RESUMEN
Viral mutations are an emerging concern in reducing SARS-CoV-2 vaccination efficacy. Second-generation vaccines will need to elicit neutralizing antibodies against sites that are evolutionarily conserved across the sarbecovirus subgenus. Here, we immunized mice containing a human antibody repertoire with diverse sarbecovirus receptor-binding domains (RBDs) to identify antibodies targeting conserved sites of vulnerability. Antibodies with broad reactivity against diverse clade B RBDs targeting the conserved class 4 epitope, with recurring IGHV/IGKV pairs, were readily elicited but were non-neutralizing. However, rare class 4 antibodies binding this conserved RBD supersite showed potent neutralization of SARS-CoV-2 and all variants of concern. Structural analysis revealed that the neutralizing ability of cross-reactive antibodies was reserved only for those with an elongated CDRH3 that extends the antiparallel beta-sheet RBD core and orients the antibody light chain to obstruct ACE2-RBD interactions. These results identify a structurally defined pathway for vaccine strategies eliciting escape-resistant SARS-CoV-2 neutralizing antibodies.
Asunto(s)
Betacoronavirus/fisiología , Vacunas contra la COVID-19/inmunología , Infecciones por Coronavirus/inmunología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/fisiología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Animales , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/metabolismo , Secuencia Conservada/genética , Evolución Molecular , Humanos , Inmunización , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Unión Proteica , Dominios Proteicos/genética , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Desarrollo de VacunasRESUMEN
Respiratory syncytial virus (RSV) is a leading cause of acute respiratory infection amongst all ages, causing a significant global health burden. Preventative and therapeutic options for RSV infection have long been under development, and recently, several widely-publicised vaccines targeting older adult and maternal populations have become available. Promising monoclonal antibody (mAb) and antiviral (AV) therapies are also progressing in clinical trials, with the prophylactic mAb nirsevimab recently approved for clinical use in infant populations. A systematic review on current progress in this area is lacking. We performed a systematic literature search (PubMed, Embase, Web of Science, ClinicalTrials.gov, EudraCT, ANZCTR-searched Nov 29th, 2023) to identify studies on all RSV-specific mAbs and AV therapies that has undergone human clinical trials since year 2000. Data extraction focused on outcomes related to the therapeutic efficacy and safety of the intervention on trial, and all studies were graded against the OCEBM Levels of Evidence Table. Results from 59 studies were extracted, covering efficacy and safety data on six mAbs (motavizumab, motavizumab-YTE, nirsevimab, ALX-0171, suptavumab, clesrovimab) and 12 AV therapies (ALN-RSV01, RSV604, presatovir, MDT-637, lumicitabine, IFN-α1b, rilematovir, enzaplatovir, AK0529, sisunatovir, PC786, EDP-938). Of the mAbs reviewed, nirsevimab and clesrovimab hold considerable promise. The timeline for RSV-specific AV availability is less advanced, although EDP-938 and AK0529 have reported promising phase 2 efficacy and safety data. Moving forward, passive immunisation and treatment options for RSV infection will play a significant role in reducing the health burden of RSV, complementing recent advancements in vaccine development. TRIAL REGISTRATION: PROSPERO registration: CRD42022376633.
Asunto(s)
Anticuerpos Monoclonales , Antivirales , Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Humanos , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/administración & dosificación , Anticuerpos Antivirales/efectos adversos , Anticuerpos Antivirales/inmunología , Antivirales/administración & dosificación , Antivirales/efectos adversos , Antivirales/inmunología , Ensayos Clínicos como Asunto , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Infecciones por Virus Sincitial Respiratorio/prevención & control , Infecciones por Virus Sincitial Respiratorio/inmunología , Virus Sincitial Respiratorio Humano/inmunología , Virus Sincitial Respiratorio Humano/efectos de los fármacos , Resultado del TratamientoRESUMEN
As many as 5%-10% of infants with symptomatic congenital cytomegalovirus (cCMV) disease, or 0.4%-0.8% of all liveborn infants with cCMV infection, die in early infancy in high-income countries. However, estimates are uncertain due to several potential biases that can result from data limitations and study designs. First, infants with cCMV infections who die prior to diagnosis, which usually occurs at 1-4 weeks after birth, may be excluded from both the count of deaths and the denominator of cCMV births, resulting in left truncation and immortal time biases. These 'biases' are features of the data and do not reflect bias on the part of researchers, but understanding the potential existence of threats to validity can help with interpretation of findings. Left truncation of infant deaths occurring prior to diagnosis of cCMV can result in understatement of the burden of infant deaths due to cCMV. Conversely, overestimation of infant deaths associated with symptomatic cCMV may occur in clinical case series owing to greater representation of relatively severely affected infants owing to ascertainment and referral biases. In this review, we summarise the characteristics of 26 studies that reported estimates of cCMV-associated infant deaths, including potential biases or limitations to which those estimates may have been subject. We discuss study designs whose implementation might generate improved estimates of infant deaths attributable to cCMV. More complete estimates of the overall public health impact of cCMV could inform current and future screening, prevention, and vaccine research.
Asunto(s)
Infecciones por Citomegalovirus , Citomegalovirus , Lactante , Humanos , Recién Nacido , Países Desarrollados , Infecciones por Citomegalovirus/diagnóstico , Mortalidad Infantil , Muerte del Lactante , Tamizaje NeonatalRESUMEN
A 32-year-old female with advanced human immunodeficiency virus infection presented to an Australian hospital with subacute, worsening symptoms of encephalitis. Metagenomic sequencing and Dengue NS3 antigen staining of brain tissue confirmed active dengue virus (DENV) encephalitis. The most recent possible DENV exposure was months prior in West Africa, indicating chronicity.
Asunto(s)
Virus del Dengue , Dengue , Infecciones por VIH , Humanos , Femenino , Adulto , Infecciones por VIH/complicaciones , Dengue/complicaciones , Dengue/diagnóstico , Virus del Dengue/genética , Encefalitis Viral/virología , Encefalitis Viral/diagnóstico , Encéfalo/patología , Encéfalo/diagnóstico por imagen , Encéfalo/virología , Australia , Enfermedad CrónicaRESUMEN
Using sequential immunoassays for the screening of blood donors is well described for viral serology testing but not for the screening of syphilis. In this study, we report the evaluation results and 2-year sequential testing data using two highly sensitive automated serology assays, the Alinity s Syphilis chemiluminescent immunoassay for screening, with all repeatedly reactive samples then tested on the Elecsys Syphilis electrochemiluminescence immunoassay. We screened 1,767,782 blood donor samples between 7 July 2021 and 6 July 2023 and found the Alinity false-positive rate to be low at 0.08% (1,456/1,767,782). The common false-positive rate between the two assays was also low (3.83%, 58/1,514). Concordantly reactive samples were further tested using a Treponema pallidum particle agglutination test, a rapid plasma reagin test, and a fluorescent treponemal antibody absorption test. There were 262/1,376 concordantly reactive Alinity and Elecsys blood donor samples with reactivity on one or more of the confirmatory tests. A total of 26/1,376 donors had a current syphilis infection, 152/1,376 reported a past history of syphilis and had been treated, and 84/1,376 did not report a past history of syphilis. We suggest that future studies could explore the use of sequential immunoassays to aid in the serodiagnosis for syphilis. IMPORTANCE: The serodiagnosis for syphilis usually follows two methodologies-a "traditional" algorithm using a non-treponemal test followed by confirmation using a treponemal test, or a "reverse" algorithm using a treponemal test followed by a non-treponemal test. There are limited reports in the literature of using a modified reverse algorithm (treponemal test followed by a second treponemal test), and to the best of knowledge, there are currently no published articles using two highly sensitive automated immunoassays to aid the serodiagnosis of syphilis. In addition, the Treponema pallidum particle agglutination (TPPA) assay is commonly used as a confirmatory test for the diagnosis of syphilis. With the withdrawal of the TPPA assay from Australia and presumably from the global market also, alternative testing algorithms are now required. This study provides proof of concept for using sequential immunoassays in the diagnosis of syphilis.
Asunto(s)
Donantes de Sangre , Serodiagnóstico de la Sífilis , Sífilis , Treponema pallidum , Humanos , Sífilis/diagnóstico , Sífilis/sangre , Inmunoensayo/métodos , Serodiagnóstico de la Sífilis/métodos , Treponema pallidum/inmunología , Tamizaje Masivo/métodos , Anticuerpos Antibacterianos/sangre , Reacciones Falso Positivas , Automatización de Laboratorios/métodos , Sensibilidad y Especificidad , Femenino , MasculinoRESUMEN
This study retrospectively analyzed the genetic characteristics of influenza A H3N2 (A/H3N2) viruses circulating in New South Wales (NSW), the Australian state with the highest number of influenza cases in 2022, and explored the phylodynamics of A/H3N2 transmission within Australia during this period. Sequencing was performed on 217 archived specimens, and A/H3N2 evolution and spread within Australia were analyzed using phylogenetic and phylodynamic methods. Hemagglutinin genes of all analyzed NSW viruses belonged to subclade 3C.2a1b.2a.2 and clustered together with the 2022 vaccine strain. Complete genome analysis of NSW viruses revealed highly frequent interclade reassortments between subclades 3C.2a1b.2a.2 and 3C.2a1b.1a. The estimated earliest introduction time of the dominant subgroup 3C.2a1b.2a.2a.1 in Australia was February 22, 2022 (95% highest posterior density: December 19, 2021-March 13, 2022), following the easing of Australian travel restrictions, suggesting a possible international source. Phylogeographic analysis revealed that Victoria drove the transmission of A/H3N2 viruses across the country during this season, while NSW did not have a dominant role in viral dissemination to other regions. This study highlights the importance of continuous surveillance and genomic characterization of influenza viruses in the postpandemic era, which can inform public health decision-making and enable early detection of novel strains with pandemic potential.
Asunto(s)
COVID-19 , Subtipo H3N2 del Virus de la Influenza A , Gripe Humana , Filogenia , Humanos , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/clasificación , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , Gripe Humana/virología , Gripe Humana/transmisión , Estudios Retrospectivos , COVID-19/epidemiología , COVID-19/transmisión , COVID-19/virología , COVID-19/prevención & control , Australia/epidemiología , Nueva Gales del Sur/epidemiología , SARS-CoV-2/genética , SARS-CoV-2/clasificación , Filogeografía , Estaciones del Año , Genoma Viral/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Virus Reordenados/genética , Virus Reordenados/clasificaciónRESUMEN
Among the environmental factors associated with type 1 diabetes (T1D), viral infections of the gut and pancreas has been investigated most intensely, identifying enterovirus infections as the prime candidate trigger of islet autoimmunity (IA) and T1D development. However, the association between respiratory tract infections (RTI) and IA/T1D is comparatively less known. While there are significant amounts of epidemiological evidence supporting the role of respiratory infections in T1D, there remains a paucity of data characterising infectious agents at the molecular level. This gap in the literature precludes the identification of the specific infectious agents driving the association between RTI and T1D. Furthermore, the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on the development of IA/T1D remains undeciphered. Here, we provide a comprehensive overview of the evidence to date, implicating RTIs (viral and non-viral) as potential risk factors for IA/T1D.
Asunto(s)
COVID-19 , Diabetes Mellitus Tipo 1 , Islotes Pancreáticos , Infecciones del Sistema Respiratorio , Humanos , Islotes Pancreáticos/patología , COVID-19/patología , SARS-CoV-2 , Infecciones del Sistema Respiratorio/patologíaRESUMEN
Phagocytic responses by effector cells to opsonized viruses have been recognized to play a key role in antiviral immunity. Limited data on coronavirus disease 2019 suggest that the role of Ab-dependent and -independent phagocytosis may contribute to the observed immunological and inflammatory responses; however, their development, duration, and role remain to be fully elucidated. In this study of 62 acute and convalescent patients, we found that patients with acute coronavirus disease 2019 can mount a phagocytic response to autologous plasma-opsonized Spike protein-coated microbeads as early as 10 d after symptom onset, while heat inactivation of this plasma caused 77-95% abrogation of the phagocytic response and preblocking of Fc receptors showed variable 18-60% inhibition. In convalescent patients, phagocytic response significantly correlated with anti-Spike IgG titers and older patients, while patients with severe disease had significantly higher phagocytosis and neutralization functions compared with patients with asymptomatic, mild, or moderate disease. A longitudinal subset of the convalescent patients over 12 mo showed an increase in plasma Ab affinity toward Spike Ag and preservation of phagocytic and neutralization functions, despite a decline in the anti-Spike IgG titers by >90%. Our data suggest that early phagocytosis is primarily driven by heat-liable components of the plasma, such as activated complements, while anti-Spike IgG titers account for the majority of observed phagocytosis at convalescence. Longitudinally, a significant increase in the affinity of the anti-Spike Abs was observed that correlated with the maintenance of both the phagocytic and neutralization functions, suggesting an improvement in the quality of the Abs.
Asunto(s)
COVID-19 , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Antivirales , Humanos , Inmunoglobulina G , Receptores Fc , SARS-CoV-2 , Glicoproteína de la Espiga del CoronavirusRESUMEN
Avian paramyxovirus type 1 (APMV-1) is a virus of birds that results in a range of outcomes, from asymptomatic infections to outbreaks of systemic respiratory and neurologic disease, depending on the virus strain and the avian species affected. Humans are rarely affected; those who are predominantly experience mild conjunctivitis. We report a fatal case of neurologic disease in a 2-year-old immunocompromised child in Australia. Metagenomic sequencing and histopathology identified the causative agent as the pigeon variant of APMV-1. This diagnosis should be considered in neurologic conditions of undefined etiologies. Agnostic metagenomic sequencing methods are useful in such settings to direct diagnostic and therapeutic efforts.
Asunto(s)
Enfermedades Transmisibles , Enfermedad de Newcastle , Animales , Preescolar , Humanos , Australia/epidemiología , Columbidae , Enfermedad de Newcastle/epidemiología , Enfermedad de Newcastle/patología , Virus de la Enfermedad de Newcastle , FilogeniaRESUMEN
Plasmonic nanoparticles are finding applications within the single molecule sensing field in a "dimer" format, where interaction of the target with hairpin DNA causes a decrease in the interparticle distance, leading to a localized surface plasmon resonance shift. While this shift may be detected using spectroscopy, achieving statistical relevance requires the measurement of thousands of nanoparticle dimers and the timescales required for spectroscopic analysis are incompatible with point-of-care devices. However, using dark-field imaging of the dimer structures, simultaneous digital analysis of the plasmonic resonance shift after target interaction of thousands of dimer structures may be achieved in minutes. The main challenge of this digital analysis on the single-molecule scale was the occurrence of false signals caused by non-specifically bound clusters of nanoparticles. This effect may be reduced by digitally separating dimers from other nanoconjugate types. Variation in image intensity was observed to have a discernible impact on the color analysis of the nanoconjugate constructs and thus the accuracy of the digital separation. Color spaces wherein intensity may be uncoupled from the color information (hue, saturation, and value (HSV) and luminance, a* vector, and b* vector (LAB) were contrasted to a color space which cannot uncouple intensity (RGB) to train a classifier algorithm. Each classifier algorithm was validated to determine which color space produced the most accurate digital separation of the nanoconjugate types. The LAB-based learning classifier demonstrated the highest accuracy for digitally separating nanoparticles. Using this classifier, nanoparticle conjugates were monitored for their plasmonic color shift after interaction with a synthetic RNA target, resulting in a platform with a highly accurate yes/no response with a true positive rate of 88% and a true negative rate of 100%. The sensor response of tested single stranded RNA (ssRNA) samples was well above control responses for target concentrations in the range of 10 aM-1 pM.
Asunto(s)
Nanoconjugados , Resonancia por Plasmón de Superficie , Color , Aprendizaje Automático , Nanotecnología/métodos , Resonancia por Plasmón de Superficie/métodosRESUMEN
The long-term health consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are still being understood. The molecular and phenotypic properties of SARS-CoV-2 antigen-specific T cells suggest a dysfunctional profile that persists in convalescence in those who were severely ill. By contrast, the antigen-specific memory B-cell (MBC) population has not yet been analyzed to the same degree, but phenotypic analysis suggests differences following recovery from mild or severe coronavirus disease 2019 (COVID-19). Here, we performed single-cell molecular analysis of the SARS-CoV-2 receptor-binding domain (RBD)-specific MBC population in three patients after severe COVID-19 and four patients after mild/moderate COVID-19. We analyzed the transcriptomic and B-cell receptor repertoire profiles at ~2 months and ~4 months after symptom onset. Transcriptomic analysis revealed a higher level of tumor necrosis factor-alpha (TNF-α) signaling via nuclear factor-kappa B in the severe group, involving CD80, FOS, CD83 and TNFAIP3 genes that was maintained over time. We demonstrated the presence of two distinct activated MBCs subsets based on expression of CD80hi TNFAIP3hi and CD11chi CD95hi at the transcriptome level. Both groups revealed an increase in somatic hypermutation over time, indicating progressive evolution of humoral memory. This study revealed distinct molecular signatures of long-term RBD-specific MBCs in convalescence, indicating that the longevity of these cells may differ depending on acute COVID-19 severity.
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COVID-19 , Humanos , SARS-CoV-2 , Células B de Memoria , Convalecencia , Anticuerpos AntiviralesRESUMEN
PURPOSE OF REVIEW: This review describes current knowledge of ganciclovir (GCV) and valganciclovir (ValGCV) pharmacokinetic/pharmacodynamic characteristics, highlighting the likely contribution from host genetic factors to interpatient variability. The evidence and challenges surrounding optimization of drug dosing through therapeutic drug monitoring (TDM) are examined, with recommendations made. RECENT FINDINGS: Pharmacokinetic studies of current dosing guidelines have shown high interindividual and intraindividual variability of GCV concentrations. This is sometimes associated with a slow decline in cytomegalovirus (CMV) viral load in some transplant recipients. A high incidence of GCV-associated myelosuppression has limited the use of this drug in the transplant setting. Patient groups identified to benefit from GCV TDM include pediatric patients, cystic fibrosis with lung transplantation, obese with kidney transplantation, and patients with fluctuating renal function or on hemodialysis. The emergence of refractory resistant CMV, particularly in immune compromised patients, highlights the importance of appropriate dosing of these antivirals. Host genetic factors need to be considered where recently, two host genes were shown to account for interpatient variation during ganciclovir therapy. Therapeutic Drug Monitoring has been shown to improve target antiviral-level attainment. The use of TDM may guide concentration-based dose adjustment, potentially improving virological and clinical outcomes. However, evidence supporting the use of TDM in clinical practice remains limited and further study is needed in the transplant cohort. SUMMARY: Further studies examining novel biomarkers are needed to guide target concentrations in prophylaxis and treatment. The use of TDM in transplant recipients is likely to improve the clinical efficacy of current antivirals and optimize outcomes in transplant recipients.
Asunto(s)
Infecciones por Citomegalovirus , Trasplante de Órganos , Humanos , Niño , Ganciclovir/uso terapéutico , Ganciclovir/farmacología , Antivirales/farmacología , Infecciones por Citomegalovirus/prevención & control , Monitoreo de Drogas , Trasplante de Órganos/efectos adversosRESUMEN
Acute respiratory infection is the third most frequent cause of mortality worldwide, causing over 4.25 million deaths annually. Although most diagnosed acute respiratory infections are thought to be of viral origin, the aetiology often remains unclear. The advent of next-generation sequencing (NGS) has revolutionised the field of virus discovery and identification, particularly in the detection of unknown respiratory viruses. We systematically reviewed the application of NGS technologies for detecting respiratory viruses from clinical samples and outline potential barriers to the routine clinical introduction of NGS. The five databases searched for studies published in English from 01 January 2010 to 01 February 2021, which led to the inclusion of 52 studies. A total of 14 different models of NGS platforms were summarised from included studies. Among these models, second-generation sequencing platforms (e.g., Illumina sequencers) were used in the majority of studies (41/52, 79%). Moreover, NGS platforms have proven successful in detecting a variety of respiratory viruses, including influenza A/B viruses (9/52, 17%), SARS-CoV-2 (21/52, 40%), parainfluenza virus (3/52, 6%), respiratory syncytial virus (1/52, 2%), human metapneumovirus (2/52, 4%), or a viral panel including other respiratory viruses (16/52, 31%). The review of NGS technologies used in previous studies indicates the advantages of NGS technologies in novel virus detection, virus typing, mutation identification, and infection cluster assessment. Although there remain some technical and ethical challenges associated with NGS use in clinical laboratories, NGS is a promising future tool to improve understanding of respiratory viruses and provide a more accurate diagnosis with simultaneous virus characterisation.
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COVID-19 , Virus de la Influenza A , Infecciones del Sistema Respiratorio , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Virus de la Influenza B , Infecciones del Sistema Respiratorio/diagnóstico , SARS-CoV-2RESUMEN
The first dominant SARS-CoV-2 Omicron variant BA.1 harbours 35 mutations in its Spike protein from the original SARS-CoV-2 variant that emerged late 2019. Soon after its discovery, BA.1 rapidly emerged to become the dominant variant worldwide and has since evolved into several variants. Omicron is of major public health concern owing to its high infectivity and antibody evasion. This review article examines the theories that have been proposed on the evolution of Omicron including zoonotic spillage, infection in immunocompromised individuals and cryptic spread in the community without being diagnosed. Added to the complexity of Omicron's evolution are the multiple reports of recombination events occurring between co-circulating variants of Omicron with Delta and other variants such as XE. Current literature suggests that the combination of the novel mutations in Omicron has resulted in the variant having higher infectivity than the original Wuhan-Hu-1 and Delta variant. However, severity is believed to be less owing to the reduced syncytia formation and lower multiplication in the human lung tissue. Perhaps most challenging is that several studies indicate that the efficacy of the available vaccines have been reduced against Omicron variant (8-127 times reduction) as compared to the Wuhan-Hu-1 variant. The administration of booster vaccine, however, compensates with the reduction and improves the efficacy by 12-35 fold. Concerningly though, the broadly neutralising monoclonal antibodies, including those approved by FDA for therapeutic use against previous SARS-CoV-2 variants, are mostly ineffective against Omicron with the exception of Sotrovimab and recent reports suggest that the Omicron BA.2 is also resistant to Sotrovimab. Currently two new Omicron variants BA.4 and BA.5 are emerging and are reported to be more transmissible and resistant to immunity generated by previous variants including Omicron BA.1 and most monoclonal antibodies. As new variants of SARS-CoV-2 will likely continue to emerge it is important that the evolution, and biological consequences of new mutations, in existing variants be well understood.
Asunto(s)
COVID-19 , SARS-CoV-2 , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Humanos , SARS-CoV-2/genéticaRESUMEN
Acute respiratory infections (ARIs) are a major cause of morbidity among children. Respiratory viruses are commonly detected in both symptomatic and asymptomatic periods. The rates of infection and community epidemiology of respiratory viruses in healthy children needs further definition to assist interpretation of molecular diagnostic assays in this population. Children otherwise healthy aged 1 to 8 years were prospectively enrolled in the study during two consecutive winters, when ARIs peak in New Zealand. Parents completed a daily symptom diary for 8 weeks, during which time they collected a nasal swab from the child for each clinical ARI episode. A further nasal swab was collected by research staff during a clinic visit at the conclusion of the study. All samples were tested for 15 respiratory viruses commonly causing ARI using molecular multiplex polymerase chain reaction assays. There were 575 ARIs identified from 301 children completing the study, at a rate of 1.04 per child-month. Swabs collected during an ARI were positive for a respiratory virus in 76.8% (307 of 400), compared with 37.3% (79 of 212) of swabs collected during asymptomatic periods. The most common viruses detected were human rhinovirus, coronavirus, parainfluenza viruses, influenzavirus, respiratory syncytial virus, and human metapneumovirus. All of these were significantly more likely to be detected during ARIs than asymptomatic periods. Parent-administered surveillance is a useful mechanism for understanding infectious disease in healthy children in the community. Interpretation of molecular diagnostic assays for viruses must be informed by understanding of local rates of asymptomatic infection by such viruses.
Asunto(s)
Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/virología , Virus/aislamiento & purificación , Enfermedad Aguda , Infecciones Asintomáticas/epidemiología , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Masculino , Técnicas de Diagnóstico Molecular , Reacción en Cadena de la Polimerasa Multiplex , Nueva Zelanda/epidemiología , Nariz/virología , Vigilancia de la Población , Prevalencia , Infecciones del Sistema Respiratorio/diagnóstico , Estaciones del Año , Virus/clasificación , Virus/genéticaRESUMEN
Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infection hospitalisations in Aboriginal infants specifically those aged <6 months. Maternally derived RSV antibody (Ab) can protect against severe RSV disease in infancy. However, the efficiency of transplacental transfer of maternal anti-RSV Ab remains unknown in Aboriginal infants. We characterised RSV Ab in Australian First Nations mother-infant pairs (n = 78). We investigated impact of covariates including low birthweight, gestational age (GA), sex of the baby, maternal age and multiparity of the mother on cord to maternal anti-RSV Ab titre ratio (CMTR) using multivariable logistic regression model. All (n = 78) but one infant was born full term (median GA: 39 weeks, interquartile range: 38-40 weeks) and 56% were males. The mean log2 RSV Ab titre was 10.7 (SD± 1.3) in maternal serum and 11.0 (SD ± 1.3) in cord serum at birth; a ratio of 1.02 (SD ± 0.06). One-third of the pairs had a CMTR of <1 indicating impaired transfer. Almost 9% (7/78) of the term infants had cord RSV Ab levels below Asunto(s)
Pueblos Indígenas
, Infecciones por Virus Sincitial Respiratorio
, Virus Sincitial Respiratorio Humano
, Adulto
, Anticuerpos Antivirales
, Australia
, Femenino
, Humanos
, Lactante
, Recién Nacido
, Modelos Logísticos
, Masculino
, Madres
, Análisis Multivariante
, Adulto Joven
RESUMEN
Severe acute respiratory syndrome related coronavirus-2 (SARS-CoV-2) is the cause of Covid-19 which was classified as a global pandemic in March 2020. The increasing global health and economic burden of SARS-CoV-2 has necessitated urgent investigations into the pathogenesis of disease and development of therapeutic and vaccination regimens. Human trials of vaccine and antiviral candidates have been undertaken, but basic pathogenetic studies are still required to inform these trials. Gaps in understanding of cellular infection by, and immunity to, SARS-CoV-2 mean additional models are required to assist in improved design of these therapeutics. Human organoids are three-dimensional models that contain multiple cell types and mimic human organs in ex vivo culture conditions. The SARS-CoV-2 virus has been implicated in causing not only respiratory injury but also injury to other organs such as the brain, liver and kidneys. Consequently, a variety of different organoid models have been employed to investigate the pathogenic mechanisms of disease due to SARS-CoV-2. Data on these models have not been systematically assembled. In this review, we highlight key findings from studies that have utilised different human organoid types to investigate the expression of SARS-CoV-2 receptors, permissiveness, immune response, dysregulation of cellular functions, and potential antiviral therapeutics.
Asunto(s)
Interacciones Huésped-Patógeno/inmunología , Modelos Biológicos , Organoides/inmunología , Receptores Virales/antagonistas & inhibidores , SARS-CoV-2/patogenicidad , Glicoproteína de la Espiga del Coronavirus/antagonistas & inhibidores , Enzima Convertidora de Angiotensina 2/antagonistas & inhibidores , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/inmunología , Antivirales/farmacología , Encéfalo/efectos de los fármacos , Encéfalo/inmunología , Encéfalo/virología , COVID-19/inmunología , COVID-19/patología , COVID-19/virología , Técnicas de Cultivo de Célula , Colon/efectos de los fármacos , Colon/inmunología , Colon/virología , Citocinas/genética , Citocinas/inmunología , Interacciones Huésped-Patógeno/efectos de los fármacos , Humanos , Hígado/efectos de los fármacos , Hígado/inmunología , Hígado/virología , Pulmón/efectos de los fármacos , Pulmón/inmunología , Pulmón/virología , Organoides/efectos de los fármacos , Organoides/virología , Receptores Virales/genética , Receptores Virales/inmunología , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/inmunología , Serina Endopeptidasas/genética , Serina Endopeptidasas/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Tratamiento Farmacológico de COVID-19RESUMEN
Cellular receptors in human cytomegalovirus (HCMV) mother to child transmission play an important role in congenital infection. Placental trophoblast cells are a significant cell type in placental development, placental functional processes, and in HCMV transmission. Different cells within the placental floating and chorionic villi present alternate receptors for HCMV cell entry. Syncytiotrophoblasts present neonatal Fc receptors that bind and transport circulating maternal immunoglobulin G across the placental interface which can also be bound to HCMV virions, facilitating viral entry into the placenta and foetal circulation. Cytotrophoblast express HCMV receptors including integrin-α1ß1, integrin-αVß3, epidermal growth factor receptor and platelet-derived growth factor receptor alpha. The latter interacts with HCMV glycoprotein-H, glycoprotein-L and glycoprotein-O (gH/gL/gO) trimers (predominantly in placental fibroblasts) and the gH/gL/pUL128, UL130-UL131A pentameric complex in other placental cell types. The pentameric complex allows viral tropism of placental trophoblasts, endothelial cells, epithelial cells, leukocytes and monocytes. This review outlines HCMV ligands and target receptor proteins in congenital HCMV infection.
Asunto(s)
Citomegalovirus , Células Endoteliales , Interacciones Huésped-Patógeno , Placenta/virología , Femenino , Glicoproteínas , Humanos , Transmisión Vertical de Enfermedad Infecciosa , EmbarazoRESUMEN
Viruses are postulated as primary candidate triggers of islet autoimmunity (IA) and type 1 diabetes (T1D), based on considerable epidemiological and experimental evidence. Recent studies have investigated the association between all viruses (the 'virome') and IA/T1D using metagenomic next-generation sequencing (mNGS). Current associations between the early life virome and the development of IA/T1D were analysed in a systematic review and meta-analysis of human observational studies from Medline and EMBASE (published 2000-June 2020), without language restriction. Inclusion criteria were as follows: cohort and case-control studies examining the virome using mNGS in clinical specimens of children ≤18 years who developed IA/T1D. The National Health and Medical Research Council level of evidence scale and Newcastle-Ottawa scale were used for study appraisal. Meta-analysis for exposure to specific viruses was performed using random-effects models, and the strength of association was measured using odds ratios (ORs) and 95% confidence intervals (CIs). Eligible studies (one case-control, nine nested case-control) included 1,425 participants (695 cases, 730 controls) and examined IA (n = 1,023) or T1D (n = 402). Meta-analysis identified small but significant associations between IA and number of stool samples positive for all enteroviruses (OR 1.14, 95% CI 1.00-1.29, p = 0.05; heterogeneity χ2 = 1.51, p = 0.68, I2 = 0%), consecutive positivity for enteroviruses (1.55, 1.09-2.20, p = 0.01; χ2 = 0.19, p = 0.91, I2 = 0%) and number of stool samples positive specifically for enterovirus B (1.20, 1.01-1.42, p = 0.04; χ2 = 0.03, p = 0.86, I2 = 0%). Virome analyses to date have demonstrated associations between enteroviruses and IA that may be clinically significant. However, larger prospective mNGS studies with more frequent sampling and follow-up from pregnancy are required to further elucidate associations between early virus exposure and IA/T1D.
Asunto(s)
Autoinmunidad , Diabetes Mellitus Tipo 1 , Viroma/genética , Niño , Diabetes Mellitus Tipo 1/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Lactante , Estudios ProspectivosRESUMEN
AIMS: Cytomegalovirus (CMV) is a preventable cause of neurodevelopmental disability. Australian guidelines recommend that pregnant women are informed about CMV to reduce their risk of infection; however, less than 10% of maternity health professionals routinely provide prevention advice. The aim was to develop and evaluate the effectiveness of an eLearning course for midwives to improve knowledge and confidence about CMV. MATERIALS AND METHODS: Participants undertaking the course between March and November 2020 were invited to complete an evaluation questionnaire: before the course (T1), immediately after (T2) and three months post completion (T3). A linear mixed model was used to evaluate change in participant scores; P < 0.05 was considered statistically significant. RESULTS: Midwives (316/363, 87%), midwifery students (29/363, 8%) and nurses (18/363, 5%) participated. At T1 80% indicated they had not received education about CMV. Total adjusted mean scores for questionnaires completed between T1 (n = 363) and T2 (n = 238) increased significantly (from 17.2 to 22.8, P < 0.001). Limited available T3 scores (n = 27) (-1.7, P < 0.001), while lower than T2, remained higher than at T1 (+3.6, P < 0.001). Participants' awareness of CMV information resources improved from 10 to 97% from T1 to T2. Confidence in providing CMV advice increased from 6 to 95% between T1 and T2 (P < 0.001) and was maintained at T3. Almost all (99%) participants indicated they would recommend the course to colleagues. CONCLUSION: Participants who completed the eLearning course had significantly improved knowledge and confidence in providing advice about CMV. Programs targeting other maternity health professionals should be considered, to further support the implementation of the congenital CMV prevention guidelines.