The aetiology and incidence of infective endocarditis in people living with rheumatic heart disease in tropical Australia.

PURPOSE: To define the incidence and microbiological aetiology of infective endocarditis (IE) in patients with rheumatic heart disease (RHD) in tropical Australia. METHODS: A retrospective study that examined all episodes of IE between January 1998 and June 2021 among individuals on the RHD register in Far North Queensland, Australia. RESULTS: There were 1135 individuals with a diagnosis of RHD on the register during the study period, representing 10962 patient-years at risk. Overall, there were 18 episodes of definite IE occurring in 16 individuals, although only 7 episodes occurred in native valves (11 occurred in prosthetic valves) equating to 0.7 episodes of native valve IE/1000 patient-years. No patient with mild RHD - and only one child with RHD - developed IE during the study period. Despite the study's tropical location, the causative organism was usually typical skin or oral flora. Among individuals with an indication for benzathine penicillin G (BPG) prophylaxis, only 1/6 episodes of IE due to a penicillin-susceptible organism received BPG in the month before presentation. CONCLUSION: Although RHD predisposes individuals to IE, the absolute risk of IE in native valve disease in tropical Australia is low and might be reduced further by improved adherence to secondary BPG prophylaxis.

The temporospatial epidemiology of rheumatic heart disease in Far North Queensland, tropical Australia 1997-2017; impact of socioeconomic status on disease burden, severity and access to care.

BACKGROUND: The incidence of rheumatic heart disease (RHD) among Indigenous Australians remains one of the highest in the world. Many studies have highlighted the relationship between the social determinants of health and RHD, but few have used registry data to link socioeconomic disadvantage to the delivery of patient care and long-term outcomes. METHODS: A retrospective study of individuals living with RHD in Far North Queensland (FNQ), Australia between 1997 and 2017. Patients were identified using the Queensland state RHD register. The Socio-Economic Indexes for Areas (SEIFA) Score-a measure of socioeconomic disadvantage-was correlated with RHD prevalence, disease severity and measures of RHD care. RESULTS: Of the 686 individuals, 622 (90.7%) were Indigenous Australians. RHD incidence increased in the region from 4.7/100,000/year in 1997 to 49.4/100,000/year in 2017 (p<0.001). In 2017, the prevalence of RHD was 12/1000 in the Indigenous population and 2/1000 in the non-Indigenous population (p<0.001). There was an inverse correlation between an area's SEIFA score and its RHD prevalence (rho = -0.77, p = 0.005). 249 (36.2%) individuals in the cohort had 593 RHD-related hospitalisations; the number of RHD-related hospitalisations increased during the study period (p<0.001). In 2017, 293 (42.7%) patients met criteria for secondary prophylaxis, but only 73 (24.9%) had good adherence. Overall, 119/686 (17.3%) required valve surgery; the number of individuals having surgery increased over the study period (p = 0.02). During the study 39/686 (5.7%) died. Non-Indigenous patients were more likely to die than Indigenous patients (9/64 (14%) versus 30/622 (5%), p = 0.002), but Indigenous patients died at a younger age (median (IQR): 52 (35-67) versus 73 (62-77) p = 0.013). RHD-related deaths occurred at a younger age in Indigenous individuals than non-Indigenous individuals (median (IQR) age: 29 (12-58) versus 77 (64-78), p = 0.007). CONCLUSIONS: The incidence of RHD, RHD-related hospitalisations and RHD-related surgery continues to rise in FNQ. Whilst this is partly explained by increased disease recognition and improved delivery of care, the burden of RHD remains unacceptably high and is disproportionately borne by the socioeconomically disadvantaged Indigenous population.

Echocardiographic Screening Detects a Significant Burden of Rheumatic Heart Disease in Australian Torres Strait Islander Children and Missed Opportunities for its Prevention.

Rheumatic heart disease (RHD) is almost entirely preventable, but its incidence in indigenous Australians remains one of the highest in the world. A community-based echocardiogram screening program of 862 Torres Strait Islander children identified 25 (2.9%) new cases of RHD. Among these 25 children, 5/7 (71%) prior acute rheumatic fever presentations had not been recognized. There was a history of microbiologically confirmed group A Streptococcus infection in 17/25 (68%) children with RHD compared with 9/25 (36%) controls (odds ratio [OR] [95% CI]: 3.78 [1.17-12.19], P = 0.03). This was more likely to be a skin swab (16/25 [64%] cases versus 6/25 [24%] controls) than a throat swab (1/25 [4%] cases versus 3/25 [12%] controls) (OR [95% CI]: 5.33 [1.51-18.90] [P = 0.01]), supporting a role for skin infection in RHD pathogenesis. Household crowding and unemployment were common in the cohort, emphasizing the need for prioritizing strategies that address the social determinants of health.

Antibiotic Prophylaxis for Melioidosis in Patients Receiving Hemodialysis in the Tropics? One Size Does Not Fit All.

Melioidosis has a high case fatality rate and is more common in patients with chronic kidney disease. Some authors recommended trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis for all hemodialysis (HD) patients during the wet season in melioidosis-endemic regions. Historical data were reviewed to determine if TMP/SMX prophylaxis was warranted in the HD population of Far North Queensland, Australia. Between 1997 and 2017, there were 242 culture-confirmed cases of melioidosis in the region, three (1.2%) occurred in HD patients; all survived without intensive care support. During the study period, there were 843 HD patients in the region with 3,024 cumulative patient years of risk. Even assuming 100% efficacy, it would have been necessary to prescribe TMP/SMX for 1,008 patient years to prevent one case of melioidosis. Given the significant additional cost and potentially life-threatening side effects of TMP/SMX therapy, clinicians should review the local epidemiology of melioidosis before the implementation of universal TMP/SMX prophylaxis in their HD population.