Summary

Acute rheumatic fever (ARF) refers to an autoimmune response to infection of the upper respiratory tract (and possibly of the skin) by group A streptococcus (Strep A) bacteria.

Rheumatic heart disease (RHD) is caused by damage to heart valves as a result of one or more ARF episodes. An affected heart valve can become scarred and stiffer, obstructing blood flow or it can fail to close properly, causing blood to flow backwards in the heart instead of forward around the body. Damage from RHD can lead to heart failure, stroke, and even death (RHD Australia 2020).

This is the third annual report from the National RHD data collection. It presents information on ARF and RHD in Australia drawn from the established jurisdictional registers. Data in the collection are updated over time as the jurisdictional programs undertake data cleaning and quality improvement activity, so numbers in this report may not match those in previous reports. In addition, rates presented in this report have been calculated using revised Aboriginal and Torres Strait Islander population estimates based on the 2016 Census, and should not be compared with those in previously published reports.

In early 2020, RHDAustralia released the third edition of the national guidelines for ARF and RHD. The data in this report were collected before the publication of the new guidelines. As such, the data and analyses reflect the second edition of the guidelines. Changes to the data collection flowing from the third edition of the guidelines, such as definitions of risk and diagnostic criteria, will be implemented into future collections and reports.

How many people have ARF?

In 2015–2019, a total of 2,244 notifications of ARF were recorded in Queensland, Western Australia, South Australia and the Northern Territory (5 per 100,000 population over the 5 years combined). During this period the number and rate of notifications increased, from 342 (4 per 100,000) cases diagnosed in 2015 to 477 (5 per 100,000) in 2019.

Indigenous Australians accounted for 95% (2,128) of the ARF notifications during this period (96 per 100,000 population over the 5 years combined). The number and rate of notifications increased from 327 (77 per 100,000) in 2015 to 463 (102 per 100,000) in 2019. ARF was more common among Indigenous females (1,186 cases, 107 per 100,000) than males (942 cases, 86 per 100,000)—with the highest rates among Indigenous Australians aged 5–14 (1,029 notifications, 208 per 100,000).

ARF cases among non-Indigenous Australians (116 cases, less than 1 per 100,000) were mainly in Queensland (73%, 85 cases). ARF was more common among non-Indigenous males than non-Indigenous females. The median age at diagnosis among non-Indigenous Australians was 16 years, compared to 14 years among Indigenous Australians. Of non-Indigenous ARF cases, 45% identified as Maori and Pacific Islander people and 12% were from other high risk groups.

How many people have RHD?

As at 31 December 2019, there were 5,385 people living with RHD recorded on the 4 jurisdictional registers. Of these, nearly 3 in 10 (1,558) were aged under 25, 2 in 3 (3,561) were females, the greatest number were living in the Northern Territory (2,308), and 4 in 5 diagnoses (4,337, 81%) were among Indigenous Australians. The median age for RHD diagnosis among Indigenous Australians (22 years) was younger than for non-Indigenous Australians (50 years).

In 2015–2019, 1,325 new RHD diagnoses among Indigenous Australians were reported to the jurisdictional registers (60 per 100,000 population). New RHD diagnoses were more common among Indigenous females compared to males (76 and 44 diagnoses per 100,000, respectively), and just over half of new diagnoses were among people aged under 25 years (723 diagnoses). The greatest number and highest rate of new diagnoses among Indigenous Australians was in the Northern Territory (557, or 150 per 100,000).

How many people died with RHD?

In 2015–2019, 399 deaths were reported for people with RHD listed on one of the four jurisdictional registers. Of these, 287 people (72%) were Indigenous Australians. The median age of death was 52 years for Indigenous males and 53 years for Indigenous females, compared with 72 years for non-Indigenous males and 71 years for non-Indigenous females.

How many Indigenous Australians are prescribed secondary prophylaxis?

Secondary prophylaxis with regular benzylbenzathine penicillin G (BPG) is the only RHD control strategy shown to reduce recurrences, delay progression, and be cost effective at community and individual levels (RHD Australia 2012). Between 2015 and 2019, the recommended regimen to prevent recurrences of ARF, and progression to RHD, involved regular intramuscular injections of BPG every 21–28 days, for a minimum of 10 years.

The methodology for analysing adherence to secondary prophylaxis treatment in this report has been changed from previous reports. This report includes people prescribed 21-day, as well as 28-day prophylaxis, and includes those who were prescribed prophylaxis but did not receive any of their prescribed doses.

In 2019, among Indigenous Australians prescribed 3 or 4-weekly BPG:

  • 19% (783 people) received 100% or more of their prescribed doses
  • 18% (755) received 80% to 99% of their prescribed doses
  • 29% (1,177) received 50% to 79% of their prescribed doses
  • 34% (1,394) received less than 50% of their prescribed doses, including 317 people who received no doses.

In 2019, among 4,508 Australians prescribed BPG, there were 131 recurrent ARF episodes. The majority of these recurrences are most likely a result of delayed doses of or low adherence to regular BPG.