Group A streptococcal bacteraemia at a tertiary hospital in Melbourne: concern of an under‐reported risk group in Australia

Abstract

Background Invasive group A streptococcal (iGAS) infections are increasing worldwide with at‐risk groups being children, pregnant women and the elderly. In 2017, there was a rise in iGAS cases in Victoria, prompting a Chief Health Officer advisory. Aims To describe the characteristics of patients with GAS bacteraemia admitted to a tertiary hospital. To compare at‐risk groups in our population with those identified in the Victorian Government health alert. Methods Retrospective review of patients with GAS bacteraemia admitted between June 2014 and December 2017 at a tertiary hospital in Melbourne, Victoria. Results Forty‐three cases of GAS bacteraemia occurred. Average age was 52 years (range 15–88 years) with 63% male. Average length of stay was 14 days (range 0–72 days) and all‐cause mortality occurred in two (5%) cases. Twelve (28%) patients presented with shock, 11 (26%) required intensive care unit admission and 13 (30%) surgical intervention. A history of intravenous drug use was documented in 18 (42%) cases and was commonly complicated by bone or joint involvement or thrombosis. Typing of GAS samples identified 22 different emm‐types. Conclusion GAS bacteraemia resulted in significant morbidity and prolonged hospitalisation. In contrast to the at‐risk groups identified in the Victorian Government health advisory, the commonest risk group in this series were people who inject drugs and most commonly middle‐aged men. Invasive GAS should be considered if a person who injects drugs presents with acute severe sepsis.

Streptococcus pyogenes Infective Endocarditis—Association With Injection Drug Use: Case Series and Review of the Literature

“…The incidence of IE in PWID is known to have increased alongside the opioid epidemic [ 32 ]. An association with IDU and iGAS has also been noted in reports from Australia [ 22 ], the United States [ 24 , 26 ], and Canada [ 27 ], and GAS IE was found to be 10-fold more frequent in PWID with iGAS than those without IDU in the United States [ 26 ]. Among 10 Centers for Disease Control and Prevention Active Bacterial Core surveillance sites, the highest rate of IDU among people with iGAS infections was in 6 Maryland counties surrounding Baltimore City (range, 1.8%–19.3%) [ 26 ].…”

“…Reports from Australia, Europe, and North America have confirmed shifting epidemiology of cases, with increases in incidence and outbreaks of iGAS [ 22–28 ]. Increases in the prevalence of emm1 strains of GAS, associated with invasive streptococcal disease, have also been identified, both coincident with increases in iGAS infection (increase from 5% to 33% of upper respiratory tract isolates over 2 years) [ 25 ] and in periods of stable iGAS incidence [ 28 ].Thus, both increased iGAS cases overall and more invasive GAS species are plausible explanations for the high number of GAS IE seen in this series.…”

The epidemiology of invasive group A streptococcal disease in Victoria, 2007–2017: an analysis of linked datasets

“…It is likely that these risk factors are not well captured by ICD‐10‐AM codes (Supplementary File 1.2), which are loosely defined and do not specifically identify injecting drug use. The potential inadequacy of ICD‐10 codes is highlighted by a single‐centre study of GAS bacteraemia in Melbourne, Victoria from 2014 to 2017 where 18/43 patients (42%) had a history of injecting drug use, 36 whereas our study, which should include all of these cases and covers additional years, only identified 13 cases with drug use coded. A more detailed analysis of prospectively collected data could examine temporal and geographical variation in the prevalence of comorbidities, rates of co‐infection such as influenza, and risk factors such as injecting drug use.…”