COVID-19 in immunocompromised children: comparison of SARS-CoV-2 viral load dynamics between the first and third waves.

SARS-CoV-2 dynamics across different COVID-19 waves has been unclear in immunocompromised children. We aimed to compare the dynamics of SARS-CoV-2 RNA viral load (VL) during the first and third waves of COVID-19 in immunocompromised children. A retrospective and longitudinal cohort study was conducted in a pediatric referral hospital of Argentina.

Comparison of SARS-CoV-2 viral load in asymptomatic and symptomatic children attended in a referral public pediatric hospital in Argentina.

At present, different reports have shown that children reach similar SARS-CoV-2 viral load (VL) levels compared to adults; however, the impact of VL on children remains ambiguous when asymptomatic versus symptomatic cases are compared. Thus, the aim of this study was to assess VL at the time of diagnosis in asymptomatic and symptomatic SARS-CoV-2 infected children. VL analysis was retrospectively carried out from nasopharyngeal swabs on 82 SARS-CoV-2 infected children, from March to October 2020.

Case Report: Hyperinflammatory Status in an Immunocompromised Child With a Highly Sustained Viral Load of SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) is spreading throughout the world. Limited data are available for the dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load (VL) in immunocompromised pediatric patients. Here, we report the clinical characteristics and the dynamics of SARS-CoV-2 VL of a pediatric patient with acute myeloid leukemia who developed a hyperinflammatory status mimicked MIS-C.

A new highly sensitive single-tube nested real-time PCR assay: Clinical utility in perinatal HIV-1 diagnosis.

Real time PCR is one of the major tools for molecular diagnosis, however not always reaches the required sensitivity, especially in detecting early infectious disease. To overcome this problem, nested PCR is commonly performed, since it is highly sensitive, but it is time-consuming, prone to cross-contamination and difficult to standardize. Therefore, we developed a sensitive and specific single-tube nested real-time PCR (STN-real-time PCR) assay and evaluated its clinical utility on early infant HIV-1 diagnosis (EID).

Unraveling HIV-1 diagnosis in special pediatric cases.

Background: Early HIV-1 diagnosis and initiation of antiretroviral treatment is essential to prevent AIDS, and reduce mortality in children. HIV-1 molecular diagnosis in children before 18 months of age require, two independent samples to confirm a result. However, some patients have discordant virologic results in different samples, raising uncertainty for a conclusive diagnosis.

Pre-treatment drug resistance and HIV-1 subtypes in infants from Argentina with and without exposure to antiretroviral drugs for prevention of mother-to-child transmission.

Objectives: To assess the prevalence and patterns of pre-treatment HIV drug resistance (PDR) and HIV-1 subtype in infants from Argentina with exposure to different antiretroviral drugs (ARVs) for the prevention of mother-to-child transmission (PMTCT).

Patients And Methods: HIV-1 genotyping was performed in 115 infants (median age = 2.3 months) born between 2007 and 2014 to screen for drug resistance mutations (DRMs) before starting first-line ART.

Molecular Epidemiology and Spatio-Temporal Dynamics of the H3N8 Equine Influenza Virus in South America.

Equine influenza virus (EIV) is considered the most important respiratory pathogen of horses as outbreaks of the disease lead to substantial economic losses. The H3N8 EIV has caused respiratory disease in horses across the world, including South American countries. Nucleotide and deduced amino acid sequences for the complete haemagglutinin gene of the H3N8 EIV detected in South America since 1963 were analyzed.

Rich bacterial assemblages from Maritime Antarctica (Potter Cove, South Shetlands) reveal several kinds of endemic and undescribed phylotypes.

Bacterial richness in maritime Antarctica has been poorly described to date. Phylogenetic affiliation of seawater free-living microbial assemblages was studied from three locations near the Argentinean Jubany Station during two Antarctic summers. Sixty 16S RNA cloned sequences were phylogenetically affiliated to Alphaproteobacteria (30/60 clones), Gammaproteobacteria(19/60 clones), Betaproteobacteria and Cytophaga-Flavobacteriia-Bacteroides (CFB), which were (2/60) and (3/60) respectively.

Short communication: Emergence of novel A/G recombinant HIV-1 strains in Argentina.

The predominant circulating HIV-1 strains in South America are subtype B and B/F recombinants with different distributions among countries. However, the emergence of other subtypes is a matter of concern and needs continuous monitoring. We identified three different A/G recombinants in Argentina, two of them in vertically infected children from unlinked mothers and one in an adult female.

Spreading of hepatitis C virus subtypes 1a and 1b through the central region of Argentina.

The recent history of the hepatitis C virus (HCV) subtypes 1a and 1b in the central region of Argentina is hypothesized by phylogeographic reconstruction using coalescent based Bayesian analyses. Direct partial E2 sequences from HCV 1a and 1b infected patients attending different health-care centers of the country were analyzed. The inferred date of the most recent common ancestor (tMRCA) for HCV-1a was: 1962 (between 1943 and 1977) and for HCV-1b was earlier: 1929 (between 1895 and 1953).

Hepatitis C virus diversification in Argentina: comparative analysis between the large city of Buenos Aires and the small rural town of O'Brien.

Background: The estimated prevalence of HCV infection in Argentina is around 2%. However, higher rates of infection have been described in population studies of small urban and rural communities. The aim of this work was to compare the origin and diversification of HCV-1b in samples from two different epidemiological scenarios: Buenos Aires, a large cosmopolitan city, and O'Brien, a small rural town with a high prevalence of HCV infection.

High prevalence of hepatitis C virus genotype 1b infection in a small town of Argentina. Phylogenetic and Bayesian coalescent analysis.

Previous studies in Argentina have documented a general prevalence of Hepatitis C Virus (HCV) infection close to 2%. In addition, a high prevalence of HCV has been recently reported in different Argentinean small rural communities. In this work, we performed a study aimed at analyzing the origins and diversification patterns of an HCV outbreak in Wheelwright, a small rural town located in Santa Fe province (Argentina).

Bovine leukemia virus can be classified into seven genotypes: evidence for the existence of two novel clades.

Previous studies have classified the env sequences of bovine leukemia virus (BLV) provirus from different locations worldwide into between two and four genetic groupings. These different studies gave unique names to the identified groups and no study has yet integrated all the available sequences. Thus, we hypothesized that many of the different groups previously identified actually correspond to a limited group of genotypes that are unevenly distributed worldwide.

Simple procedures to obtain exogenous internal controls for use in RT-PCR detection of bovine pestiviruses.

Pestiviruses are ubiquitous pathogens of cattle and frequent adventitious viruses in biologicals. Furthermore, it has been suggested that these agents might be related to infantile gastroenteritis and microencephaly. Since the virus is highly prevalent in fetal bovine serum, the risk of contamination is high in most laboratories.