The SARS-CoV-2 pandemic poses the greatest global public health challenge in a century. Neutralizing antibody is a correlate of protection and data on kinetics of virus neutralizing antibody ...responses are needed. We tested 293 sera from an observational cohort of 195 reverse transcription polymerase chain reaction (RT-PCR) confirmed SARS-CoV-2 infections collected from 0 to 209 days after onset of symptoms. Of 115 sera collected ≥61 days after onset of illness tested using plaque reduction neutralization (PRNT) assays, 99.1% remained seropositive for both 90% (PRNT
) and 50% (PRNT
) neutralization endpoints. We estimate that it takes at least 372, 416 and 133 days for PRNT
titres to drop to the detection limit of a titre of 1:10 for severe, mild and asymptomatic patients, respectively. At day 90 after onset of symptoms (or initial RT-PCR detection in asymptomatic infections), it took 69, 87 and 31 days for PRNT
antibody titres to decrease by half (T
) in severe, mild and asymptomatic infections, respectively. Patients with severe disease had higher peak PRNT
and PRNT
antibody titres than patients with mild or asymptomatic infections. Age did not appear to compromise antibody responses, even after accounting for severity. We conclude that SARS-CoV-2 infection elicits robust neutralizing antibody titres in most individuals.
Abstract
SARS-CoV-2 infection of children leads to a mild illness and the immunological differences with adults are unclear. Here, we report SARS-CoV-2 specific T cell responses in infected adults ...and children and find that the acute and memory CD4
+
T cell responses to structural SARS-CoV-2 proteins increase with age, whereas CD8
+
T cell responses increase with time post-infection. Infected children have lower CD4
+
and CD8
+
T cell responses to SARS-CoV-2 structural and ORF1ab proteins when compared with infected adults, comparable T cell polyfunctionality and reduced CD4
+
T cell effector memory. Compared with adults, children have lower levels of antibodies to β-coronaviruses, indicating differing baseline immunity. Total T follicular helper responses are increased, whilst monocyte numbers are reduced, indicating rapid adaptive co-ordination of the T and B cell responses and differing levels of inflammation. Therefore, reduced prior β-coronavirus immunity and reduced T cell activation in children might drive milder COVID-19 pathogenesis.
Transmission of SARS-CoV-2 from humans to other mammals, including pet animals, has been reported. However, with the exception of farmed mink, there is no previous evidence that these infected ...animals can infect humans, resulting in sustained human-to-human transmission. Following a confirmed SARS-CoV-2 infection of a pet shop worker, animals in the shop and the warehouse supplying it were tested for evidence of SARS-CoV-2 infection.
In this case study, viral swabs and blood samples were collected from animals in a pet shop and its corresponding warehouse in Hong Kong. Nasal swab or saliva samples from human COVID-19 patients epidemiologically linked to the pet shop and from subsequent local cases confirmed to be infected by SARS-CoV-2 delta variant were collected. Oral swabs were tested by quantitative RT-PCR (RT-qPCR) for SARS-CoV-2 and blood samples were serologically tested by a surrogate virus neutralisation test and plaque reduction neutralisation test. The SARS-CoV-2 RT-qPCR positive samples were sequenced by next generation viral full genome sequencing using the ISeq sequencing platform (Illumina), and the viral genomes were phylogenetically analysed.
Eight (50%) of 16 individually tested Syrian hamsters in the pet shop and seven (58%) of 12 Syrian hamsters in the corresponding warehouse were positive for SARS-CoV-2 infection in RT-qPCR or serological tests. None of the dwarf hamsters (n=75), rabbits (n=246), guinea pigs (n=66), chinchillas (n=116), and mice (n=2) were confirmed positive for SARS-CoV-2 in RT-qPCR tests. SARS-CoV-2 viral genomes deduced from human and hamster cases in this incident all belong to the delta variant of concern (AY.127) that had not been circulating locally before this outbreak. The viral genomes obtained from hamsters were phylogenetically related with some sequence heterogeneity. Phylogenetic dating suggests infection in these hamsters occurred around Oct 14, 2021 (95% CI Sept 15 to Nov 9, 2021). Multiple zoonotic transmission events to humans were detected, leading to onward human-to-human transmission.
Pet hamsters can be naturally infected with SARS-CoV-2. The virus can circulate among hamsters and lead to human infections. Both genetic and epidemiological results strongly suggest that there was more than one hamster-to-human transmission event in this study. This incident also led to onward human transmission. Importation of SARS-CoV-2-infected hamsters was a likely source of this outbreak.
US National Institutes of Health, Research Grants Council of Hong Kong, Food and Health Bureau, and InnoHK.
Surrogate neutralization assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that can be done without biosafety level 3 containment and in multiple species are desirable. We ...evaluate a recently developed surrogate virus neutralization test (sVNT) in comparison to 90% plaque reduction neutralization tests (PRNT
) in human, canine, cat, and hamster sera. With PRNT
as the reference, sVNT had sensitivity of 98.9% and specificity of 98.8%. Using a panel of immune sera corresponding to other coronaviruses, we confirm the lack of cross-reactivity to other coronaviruses in SARS-CoV-2 sVNT and PRNT
, except for cross-reactivity to SARS-CoV-1 in sVNT.
The antibody response magnitude and kinetics may impact clinical severity, serological diagnosis and long-term protection of COVID-19, which may play a role in why children experience lower ...morbidity. We therefore tested samples from 122 children in Hong Kong with symptomatic (n = 78) and asymptomatic (n = 44) SARS-CoV-2 infections up to 200 days post infection, relative to 71 infected adults (symptomatic n = 61, and asymptomatic n = 10), and negative controls (n = 48). We assessed serum IgG antibodies to a 14-wide antigen panel of structural and accessory proteins by Luciferase Immuno-Precipitation System (LIPS) assay and circulating cytokines. Infected children have lower levels of Spike, Membrane, ORF3a, ORF7a, ORF7b antibodies, comparable ORF8 and elevated E-specific antibodies than adults. Combination of two unique antibody targets, ORF3d and ORF8, can accurately discriminate SARS-CoV-2 infection in children. Principal component analysis reveals distinct pediatric serological signatures, and the highest contribution to variance from adults are antibody responses to non-structural proteins ORF3d, NSP1, ORF3a and ORF8. From a diverse panel of cytokines that can modulate immune priming and relative inflammation, IL-8, MCP-1 and IL-6 correlate with the magnitude of pediatric antibody specificity and severity. Antibodies to SARS-CoV-2 internal proteins may become an important sero surveillance tool of infection with the roll-out of vaccines in the pediatric population.
Objective To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer.Design Meta-analysis of randomised controlled trials with ...data extraction and quality assessment performed independently by two researchers.Data sources Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews.Study selection Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment.Results There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions.Conclusions Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power output, and improved quality of life.
Summary
Background
Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe cutaneous adverse drug reaction. However, its histopathological features have not been well defined.
...Objectives
To identify the clinicohistopathological findings of DRESS, and analyse the cutaneous histopathological changes observed in DRESS compared with those observed in maculopapular exanthema (MPE).
Methods
In a retrospective study, conducted at Chang Gung Memorial Hospital (Taiwan) between 2001 and 2011, we compared the clinicohistopathological features of 32 patients with probable/definite DRESS (defined by the RegiSCAR scoring system) with those of 17 patients with MPE.
Results
The major pathological changes observed in patients with DRESS included dyskeratosis (97%), epidermal spongiosis (78%), interface vacuolization (91%), perivascular lymphocytic infiltration (97%) and eosinophilic infiltration (72%). Many pathological features were common to both MPE and DRESS. However, severe dyskeratosis, epidermal spongiosis and severe interface vacuolization were significantly more prominent in cases of DRESS (P < 0·05). The presence of severe dyskeratosis was significantly associated with the clinical severity of renal impairment (P = 0·01).
Conclusions
The severe dyskeratosis detected in patients with DRESS may correlate with a greater extent of systemic involvement compared with that noted in MPE. However, the histopathological changes associated with DRESS are not entirely specific.
What's already known about this topic?
Drug reaction with eosinophilia and systemic symptoms (DRESS) is characterized by severe skin rash, fever, haematological abnormalities and internal organ involvement.
What does this study add?
On histopathological examination, epidermal spongiosis, severe dyskeratosis and interface vacuolization were more commonly noted in DRESS than in maculopapular exanthema (MPE).
Severe dyskeratosis, observed in DRESS, may correlate with a greater extent of systemic involvement compared with that noted in MPE.
Middle East respiratory syndrome coronavirus (MERS-CoV) causes a zoonotic respiratory disease of global public health concern, and dromedary camels are the only proven source of zoonotic infection. ...Although MERS-CoV infection is ubiquitous in dromedaries across Africa as well as in the Arabian Peninsula, zoonotic disease appears confined to the Arabian Peninsula. MERS-CoVs from Africa have hitherto been poorly studied. We genetically and phenotypically characterized MERS-CoV from dromedaries sampled in Morocco, Burkina Faso, Nigeria, and Ethiopia. Viruses from Africa (clade C) are phylogenetically distinct from contemporary viruses from the Arabian Peninsula (clades A and B) but remain antigenically similar in microneutralization tests. Viruses from West (Nigeria, Burkina Faso) and North (Morocco) Africa form a subclade, C1, that shares clade-defining genetic signatures including deletions in the accessory gene ORF4b. Compared with human and camel MERS-CoV from Saudi Arabia, virus isolates from Burkina Faso (BF785) and Nigeria (Nig1657) had lower virus replication competence in Calu-3 cells and in ex vivo cultures of human bronchus and lung. BF785 replicated to lower titer in lungs of human DPP4-transduced mice. A reverse genetics-derived recombinant MERS-CoV (EMC) lacking ORF4b elicited higher type I and III IFN responses than the isogenic EMC virus in Calu-3 cells. However, ORF4b deletions may not be the major determinant of the reduced replication competence of BF785 and Nig1657. Genetic and phenotypic differences in West African viruses may be relevant to zoonotic potential. There is an urgent need for studies of MERS-CoV at the animal–human interface.
Objective
The diagnostic yield for congenital heart defects (CHD) with routine genetic testing is around 10%–20% when considering pathogenic CNVs or aneuploidies as positive findings. This is a pilot ...study to investigate the utility of genome sequencing (GS) for prenatal diagnosis of CHD.
Methods
Genome sequencing (GS, 30X) was performed on 13 trios with CHD for which karyotyping and/or chromosomal microarray results were non‐diagnostic.
Results
Trio GS provided a diagnosis for 4/13 (30.8%) fetuses with complex CHDs and other structural anomalies. Findings included pathogenic or likely pathogenic variants in DNAH5, COL4A1, PTPN11, and KRAS. Of the nine cases without a genetic etiology by GS, we had outcome follow‐up data on eight. For five of them (60%), the parents chose to keep the pregnancy. A balanced translocation 46,XX,t(14; 22)(q32.33; q13.31)mat was detected in a trio with biallelic DNAH5 mutations, which together explained the recurrent fetal situs inversus and dextrocardia that was presumably due to de novo Phelan‐McDermid syndrome. A secondary finding of a BRCA2 variant and carrier status of HBB, USH2A, HBA1/HBA2 were detected in the cohort.
Conclusions
GS expands the diagnostic scope of mutation types over conventional testing, revealing the genetic etiology for fetal heart anomalies. Patients without a known genetic abnormality indicated by GS likely opted to keep pregnancy especially if the heart defect could be surgically repaired. We provide evidence to support the application of GS for fetuses with CHD.
Key points
What's already known about this topic?
The diagnostic yield of exome sequencing for fetuses with structural abnormalities after undiagnostic conventional testing is 20%–30%. The diagnostic yield of genome sequencing for fetal heart defects is not established.
What does this study add?
This study demonstrated that genome sequencing has a diagnostic yield of 30.5% in fetuses with congenital heart defects (CHD) and is even higher in cases with complex CHD and syndromic abnormalities.
Pulmonary stenosis with other structural anomalies is more commonly associated with a genetic diagnosis, while a molecular genetic diagnosis is less frequently achieved for isolated aortic anomalies.
Genome sequencing provided an integrated analysis of a range of mutation types and also detected additional clinically relevant genetic findings such as chromosomal structural rearrangements.
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