Airborne virus shedding of the alpha, delta, omicron SARS-CoV-2 variants and influenza virus in hospitalized patients.

Airborne transmission is an important transmission route for the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological data indicate that certain SARS-CoV-2 variants, like the omicron variant, are associated with higher transmissibility. We compared virus detection in air samples between hospitalized patients infected with different SARS-CoV-2 variants or influenza virus. The study was performed during three separate time periods in which subsequently the alpha, delta, and omicron SARS-CoV-2 variants were predominant. In total, 79 patients with coronavirus disease 2019 (COVID-19) and 22 patients with influenza A virus infection were included. Collected air samples were positive in 55% of patients infected with the omicron variant in comparison to 15% of those infected with the delta variant (p < 0.01). In multivariable analysis, the SARS-CoV-2 omicron BA.1/BA.2 variant (as compared to the delta variant) and the viral load in nasopharynx were both independently associated with air sample positivity, but the alpha variant and COVID-19 vaccination were not. The proportion of positive air samples patients infected with the influenza A virus was 18%. In conclusion, the higher air sample positivity rate of the omicron variant compared to previous SARS-CoV-2 variants may partially explain the higher transmission rates seen in epidemiological trends.

Rapid screening method for the detection of SARS-CoV-2 variants of concern.

BACKGROUND: Comprehensive and up-to-date monitoring of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOC) is crucial as these are characterized by their increased transmissibility, immune evasion and virulence. OBJECTIVES: To describe the wide-scale implementation of a reverse transcriptase polymerase chain reaction (RT-PCR) multiple variants assay with melting curve analysis as a routine procedure. STUDY DESIGN: We prospectively performed multiple variants RT-PCR on consecutive SARS-CoV-2 RT-PCR positive samples from patients, healthcare workers and nursing home residents from our hospital catchment area. This technique was implemented in our automated Roche FLOW system with a turn-around time of 6 h. RESULTS: Between February 1 and May 2, 2021, 989 samples were tested by the variant RT-PCR. Our method was validated by comparison of variant RT-PCR to whole genome sequencing testing. We observed an increase over time in the proportion of UK variant that became the dominant variant, and the concurrent emergence of the South-African and Brazilian variants. Prompt public health responses for infection control were possible because of this rapid screening method, resulting in early detection and reduction of unnoticed spread of VOC as early as possible. CONCLUSION: A variant RT-PCR with additional melting curve analyses is a feasible, rapid and efficient screening strategy that can be implemented in routine microbiological laboratories.

[A neonate with rectal bleeding]. / Een pasgeborene met rectaal bloedverlies.

BACKGROUND: Rectal bleeding in neonates is commonly associated with non-significant anal fissures or with the severe condition necrotising enterocolitis (NEC). A 'banal' bacterial colitis is often considered unlikely and, subsequently, diagnostics for this condition are usually not conducted. CASE DESCRIPTION: We describe the case of an otherwise healthy neonate who experienced rectal blood loss as a result of Campylobacterjejuni infection. CONCLUSION: The diagnosis 'infectious colitis' should be considered in cases of rectal bleeding in neonates. Antibiotic treatment for Campylobacter infection is advised for children under the age of three months, since the risk of a fulminant disease trajectory is high in this patient group.

Differential complement activation pathways promote C3b deposition on native and acetylated LDL thereby inducing lipoprotein binding to the complement receptor 1.

Lipoproteins can induce complement activation resulting in opsonization and binding of these complexes to complement receptors. We investigated the binding of opsonized native LDL and acetylated LDL (acLDL) to the complement receptor 1 (CR1). Binding of complement factors C3b, IgM, C1q, mannose-binding lectin (MBL), and properdin to LDL and acLDL were investigated by ELISA. Subsequent binding of opsonized LDL and acLDL to CR1 on CR1-transfected Chinese Hamster Ovarian cells (CHO-CR1) was tested by flow cytometry. Both native LDL and acLDL induced complement activation with subsequent C3b opsonization upon incubation with normal human serum. Opsonized LDL and acLDL bound to CR1. Binding to CHO-CR1 was reduced by EDTA, whereas MgEGTA only reduced the binding of opsonized LDL, but not of acLDL suggesting involvement of the alternative pathway in the binding of acLDL to CR1. In vitro incubations showed that LDL bound C1q, whereas acLDL bound to C1q, IgM, and properdin. MBL did neither bind to LDL nor to acLDL. The relevance of these findings was demonstrated by the fact that ex vivo up-regulation of CR1 on leukocytes was accompanied by a concomitant increased binding of apolipoprotein B-containing lipoproteins to leukocytes without changes in LDL-receptor expression. In conclusion, CR1 is able to bind opsonized native LDL and acLDL. Binding of LDL to CR1 is mediated via the classical pathway, whereas binding of acLDL is mediated via both the classical and alternative pathways. Binding of lipoproteins to CR1 may be of clinical relevance due to the ubiquitous cellular distribution of CR1.

Stroke-associated infection is an independent risk factor for poor outcome after acute ischemic stroke: data from the Netherlands Stroke Survey.

BACKGROUND: Infections are a common and serious threat to patients with acute ischemic stroke. The aim of this study was to assess the effect of infection on mortality and functional outcome at discharge and at 1 year. METHODS: From a consecutive cohort study in 11 centers, the Netherlands Stroke Survey, we selected 521 patients with ischemic stroke admitted to hospital within 48 h of onset. Stroke-associated infection was defined as infection occurring within 7 days after admission. Poor outcome (modified Rankin score >2) was recorded at discharge and at 1 year. RESULTS: Stroke-associated infection occurred in 78 patients (15%); 39 of these (7.5%) had pneumonia and 23 (4.4%) had urinary tract infection. Overall, 276 patients (53%) had a poor outcome at 1 year. Poor outcome was recorded in 69 patients with stroke-associated infection (88%), and 37 of the 78 patients with stroke-associated infection (47%) had died at 1 year. After adjustment for confounders, stroke-associated infection was associated with poor outcome at discharge [odds ratio (OR) 2.6, 95% confidence interval (CI) 1.0-6.7] and at 1 year (OR 3.8, 95% CI 1.8-8.9). Pneumonia had a stronger association with poor outcome at 1 year (OR 10, 95% CI 2.2-46). CONCLUSIONS: This study suggests that stroke-associated infection, in particular pneumonia, is independently associated with poor functional outcome after ischemic stroke.

Propionibacterium acnes and the pathogenesis of progressive macular hypomelanosis.

BACKGROUND: Progressive macular hypomelanosis is a common hypopigmentation mainly on the central parts of the trunk, predominantly in young adults, especially women. It is often mistaken for pityriasis versicolor and pityriasis alba. It occurs in all races and has been described in many parts of the world. We discovered follicular red fluorescence restricted to lesional skin. We suspected a relation with a porphyrin-producing bacteria residing in sebum of the pilosebaceous duct, and we therefore performed a study in 8 patients. Observation In all biopsy specimens taken from lesional skin of 8 women, we could demonstrate gram-positive bacteria in the pilosebaceous duct, and a mild perifollicular lymphocytic infiltrate was seen. In all but 1 patient, Propionibacterium acnes was yielded from cultured biopsy specimens taken from follicular lesional skin. Healthy follicular skin did not show bacteria in histological sections, and cultures did not yield anaerobic bacteria. CONCLUSIONS: There seems to be a relation between the presence of P acnes and the hypopigmented macules. We propose that a factor is produced by these strains of P acnes, which interfere with melanogenesis. Based on these observations, we are undertaking a clinical trial to find a treatment for this troubling, intractable disease.

Nosocomial Mycobacterium bovis-bacille Calmette-Guérin infections due to contamination of chemotherapeutics: case finding and route of transmission.

We studied nosocomial infections due to Mycobacterium bovis bacille Calmette-Guérin (BCG) Onco-TICE bacteria, transmitted by contamination of medication prepared in BCG Onco-TICE-contaminated hoods in the pharmacy, in 5 immunocompromised patients at 3 hospitals. The BCG strains cultured from the patients had the same DNA profile as the BCG Onco-TICE strain used for bladder instillation. To prevent these infections, a change from open to closed preparation was made; strictly separated preparation in time of BCG Onco-TICE instillation and chemotherapy was enforced, the biological safety cabinet was disinfected between preparations, and gloves were changed between preparations.