Acute rheumatic fever and rheumatic heart disease in Australia

Delivery of benzathine benzylpenicillin G to First Nations people in Queensland, Western Australia, South Australia and the Northern Territory

Proportion of doses delivered is calculated as the proportion of the scheduled 13 doses per year for patients on a 28-day benzathine benzylpenicillin G (BPG) regime or 17 doses for patients on a 21-day regime. Patients who commenced part-way through the year have been included with an adjusted expected number of doses. Patients who should have been on BPG but did not receive a dose in 2024 were also included in the analysis.

Reporting of secondary prophylaxis data is affected by limitations of the register functions (such as whether doses of oral antibiotics received for short periods instead of intramuscular injections can be recorded), as well as the reliance on active notification of secondary prophylaxis doses. BPG delivery rates may be higher than are reported in this report.

Benzathine benzylpenicillin G delivery in 2024

There were 5,282 First Nations people eligible for inclusion in calculations about benzathine benzylpenicillin G (BPG) delivery in 2024. Of these:

• 32% (1,712) received 80% to 100% of their prescribed doses
• 34% (1,806) received 40% to 79% of their prescribed doses
• 21% (1,122) received 1% to 39% of their prescribed doses
• 12% (642) did not receive any doses (Supplementary table 5.1).

To provide effective protection against recurrent ARF, patients should receive at least 80% of the prescribed doses. The proportion of people who received BPG at this level in each jurisdiction was:

• 41% (1,054 people) in the Northern Territory
• 30% (95) in South Australia
• 26% (251) in Western Australia
• 22% (310) in Queensland (Figure 5.1; Supplementary table 5.1). 

The proportion of people who received at least 80% of prescribed doses was the highest in remote areas (35%). This proportion was the same for Major cities and regional areas (26%) and both were much lower than remote areas (Figure 5.2; Supplementary table 5.2).

Women and children had the highest rates of doses of BPG delivered

In 2024, among First Nations people prescribed prophylaxis:

• the proportion of females who received at least 80% of doses was higher than that of males, while the proportion of males receiving less than 40% of doses was higher than that of females (Figure 5.3; Supplementary table 5.3)
• delivery was highest among people aged 0–14, with 47% receiving at least 80% of doses (Figure 5.4; Supplementary table 5.4).

BPG has decreased since 2020

The proportion of First Nations people receiving at least 80% of their prescribed doses decreased from 34.8% in 2020 to 27.6% in 2022. It then rebounded to 30.7% in 2023 and increased further to 32.4% in 2024 (Figure 5.5). Although the adherence level of BPG had a downward trend over last five years, these changes were not statistically significant. In 2024, 12% of First Nations people prescribed BPG did not receive any of their prescribed doses (Supplementary table 5.5).

Although there is an ongoing worldwide shortage of BPG supply, the delivery of prophylaxis to ARF/RHD patients in Australia was not affected due to the efforts of health professionals and administrators in sourcing and managing the available doses (TGA 2024). Suboptimal outcomes in BPG delivery are likely caused by low awareness of ARF and RHD and their management among both health professionals and patients, as well as poor understanding of the need for management actions such as reporting secondary prophylaxis to jurisdictional registers. Other challenges in delivering treatment relate to patients not attending primary clinics due to injection pain, lack of transport and funds, disengagement from health services, lack of understanding, racism, and competing priorities, as well as workforce pressures in Inner regional and outer regional and Remote and very remote areas.

ARF recurrence rates among First Nations people who were prescribed benzathine benzylpenicillin G in Queensland, Western Australia, South Australia and the Northern Territory

Adherence to secondary prophylaxis reduces the likelihood of recurrence. Trends in the number of recurrent ARF episodes among people prescribed secondary prophylaxis may be used to monitor the effectiveness of ARF and RHD program implementation. Recurrence rates are calculated using the rate per 100 patient-years. Further information on patient-years can be found in Appendix A.

Some of the people included in this analysis have a diagnosis of RHD but no prior record of ARF. For the purposes of this analysis, any diagnosis of ARF in these individuals during the analysis period was considered to be a recurrence.

Patients who were never prescribed prophylaxis were excluded from this analysis, regardless of whether they experienced a recurrence of ARF during the reporting period.

ARF recurrence rates per 100 patient-years

• 138 ARF recurrences were reported among those prescribed benzathine benzylpenicillin G (BPG) (2.8 recurrences per 100 patient-years)
• most recurrences were in the Northern Territory (109 recurrences)
• the rate of ARF recurrences per 100 patient-years was also highest in the Northern Territory (4.6 recurrences per 100 patient-years) and lowest in Western Australia (0.9 recurrences per 100 patient-years)
• the rate of recurrence fluctuated with age, with the highest risk among those aged 5–14. There were no recurrences in those under 5 or 65 and over (Figures 5.6 and 5.7; Supplementary table 5.7).
• From 2020 to 2024, the ARF recurrence rate per 100 patient-years among First Nations people prescribed BPG decreased from 3.5 to 2.8, though this change was not statistically significant (Figure 5.8; Supplementary table 5.8).