Viral communicable diseases

Introduction

This section includes selected communicable diseases caused by viral infections. Specifically, acute respiratory infections from COVID-19, influenza, respiratory syncytial virus (RSV) infection and the emerging disease, mpox.

Communicable diseases can cause widespread illness, with severe outcomes for vulnerable populations, including children, the elderly, and immunocompromised individuals. Disease surveillance is an important component of outbreak preparedness, prevention and response along with two-way communication, public awareness and preventive measures like immunisation, to mitigate the impact of these diseases on communities.

Information in this section is presented as weekly counts, age-specific rates (ASpR) and age-standardised rates (ASRs or standardised rates) by sociodemographic characteristics including by remoteness¹ and the area-based index of relative socioeconomic advantage and disadvantage.² Further information, including weekly updates of all communicable disease conditions reported in Queensland, is available on the Queensland Health Surveillance reports.

Health burden

Nationally, for the subset of conditions included in this section, the number and standardised rates for years of healthy life lost in 2024 were:

• COVID-19: 43,950 years (standardised rate 1.2 per 1,000 persons)
• lower respiratory infections (including influenza and pneumonia): 46,968 years (standardised rate 1.4 per 1,000 persons).³

Corresponding health expenditure information for 2022–23 was $3.247 billion (lower respiratory infections) and $1.823 billion (COVID-19).⁴

Acute respiratory infections

COVID-19, influenza and Respiratory Syncytial Virus (RSV) are all respiratory infections caused by viruses, primarily spread from person to person through airborne and droplet transmission from an infected person through breathing, talking, coughing or sneezing. These viruses can spread when they come into contact with the mucous membranes of the mouth, eyes, or nose. Additionally, these viruses may contaminate surfaces, and infection can occur if a person touches these surfaces and then transfers the virus to their body. Risk of infection is best managed by keeping up-to-date with recommended vaccination, and practising good hand and respiratory hygiene.

• COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. It can affect individuals of all age groups. Most infected individuals experience mild to moderate symptoms and recover without requiring hospitalisation. However, older adults and those with underlying medical conditions are at a higher risk of developing severe disease or death from COVID-19.
• Influenza (‘the flu’) is not the same as a common cold. Influenza is caused by infection with one of four influenza viruses (A, B, C, and D). It is a highly contagious disease and while most people who contract influenza will recover without treatment, it can be a serious illness resulting in hospitalisation and death. Influenza occurs year round, with influenza circulation typically increasing in Queensland from May to September with the peak usually in August. Influenza vaccination is recommended in pregnancy and annually for children, older adults and those with underlying medical conditions. These groups are at a higher risk of severe disease or death from influenza.
• RSV is a common cause of respiratory illness, but it is not the common cold. RSV can affect people of all ages and is one of the most common causes of hospitalisation in infants and young children. Almost all children experience at least one RSV infection within the first two years of life. Older adults with complications in their heart, lungs, or immune system are at greater risk of serious illness and may be admitted to hospital. Public health strategies, including improved awareness, timely diagnosis, vaccination, and infection control measures, are essential for mitigating RSV-related morbidity and mortality, especially among vulnerable populations.

COVID-19

There were 74,331 COVID-19 cases reported in 2024, with a standardised rate of 13.0 per 1,000 persons (Figure 1). In 2024, higher numbers of cases were observed in summer and winter months.

Sociodemographic differences

In 2024, Queensland standardised rates for COVID-19 were (Figure 1):

• 28.5% higher among females than males (14.6 compared to 11.4 per 1,000, respectively)
• highest for those in remote areas, while those in outer regional areas were lowest
• 15.4% higher for those in the most disadvantaged areas than for those in the most advantaged areas.

In adults 75 years and older age-specific rates were 9.2 times higher than for those 5 to 19 years in 2024.

Trends

From 2020 to 2024, there have been 1,827,215 identified cases of COVID-19 in Queensland as of 13 January 2025. Annual standardised rates over that time period align with the transition from ‘keeping the virus out’ during the early phases of pandemic to the easing of many public health measures after high rates of vaccination were achieved in the population. Males and females showed similar trends over this period, with standardised rates somewhat higher for females than males in each year.

Figure 1: Queensland COVID-19 cases, rates and trends

Influenza

There were 79,406 cases reported in 2024 for a standardised rate of 15.4 per 1,000 persons. The influenza rate (Figure 2) was 18.4% higher than COVID-19 (Figure 1). In 2024, the weekly case count reflects a seasonal surge typical of influenza, emphasising the importance of timely vaccination and preventive measures during peak transmission periods.

Sociodemographic differences

In 2024, Queensland standardised rates for Influenza were (Figure 2):

• 16.9% higher among females than males (16.5 compared to 14.2 per 1,000, respectively)
• 16.6% higher among those in remote areas than those in major cities
• 5.9% higher among those in the most disadvantaged areas than those in the most advantaged areas.

Age-specific rates were 2.7 times higher for children 0 to 4 years than for adults 65 years and older.

Trends

Annual trends in standardised influenza rates since 2015 show peaks in 2017 and 2019, record lows in 2020 and 2021, coinciding with efforts to interrupt COVID-19 transmission during the pandemic. This was followed by record highs in 2023 and 2024. In most years, standardised rates were higher for females than males.

Figure 2: Queensland influenza cases, rates and trends

Respiratory Syncytial Virus

There were 42,378 RSV cases reported in 2024 for a standardised rate of 8.2 per 1,000 persons (Figure 3). In 2024, the weekly case count increased steadily through the early part of the year peaking between weeks 14 and 23 at approximately 1,500 cases per week, then gradually declining with some fluctuations in later weeks. This pattern reflects a typical seasonal outbreak over the year.

Sociodemographic differences

In 2024, Queensland standardised rates for RSV were (Figure 3):

• 18.1% higher among females than males
• 35.3% higher among those in inner regional areas than those living in outer regional areas
• 6.4% higher among those in the most advantaged areas than those in the most disadvantaged areas which contrasts with COVID-19 and influenza.

Children 0 to 4 years had the highest rates of RSV (59.8 cases per 1,000), which was 7.1 times higher than adults 65 years and older (8.4 per 1,000).⁵

Trends

The annual trend in the standardised RSV rates since 2022 shows a marked increase in 2024. Critically, while RSV circulation increased, the introduction of the Queensland program providing RSV immunisation in early infancy resulted in a marked reduction in hospitalisations with RSV among this age group.⁵ Additional information is in the Maternal and child health section.

Figure 3: Queensland RSV cases, rates and trends

Mpox

Mpox (previously known as monkeypox) is an infection caused by a virus belonging to the genus (grouping) Orthopoxvirus, which also include other viruses such as variola virus causing smallpox and the cowpox virus. Mpox has historically occurred mainly in Central and West Africa, but since May 2022 there has been a global outbreak in mpox infections caused by the clade IIb strain, including in Australia.

Since 2023, an outbreak of clade Ib mpox has been reported in Central and Eastern Africa. On 14 August 2024, mpox was declared a Public Health Emergency of International Concern (PHEIC) by the World Health Organization, in response to the surge of mpox cases in African countries. Mpox is mainly spread from person to person through very close or intimate contact with someone infected with mpox. In Australia, gay, bisexual and other men who have sex with men, and their partners, are most at risk.

Mpox cases in Queensland

There were 125 mpox cases reported in 2024 (Figure 4). Previously there had been 6 mpox cases reported in 2022 (mpox became notifiable in Queensland on 24 June 2022) and 2 mpox cases in 2023, with 7 of these 8 cases identified as acquired overseas.

In Queensland, local transmission of mpox started in May 2024 with a cluster of cases reported in weeks 20 and 21. From week 30 onward, there was increasing transmission activity in the community. Case numbers peaked in week 37 (12 cases) then declined thereafter.

Figure 4 shows mpox cases by week for 2024 and is consistent with an established local transmission dynamic over the year in Queensland. Most cases were acquired through sexual transmission among gay, bisexual and other men who have sex with men (99.2%; 124 out of 125 cases).

Figure 4: Queensland mpox epidemiological curve, 2024

Additional information

Data and statistics

For the latest information about COVID-19, visit

• Queensland Health COVID-19
• The Australian Government Department of Health and Aged Care COVID-19 reporting

For other communicable diseases, visit

• Queensland Health Communicable disease Notifiable conditions reports
• Australian Institute of Health and Welfare Infectious and communicable diseases

Strategies and information

Queensland Health Queensland Paediatric Respiratory Syncytial Virus Prevention Program

• Department of Health and Aged Care Communicable diseases
• Queensland Health Communicable disease control guidance

Section technical notes

• Notifications under-represent the incidence of communicable diseases because notifications depend on:
  • individuals presenting with the disease
  • appropriate tests having been undertaken to confirm a diagnosis
  • results being reported to Queensland Health.
• Regional comparisons are based on area-based remoteness categories and the socioeconomic index of relative socioeconomic advantage and disadvantage.