Queensland: ARF and RHD facts

Introduction

In Queensland, Aboriginal and Torres Strait Islander people are over-represented among people with acute rheumatic fever (ARF) and rheumatic heart disease (RHD). While the incidence and prevalence of both ARF and RHD remain high for Indigenous Queenslanders, ARF and RHD also disproportionately affect the Māori, Pacific Islander and refugee populations of Queensland (Queensland Health, 2018).

In Queensland, the collection of ARF and RHD notifications is funded jointly by the Australian Government Department of Health and Queensland Health. ARF has been a notifiable disease in Queensland since 1999, and the register was established in 2006. The RHD control program was established in 2009. RHD became a notifiable condition in 2018.

Overview

At 31 December 2020, there were 3,622 people living with a diagnosis of ARF and/or RHD in Queensland, representing 40% of the total 9,158 people recorded across all 5 jurisdictional registers. Of these 3,622 people in Queensland, 840 people (23%) had only ARF recorded on the register, 1,717 people (47%) had only RHD recorded and 1,065 people (29%) had both ARF and RHD recorded (Supplementary Overview Table 1).

Region of management

For each person recorded on a register, the region of management is recorded. This is the area where the patient was most recently reported to receive the majority of the primary health care for their ARF or RHD. The region of management may differ from the person’s region of diagnosis and the notifying jurisdiction. Each state or territory defines regions uniquely, based on its own specific health services boundaries. There are 33 regions spread over Queensland, Western Australia, South Australia, and the Northern Territory. NSW is considered as a whole. Regions do not cross state and territory boundaries.

Torres and Cape was the region in Queensland with the highest rate of ARF and/or RHD management (Figure 2.1) (Supplementary Overview Table 4).

Acute rheumatic fever

All Australians

In 2016–2020 in Queensland:

• 748 diagnoses of ARF were recorded in 697 people (3 per 100,000 population over the 5 years combined) (Supplementary ARF tables 1 and 2)
• the number and rate of ARF diagnoses increased from 149 (3.1 per 100,000 population) in 2016 to 172 (3.3 per 100,000 population) in 2020. There was a decrease in cases in 2019 with 138 cases recorded (2.7 per 100,000 population) (Figure 3.1) (Supplementary ARF Table 2)

• the most common age at diagnosis was 5–14, with 357 diagnoses (11 per 100,000 population). Females accounted for 403 diagnoses (54 per 100,000 population) (Figure 3.2) (Supplementary ARF Table 3a)

Indigenous Australians

In 2016–2020 in Queensland:

• 615 ARF episodes were diagnosed among Aboriginal and Torres Strait Islander people, a rate of 53 per 100,000 population (Supplementary ARF Table 2)
• the diagnosis rate among Indigenous Australians increased between 2016 and 2020—from 56 to 60 per 100,000 population (123 to 144 diagnoses, respectively) (Figure 3.3) (Supplementary ARF Table 2)

• the highest rate of diagnosis among Indigenous Australians was among those aged 5–14, accounting for 48% of all diagnoses (110 per 100,000 population, or 295 diagnoses). Females accounted for 56% of diagnoses (345 diagnoses) (Figure 3.4) (Supplementary ARF Table 3b)

• there were 149 recurrent ARF episodes recorded among Indigenous Australians (Supplementary ARF Table 7)
• the North West region had the highest incidence of ARF (Figure 3.5) (Supplementary ARF Table 4).

Rheumatic heart disease

Prevalence

At 31 December 2020, 2,725 people living with RHD were recorded on the Queensland register (Supplementary RHD Table 1).

Incidence

In 2016–2020 in Queensland:

• there were 948 reports of new RHD diagnoses (3.8 per 100,000 population). The rate increased from 2016 to 2019 (3.2 to 4.9 per 100,000 population) before dropping in 2020 (3.5 per 100,000 population) (Figure 4.1) (Supplementary RHD Table 5)

• 524 new RHD diagnoses among Indigenous Australians were reported to the jurisdictional register (45 per 100,000 population) (Supplementary RHD Table 5)
• the rate increased from 2016 to 2019 (40 to 58 per 100,000 population) before dropping in 2020 (39 per 100,000 population) (Figure 4.2). It is possible that the decrease is related to reduced access to echocardiography as a result of COVID-19 restrictions, and is not necessarily reflective of a true reduction in disease incidence (Supplementary RHD Table 5)

• new RHD diagnoses were more common among Indigenous females than males (58 and 33 diagnoses per 100,000 population, respectively) (Figure 4.3) (Supplementary RHD Table 6)
• 52% of new diagnoses were among Indigenous Australians aged under 25 (270 diagnoses) (Supplementary RHD Table 6).

Indigenous Australians with no documented previous ARF episode

RHD occurs only in someone who has had ARF, but some people with RHD have no recorded previous ARF episode on state and territory registers. ARF might not be notified to a register for various reasons, such as being diagnosed before the relevant register began; being diagnosed prior to the condition being notifiable; the person being in a jurisdiction that does not have a register; or the episode never being diagnosed.

Among Indigenous Australians in Queensland with a new RHD diagnosis in 2016–2020, 406 (78%) did not have a previous ARF episode recorded on the registers. Of these:

• the proportion was similar in females (78%) and males (77%)
• the youngest and oldest age groups were less likely to have a history of ARF recorded than those aged 25–44
• the proportion of people with no previous ARF diagnosis recorded was higher in the non-Indigenous population (93%) than the Indigenous population (78%)
• there was no clear annual trend (Supplementary RHD tables 7 and 8).

Heart surgery for RHD

• In 2016–2020 in Queensland, 281 people underwent 291 RHD surgical events. Most surgical events occurred among those aged 45–64 with 111 surgical events (38%), followed by those aged 65 and over with 58 surgical events (20%) (Supplementary RHD Table 11a).
• One third of people were Indigenous Australians, comprising 34% (95) of patients and 34% (99) of events. Most surgical events among Indigenous Australians occurred among those aged 45–64, with 31 surgical events (31%). Children aged 5–14 with RHD had 12 (12%) surgical events (Figure 4.4) (Supplementary RHD Table 11b).
• Most surgeries among non-Indigenous Australians took place in those not from a high-risk ethnic group (Supplementary RHD Table 9).

Secondary prophylaxis

Delivery of secondary prophylaxis

In 2020, 1,626 people in Queensland were prescribed a treatment regimen to prevent recurrences of ARF, and progression to RHD, involving regular intramuscular injections of BPG every 21 or 28 days. Of these, 1,371 were Indigenous Australians (Supplementary Secondary Prophylaxis Table 1).

In 2020, among Indigenous Australians in Queensland prescribed 3- or 4-weekly BPG:

• 6.0% (82 people) received 100% or more of their prescribed doses
• 17% (228 people) received 80% to 99% of their prescribed doses
• 33% (448 people) received 50% to 79% of their prescribed doses
• 45% (613) received less than 50% of their prescribed doses, including 166 people who received no doses (Supplementary Secondary Prophylaxis Table 1)
• slightly more males than females received at least 80% of doses (24% and 22%, respectively) (Figure 5.1) (Supplementary Secondary Prophylaxis Table 2)

• delivery was highest among people aged 5–14, with 38% receiving at least 80% of doses (Figure 5.2) (Supplementary Secondary Prophylaxis Table 3).

Time trend

The proportion of Indigenous Australians receiving at least 80% of their prescribed doses was stable at around 26% between 2016 and 2019. There was a slight decrease in 2020 when only 23% received at least 80% of their doses. The decrease in those receiving at least 80% of their prescribed doses could be due to the impacts of COVID-19 on health services and health service use (Figure 5.3) (Supplementary Secondary Prophylaxis Table 4).

ARF recurrence rate among people on BPG

In 2020, among Indigenous Australians prescribed BPG in Queensland, there were 30 ARF recurrences and a rate of 2.3 recurrences per 100 patient-years. The rate of recurrence per 100 patient-years generally decreased with age, with the highest risk among those aged 5–14 years (5) (Figure 5.4) (Supplementary Secondary Prophylaxis Table 5).

Between 2016 and 2020, the ARF recurrence rate per 100 patient-years among Indigenous Australians prescribed BPG varied from 1.9 to 3.0, with no clear trend (Figure 5.5) (Supplementary Secondary Prophylaxis Table 6).