Long-term intensive care unit outbreak of carbapenemase-producing organisms associated with contaminated sink drains

BACKGROUND

Between 2018 and 2022, a Belgian tertiary care hospital faced a growing issue with acquiring carbapenemase-producing organisms (CPO), mainly VIM-producing P. aeruginosa (PA-VIM) and NDM-producing Enterobacterales (CPE-NDM) among hospitalized patients in the adult intensive care unit (ICU).

AIM

To investigate this ICU long-term CPO outbreak involving multiple species and a persistent environmental reservoir.

METHODS

Active case finding, environmental sampling, whole-genome sequencing (WGS) analysis of patient and environmental strains, and implemented control strategies were described in this study.

FINDINGS

From 2018 to 2022, 37 patients became colonized or infected with PA-VIM and/or CPE-NDM during their ICU stay. WGS confirmed the epidemiological link between clinical and environmental strains collected from the sink drains with clonal strain dissemination and horizontal gene transfer mediated by plasmid conjugation and/or transposon jumps. Environmental disinfection by quaternary ammonium-based disinfectant and replacement of contaminated equipment failed to eradicate environmental sources. Interestingly, efflux pump genes conferring resistance to quaternary ammonium compounds were widespread in the isolates. As removing sinks was not feasible, a combination of a foaming product degrading the biofilm and foaming disinfectant based on peracetic acid and hydrogen peroxide has been evaluated and has so far prevented recolonization of the proximal sink drain by CPO.

CONCLUSION

The persistence in the hospital environment of antibiotic- and disinfectant-resistant bacteria with the ability to transfer mobile genetic elements poses a serious threat to ICU patients with a risk of shifting towards an endemicity scenario. Innovative strategies are needed to address persistent environmental reservoirs and prevent CPO transmission.

SARS-CoV-2 seroprevalence in a Belgian cohort of patients with cystic fibrosis

Background

In Belgium, COVID-19 epidemy began on February 4, 2020 with a peak on April 10, 2020. Patients with cystic fibrosis (CF) followed in the Cliniques universitaires Saint-Luc were rapidly isolated before the government lockdown.

Methods

After the peak of the epidemy, we measured anti-SARS-CoV-2 IgM and IgG antibodies in 149 patients and collected clinical data.

Results

Only 3 asymptomatic patients presented IgG against the virus. In one patient hospitalized for COVID-19 (positive molecular testing), we did not detect any anti-SARS-CoV-2 antibodies, as in thirty-five other symptomatic patients considered as possible cases.

Conclusions

Even if respiratory symptoms linked to CF are frequent and compatible with COVID-19, anti-SARS-CoV-2 IgG antibodies were detected only in 3 asymptomatic patients. This reassuring study concerning the risk of COVID-19 in patients with CF illustrates the difficulty to distinguish COVID-19 symptoms from respiratory exacerbations and the need of generalized molecular testing to make a precise diagnosis.

Fatal thoracic empyema involving Campylobacter rectus: A case report

We report the case of a 69-year-old man admitted for septic shock secondary to necrotic pneumoniae complicated by thoracic empyema of fatal issue. Microbiological examination of pleural liquid revealed a mixed anaerobic flora involving Campylobacter rectus and Actinomyces meyeri. Campylobacter rectus is an infrequent anaerobic pathogen of oral origin To our knowledge, this is the first case report of fatal C. rectus - associated thoracic empyema, and only the second reported case in which identification was successfully performed by MALDI-TOF MS.

Another case of "European hantavirus pulmonary syndrome" with severe lung, prior to kidney, involvement, and diagnosed by viral inclusions in lung macrophages

Puumala virus (PUUV) is considered a classic Old World etiologic agent of nephropathia epidemica (NE), or hemorrhagic fever with renal syndrome (HFRS). HFRS is considered to be distinct from hantavirus (cardio-)pulmonary syndrome (HPS or HCPS), described in the New World. Here, we report a severe case, which fulfilled most, if not all, Centers for Disease Control and Prevention (CDC) criteria for HPS, needing non-invasive ventilation and subsequent acute hemodialysis. However, the etiological agent was PUUV, as proved by serological testing, real-time polymerase chain reaction (PCR), and sequencing. Viral antigen was detected by specific anti-PUUV immunostaining, showing, for the first time, greenish intracytoplasmic inclusions in bronchoalveolar lavage (BAL) macrophages. This case definitely confirms that HPS can be encountered during PUUV infections. Interestingly, special findings could render the diagnosis easier, such as greenish homogeneous cytoplasmic inclusions, surrounded by a fine clear halo in BAL macrophages. Therefore, although the diagnosis remains difficult before the onset of renal involvement, the occurrence of severe respiratory failure mimicking community-acquired pneumonia must alert the clinician for possible HPS, especially in endemic areas.

Epidemiological investigation of a nosocomial outbreak of multidrug-resistant Corynebacterium striatum at one Belgian university hospital

During an 8-month period, 24 Corynebacterium striatum isolates recovered from lower respiratory tract specimens of 10 hospitalized patients were characterized. The organisms were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and by 16S rRNA gene sequencing. The cluster of C. striatum exclusively affected patients who had been admitted to an intensive care unit and/or subsequently transferred to one medium-size respiratory care unit. Prolonged duration of hospitalization, advanced stage of chronic obstructive pulmonary disease, recent administration of antibiotics and exposure to an invasive diagnostic procedure were the most commonly found risk factors in these patients. Seven patients were colonized and three infected. All strains displayed a similar broad spectrum resistance to antimicrobial agents, remaining susceptible to vancomycin only. Typing analysis by MALDI-TOF MS and by semi-automated repetitive sequence-based PCR (DiversiLab typing) showed that all outbreak-associated C. striatum isolates clustered together in one single type while they differed markedly from epidemiologically unrelated C. striatum isolates. Pulsed-field gel electrophoresis (PFGE) profiles revealed three distinct PFGE types among the C. striatum isolates associated with the outbreak while all external strains except one belonged to a distinct type. We conclude that C. striatum is an opportunistic nosocomial pathogen in long-term hospitalized patients and can be at the origin of major outbreaks. The routine use of MALDI-TOF MS greatly facilitated the recognition/identification of this organism in clinical samples and this technique could also offer the potential to be used as an easy and rapid epidemiological typing tool for outbreak investigation.

Clinical, virological and epidemiological assessment of 2009 influenza A (H1N1) pandemic in a Belgian university hospital

BACKGROUND

Recommendations were applied before and during the Belgian pandemic (2009) H1N1 influenza wave at a university hospital (420 beds), for optimizing isolation processes and therapeutic management of possible and confirmed infected cases.

METHODS

All patients presenting to the Emergency Department (ED) between August 1st and December 31st 2009 were screened for ILI symptoms, and were isolated for clinical assessment in case of positive screening. Patients categorized as possible influenza cases and who required hospitalization were isolated in dedicated wards. Specific diagnostic algorithms were implemented. Medical charts were retrospectively reviewed and matched with results of the microbiology laboratory. Patient's characteristics were analyzed, the contribution of laboratory diagnosis on therapy and lengh of stay (LOS) in isolation was also assessed.

RESULTS

310 patients out of 6068 had a positive screening for ILI, of these, 265 were retained as possible influenza cases and 139 required hospitalization. Twenty-eight children (8 requiring hospitalization) and 20 hospitalized adult patients had confirmed influenza infection. Five adult patients were admitted to the intensive care unit (ICU), 3 requiring extracorporeal membrane oxygenation (ECMO). There was no death related to the new influenza strain. The majority of confirmed patients were diagnosed during the Belgian epidemic wave, with a sensitivity of antigen detection of 50% in children and 35% in adults comparatively to real-time PCR (RT-PCR).

CONCLUSIONS

The impact of (2009) H1N1 pandemic influenza remained limited, except for ICU patients requiring ECMO. Implementation of screening, isolation, and virological diagnosis processes led to significant improvement of patient management.