From 'OPAT' to 'COpAT': implications of the OVIVA study for ambulatory management of bone and joint infection

Bone and joint infection contributes significantly to clinical activity within outpatient parenteral antimicrobial therapy (OPAT) services. The OVIVA (oral versus intravenous antibiotics for bone and joint infection) randomized study has challenged the practice of prolonged intravenous therapy, because non-inferiority of oral antibiotic therapy was demonstrated, thereby implying that early transition to oral therapy is an appropriate alternative to prolonged intravenous therapy. We examine the caveats to the study and discuss the implications for OPAT practice, highlighting the importance of careful oral antibiotic selection with attention to bioavailability, bone penetration, drug interactions, compliance and toxicity monitoring. We emphasize that ambulatory antibiotic therapy (whether intravenous or oral) in this patient group requires expert multidisciplinary management, monitoring and follow-up, and ideally should be undertaken within existing OPAT or, more accurately, complex outpatient antibiotic therapy (COpAT) services.

Paradoxical upgrading reaction in extra-pulmonary tuberculosis: association with vitamin D therapy

SETTING:

Glasgow, Scotland, UK.

BACKGROUND:

Paradoxical reactions in tuberculosis (TB) are a notable example of our incomplete understanding of host-pathogen interactions during anti-tuberculosis treatment.

OBJECTIVES:

To determine risk factors for a TB paradoxical reaction, and specifically to assess for an independent association with vitamin D use.

DESIGN:

Consecutive human immunodeficiency virus (HIV) negative adult patients treated for extra-pulmonary TB were identified from an Extended Surveillance of Mycobacterial Infections database. In our setting, vitamin D was variably prescribed for newly diagnosed TB patients. A previously published definition of paradoxical TB reaction was retrospectively applied to, and data on all previously described risk factors were extracted from, centralised electronic patient records. The association with vitamin D use was assessed using multivariate logistic regression.

RESULTS:

Of the 249 patients included, most had TB adenopathy; 222/249 had microbiologically and/or histologically confirmed TB. Vitamin D was prescribed for 57/249 (23%) patients; 37/249 (15%) were classified as having paradoxical reactions. Younger age, acid-fast bacilli-positive invasive samples, multiple disease sites, lower lymphocyte count and vitamin D use were found to be independent risk factors.

CONCLUSION:

We speculate that vitamin D-mediated signalling of pro-inflammatory innate immune cells, along with high antigenic load, may mediate paradoxical reactions in anti-tuberculosis treatment.

Restrictive antibiotic stewardship associated with reduced hospital mortality in gram-negative infection

INTRODUCTION

: Antimicrobial stewardship has an important role in the control of Clostridium difficile infection (CDI) and antibiotic resistance. An important component of UK stewardship interventions is the restriction of broad-spectrum beta-lactam antibiotics and promotion of agents associated with a lower risk of CDI such as gentamicin. While the introduction of restrictive antibiotic guidance has been associated with improvements in CDI and antimicrobial resistance, evidence of the effect on outcome following severe infection is lacking.

METHODS

: In 2008, Glasgow hospitals introduced a restrictive antibiotic guideline. A retrospective before/after study assessed outcome following Gram-negative bacteraemia in the 2-year period around implementation.

RESULTS

: Introduction of restrictive antibiotic guidelines was associated with a reduction in utilization of ceftriaxone and co-amoxiclav and an increase in amoxicillin and gentamicin. Approximately 1593 episodes of bacteremia were included in the study. The mortality over 1-year following Gram-negative bacteraemia was lower in the period following guideline implementation (RR 0.852, P  = 0.045). There was no evidence of a difference in secondary outcomes including ITU admission, length of stay, readmission, recurrence of bacteraemia and need for renal replacement therapy. There was a fall in CDI (RR 0.571, P  = 0.014) and a reduction in bacterial resistance to ceftriaxone and co-amoxiclav but no evidence of an increase in gentamicin resistance after guideline implementation.

CONCLUSION

: Restrictive antibiotic guidelines were associated with a reduction in CDI and bacterial resistance but no evidence of adverse outcomes following Gram-negative bacteraemia. There was a small reduction in one year mortality.

Risk of venous thromboembolism in patients treated for bacterial infection in the community with outpatient parenteral antimicrobial therapy

BACKGROUND

It is recommended that venous thromboembolism (VTE) prophylaxis be considered for patients receiving outpatient parenteral antimicrobial therapy (OPAT), but there is no published data to quantify VTE risk in this patient group.

AIM AND METHOD

The aim of this retrospective cohort study was to establish VTE incidence in patients managed through an OPAT service and assess utility of a common VTE prediction score normally used for inpatients. Consecutive episodes of OPAT between May 2009 and May 2012 were included. Patients on long-term anti-coagulants, those with an established indication for extended, outpatient VTE prophylaxis (i.e. patients referred to OPAT following hip or knee arthroplasty) were excluded. The Padua VTE Prediction Score was retrospectively applied to the cohort. The primary outcome was incidence of symptomatic VTE during or up to 90 days after completion of OPAT treatment.

RESULTS

There were 780 included patient episodes; 105 (13.5%) patients had a Padua VTE risk score >3; no patients received pharmacological VTE prophylaxis during OPAT treatment. During or up to 90 days following OPAT, two proximal lower limb DVTs were diagnosed, giving VTE incidence of 2/780 (0.26%, 95% CI: 0.03-0.92%), and there were eight deaths of which none were suspected to be related to VTE. There was one intracranial haemorrhage associated death.

CONCLUSION

This retrospective cohort study found a low incidence of VTE in OPAT patients, and does not support routine application of inpatient VTE prophylaxis algorithms to patients treated for infection in the community.