Arthur J. Morris

The post-surgical duration of antibiotic treatment for patients with active infective endocarditis (IE), receiving heart valve surgery is uncertain. We aimed to assess the antibiotic treatment received by, and outcomes of, patients with active Enterococcus faecalis IE (EFIE) receiving valve surgery. We also sought to assess whether a subset of patients with EFIE receiving valve surgery were cured with shorter durations of post-surgical antibiotic treatment. This was a national retrospective observational cohort study assessing adults (≥15 years) receiving valve surgery from one of five cardiothoracic surgical units during active EFIE over a 20-year period, 2004-2023, in Aotearoa New Zealand. We compared the post-valve surgery antibiotic duration and outcomes of patients at Te Toka Tumai Auckland, which used a protocol aiming to limit post-valve surgery antibiotic duration, with those at the other four surgical units combined. One hundred and 10 patients received valve surgery during an EFIE episode. Comparing those who received treatment at Te Toka Tumai Auckland with the other four surgical units combined, the Te Toka Tumai Auckland group received a median of 14 days less post-surgical antibiotic duration, 28 days versus 42 days, (P = 0.004); there were no relapses in either group and no difference in survival. No relapsed EFIE occurred and there was no difference in survival when comparing the groups that received shorter versus longer post-surgical antibiotic durations. Shorter antibiotic durations have significant benefits. Prospective studies are required to provide clinicians with increased assurance regarding the safety of this approach.

Background: Understanding the epidemiology of invasive non-Aspergillus mold infections is essential to inform effective therapy. This study aimed to determine the epidemiology and infection characteristics of non-Aspergillus mold infections in Australasia. Methods: A 21-center, retrospective study of proven/probable non-Aspergillus mold infections from 2016 to 2023 was conducted in Australia and New Zealand. Data collected included demographic, clinical, microbiological, treatment, and outcome information through 180 days of follow-up. Results: Of 421 cases, 346 (82.2%) were proven infections and 315 (74.8%) were localized. Lung (n = 150, 35.6%) was the most common site of infection. Twenty cases (4.8%) were due to >1 non-Aspergillus mold pathogen, resulting in 443 isolates in total. Dematiaceous molds, inclusive of Lomentospora prolificans (n = 96 of 443, 21.7%), Scedosporium spp. (n = 87 of 443, 19.6%), and other dematiaceous molds of various genera (n = 48 of 443, 10.8%), were the most common (n = 231 of 443, 52.1%), followed by Mucorales (n = 141 of 443, 31.8%). Common underlying conditions were hematological malignancy (n = 146, 34.7%) and diabetes mellitus (n = 122, 29.0%), while 68 cases (16.2%) had no comorbidities. One-third (n = 138, 32.8%) of patients received antifungal prophylaxis 30 days before non-Aspergillus mold diagnosis, and L. prolificans was the most common cause of breakthrough infections (P < .001). All-cause 90-day mortality was 31.4% (n = 132 of 421), with higher mortality observed in L. prolificans (n = 51 of 89, 57.3%) and Mucorales (n = 56 of 129, 43.4%) infections. Conclusions: Lomentospora prolificans, Scedosporium spp., and Mucorales are the most frequent non-Aspergillus mold pathogens in Australasia, with other emerging species and mixed infections encountered. Mortality from L. prolificans and Mucorales infections remains high.

Background: Scabies is a common health issue in the Pacific and may contribute to rheumatic heart disease (RHD). This study assessed the prevalence of scabies and other skin conditions among Tongan schoolchildren and examined the association between these conditions and RHD. Methods: Children from four primary schools on Tongatapu were screened for scabies, other skin conditions and RHD. Health workers were trained to recognise scabies and related skin conditions accurately. All children also underwent echocardiographic screening to detect heart valve abnormalities consistent with RHD. Statistical analysis included prevalence ratio calculations, and Fisher's exact tests to evaluate associations between skin and heart findings. Results: Four hundred children were screened (mean age: 8 years 6 months), with 18 (4.5%) having echocardiographic features of RHD. The prevalence of scabies was 29.8% (119/400), while the prevalence of impetigo was 20% and more severe bacterial skin infection was 15.5%. Children with both scabies and skin infection were 4.65 times more likely than children without any such lesions to have RHD (95% confidence interval: 1.60–13.6). Children with scabies, impetigo and bacterial infection were associated with progressively higher prevalence of RHD ( p for trend = 0.008). The population attributable fraction for scabies and infection as a potential cause of RHD was 26.5%. Conclusions: The results indicate a very high prevalence of scabies, bacterial skin infection, and RHD among Tongan school children. Enhanced treatment and control of scabies are likely to reduce the incidence of both bacterial infection and RHD. Mass drug administration is recommended.

Background: The timing of antibacterial prophylaxis in the hour before incision is unsettled due to inadequate clinical outcome data. The aim of this study was to determine whether the timing of antibacterial prophylaxis in the hour before surgery influences the surgical site infection (SSI) rate in orthopaedic and cardiac surgery procedures. Methods: Prospective SSI surveillance was undertaken in all 20 publicly funded hospitals in New Zealand for patients undergoing hip and knee arthroplasties and cardiac surgery procedures. The timing of antibacterial prophylaxis was recorded, in minutes (min), with respect to incision time. Patients were followed for 90 days after surgery. Standard definitions for SSIs were used. The SSI rate with respect to the timing of antibacterial prophylaxis was analysed in 10-minute periods. Cefazolin was the prophylactic antibiotic used in vast majority of patients. Results: The timing of prophylaxis, recorded in minutes, against incision time was available for 66 292 procedures. For all procedures, the lowest SSI rate was for prophylaxis given 21–30 min before surgery, with higher rates for prophylaxis given ≥ 31 min or more before incision. After multivariable analysis, the risk for SSI increased during the time period but only remained significant when prophylaxis was given 51–60 min before incision (odds ratio 1.7; 95% confidence interval 1.3 to 2.3) or earlier (odds ratio 2.01; 95% confidence interval 1.33 to 3.04). Conclusion: The SSI rates for prophylaxis increased if antibacterial prophylaxis was given more than 50 min before incision. The results may not be applicable to non-clean procedures or non-antibacterial prophylaxis. More outcome data are required before firm recommendations can be made for fine-tuning antibacterial prophylaxis within the 60 minutes before clean surgery.

Background: Until 2020, azole resistance in Aspergillus fumigatus complex isolates in New Zealand was due to cyp51A hot spot mutations. This report details the appearance of environment‐linked tandem repeat (TR)‐related azole resistance genotypes since 2021.Methods: Isolates were tested by broth micro‐dilution. Clinical Laboratory Standards Institute criteria were used to define wild type (WT) and non‐wild type (non‐WT) isolates, which were identified by ß‐tubulin gene sequencing and had their cyp51A genotype for azole resistance determined. Whole genome sequencing (WGS) was applied to two patient pairs of sequential WT and non‐WT isolates.Results: From January 2021 to June 2024, 15 of 147 (10.2%) A. fumigatus complex isolates were resistant or non‐WT for one or more azole agents. Genotyping detected hot spot mutations in four and TR‐associated resistance in nine. No mutations were detected in two isolates. Four of the five TR₄₆ mutations were TR₄₆/Y121F/T289A. Three of the four TR₃₄ mutations were different. WGS of the paired isolates showed that the non‐WT isolates were distinct. Azole‐containing fungicides are available for home use from garden centres. Patients with TR‐associated resistance did not have any obvious exposure to azole‐containing fungicides. There was no evidence for healthcare‐acquired transmission.Conclusions: A. fumigatus sensu stricto isolates with TR‐mutations linked to environmental resistance are now present in New Zealand. Those at risk of invasive A. fumigatus infection should receive advice to avoid high‐risk exposures. Reintroducing monitoring of azole‐containing fungicides is recommended.

Background: There are no contemporary data on the burden of healthcare-associated infections (HAIs) in New Zealand.Objectives: To estimate the economic burden of HAIs in adults in New Zealand public hospitals by number and monetary value of bed days lost; number of deaths, number of life years lost, and the monetary value (in NZ dollars); Accident Compensation Commission (ACC) HAI treatment injury payments; and disability-adjusted life years (DALYs).Methods: The annual incidence rate was calculated from the observed prevalence of HAIs in New Zealand, and length of patient stays. Total HAIs for 2021 were estimated by multiplying adult admissions by incidence rates. The excess length of stay and mortality risk attributed to those with HAI was calculated using a multistate model. Payments for treatment injuries were obtained from the ACC. DALYs for HAIs were estimated from the literature.Results: The incidence rate of HAI was 4.74%, predicting 24,191 HAIs for 2021, resulting in 76,861 lost bed days, 699 deaths, with 9,371 years of life lost (YoLL). The annual economic burden was estimated to be $955m comprised of $121m for lost bed days, $792m for cost of YoLL, and $43m ACC claims. There were 24,165 DALY which is greater than many other measured injuries in New Zealand, eg motor vehicle traffic crashes with 20,328 DALY.Conclusions: HAIs are a significant burden for patients, their families, and the public health system. Preventive guidelines for many HAIs exist and a strategic plan is needed to reduce HAIs in New Zealand.