Virological Characteristics of Hospitalized Children With SARS-CoV-2 Infection.

BACKGROUND AND OBJECTIVES: In children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, virological characteristics and correlation with disease severity have not been extensively studied. The primary objective in this study is to determine the correlation between SARS-CoV-2 viral load (VL) in infected children with age, disease severity, and underlying comorbidities. METHODS: Children <21 years, screened for SARS-CoV-2 at the time of hospitalization, who tested positive by polymerase chain reaction were included in this study. VL at different sites was determined and compared between groups. RESULTS: Of the 102 children included in this study, 44% of the cohort had asymptomatic infection, and children with >1 comorbidity were the most at risk for severe disease. VL in children with symptomatic infection was significantly higher than in children with asymptomatic infection (3.0 × 105 vs 7.2 × 103 copies per mL; P = .001). VL in the respiratory tract was significantly higher in children <1 year, compared with older children (3.3 × 107 vs 1.3 × 104 copies per mL respectively; P < .0001), despite most infants presenting with milder illness. Besides the respiratory tract, SARS-CoV-2 RNA was also detectable in samples from the gastrointestinal tract (saliva and rectum) and blood. In 13 children for whom data on duration of polymerase chain reaction positivity was available, 12 of 13 tested positive 2 weeks after initial diagnosis, and 6 of 13 continued to test positive 4 weeks after initial diagnosis. CONCLUSIONS: In hospitalized children with SARS-CoV-2, those with >1 comorbid condition experienced severe disease. SARS-CoV-2 VL in the respiratory tract is significantly higher in children with symptomatic disease and children <1 year of age.

Experimental aerosol survival of SARS-CoV-2 in artificial saliva and tissue culture media at medium and high humidity.

SARS-CoV-2, the causative agent of the COVID-19 pandemic, may be transmitted via airborne droplets or contact with surfaces onto which droplets have deposited. In this study, the ability of SARS-CoV-2 to survive in the dark, at two different relative humidity values and within artificial saliva, a clinically relevant matrix, was investigated. SARS-CoV-2 was found to be stable, in the dark, in a dynamic small particle aerosol under the four experimental conditions we tested and viable virus could still be detected after 90 minutes. The decay rate and half-life was determined and decay rates ranged from 0.4 to 2.27 % per minute and the half lives ranged from 30 to 177 minutes for the different conditions. This information can be used for advice and modelling and potential mitigation strategies.

Identification of a novel member of the family Betaflexiviridae from the hallucinogenic plant Salvia divinorum.

Betaflexiviridae is a family of plant-infecting RNA viruses with 11 recognized genera, of which genomes have diverse organization with three to six open reading frames (ORFs). A genome sequence of a novel Betaflexiviridae species, named Salvia divinorum RNA virus 1 (SdRV1), was identified in Salvia divinorum, herbal mint plant with hallucinogenic properties. The SdRV1 genome was predicted to have four ORFs encoding a replicase polyprotein (REP), a movement protein (MP), a coat protein (CP), and a putative nucleic acid-binding protein (NBP). Phylogenetic analyses based on the REP, MP, and CP sequences indicated that SdRV1 is most closely related to members of the genus Citrivirus. However, the genome organization of SdRV1 is the same as that of the genus Prunevirus. Moreover, the SdRV1 NBP had greatest sequence similarity with members of the genus Carlavirus. A complex evolutionary history involving ancestors of these three genera might have resulted in the unique phylogenetic position of SdRV1, which could be considered the founding member of a new genus in the family Betaflexiviridae. The genome sequence of SdRV1 might be useful for studies on the evolution of Betaflexiviridae. Keywords: Salvia divinorum RNA virus 1; Betaflexiviridae; Salvia divinorum.

Detection and identification of the first viruses in chia (Salvia hispanica).

Chia (Salvia hispanica), an herbaceous plant native to Latin America, has become important in the last 20 years due to its beneficial effects on health. Here, we present the first record and identification of two viruses in chia plants. The comparison of the complete nucleotide sequences showed the presence of two viral species with the typical genome organization of bipartite New World begomovirus, identified as Sida mosaic Bolivia virus 2 and Tomato yellow spot virus, according to the ICTV taxonomic criteria for begomovirus classification. DNA-A from Sida mosaic Bolivia virus 2 exhibited 96.1% nucleotide identity with a Bolivian isolate of Sida micrantha, and Tomato yellow spot virus showed 95.3% nucleotide identity with an Argentine bean isolate. This is the first report of begomoviruses infecting chia as well as of the occurrence of Sida mosaic Bolivia virus 2 in Argentina.