Snapshot of COVID-19 superinfections in Marseille hospitals: where are the common pathogens?

Episodes of bacterial superinfections have been well identified for several respiratory viruses, notably influenza. In this retrospective study, we compared the frequency of superinfections in COVID-19 patients to those found in influenza-positive patients, and to controls without viral infection. We included 42 468 patients who had been diagnosed with COVID-19 and 266 261 subjects who had tested COVID-19 negative between 26 February 2020 and 1 May 2021. In addition, 4059 patients were included who had tested positive for the influenza virus between 1 January 2017 and 31 December 2019. Bacterial infections in COVID-19 patients were more frequently healthcare-associated, and acquired in ICUs, were associated with longer ICU stays, and occurred in older and male patients when compared to controls and to influenza patients (P < 0.0001 for all). The most common pathogens proved to be less frequent in COVID-19 patients, including fewer cases of bacteraemia involving E. coli (P < 0.0001) and Klebsiella pneumoniae (P = 0.027) when compared to controls. In respiratory specimens Haemophilus influenzae (P < 0.0001) was more frequent in controls, while Streptococcus pneumoniae (P < 0.0001) was more frequent in influenza patients. Likewise, species associated with nosocomial transmission, such as Pseudomonas aeruginosa and Staphylococcus epidermidis, were more frequent among COVID-19 patients. Finally, we observed a high frequency of Enterococcus faecalis bacteraemia among COVID-19 patients, which were mainly ICU-acquired and associated with a longer timescale to acquisition.

Incidence and Outcome of Coinfections with SARS-CoV-2 and Rhinovirus.

BACKGROUND: We aimed to compare the clinical severity in patients who were coinfected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and rhinovirus or monoinfected with a single one of these viruses. METHODS: The study period ranged from 1 March 2020 to 28 February 2021 (one year). SARS-CoV-2 and other respiratory viruses were identified by real-time reverse-transcription-PCR as part of the routine work at Marseille University hospitals. Bacterial and fungal infections were detected by standard methods. Clinical data were retrospectively collected from medical files. This study was approved by the ethical committee of our institute. RESULTS: A total of 6034/15,157 (40%) tested patients were positive for at least one respiratory virus. Ninety-three (4.3%) SARS-CoV-2-infected patients were coinfected with another respiratory virus, with rhinovirus being the most frequent (62/93, 67%). Patients coinfected with SARS-CoV-2 and rhinovirus were significantly more likely to report a cough than those with SARS-CoV-2 monoinfection (62% vs. 31%; p = 0.0008). In addition, they were also significantly more likely to report dyspnea than patients with rhinovirus monoinfection (45% vs. 36%; p = 0.02). They were also more likely to be transferred to an intensive care unit and to die than patients with rhinovirus monoinfection (16% vs. 5% and 7% vs. 2%, respectively) but these differences were not statistically significant. CONCLUSIONS: A close surveillance and investigation of the co-incidence and interactions of SARS-CoV-2 and other respiratory viruses is needed. The possible higher risk of increased clinical severity in SARS-CoV-2-positive patients coinfected with rhinovirus warrants further large scale studies.

Rapid Isothermal Amplification for the Buccal Detection SARS-CoV-2 in the Context of Out-Patient COVID-19 Screening.

A commercially available isothermal amplification of SARS-CoV-2 RNA was applied to self-collected saliva samples using dry dental cotton rolls, which were held in the mouth for two minutes. Of 212 tests, isothermal amplification yielded three (0.14%) invalid results, 120 (56.6%) positive results and 89 (42%) negative results. Compared to reference RT-PCR assays routinely performed simultaneously on nasopharyngeal swabs, excluding the three invalid isothermal amplification assays and one RT-PCR invalid assay, these figures indicated that 119/123 (96.7%) samples were positive in both methods and 85/85 samples were negative in both methods. Four positive buccal swabs which were missed by the isothermal amplification, exhibited Ct values of 26-34 in reference RT-PCR assays. Positive isothermal amplification detection was achieved in less than 10 min. Supervision of the self-sampling procedure was key to achieve these performances. These data support the proposal to use the protocol reported in this paper, including supervised buccal self-sampling, to screen people suspected of having COVID-19 at the point of care.

[Event-related potentials and auditory sensory memory]. / Ereigniskorrelierte Potenziale und auditives sensorisches Gedächtnis.

OBJECTIVE: Deficits in auditory short-term memory are thought to underlie developmental language disorders and dyslexia. There is, however, a lack of systematic studies of short-term memory in children at a young age. The aim of this study was to probe the duration of auditory sensory memory using objective methods in young children. METHOD: 37 two-year-old and 52 six-year-old normally developing children were included in the study. Event-related potentials (ERPs) were elicited in a passive auditory oddball paradigm with variable interstimulus intervals (ISIs of 0.5-5 s, depending on the subgroup). RESULTS: For shorter ISIs, a prominent mismatch negativity (MMN) and late discriminative negativity (LDN) were found, while a distinct P3a occurred particularly for longer ISIs. Statistical significance was proven for the dependence of MMN and LDN amplitudes on the ISI. The change in the structure of the ERP components occurred at a longer ISI for the six-year-olds than for the 2-year-olds. CONCLUSIONS: The points where MMN and LDN disappear with increasing ISI suggest that the duration of auditory sensory memory lies between 1 and 2 s in two-year-old children and between 3 and 5 s in six-year-olds. The occurrence of a P3a beyond the point where MMN and LDN can no longer be elicited, however, provides evidence that several different mechanisms with different durations of memory representations are involved in short-term storage of auditory information.

Children with specific language impairment: the role of prosodic processes in explaining difficulties in processing syntactic information.

Children with specific language impairment (SLI) experience great difficulties in language comprehension and/or production whereby the majority of these children have particular problems in acquiring syntactic rules. In the speech stream boundaries of major syntactic constituents are reliably marked by prosodic cues. Therefore, prosodic information provides an important cue for discovering the syntactic structure of a language [Jusczyk, P.W., 2002. How infants adapt speech-processing capacities to native language structure. Curr. Dir. Psychol. Sci. 11, 15-18.]. Following this, the question is, whether children with SLI differ in the processing of syntactic information from normally developing children and to what extent this is related to the processing of the inherent prosodic information. Children heard either correct sentences or sentences with a word category violation (syntactic level) and a joined prosodic incongruity (prosodic level) while event-related brain potentials (ERPs) were recorded. Judging the sentence's correctness, control children performed better than children with SLI for all types of sentences. With respect to the ERPs, control children showed a bilateral early starting anterior negativity sustaining into a late anterior negativity and a P600 in posterior regions in response to incorrect sentences. Children with SLI showed a comparable P600 but unlike the control children there was only a late, clearly left lateralized anterior negativity. The complete absence of a right anterior negativity in children with SLI suggests that they may not access prosodic information in the same way normal children do. The differences in prosodic processing may in turn hamper the development of syntactic processing skills as indicated by the absence of the syntax-related early left anterior negativity.

Development of auditory sensory memory from 2 to 6 years: an MMN study.

Short-term storage of auditory information is thought to be a precondition for cognitive development, and deficits in short-term memory are believed to underlie learning disabilities and specific language disorders. We examined the development of the duration of auditory sensory memory in normally developing children between the ages of 2 and 6 years. To probe the lifetime of auditory sensory memory we elicited the mismatch negativity (MMN), a component of the late auditory evoked potential, with tone stimuli of two different frequencies presented with various interstimulus intervals between 500 and 5,000 ms. Our findings suggest that memory traces for tone characteristics have a duration of 1-2 s in 2- and 3-year-old children, more than 2 s in 4-year-olds and 3-5 s in 6-year-olds. The results provide insights into the maturational processes involved in auditory sensory memory during the sensitive period of cognitive development.

Auditory sensory memory in 2-year-old children: an event-related potential study.

Auditory sensory memory is assumed to play an important role in cognitive development, but little is known about it in young children. The aim of this study was to estimate the duration of auditory sensory memory in 2-year-old children. We recorded the mismatch negativity in response to tone stimuli presented with different interstimulus intervals. Our findings suggest that in 2-year-old children the memory representation of the standard tone remains in the sensory memory store for at least 1 s but for less than 2 s. Recording the mismatch negativity with stimuli presented at various interstimulus intervals seems to be a useful method for studying the relationship between auditory sensory memory and normal and disturbed cognitive development.

Lexical-semantic processes in children with specific language impairment.

The current study used event-related brain potentials to investigate lexical-semantic processing of words in sentences spoken by children with specific language impairment and children with normal language development. Children heard correct sentences and sentences with a violation of the selectional restriction of the verb. Control children showed an N400 effect followed by a late positivity for the incorrect sentences. In contrast, children with specific language impairment showed no N400 effect but did show a late, broadly distributed positivity. This absence of the N400 effect is due to a relatively large negativity for correct sentences, suggesting weaker lexical-semantic representations of the verbs and their selectional restrictions in children with specific language impairment.