Genomic Analysis of Multiresistant Staphylococcus capitis Associated with Neonatal Sepsis.

Coagulase-negative staphylococci (CoNS), such as Staphylococcus capitis, are major causes of bloodstream infections in neonatal intensive care units (NICUs). Recently, a distinct clone of S. capitis (designated S. capitis NRCS-A) has emerged as an important pathogen in NICUs internationally. Here, 122 S. capitis isolates from New Zealand (NZ) underwent whole-genome sequencing (WGS), and these data were supplemented with publicly available S. capitis sequence reads. Phylogenetic and comparative genomic analyses were performed, as were phenotypic assessments of antimicrobial resistance, biofilm formation, and plasmid segregational stability on representative isolates. A distinct lineage of S. capitis was identified in NZ associated with neonates and the NICU environment. Isolates from this lineage produced increased levels of biofilm, displayed higher levels of tolerance to chlorhexidine, and were multidrug resistant. Although similar to globally circulating NICU-associated S. capitis strains at a core-genome level, NZ NICU S. capitis isolates carried a novel stably maintained multidrug-resistant plasmid that was not present in non-NICU isolates. Neonatal blood culture isolates were indistinguishable from environmental S. capitis isolates found on fomites, such as stethoscopes and neonatal incubators, but were generally distinct from those isolates carried by NICU staff. This work implicates the NICU environment as a potential reservoir for neonatal sepsis caused by S. capitis and highlights the capacity of genomics-based tracking and surveillance to inform future hospital infection control practices aimed at containing the spread of this important neonatal pathogen.

Impact of the COVID-19 nonpharmaceutical interventions on influenza and other respiratory viral infections in New Zealand.

Stringent nonpharmaceutical interventions (NPIs) such as lockdowns and border closures are not currently recommended for pandemic influenza control. New Zealand used these NPIs to eliminate coronavirus disease 2019 during its first wave. Using multiple surveillance systems, we observed a parallel and unprecedented reduction of influenza and other respiratory viral infections in 2020. This finding supports the use of these NPIs for controlling pandemic influenza and other severe respiratory viral threats.

Impact of the COVID-19 nonpharmaceutical interventions on influenza and other respiratory viral infections in New Zealand.

Stringent nonpharmaceutical interventions (NPIs) such as lockdowns and border closures are not currently recommended for pandemic influenza control. New Zealand used these NPIs to eliminate coronavirus disease 2019 during its first wave. Using multiple surveillance systems, we observed a parallel and unprecedented reduction of influenza and other respiratory viral infections in 2020. This finding supports the use of these NPIs for controlling pandemic influenza and other severe respiratory viral threats.

Individualised dosing of amikacin in neonates: a pharmacokinetic/pharmacodynamic analysis.

PURPOSE: To examine the pharmacokinetics of amikacin and its pharmacokinetic pharmacodynamic (PKPD) relationship in neonates. To develop an alternative dosing strategy for amikacin in neonates. METHODS: A population PKPD analysis was performed using data collected from 80 neonates with gestational ages from 24 to 41 weeks. The final pharmacokinetic model analysed 358 amikacin concentrations. All neonates were > 72 hours postnatal age. Simulations were performed to develop a new dosing strategy. RESULTS: The final covariate model was clearance = 0.23 x (current weight/2)(0.691) x (postmenstrual age/40)(3.23) and volume of distribution = 0.957 x (current weight/2)(0.89). Following the logistic regression analysis of treatment failure, new amikacin target concentrations were estimated and used in development of an alternative dosing strategy. CONCLUSION: Simulation of a new dosing regimen yielded the following recommendations: 15 mg/kg at 36-h intervals, 14 mg/kg at 24-h intervals and 15 mg/kg at 24-h intervals for neonates < or = 28 weeks, 29-36 weeks and > or = 37 weeks postmenstrual age respectively.

The burden of Legionnaires' disease in New Zealand (LegiNZ): a national surveillance study.

BACKGROUND: Legionnaires' disease is under-diagnosed because of inconsistent use of diagnostic tests and uncertainty about whom to test. We assessed the increase in case detection following large-scale introduction of routine PCR testing of respiratory specimens in New Zealand. METHODS: LegiNZ was a national surveillance study done over 1-year in which active case-finding was used to maximise the identification of cases of Legionnaires' disease in hospitals. Respiratory specimens from patients of any age with pneumonia, who could provide an eligible lower respiratory specimen, admitted to one of 20 participating hospitals, covering a catchment area of 96% of New Zealand's population, were routinely tested for legionella by PCR. Additional cases of Legionnaires' disease in hospital were identified through mandatory notification. FINDINGS: Between May 21, 2015, and May 20, 2016, 5622 eligible specimens from 4862 patients were tested by PCR. From these, 197 cases of Legionnaires' disease were detected. An additional 41 cases were identified from notification data, giving 238 cases requiring hospitalisation. The overall incidence of Legionnaires' disease cases in hospital in the study area was 5·4 per 100 000 people per year, and Legionella longbeachae was the predominant cause, found in 150 (63%) of 238 cases. INTERPRETATION: The rate of notified disease during the study period was three-times the average over the preceding 3 years. Active case-finding through systematic PCR testing better clarified the regional epidemiology of Legionnaires' disease and uncovered an otherwise hidden burden of disease. These data inform local Legionnaires' disease testing strategies, allow targeted antibiotic therapy, and help identify outbreaks and effective prevention strategies. The same approach might have similar benefits if applied elsewhere in the world. FUNDING: Health Research Council of New Zealand.

A comparison of the prophylactic efficacy of ceftriaxone and cefotaxime in abdominal surgery.

BACKGROUND: Although ceftriaxone (R) and cefotaxime (C) are highly effective antibiotics, few studies have directly compared their prophylactic efficacy. METHODS: In a prospective, randomized, double blind study of 1,013 patients undergoing abdominal surgery, the prophylactic use of ceftriaxone and cefotaxime were compared. Intravenous cephalosporin, 1 g, was given at induction of anesthesia, with intravenous metronidazole, 500 mg, also being given for colorectal surgery. RESULTS: The difference in wound infection (R 8%, C 12%, P <0.05) was due to appendicectomies not receiving metronidazole, (R 6%, C 18%, P <0.03) and was no longer present when these cases were excluded from analysis (R 8%, C 10%). Of note chest and urinary tract infection (R 6%, C 11%, P <0.02) and "any" infection (R 20%, C 27%, P <0.05) were reduced with ceftriaxone. CONCLUSIONS: Both antibiotics provide comparable wound prophylaxis as long as metronidazole is added for colorectal and appendiceal surgery. Ceftriaxone may be more versatile having the additional apparent benefits of reducing other postoperative infections, being less dependent on metronidazole as an adjunct and providing a more effective prophylactic cover against Staphylococcus aureus.

Using cost of infection as a tool to demonstrate a difference in prophylactic antibiotic efficacy: a prospective randomized comparison of the pharmacoeconomic effectiveness of ceftriaxone and cefotaxime prophylaxis in abdominal surgery.

The purpose of this study was to test the hypothesis that cost, as well as frequency of infection, could be used to demonstrate a difference in the performance of prophylactic antibiotics. In a prospective, randomized, double-blind study, 1013 patients undergoing abdominal surgery were given 1 g of intravenous ceftriaxone (R) or cefotaxime (C) at induction of anesthesia, and an additional 500 mg of metronidazole for colorectal surgery. Infection was checked for during the hospital stay and at 30 days postoperatively. The inpatient, outpatient, and community costs of infection were prospectively collected. The frequency of wound infection for appendectomies when additional metronidazole was not administered was greater with cefotaxime (R 6%, C 18%, p < 0.05), but the cost of infection was the same (average cost R $994 +/- SD $1101, C $878 +/- $1318). For all other procedures, the frequency of wound infection was similar (R 8%, C 10%), but the cost was less with ceftriaxone (R $887 +/- $1743, C $2995 +/- $6592, p < 0.05). Ceftriaxone decreased the frequency but not the cost of chest and urinary infection (frequency R 6%, C 11%, p < 0.02, cost R $1273 +/- 2338, C $1615 +/- 4083). Differences in both the frequency and cost of all infection are also presented. Ceftriaxone decreased either the frequency or the cost of different postoperative infections. The cost of infection can increase the discriminatory power of trials comparing antibiotic effectiveness.