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Infectious diseases

Health occupations Letters 17 February 2020 Free

Antibiotic use in animals and humans in Australia

To the Editor: The recent perspective on antibiotic use in animals and humans in Australia1 provides an overview based on sales of antibiotics for livestock during the period 2005–2010. Unfortunately, these are the most recent data available, an important limitation that the authors highlight. Here, I provide details of significant initiatives implemented within the Australian livestock industries since 2010. Indeed, a perspective article published in the MJA in 20122 described the low level of antimicrobial resistance in bacterial isolates from food animals and food products together with work on updating prescribing guidelines and developments in infection control. A comprehensive summary of antimicrobial stewardship (AMS) activities in the pork, poultry, red meat and dairy industries published in 20183 describes the five Rs approach to AMS: taking responsibility for every decision to use antibiotics, reviewing current and ongoing antibiotic use, and reduction, refinement and replacement of antibiotics. A critical element of AMS in livestock practice is focused on removing the need for antibiotics by ensuring that there are biosecurity measures (bio‐exclusion, biocontainment, and individual animal resilience) operating to minimise the presence of pathogens and increase the immunocompetence of animals. Vaccination is a key component of AMS and new vaccine development is an ongoing area of research, with many examples of disease reduction and decreased antibiotic use following the introduction of vaccines.4 The use of antibiotics in livestock in Australia was assessed in the recent global review of antimicrobial resistance,5 and among the 29 countries included in the review, Australia ranked fifth, well below Denmark, a country considered the benchmark for antibiotic use. In addition to the quantity of use, significant attention is paid in Australia to the quality of use of antibiotics, as highlighted in a recent prescribing guideline.6 The absence of current data on antibiotic use remains an important limitation that must be reversed. Nevertheless, there are a multitude of AMS activities being actively implemented which will ensure, as reported in the 2018 article,2 that “Australia's food supply is one of the safest and cleanest in the world”.

Stephen W Page

Infectious diseases Letters 3 February 2020 Free

The impact of rapid molecular diagnostic testing for respiratory viruses on outcomes for emergency department patients

To the Editor: Uncontrolled before‐and‐after studies are highly prone to bias. Wabe and colleagues report on the impact of rapid influenza testing on outcomes for emergency department (ED) patients.1 They compared outcomes across four hospitals between the 2016 influenza season, when standard testing was used, and 2017, when rapid testing was used. Rapid testing was associated with shorter test turnaround times, more patients receiving results, and lower admission rates. Before‐and‐after studies use historical controls, in this case the prior influenza season, to evaluate the impact of interventions. This may be adequate for comparing simple indicators, such as test turnaround time, or for generating hypotheses. However, uncontrolled before‐and‐after studies are not useful for assessing more complex outcomes, such as admission rates, which are highly vulnerable to bias from other factors that may impact the observed results. For this reason, they are discouraged by some publishing groups.2 Frequent genetic drift in influenza virus strains causes variations in the burden and severity of illness each year, which influences ED presentations, testing and admission rates. The 2017 influenza season saw unprecedented numbers of influenza cases and ED presentations in NSW,3 which likely influenced admission practices. Teasing out the effect of rapid testing on admission rates is therefore not possible using an uncontrolled comparison between two disparate influenza seasons, in the manner of Wabe and colleagues. The steps taken to attempt to reduce seasonal effects cannot address this. It is also not possible to determine the net direction of biases in this study. Given the higher cost of rapid tests, it is important to have good estimates of their impact to inform economic evaluations. There are stronger methodologies that still allow timely evaluation using routinely collected data. At minimum, a comparison could be made to hospitals that did not implement rapid testing. When data from more seasons are available, an interrupted time series analysis may be appropriate.4 Interventions that mitigate the burden of seasonal influenza on health services are critical. Rapid testing is likely one such intervention, and therefore warrants careful evaluation with robust methodologies to inform its use.

Anthea L Katelaris · Ross M Andrews · Jeremy McAnulty

Mja2 50443
Women's health Letters 13 January 2020 Free

Influenza and pertussis vaccination of women during pregnancy in Victoria, 2015–2017

To the Editor: As reported by Rowe and colleagues1 in their retrospective analysis of maternal immunisation, uptake of influenza and acellular pertussis vaccines among pregnant women remains unacceptably low. One contributing factor may be inconsistent messaging. Historically, vaccine manufacturers have included precautions about the lack of data on use in pregnancy in their product information sheets. Such precautions have been shown to lead to vaccination hesitancy and refusal among pregnant women.2,3 In contrast, the current edition of the Australian Immunisation Handbook states: “Pregnant women are routinely recommended to receive influenza vaccine … and pertussis‐containing vaccine”.4 In 2018, the Therapeutic Goods Administration asked its Advisory Committee on Vaccines to provide independent expert advice on the available safety data on influenza vaccination in pregnancy with regards to the pregnancy category of influenza vaccines. The Advisory Committee on Vaccines advised that “adoption of Australian Pregnancy Category A should be considered by sponsors for certain inactivated influenza vaccines”.5 Pregnancy Category A signals to doctors and the public that the vaccine has been used by large numbers of expectant mothers with no evidence of harm to their babies. This is in line with the Australian Immunisation Handbook: “Clinical trial data and observational studies show no increased risk of congenital defects or adverse effects in the fetuses of women who received influenza vaccine during pregnancy”.4 Following the publication of the Advisory Committee on Vaccines statement, two of the four adult influenza vaccines and one of the two acellular pertussis vaccines used to vaccinate pregnant women in Australia have changed their pregnancy category to Category A. These changes show that the Australian regulator is receptive to feedback from the medical community on how to improve immunisation rates. Hopefully, the reclassification of the pregnancy category of these vaccines will translate into increased maternal uptake and better outcomes for Australian mothers and babies.

Heidi Shukralla · Michael Coory

Mja2 50429
Women's health Letters 18 November 2019 Free

Influenza and pertussis vaccination of women during pregnancy in Victoria, 2015–2017

To the Editor: We read with interest the recent publication by Rowe and colleagues.1 The authors reported low influenza vaccine coverage (39%) among pregnant women in Victoria from 2015 to 2017. Individual‐level factors associated with this finding included greater maternal age, primigravidity, early antenatal care and GP‐led antenatal care.1 As the authors accurately concluded, integrating vaccine delivery into antenatal care pathways is important to improve pregnant women's vaccination coverage.1 Our team reported on this previously, with coverage approximating 90% achieved by introducing standing orders for midwives.2 In collaboration with key stakeholders from six Victorian maternity services, a Monash University‐led project funded by Better Care Victoria is currently underway to implement integrated vaccination strategies and measure the cost and magnitude of improvement in maternal immunisation coverage in Victoria,3 the results of which will be available by the end of 2019. One of the key findings in the article by Rowe and colleagues1 is higher odds of influenza vaccination in women who gave birth after 37 weeks' gestation compared with women who gave birth before 28 weeks (adjusted odds ratio [aOR], 4.74; 95% CI, 3.54–6.35). A similar finding was reported for women who gave birth between 28 and 36 weeks gestation (aOR, 4.13; 95% CI, 3.07–5.56).1 This finding has two important implications. Firstly, it may indicate a potential beneficial effect of influenza vaccine received by pregnant women in reducing pre‐term birth (< 37 weeks' gestation). This is consistent with a recent systematic review and meta‐analysis that reported inactivated influenza vaccine to have a protective effect against pre‐term birth and low birth weight.4 Secondly, this finding may serve as an opportunity to emphasise the safety and benefits of influenza vaccines on perinatal outcomes. As the authors alluded to in their discussion, pregnant women tend to view influenza as primarily a health risk for themselves rather than for their infants.1 Given the importance of health care providers' recommendations in encouraging influenza vaccination among pregnant women, timely dissemination of the potential benefit in lowering the chance of pre‐term birth could further empower health care providers to recommend influenza vaccines to pregnant women.5

Khai Lin Kong · Michelle L Giles · Euan M Wallace

Mja2 50387
Infectious diseases Narrative review 7 October 2019 Free

Phage therapy for severe bacterial infections: a narrative review

Activity against antibiotic-resistant pathogens and a lack of serious side effects make phage therapy an attractive treatment option to combat refractory bacterial infections

Aleksandra Petrovic Fabijan · Ali Khalid · Susan Maddocks · Josephine Ho · Timothy Gilbey · Indy Sandaradura · Ruby CY Lin · Nouri Ben Zakour · Carola Venturini · Bethany Bowring · Jonathan R Iredell

Mja2 50355
Pharmacology Letters 16 September 2019 Free

First reported case of extensively drug‐resistant typhoid in Australia

To the Editor: The period from January to March marks the peak season for travellers returning to Australia, and typhoid is a key illness of concern. Since 2016, an extensively drug‐resistant (XDR) typhoid clade has emerged in Pakistan, showing resistance to all first‐line agents.1,2 Over the past 2 years, seven cases have been reported in returned travellers — mostly children — from Pakistan to England, Germany and the United States.1,3,4 We report here the first case of XDR typhoid identified in Australia. A 20‐month‐old Australian‐born girl presented to the Children's Hospital at Westmead with features of enteric fever 14 days after her return from a 3‐month trip to Karachi. Diarrhoea began in Pakistan 6 weeks before her return, and continued despite the use of oral antibiotics prescribed locally in Pakistan. Ten days of high fevers, irritability, vomiting and reduced oral intake prompted admission to our hospital. She was a previously well child and had received routine vaccines. No additional pre‐travel vaccinations had been recommended. Blood and stool cultures grew extended spectrum β‐lactamase‐producing Salmonella enterica serovar Typhi. The isolate showed microbiological features typical for the XDR clade, with resistance to chloramphenicol, ampicillin, trimethoprim–sulfamethoxazole, fluoroquinolones and third‐generation cephalosporins (Box). The isolate was susceptible to meropenem and had an azithromycin minimum inhibitory concentration of 12 mg/L. The child responded to intravenous meropenem and oral azithromycin and was discharged after an uncomplicated 8‐day admission to complete a further week of azithromycin. Notification to the local public health unit facilitated contact tracing. This case was one of 12 travel‐associated, culture‐positive enteric fever cases managed at our hospital in the first 3 months of 2019. This continues a trend toward a higher incidence of enteric fever, as previously reported at our hospital from 2003 to 2015.5 This case highlights the emerging threat of XDR typhoid and the broader global issue of escalating antimicrobial resistance, to which Australia is not immune, especially given increasing travel connectivity. Typhoid must be considered as a diagnosis for febrile returned travellers from endemic regions, including South and South‐East Asia. Typhoid vaccination is recommended from 2 years of age if travel is planned to these regions. The important role of general practitioners in providing travel‐related vaccine advice and care to returning travellers must not be underestimated. Box – European Committee on Antimicrobial Susceptibility Testing (EUCAST) disc diffusion demonstrating zones of inhibition to cefotaxime (COX), amoxicillin–clavulanate (AMC), cefepime (FEP), meropenem (MEM), ampicillin (AMP), imipenem (IMP), ciprofloxacin (CIP), amikacin (AKN), piperacillin–tazobactam (PTZ), fosfomycin (FOS); trimethoprim–sulfamethoxazole (SXT) and gentamicin (GMN)

Annaleise Howard‐Jones · Alison M Kesson · Alexander C Outhred · Philip N Britton

Mja2 50316

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