Eurosurveillance - Volume 30, Issue 14, 10 April 2025

Ceftazidime/avibactam, launched in the United Kingdom (UK) in March 2017, is an antibiotic against multidrug-resistant Gram-negative pathogens. It was selected for the government’s subscription model pilot, for incentivising new antibiotic development, which began in December 2020.

Ahead of the pilot, we assessed ceftazidime/avibactam testing, resistance (2016−2020) and usage (2017−2020) levels in England, as baselines for future surveillance.

From routine surveillance samples, we retrieved reported ceftazidime/avibactam resistance categorisation. From reference laboratory samples, we reviewed minimum inhibitory concentration (MICs) and molecular data. Among surveillance samples, per cent resistance was estimated. Referred samples’ MICs, by carbapenemase gene presence, were investigated. Ceftazidime/avibactam hospital use was measured in defined daily doses (DDDs).

Overall, 6.3% (4,200/66,914; 95% confidence interval (95%CI): 6.1–6.4%) of surveillance-reported ceftazidime/avibactam-tested Gram-negative bacteria were resistant. Percentage resistance per bacterial species varied over time, somewhat stabilising as testing was established, with between April 2019 and March 2020, 1.3% Escherichia coli (288/22,736; 95%CI: 1.1−1.4%), 12.6% Pseudomonas aeruginosa (690/5,495; 95%CI: 11.7−13.5%) and 6.1% of Klebsiella pneumoniae (314/5,179; 95%CI: 5.4−6.7%) being resistant. For 8,437 referred Enterobacterales, MIC determination found 11.5% (968/8,437; 95%CI: 10.8–12.2%) resistant. Among resistant isolates, 89.3% (864/968; 95%CI: 87.1–91.1%) had metallo-β-lactamase (MBL) genes. Of 908 MBL-negative isolates, producing ≥ 1 non-metallo-carbapenemase(s), 2.1% (19/908; 95%CI: 1.3–3.2%) were resistant. Since March 2017, 69.5% (105/151) of English National Health Service Trusts used ceftazidime/avibactam. Monthly usage progressed from 21 to 744 DDDs in March 2020.

For appropriate treatment, carbapenemase gene detection and variant identification in ceftazidime/avibactam surveillance matters. Detecting emerging resistant pathogens and preventing spread within healthcare settings requires vigilance.

Enteric fevers (EF) are caused by infections with Salmonella Typhi (STY) or Salmonella Paratyphi (SP) A-C (except the SPB enteric pathovar) and exhibit increasing antimicrobial resistance (AMR). Notification is mandatory in Germany.

To describe characteristics and trends of notified EF cases in Germany.

We analysed German EF notifications 2001–2023 fulfilling the case definition. We calculated numbers of imported EF cases per 100,000 air travellers by country of exposure 2012–2023.

In 2001–2023, 2,670 confirmed EF cases were notified: 56% (1,498/2,670) STY, 44% (1,172/2,670) SP, with seasonal peaks in April–May and August–September. Aside from years with COVID-19-related travel restrictions, STY notifications were stable, while SP notifications decreased. Median age of EF cases was 26 years (range: 0–93) and 55% (1,458/2,663) were male. Of cases with information, 93% (2,491/2,670) had fever, 71% (1,906/2,670) diarrhoea, 78% (2,033/2,607) were hospitalised (STY: 85% (1,234/1,459) vs SP: 70% (799/1,148), p < 0.001) and four died (two STY, one SPA, one SPB). Of STY cases, 7% (88/1,221) reported vaccination. Overall, 86% (2,251/2,613) of cases acquired EF abroad, most commonly in India, Pakistan and Türkiye. Ciprofloxacin resistance was reported for 50/59 STY and 16/18 SPA cases and cefotaxime resistance for 10/57 STY cases (exposure: Pakistan (9/10), India (1/10)) with information since 2017. We also report outbreaks and incidence among travellers.

Most cases were imported and had high hospitalisation rates and AMR. Typhoid vaccination was underutilised, highlighting that additional ways to reach at-risk travellers with information and vaccination offers are needed.

Respiratory syncytial virus (RSV) is a leading cause of hospitalisation in children worldwide. Recent regulatory approval of monoclonal antibody (mAb) nirsevimab for infants and the RSVpreF vaccine for pregnant women offers promising approaches to mitigate RSV-associated morbidity.

To evaluate potential impacts of routine prophylactic campaigns (mAbs targeting infants or maternal vaccination) introduced in the 2024/25 season on hospitalisations from RSV lower respiratory tract infections in Lombardy, Italy.

We used a catalytic model informed by data from pre-COVID-19 pandemic (before 2020) and post-pandemic periods (until 2022) to quantify the number of cases and hospitalisations that could be averted by seasonal nirsevimab administration to infants and RSVpreF maternal vaccination, considering changes in susceptibility caused by reduced RSV circulation during the pandemic.

As a marked proportion of RSV hospitalisations occurs in infants aged ≤ 1 year, seasonal mAb administration to 80% of newborns (uptake levels observed in Spain) was estimated to avert 50.2% (95% CI: 43.5–55.8) of hospitalisations in the total population. Coverage levels close to those observed for childhood vaccines (95%) could result in an additional average 18% reduction in hospitalisations. Vaccination of 65% of pregnant women, resembling the diphtheria–tetanus–pertussis vaccine coverage in Lombardy for this population, was estimated to avert 30.5% (95% CI: 19.6–39.7) of hospitalisations. At influenza vaccine coverage (12%), less than 8% of hospitalisations could be averted by maternal immunisation.

Routine nirsevimab administration to infants demonstrates clear potential to reduce RSV-associated hospitalisations. Maternal immunisation can help in achieving high protection in at-risk populations.