Communicable diseases

Communicable diseases are infectious diseases caused by bacteria, viruses, parasites, fungi, and prions.¹ The key difference is that communicable diseases can be transmitted from one person or animal to another, or by contact with a contaminated environment.

Communicable diseases of public health significance are notifiable by law in Queensland and in other jurisdictions. There are over 120 notifiable conditions in Queensland.² In 2022, there were 1,580,166 notifications of COVID-19³ and a further 144,986 notifications for all other notifiable conditions.

COVID-19, human immunodeficiency virus (HIV) and Ross River virus disease are examples of viral communicable diseases while syphilis and salmonellosis are bacterial communicable diseases. The following pages highlight a range of public health actions, including vaccination, that are implemented to prevent and/or reduce the transmission of, or severity of, the disease:

Health burden

Communicable diseases can cause significant morbidity and mortality, particularly affecting vulnerable groups such as the very young, the very old, and people with underlying health conditions. They can cause short term (acute) or long term (chronic) health conditions, or both.

Nationally, in 2022, infectious diseases caused 247,557 healthy years of life lost for an age-standardised rate (ASR or standardised rate) of 7.9 per 1,000 persons. There was a large increase from 2018 (91,843 years), predominantly driven by COVID-19.

For selected communicable diseases included in this section, the number and age-standardised rate of years of healthy life lost in 2022 were:

• Viral communicable diseases
  • COVID-19: 151,388 years (standardised rate 4.8 per 1,000 persons)
  • HIV: 2,842 years (standardised rate 0.11 per 1,000 persons)
  • Ross River virus disease: 96 years (standardised rate less than 0.5 per 1,000 persons).
• Bacterial communicable diseases
  • Syphilis: 54 years (standardised rate less than 0.5 per 1,000 persons)
  • Salmonellosis: 465 years (standardised rate less than 0.5 per 1,000 persons).

Corresponding disease expenditure for 2019–20 was $182.9 million (COVID-19), $369.7 million (HIV), $5.3 million (Ross River virus disease), $12.5 million (syphilis) and $17.5 million (salmonellosis ).⁴

Additional information

Data and statistics

• Communicable disease Notifiable conditions reports are updated weekly and available on the Queensland Health website.

Strategies and information

More information about communicable diseases and how they are controlled is available from the Queensland Health Communicable disease control and guidance website.

Section technical notes

• Notifications under-represent the incidence of communicable diseases because notifications depend on:
  • individuals presenting with the disease
  • having the appropriate tests undertaken to confirm a diagnosis
  • results being reported to Queensland Health.
• Laboratories, the source of most notifications, may not record First Nations status causing under-reporting among First Nations peoples.

References

1. Heymann DL. Control of Communicable Diseases Manual. 2022. Accessed 4 July  2021.
2. Queensland Health. Communicable disease control guidance. 10 November 2022.
3. Queensland Health. Notifiable conditions annual reporting. 2022. Accessed 14 November 2022.
4. Australian Institute of Health and Welfare. Disease Expenditure in Australia 2019-20. 2022. Accessed 20 December 2022.