implemented a blood donor deferral policy from people who had resided in the United Kingdom (UK) for 6 months or more during the period 1980 to 1996. No cases of bovine spongiform encephalopathy have been found in Australian cattle nor have there been any cases of vCJD in Australia to date.

Since 1991, national communicable disease notification data has been collected and collated under the National Notifiable Diseases Surveillance System (NNDSS). In 2000, Australian States and Territories agreed with the Commonwealth to collect more comprehensive data on each case notified to the NNDSS and began planning for enhanced surveillance for a number of key diseases. The new data set will provide more detail on the causative organism and the vaccination status of the case, and provide more comprehensive epidemiological data. This will allow more sophisticated analyses of the national communicable diseases data set. Improvements in the electronic transfer of data from States and Territories to NNDSS continued in 2000. Development of a new data acquisition system was commenced and discussion around appropriate data collection for enhanced tuberculosis (TB) surveillance was initiated. This enhanced surveillance was an initiative of the National TB Advisory Committee and will improve national monitoring of TB in Australia by recording complete clinical data, including antibiotic susceptibility, and outcomes of treatment on all notified cases.

In summary, communicable disease control in Australia in 2000 was advanced by the certification of polio eradication and the introduction of new vaccine initiatives for pneumococcal disease. Improvements to understanding the epidemiology of foodborne disease in Australia through the OzFoodNet initiative and the prevalence of antibiotic resistance will have long-term benefits for disease control. Improvements to data quality and information systems will further enhance the national surveillance system and communicable disease control.

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Introduction

It is of critical importance to collect, analyse and report surveillance data on potential communicable diseases. This action is essential to the success of public health efforts. Surveillance allows the detection of disease outbreaks prompting the appropriate investigation and control measures to be instigated. Surveillance also allows for the monitoring of trends in disease prevalence and considers the impact and effectiveness of interventions to control the spread of diseases. Surveillance systems exist at national, state and local levels. State and local surveillance systems are crucial to the timely and effective detection and management of outbreaks and in assisting in the effective implementation of national policies. The national surveillance system combines some of the data collected from state and territory-based systems to provide an overview at a national level. Specific functions of the national surveillance system include: detection and management of outbreaks affecting more than one jurisdiction; monitoring of the need for and impact of national control programs; guidance of national policy development; resource allocation and description of the epidemiology of rare diseases for which there are only a few notifications in each jurisdiction. National surveillance also assists with quarantine activities and facilitates agreed international collaborations such as reporting to the WHO.

The National Notifiable Diseases Surveillance System was established in its current form in 1991, under the auspices of the Communicable Diseases Network Australia (CDNA, formally the Communicable Diseases Network of Australia and New Zealand). The CDNA monitors the notification/reporting of an agreed list of communicable diseases in Australia. Data are regularly published in the Communicable Diseases Intelligence (CDI)journal and on the Communicable Diseases - Australia Website.This is achieved through the national collation of notifications of these diseases received by health authorities in the States and Territories. In 2000, 50 diseases or disease categories were included, largely as recommended by the National Health and Medical Research Council (NHMRC).⁶[ In years since 2000 the list of notifiable diseases and categories has undergone review and revision. Information collected on notifiable diseases has been published in the Annual Report of the NNDSS since 1991.[^{7,8,9,10,11,12,13,14,15}

In 2000, 50 diseases or disease categories were nationally notifiable in Australia (Table 1) and the national case definitions used in this year are listed in Appendix 1a-1h.

Top of pageTable 1. Diseases notified to the National Notifiable Diseases Surveillance System, Australia, 2000

Disease group	Disease	Comments
Bloodborne diseases	Hepatitis B (incident)	All jurisdictions
	Hepatitis B (unspecified)	All jurisdictions except NT
	Hepatitis C (incident)	All jurisdictions except NT, Qld*
	Hepatitis C (unspecified)	All jurisdictions
	Hepatitis D	All jurisdictions except WA
	Hepatitis (NEC)	All jurisdictions except WA
Gastrointestinal diseases	Botulism	All jurisdictions except WA
	Campylobacteriosis	All jurisdictions except NSW
	Haemolytic uraemic syndrome	All jurisdictions
	Hepatitis A	All jurisdictions
	Hepatitis E	All jurisdictions except WA
	Listeriosis	All jurisdictions
	Salmonellosis	All jurisdictions
	Shigellosis	All jurisdictions except NSW
	SLTEC,VTEC	All jurisdictions except Qld, WA
	Typhoid	All jurisdictions
	Yersiniosis	All jurisdictions except NSW
Quarantinable diseases	Cholera	All jurisdictions
	Plague	All jurisdictions
	Rabies	All jurisdictions
	Viral haemorrhagic fever	All jurisdictions
	Yellow fever	All jurisdictions
Sexually transmitted infections	Chancroid	All jurisdictions
	Chlamydial infections	All jurisdictions
	Donovanosis	All jurisdictions except NSW, SA
	Gonococcal infection	All jurisdictions
	Lymphogranuloma venereum	All jurisdictions except WA
	Syphilis	All jurisdictions
Vaccine preventable diseases	Diphtheria	All jurisdictions
	Haemophilus influenzae type B	All jurisdictions
	Measles	All jurisdictions
	Mumps	All jurisdictions except Qld †
	Pertussis	All jurisdictions
	Poliomyelitis	All jurisdictions
	Rubella	All jurisdictions
	Tetanus	All jurisdictions
Vectorborne diseases	Arbovirus infection (NEC)	All jurisdictions
	Barmah Forest virus infection	All jurisdictions
	Dengue	All jurisdictions
	Malaria	All jurisdictions
	Ross River virus infection	All jurisdictions
Zoonoses	Brucellosis	All jurisdictions
	Hydatid disease	All jurisdictions except NSW
	Leptospirosis	All jurisdictions
	Ornithosis	All jurisdictions except NSW and Qld
	Q fever	All jurisdictions
Other bacterial infections	Legionellosis	All jurisdictions
	Leprosy	All jurisdictions
	Meningococcal infection	All jurisdictions
	Tuberculosis	All jurisdictions

*Notifications of hepatitis C (incident) were reported under hepatitis C (unspecified) in the Northern Territory and Queensland.
† Notifications of mumps was removed from the notification list in Queensland from 2 July 1999 and the entire year of 2000.
NEC: not elsewhere classified

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Methods

Australia is a federation of six States (New South Wales, Queensland, South Australia, Tasmania, Victoria and Western Australia) and two Territories (the Australian Capital Territory and the Northern Territory). The States and Territories collect notifications of communicable diseases under their public health legislation. The Commonwealth (or Federal) Government does not have any legislated responsibility for public health apart from human quarantine. States and Territories have agreed to forward data on communicable diseases to the DoHA for the purposes of national communicable disease surveillance.

In 2000, data were transmitted from States and Territories to DoHA, fortnightly. Summaries of the data were published on the Communicable Diseases - Australia Website fortnightly and in the CDI monthly. The Commonwealth received final data sets from the States and Territories of cases reported in 2000 by August 2001. Missing data and apparent errors together with any queries arising from the data were returned to jurisdictions for review, correction of errors and ascertainment of completeness of case information for the year.

For each case the national data set includes fields for a unique record reference number; jurisdiction of notification; disease code; age; sex; Indigenous status; postcode of residence; the date of onset of the disease and date of report to the State or Territory health authority. Analysis of the data by Indigenous status was not possible because of the incomplete reporting of this information. Additional information was available on the species and serogroups isolated in cases of legionellosis, meningococcal disease and malaria, and on the vaccination status in cases of childhood vaccine preventable diseases. Additional information was obtained from States and Territories concerning mortality and specific health risk factors of some diseases.

Analyses in this report are based on date of disease onset, unless specified. For analysis of seasonal trends, notifications were reported by month of onset. Population notification rates were calculated using 2000 mid-year estimates of the resident population supplied by the Australian Bureau of Statistics (ABS). An adjusted rate was calculated where a disease was not notifiable in a State or Territory, using a denominator which excluded that population.

Maps were generated using MapInfo based on the postcode of residence and allocated to Australian Bureau of Statistics Statistical Divisions (Map 1). The two Statistical Divisions that make up the Australian Capital Territory were combined, as the population for one division is very small. Notifications for Darwin and the remainder of the Northern Territory were also combined to calculate rates for the Northern Territory as a whole. In general, notification rates for Statistical Divisions were depicted in maps or discussed in the text only where the number of notifications was sufficiently large for these to be meaningful.

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Notes on interpretation

The notifications compiled by the NNDSS may be influenced by a number of factors that should be considered when interpreting the data. Due to under-reporting, notified cases are likely to only represent a proportion of the total number of cases that occurred (Figure 1). This proportion (the 'notified fraction') may vary between diseases, between States and Territories and with time.

Figure 1. Communicable disease surveillance pyramid

Adopted from CDC Website. (http://www.cdc.gov/foodnet/surveillance_pages/burden_pyramid.htm)

The burden of illness pyramid is a model for understanding disease reporting. This illustration shows the chain of events that must occur for an episode of illness in the population to be registered in surveillance. At the bottom of the pyramid, 1) some of the general population is exposed to an organism; 2) some exposed persons become ill; 3) the illness is sufficiently troubling that some persons seek care; 4) a specimen is obtained from some persons and submitted to a clinical laboratory; 5) a laboratory appropriately tests the specimen; 6) the laboratory identifies the causative organism and thereby confirms the case, or the diagnosing doctors confirms the case on clinical grounds; 7) the laboratory-confirmed or clinically confirmed case is reported to a local or state health department, then to the Commonwealth.

Methods of surveillance may vary between jurisdictions, each with different requirements for notification by medical practitioners, laboratories and hospitals. In addition, the list of notifiable diseases and the case definitions may vary between jurisdictions.

Postcode information usually reflects the postcode of residence. However, the postcode of residence may not necessarily represent the place of acquisition of the disease, or the area in which public health action was taken in response to the notification.

As no personal identifiers are collected in records, duplication in reporting may occur if patients moved from one jurisdiction to another and were notified in both. Data from those Statistical Divisions with small populations (Map 1) may result in high notification rates even with small numbers of cases.

The completeness of data in this report is summarised in Appendix 2. The patient's sex was missing in 0.5 per cent of notifications (n=420) and patient's age missing in 0.4 per cent of notifications (n=340). The patient's Indigenous status was reported for 28,552 notifications (31.8%) nationally. The proportion of reports with missing data in these fields varied by State or Territory, and also by disease.

Data were analysed by date of disease onset, unless specified. The date of disease onset is uncertain for some communicable diseases and is often equivalent to the date of presentation to a medical practitioner or date of specimen collection at a laboratory. Analysis by disease onset is an attempt to estimate disease activity within a reporting period. Analysis by date of onset should be interpreted with caution, particularly for chronic diseases such as hepatitis B and C, as considerable time may have elapsed between onset and report date for these diseases. To overcome this problem, analysis was performed by report date for hepatitis B (unspecified) and hepatitis C (unspecified).

Rates per 100,000 population were calculated using State/Territory and national population estimates for mid-year 2000 (Appendix 3) supplied by the Australian Bureau of Statistics. Mortality statistics for 2000 were available from the ABS in 2001. The Australian Institute of Health and Welfare (AIHW) supplied hospital admission data for the financial year 1999/2000.

Between May and August every year, the NNDSS receives a final annual dataset from all jurisdictions to update its system. This yearly operation only updates the notifications reported to the NNDSS during the last calendar year. States and Territories continue to revise totals from previous years as duplicates are removed and other data corrected. However, the NNDSS had not revised its historical notifications since 1991. As a result, there was considerable difference in the number of notifications held in the NNDSS and the State and Territory records. Providing high quality and precise information that is consistent with State and Territory records is a vital part of maintaining good surveillance information. In 2001, the CDNA approved the revising of the NNDSS records with jurisdictions' 1991 to 1999 historical notifications. During November to December 2001, all jurisdictions, except Victoria resent notifications collected between 1991 and 1999, to the NNDSS. Victoria confirmed that records held at the Commonwealth level were accurate. Comparative historical data for 1991 to 1999 used in this report represents more accurate information and may vary from previous reports.

During 2000, data were analysed monthly and the result and commentary published in CDI. In contrast, this report is based on 'finalised' annual data from each jurisdiction, from which duplicates or erroneous records have been removed. For this reason, totals in this report may vary from the cumulative totals of the numbers reported in the monthly CDI reports. This report is informed by the discussions and comments of members of the CDNA, who met fortnightly by teleconference to discuss developments in communicable disease in their jurisdiction. The CDNA data managers also met through 2000 and their contribution to accurate data in this report is gratefully acknowledged.

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Results

Summary of 2000 data

There were a total of 89,740 communicable disease notifications for 2000 (Table 2). Notification rates per 100,000 population for each disease by State or Territory are described in Table 3.

The number of notifications in 2000 was an increase of 5.9 per centon notifications in 1999 (84,743) and the largest number of reports since the NNDSS commenced in 1991 (Figure 2). Nationally in 2000, bloodborne infections remained the most frequently notified disease group (28,341 cases; 32% of total), followed by 24,319 sexually transmitted infections (27%), 21,303 gastrointestinal infections (24%), 6,617 vaccine preventable diseases (7%), 6,069 vectorborne diseases (7%), 2,121 other bacterial infections (2%), 969 zoonotic infections (1%) and only one case of a quarantinable disease (Figure 3).

Figure 2. Trends in notification rates of communicable diseases, Australia, 1991 to 2000



Figure 3. Breakdown of communicable disease notifications by disease category



The major changes in notifications in 2000 are shown in Figure 4. as a ratio of notifications received in the year compared with the mean of the preceding 5 years. Only diseases with major changes in numbers of notifications in 2000 are shown. There were major increases in notifications of legionellosis and dengue. Increases were also noted in the reporting of hepatitis B (both incident and unspecified), hepatitis C (incident), gonococcal infection, mumps, malaria and meningococcal infection. Measles notifications fell by more than 50 per cent compared with 1999. Declines in Haemophilus influenzae type b (Hib) infections and rubella were also noted.

Top of pageFigure 4. Selected diseases from National Notifiable Diseases Surveillance System, comparison of totals for 2000 with previous 5 year mean



In 2000, infectious diseases accounted for 3.6 per cent of all deaths in Australia (4,582 deaths, 23.9 deaths per 100,000 population). Pneumonia and influenza remained as the major death cause of infectious diseases, accounting for more 50 per cent of deaths from infectious diseases (2,937 deaths, 15.3 deaths per 100,000 population). Death rates from pneumonic and influenza generally increased with age and were greater for males than females aged 60 years and over. However, the highest rate was in the 35 to 39 year age group (2.2 deaths per 100,000 population) for HIV/AIDS. There was a total of 12,859 infectious disease related hospitalisations during the 1999/2000 financial year. (Source: National Hospital Morbidity Database, 1990-2000: AIHW) Among these hospitalisations, influenza/pneumonia was the most common cause for admission, accounting for 20.1 per cent of the total hospitalisations (2,591 admissions). It should be noted that a range of causative agents are included in the broad ICD-10 coding group of 'influenza/pneumonia'.

Top of pageTable 2. Notifications of communicable diseases, Australia, 2000, by State or Territory*

Disease	ACT	NSW	NT	Qld	SA	Tas	Vic	WA	Aust
Bloodborne diseases
Hepatitis B (incident)	3	96	6	56	30	18	114	72	395
Hepatitis B (unspecified)†‡	48	3,893	NN	896	257	48	1,964	802	7,908
Hepatitis C (incident)	20	139	-	-	89	31	87	75	441
Hepatitis C (unspecified)†‡§	212	7,265	183	3,395	788	335	5,730	1,661	19,569
Hepatitis D	0	10	0	5	0	0	12	NN	27
Hepatitis (NEC)	0	1	0	0	0	0	0	NN	1
Gastrointestinal diseases
Botulism	0	0	1	0	0	0	1	NN	2
Campylobacteriosis||	333	-	182	3,675	1,883	510	5,037	1,975	13,595
Haemolytic uraemic syndrome	0	9	0	2	1	0	2	1	15
Hepatitis A	5	200	44	133	54	3	193	180	812
Hepatitis E	0	9	0	0	0	1	0	NN	10
Listeriosis	0	18	3	13	7	3	10	13	67
Salmonellosis	105	1,409	304	1,827	450	131	1,021	904	6,151
Shigellosis||	7	-	114	108	30	2	120	106	487
SLTEC,VTEC¶	0	0	0	NN	33	0	0	NN	33
Typhoid	0	27	0	2	3	0	14	12	58
Yersiniosis||	3	-	2	59	0	0	8	1	73
Quarantinable diseases
Cholera	0	0	0	0	1	0	0	0	1
Plague	0	0	0	0	0	0	0	0	0
Rabies	0	0	0	0	0	0	0	0	0
Viral haemorrhagic fever	0	0	0	0	0	0	0	0	0
Yellow fever	0	0	0	0	0	0	0	0	0
Sexually transmissible diseases
Chancroid	0	0	0	0	0	0	0	0	0
Chlamydial infection	243	3,482	959	4,931	1,023	332	3,336	2,560	16,866
Donovanosis	0	NN	5	6	NN	0	0	1	12
Gonococcal infection**	14	1,060	1,128	1,137	270	17	742	1,318	5,686
Lymphogranuloma venereum	0	0	0	0	0	0	0	NN	0
Syphilis††	13	541	175	887	13	9	8	109	1,755
Vaccine preventable diseases
Diphtheria	0	0	0	0	0	0	0	0	0
Haemophilus influenzae type b	0	8	2	12	2	0	3	1	28
Measles	3	35	0	26	11	1	21	10	107
Mumps	17	92	4	NN	15	2	43	39	212
Pertussis	208	3,683	5	525	588	143	699	91	5,942
Poliomyelitis	0	0	0	0	0	0	0	0	0
Rubella‡‡	4	191	0	46	7	1	67	6	322
Tetanus	0	2	0	0	3	0	1	0	6
Vectorborne diseases
Arbovirus infection NEC	0	12	9	10	0	1	26	11	69
Barmah Forest virus infection	0	190	9	346	12	0	19	58	634
Dengue	1	21	93	84	6	0	2	8	215
Malaria	18	231	76	409	41	7	115	54	951
Ross River virus infection	16	746	128	1,477	415	8	326	1,084	4,200
Zoonoses
Brucellosis	0	1	0	26	0	0	0	0	27
Hydatid infection	0	NN	0	8	0	0	13	5	26
Leptospirosis	1	53	8	134	8	0	35	4	243
Ornithosis	0	NN	1	NN	6	6	85	2	100
Q fever	0	130	0	390	11	1	27	14	573
Other diseases
Legionellosis	5	41	1	47	89	4	250	35	472
Leprosy	0	2	0	1	1	0	0	0	4
Meningococcal infection	5	253	9	60	32	15	162	85	621
Tuberculosis	18	438	43	89	58	10	284	84	1,024
Total	1,302	24,288	3,494	20,822	6,237	1,639	20,577	11,381	89,740

* Analysis by date of onset, except for hepatitis B and hepatitis C unspecified, where analysis is by report date. Date of onset 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 NNDSS.
† Unspecified hepatitis includes cases with hepatitis in whom the duration of illness can not be determined.
‡ The analysis was performed by report date.
§ Includes hepatitis C (incident) cases in Northern Territory and Queensland.
|| Notified as 'foodborne disease' or 'gastroenteritis in an institution' in New South Wales.
¶ Infections with Shiga-like toxin (verotoxin) producing E. coli (SLTEC/VTEC).
** Northern Territory, Queensland, South Australia, Victoria, and Western Australia: includes gonococcal neonatal ophthalmia.
†† Includes congenital syphilis.
‡‡ Includes congenital rubella.
NN Not notifiable.
NEC Not Elsewhere Classified.
- Elsewhere classified.

Top of pageTable 3. Notification rates of communicable diseases, Australia, 2000, by State or Territory (rate per 100,000 population)*

Disease	ACT	NSW	NT	Qld	SA	Tas	Vic	WA	Aust
Bloodborne diseases
Hepatitis B (incident)	1.0	1.5	3.1	1.6	2.0	3.8	2.4	3.8	2.1
Hepatitis B (unspecified)†‡	15.3	60.2	NN	25.1	17.2	10.2	41.2	42.6	41.7
Hepatitis C (incident)	6.4	2.2	-	-	5.9	6.6	1.8	4.0	2.9
Hepatitis C (unspecified)†‡§	67.5	112.4	93.6	95.2	52.6	71.2	120.2	88.2	102.2
Hepatitis D	0.0	0.2	0.0	0.1	0.0	0.0	0.3	NN	0.2
Hepatitis (NEC)	0.0	< 0.1	0.0	0.0	0.0	0.0	0.0	NN	< 0.1
Gastrointestinal diseases
Botulism	0.0	0.0	0.5	0.0	0.0	0.0	< 0.1	NN	< 0.1
Campylobacteriosis||	106.0	-	93.1	103.0	125.7	108.4	105.7	104.8	107.1
Haemolytic uraemic syndrome	0.0	0.1	0.0	0.1	0.1	0.0	< 0.1	0.1	0.1
Hepatitis A	1.6	3.1	22.5	3.7	3.6	0.6	4.0	9.6	4.2
Hepatitis E	0.0	0.1	0.0	0.0	0.0	0.2	0.0	NN	0.1
Listeriosis	0.0	0.3	1.5	0.4	0.5	0.6	0.2	0.7	0.3
Salmonellosis	33.4	21.8	155.5	51.2	30.0	27.9	21.4	48.0	32.1
Shigellosis||	2.2	-	58.3	3.0	2.0	0.4	2.5	5.6	3.8
SLTEC,VTEC¶	0.0	0.0	0.0	NN	2.2	0.0	0.0	NN	0.2
Typhoid	0.0	0.4	0.0	0.1	0.2	0.0	0.3	0.6	0.3
Yersiniosis||	1.0	-	1.0	1.7	0.0	0.0	0.2	0.1	0.6
Quarantinable diseases
Cholera	0.0	0.0	0.0	0.0	0.1	0.0	0.0	0.0	< 0.1
Plague	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Rabies	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Viral haemorrhagic fever	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Yellow fever	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Sexually transmissible diseases
Chancroid	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Chlamydial infection	77.4	53.9	490.6	138.3	68.3	70.6	70.0	135.9	88.0
Donovanosis	0.0	NN	2.6	0.2	NN	0.0	0.0	0.1	0.1
Gonococcal infection**	4.5	16.4	577.1	31.9	18.0	3.6	15.6	70.0	29.7
Lymphogranuloma venereum	0.0	0.0	0.0	0.0	0.0	0.0	0.0	NN	0.0
Syphilis††	4.1	8.4	89.5	24.9	0.9	1.9	0.2	5.8	9.2
Vaccine preventable diseases
Diphtheria	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Haemophilus influenzae type b	0.0	0.1	1.0	0.3	0.1	0.0	0.1	0.1	0.1
Measles	1.0	0.5	0.0	0.7	0.7	0.2	0.4	0.5	0.6
Mumps	5.4	1.4	2.0	NN	1.0	0.4	0.9	2.1	1.4
Pertussis	66.2	57.0	2.6	14.7	39.3	30.4	14.7	4.8	31.0
Poliomyelitis	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Rubella‡‡	1.3	3.0	0.0	1.3	0.5	0.2	1.4	0.3	1.7
Tetanus	0.0	< 0.1	0.0	0.0	0.2	0.0	< 0.1	0.0	< 0.1
Vectorborne diseases
Arbovirus infection NEC	0.0	0.2	4.6	0.3	0.0	0.2	0.5	0.6	0.4
Barmah Forest virus infection	0.0	2.9	4.6	9.7	0.8	0.0	0.4	3.1	3.3
Dengue	0.3	0.3	47.6	2.4	0.4	0.0	< 0.1	0.4	1.1
Malaria	5.7	3.6	38.9	11.5	2.7	1.5	2.4	2.9	5.0
Ross River virus infection	5.1	11.5	65.5	41.4	27.7	1.7	6.8	57.5	21.9
Zoonoses
Brucellosis	0.0	< 0.1	0.0	0.7	0.0	0.0	0.0	0.0	0.1
Hydatid infection	0.0	NN	0.0	0.2	0.0	0.0	0.3	0.3	0.2
Leptospirosis	0.3	0.8	4.1	3.8	0.5	0.0	0.7	0.2	1.3
Ornithosis	0.0	NN	0.5	NN	0.4	1.3	1.8	0.1	1.1
Q fever	0.0	2.0	0.0	10.9	0.7	0.2	0.6	0.7	3.0
Other bacterial infections
Legionellosis	1.6	0.6	0.5	1.3	5.9	0.9	5.2	1.9	2.5
Leprosy	0.0	< 0.1	0.0	< 0.1	0.1	0.0	0.0	0.0	< 0.1
Meningococcal infection	1.6	3.9	4.6	1.7	2.1	3.2	3.4	4.5	3.2
Tuberculosis	5.7	6.8	22.0	2.5	3.9	2.1	6.0	4.5	5.3
Total	414.6	375.8	1,787.6	583.8	416.5	348.4	431.8	604.1	468.4

* Analysis by date of onset, except for hepatitis B and hepatitis C unspecified, where analysis is by report date. Date of onset 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 NNDSS.
† Unspecified hepatitis includes cases with hepatitis in whom the duration of illness can not be determined.
‡ The analysis was performed by report date.
§ Includes hepatitis C (incident) cases in Northern Territory and Queensland.
|| Notified as 'foodborne disease' or 'gastroenteritis in an institution' in New South Wales.
¶ Infections with Shiga-like toxin (verotoxin) producing E. coli (SLTEC/VTEC).
** Northern Territory, Queensland, South Australia, Victoria, and Western Australia: includes gonococcal neonatal ophthalmia.
†† Includes congenital syphilis.
‡‡ Includes congenital rubella.
NN Not notifiable.
NEC Not Elsewhere Classified.
- Elsewhere classified.

This article was published in Communicable Diseases Intelligence Volume 26, No 2, June 2002