Epidemiology of acute infections in people who inject drugs in Australia.

ISSUES: People who inject drugs are at risk of acute infections, such as skin and soft tissue infections, infective endocarditis, bone and joint infections and bloodstream infections. There has been an increase in these infections in people who inject drugs internationally over the past 10 years. However, the local data regarding acute infections in Australia has not been well described. APPROACH: We review the epidemiology of acute infections and associated morbidity and mortality amongst people who inject drugs in Australia. We summarise risk factors for these infections, including the concurrent social and psychological determinants of health. KEY FINDINGS: The proportion of people who report having injected drugs in the prior 12 months in Australia has decreased over the past 18 years. However, there has been an increase in the burden of acute infections in this population. This increase is driven largely by skin and soft tissue infections. People who inject drugs often have multiple conflicting priorities that can delay engagement in care. IMPLICATIONS: Acute infections in people who inject drugs are associated with significant morbidity and mortality. Acute infections contribute to significant bed days, surgical requirements and health-care costs in Australia. The increase in these infections is likely due to a complex interplay of microbiological, individual, social and environmental factors. CONCLUSION: Acute infections in people who inject drugs in Australia represent a significant burden to both patients and health-care systems. Flexible health-care models, such as low-threshold wound clinics, would help directly target, and address early interventions, for these infections.

Epidemiology and Management of invasive infections among people who Use drugs (EMU): protocol for a prospective, multicentre cohort study.

INTRODUCTION: People who inject drugs (PWID) are at risk of invasive infections such as bloodstream infections, endocarditis, osteomyelitis and septic arthritis. Such infections require prolonged antibiotic therapy, but there is limited evidence about the optimal care model to deliver to this population. The Epidemiology and Management of invasive infections among people who Use drugs (EMU) study aims to (1) describe the current burden, clinical spectrum, management and outcomes of invasive infections in PWID; (2) determine the impact of currently available models of care on completion of planned antimicrobials for PWID admitted to hospital with invasive infections and (3) determine postdischarge outcomes of PWID admitted with invasive infections at 30 and 90 days. METHODS AND ANALYSIS: EMU is a prospective multicentre cohort study of Australian public hospitals who provide care to PWIDs with invasive infections. All patients who have injected drugs in the previous six months and are admitted to a participating site for management of an invasive infection are eligible. EMU has two components: (1) EMU-Audit will collect information from medical records, including demographics, clinical presentation, management and outcomes; (2) EMU-Cohort will augment this with interviews at baseline, 30 and 90 days post-discharge, and data linkage examining readmission rates and mortality. The primary exposure is antimicrobial treatment modality, categorised as inpatient intravenous antimicrobials, outpatient antimicrobial therapy, early oral antibiotics or lipoglycopeptide. The primary outcome is confirmed completion of planned antimicrobials. We aim to recruit 146 participants over a 2-year period. ETHICS AND DISSEMINATION: EMU has been approved by the Alfred Hospital Human Research Ethics Committee (Project number 78815.) EMU-Audit will collect non-identifiable data with a waiver of consent. EMU-Cohort will collect identifiable data with informed consent. Findings will be presented at scientific conferences and disseminated by peer-review publications. TRIAL REGISTRATION NUMBER: ACTRN12622001173785; Pre-results.

Review of management priorities for invasive infections in people who inject drugs: highlighting the need for patient-centred multidisciplinary care.

There has been a global increase in the burden of invasive infections in people who inject drugs (PWID). It is essential that patient-centred multidisciplinary care is provided in the management of these infections to engage PWID in care and deliver evidence-based management and preventive strategies. The multidisciplinary team should include infectious diseases, addictions medicine (inclusive of alcohol and other drug services), surgery, psychiatry, pain specialists, pharmacy, nursing staff, social work and peer support workers (where available) to help address the comorbid conditions that may have contributed to the patient's presentation. PWID have a range of antimicrobial delivery options that can be tailored in a patient-centred manner and thus are not limited to prolonged hospital admissions to receive intravenous antimicrobials for invasive infections. These options include discharge with outpatient parenteral antimicrobial therapy, long-acting lipoglycopeptides (dalbavancin and oritavancin) and early oral antimicrobials. Open and respectful discussion with PWID including around harm reduction strategies may decrease the risk of repeat presentations with injecting-related harms.

Clinical and financial burden of spinal infections in people who inject drugs.

BACKGROUND: People who inject drugs (PWID) are known to be at increased risk of infectious diseases including bacterial and blood-borne viral infections. However, there is limited literature surrounding the burden of spinal infections as a complication of injecting drug use (IDU). AIMS: To quantify the clinical and financial burden of IDU-related spinal infections. METHODS: Retrospective chart review of adult PWID with spinal infections requiring hospital admission to a tertiary health service in Melbourne, Australia between 2011 and 2019. RESULTS: Fifty-seven PWID with 63 episodes of spinal infections were identified with a median hospital stay of 47 days (interquartile range (IQR) 16; range 4-243 days). One-third of episodes required neurosurgical intervention and 11 (17%) episodes required intensive care unit admission (range 2-17 days). Staphylococcus aureus was the most common causative pathogen, present in three-quarters of all episodes (n = 47). The median duration of antibiotic regime was 59 days (IQR 42) and longer courses were associated with known bacteraemia (P = 0.048), polymicrobial infections (P = 0.001) and active IDU (P = 0.066). Predictors of surgery include neurological symptoms at presentation (relative risk (RR) 2.6; P = 0.010), inactive IDU status (RR 3.0; P = 0.002), a diagnosis of epidural abscess (RR 4.1; P = 0.001) and spinal abscess (RR ∞; P < 0.001). Completion of planned antimicrobial therapy was reported in 51 (82%) episodes. Average expenditure per episode was  A$61 577. CONCLUSIONS: Spinal infections in PWID are an underreported serious medical complication of IDU. Although mortality is low, there is significant morbidity with prolonged admissions, large antimicrobial requirements and surgical interventions generating a substantial cost to the health system.

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

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.

Identification and management of congenital parvovirus B19 infection.

Parvovirus B19 (B19V) infection is well known for its mild, self-limiting clinical presentations in children, such as erythema infectiosum. Approximately 40% of women of childbearing age are susceptible to B19V infection. While maternal B19V infection usually has a good prognosis, B19V can cause severe fetal anaemia and pregnancy loss due to its ability to suppress erythroid progenitor cells. Non-invasive ultrasound monitoring for fetal anaemia is usually performed if maternal seroconversion occurs in the first 20 weeks of gestation, with amniocentesis for fetal infection reserved for those who first present with fetal anaemia or hydrops of unknown cause. Intrauterine transfusion is the standard treatment for severe fetal anaemia and is associated with a significant improvement in survival. However, survivors of hydrops fetalis may have a higher rate of long-term neurodevelopmental complications compared with non-hydropic survivors. This review aims to synthesise published data on the diagnosis, surveillance and outcomes of congenital parvovirus infection to assist clinicians in diagnosing and managing this important condition.

Clinical evaluation of AusDiagnostics SARS-CoV-2 multiplex tandem PCR assay.

BACKGROUND: In the context of the pandemic, the rapid emergency use authorisation of diagnostic assays for SARS-CoV-2 has meant there are few peer-reviewed published studies of clinical performance of commercial assays. AIMS: To evaluate the clinical performance of AusDiagnostics respiratory multiplex tandem PCR assay including SARS-CoV-2. METHODS: We reviewed the results following implementation of AusDiagnostics respiratory multiplex tandem PCR assay including SARS-CoV-2, and compared with an in-house RT-PCR assay at our State Reference Laboratory. RESULTS: Initial validation using AusDiagnostics coronavirus multiplex tandem PCR assay including SARS-CoV-2 demonstrated good concordance with the State Reference Laboratory. After implementing the AusDiagnostics respiratory multiplex tandem PCR assay including SARS-CoV-2, we tested 7839 samples. 127 samples in which SARS-CoV-2 was detected using the AusDiagnostics assay were referred for testing at the State Reference Laboratory, with concordant results in 118/127 (92.9%) of samples. After resolution of discrepancies, 125/127 (98.4%) of AusDiagnostics results were determined to be true positive results. Out of 7839 samples tested for SARS-CoV-2 during this period, only 2 tests (0.02%) were indeterminate results. CONCLUSION: The AusDiagnostics respiratory MT-PCR assay is a reliable assay for detection of SARS-CoV-2.

Emergence of Attenuated Measles Illness Among IgG-positive/IgM-negative Measles Cases: Victoria, Australia, 2008-2017.

BACKGROUND: Waning measles immunity among vaccinated individuals may result in an attenuated illness. This study compares the epidemiological, clinical, and laboratory profile of measles cases with waning immunity with other measles cases. METHODS: Polymerase chain reaction-positive (+) measles cases notified to Victoria's Department of Health and Human Services from 2008 to 2017 with immunoglobulin (Ig) M and IgG tested at diagnosis were classified according to serology at diagnosis: IgG negative (-) (nonimmune), IgM+/IgG+ (indeterminate), or IgM-/IgG+ (waning immunity). RESULTS: Between 2008 and 2017, 297 measles cases were notified, of whom 190 (64%) were included; 151 of 190 (79%) were nonimmune at diagnosis, 26 (14%) were indeterminate, and 13 (7%) had waning immunity. Between 2008-2013 and 2014-2017, the proportion of cases with waning immunity increased from 0 of 87 (0%) to 13 of 103 (13%) (P < .001) and the diagnostic sensitivity of initial IgM fell from 93% to 81% (P = .012), respectively. Seven (54%) waning immunity cases reported receiving measles-containing vaccines; 1 case had 2 documented doses. Compared with nonimmune and indeterminate cases, waning immunity cases were more likely to be male; less likely to report fever, coryza, and cough; and had lower burden of virus (higher cycle threshold values). Waning immunity cases had higher IgG titers than indeterminate cases (mean optical density values, 1.96 vs 0.71; P = .004). Onward transmission from 1 waning immunity case was documented. CONCLUSIONS: Waning immunity among measles cases, associated with secondary vaccine failure and modified clinical illness, is emerging in Victoria with transmission potential.