The severe acute respiratory syndrome coronavirus 2 Omicron BA.1 sublineage has been supplanted in many countries by the BA.2 sublineage. BA.2 differs from BA.1 by about 21 mutations in its spike. In ...this study, we first compared the sensitivity of BA.1 and BA.2 to neutralization by nine therapeutic monoclonal antibodies (mAbs). In contrast to BA.1, BA.2 was sensitive to cilgavimab, partly inhibited by imdevimab and resistant to adintrevimab and sotrovimab. We then analyzed sera from 29 immunocompromised individuals up to 1 month after administration of Ronapreve (casirivimab and imdevimab) and/or Evusheld (cilgavimab and tixagevimab) antibody cocktails. All treated individuals displayed elevated antibody levels in their sera, which efficiently neutralized the Delta variant. Sera from Ronapreve recipients did not neutralize BA.1 and weakly inhibited BA.2. Neutralization of BA.1 and BA.2 was detected in 19 and 29 out of 29 Evusheld recipients, respectively. As compared to the Delta variant, neutralizing titers were more markedly decreased against BA.1 (344-fold) than BA.2 (nine-fold). We further report four breakthrough Omicron infections among the 29 individuals, indicating that antibody treatment did not fully prevent infection. Collectively, BA.1 and BA.2 exhibit noticeable differences in their sensitivity to therapeutic mAbs. Anti-Omicron neutralizing activity of Ronapreve and, to a lesser extent, that of Evusheld is reduced in patients' sera.
Dermatophytes are among the most common fungal agents causing superficial skin infections worldwide. Epidemiology of these infections is evolving and variable in every country. This report presents ...the Belgian epidemiological data regarding the distribution of dermatophytes species isolated by the two national reference centers for mycosis during a period of 5 years (2012–2016).
Trichophyton rubrum
was the most frequently isolated species, considering all sampling sites (60.3% on average between 2012 and 2016). More precisely, this dermatophyte was the major agent of
Tinea unguium
and
Tinea corporis
during this period, followed by species of the
Trichophyton mentagrophytes
complex
.
Moreover,
Microsporum audouinii
was the main etiological agent of
Tinea capitis
(TC) with a frequency of 52.5% on average between 2012 and 2016. Other African dermatophytes species such as
Trichophyton soudanense
and
Trichophyton violaceum
were also agents of TC with a respective prevalence of 11.6% and 11.5% on average. This study highlights a different dermatophyte distribution in Belgium in comparison with other European countries.
is an important and frequently carried respiratory pathogen that has the potential to cause serious invasive diseases, such as pneumonia, meningitis, and sepsis. Young children and older adults are ...among the most vulnerable to developing serious disease. With the arrival of the COVID-19 pandemic and the concomitant restrictive measures, invasive disease cases caused by respiratory bacterial species, including pneumococci, decreased substantially. Notably, the stringency of the containment measures as well as the visible reduction in the movement of people appeared to coincide with the drop in invasive disease cases. One could argue that wearing protective masks and adhering to social distancing guidelines to halt the spread of the SARS-CoV-2 virus, also led to a reduction in the person-to-person transmission of respiratory bacterial species. Although plausible, this conjecture is challenged by novel data obtained from our nasopharyngeal carriage study which is performed yearly in healthy daycare center attending children. A sustained and high pneumococcal carriage rate was observed amid periods of stringent restrictive measures. This finding prompts us to revisit the connection between nasopharyngeal colonization and invasion and invites us to look closer at the nasopharyngeal microbiome as a whole.
Illustrated by a clinical case supplemented by epidemiologic data, early reinfections with SARS-CoV-2 Omicron BA.1 after infection with Delta variant, and reinfection with Omicron BA.2 after Omicron ...BA.1 infection, can occur within 60 days, especially in young, unvaccinated persons. The case definition of reinfection, which influences retesting policies, should be reconsidered.
Public holidays have been associated with SARS-CoV-2 incidence surges, although a firm link remains to be established. This association is sometimes attributed to events where transmissions occur at ...a disproportionately high rate, known as superspreading events. Here, we describe a sudden surge in new cases with the Omicron BA.1 strain amongst higher education students in Belgium. Contact tracers classed most of these cases as likely or possibly infected on New Year's Eve, indicating a direct trigger by New Year celebrations. Using a combination of contact tracing and phylogenetic data, we show the limited role of superspreading events in this surge. Finally, the numerous simultaneous transmissions allowed a unique opportunity to determine the distribution of incubation periods of the Omicron strain. Overall, our results indicate that, even under social restrictions, a surge in transmissibility of SARS-CoV-2 can occur when holiday celebrations result in small social gatherings attended simultaneously and communitywide.
After switching from 13-valent to 10-valent pneumococcal conjugate vaccine (PCV10) (2015–2016) for children in Belgium, we observed rapid reemergence of serotype 19A invasive pneumococcal disease ...(IPD). Whole-genome sequencing of 166 serotype 19A IPD isolates from children (n = 54) and older adults (n = 56) and carriage isolates from healthy children (n = 56) collected after the vaccine switch (2017–2018) showed 24 sequence types (STs). ST416 (global pneumococcal sequence cluster GPSC 4) and ST994 (GPSC146) accounted for 75.9% of IPD strains from children and 65.7% of IPD (children and older adults) and carriage isolates in the PCV10 period (2017–2018). These STs differed from predominant 19A IPD STs after introduction of PCV7 (2011) in Belgium (ST193 GPSC11 and ST276 GPSC10), which indicates that prediction of emerging strains cannot be based solely on historical emerging strains. Despite their susceptible antimicrobial drug profiles, these clones spread in carriage and IPD during PCV10 use.
This retrospective multi-center matched cohort study assessed the risk for severe COVID-19 (combination of severity indicators), intensive care unit (ICU) admission, and in-hospital mortality in ...hospitalized patients when infected with the Omicron variant compared to when infected with the Delta variant. The study is based on a causal framework using individually-linked data from national COVID-19 registries. The study population consisted of 954 COVID-19 patients (of which, 445 were infected with Omicron) above 18 years old admitted to a Belgian hospital during the autumn and winter season 2021–2022, and with available viral genomic data. Patients were matched based on the hospital, whereas other possible confounders (demographics, comorbidities, vaccination status, socio-economic status, and ICU occupancy) were adjusted for by using a multivariable logistic regression analysis. The estimated standardized risk for severe COVID-19 and ICU admission in hospitalized patients was significantly lower (RR = 0.63; 95% CI (0.30; 0.97) and RR = 0.56; 95% CI (0.14; 0.99), respectively) when infected with the Omicron variant, whereas in-hospital mortality was not significantly different according to the SARS-CoV-2 variant (RR = 0.78, 95% CI (0.28–1.29)). This study demonstrates the added value of integrated genomic and clinical surveillance to recognize the multifactorial nature of COVID-19 pathogenesis.
•There are few reported studies on the occurrence of SARS-CoV-2 co-infection.•Whole-genome sequencing allows identification of SARS-CoV-2 variants causing coinfection.•Genomic evidence of ...co-infection with the Omicron and Delta variants is reported.
On November 24, 2021, a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant assigned to the lineage B.1.1.529 (Omicron) was first reported to the World Health Organization from South Africa. Despite the co-circulation of several SARS-CoV-2 variants, co-infection by different variants is not commonly identified. Here, we report two cases of SARS-CoV-2 co-identifications with the Omicron and Delta variants.
The COVID-19 pandemic highlighted the importance of diagnostic testing against curbing the spread of SARS-CoV-2. The urgent need and scale for diagnostic tools resulted in manufacturers of SARS-CoV-2 ...assays receiving emergency authorization that lacked robust analytical or clinical evaluation. As it is highly likely that testing for SARS-CoV-2 will continue to play a central role in public health, the performance characteristics of assays should be evaluated to ensure reliable diagnostic outcomes are achieved.
VALCOR or "VALidation of SARS-CORona Virus-2 assays" is a study protocol designed to set up a framework for test validation of SARS-CoV-2 virus assays. Using clinical samples collated from VALCOR, the performance of Aptima SARS-CoV-2 assay was assessed against a standard comparator assay. Diagnostic test parameters such as sensitivity, specificity and overall per cent agreement were calculated for the clinical performance of Aptima SARS-CoV-2 assay.
A total of 180 clinical samples were tested with an addition of 40 diluted clinical specimens to determine the limit of detection. When compared to the standard comparator assay Aptima had a sensitivity of 100.0% 95% CI 95.9-100.0 and specificity of 96.7% 95% CI 90.8-99.3. The overall percent agreement was 98.3% with an excellent Cohen's coefficient of κ = 0.967 95% CI 0.929-1.000. For the limit of detection, Aptima was able to detect all of the diluted clinical samples.
In conclusion. validation of Aptima SARS-CoV-2 assay using clinical samples collated through the VALCOR protocol showed excellent test performance. Additionally, Aptima demonstrated high analytical sensitivity by detecting all diluted clinical samples corresponding to a low limit of detection.
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