High Incidence of Respiratory Syncytial Virus in Children with Community-Acquired Pneumonia from a City in the Brazilian Pre-Amazon Region.

INTRODUCTION: Although fewer children have been affected by the severe form of the coronavirus disease 2019 (COVID-19), community-acquired pneumonia (CAP) continues to be the leading global cause of child hospitalizations and deaths. AIM: This study investigated the incidence of respiratory syncytial virus (RSV) as well its subtypes (RSV A and B), adenovirus (ADV), rhinovirus (HRV), metapneumovirus (HMPV), coronavirus (NL63, OC43, 229E and HKU1), parainfluenza virus subtypes (PI1, PI2 and PI3), bocavirus and influenza A and B viruses (FluA and FluB) in children diagnosed with CAP during the COVID-19 pandemic. METHODS: A total of 200 children with clinically confirmed CAP were initially recruited, of whom 107 had negative qPCR results for SARS-CoV-2 and were included in this study. Viral subtypes were identified using a real-time polymerase chain reaction in the nasopharyngeal swab samples. RESULTS: Viruses were identified in 69.2% of the patients. RSV infections were the most frequently identified (65.4%), with type RSV B being the most prevalent (63.5%). In addition, HCoV 229E and HRV were detected in 6.5% and 3.7% of the patients, respectively. RSV type B was associated with severe acute respiratory infection (ARI) and a younger age (less than 24 months). CONCLUSIONS: New strategies for preventing and treating viral respiratory infections, particularly RSV infections, are necessary.

Absence of Anti-RBD Antibodies in SARS-CoV-2 Infected or Naive Individuals Prior to Vaccination with CoronaVac Leads to Short Protection of Only Four Months Duration.

The COVID-19 pandemic is the biggest public health threat facing the world today. Multiple vaccines have been approved; however, the emergence of viral variants such as the recent Omicron raises the possibility of booster doses to achieve adequate protection. In Brazil, the CoronaVac (Sinovac, Beijing, China) vaccine was used; however, it is important to assess the immune response to this vaccine over time. This study aimed to monitor the anti-SARS-CoV-2 antibody responses in those immunized with CoronaVac and SARS-CoV-2 infected individuals. Samples were collected between August 2020 and August 2021. Within the vaccinated cohort, some individuals had a history of infection by SARS-CoV-2 prior to immunization, while others did not. We analyzed RBD-specific and neutralizing-antibodies. Anti-RBD antibodies were detected in both cohorts, with a peak between 45-90 days post infection or vaccination, followed by a steady decline over time. In those with a previous history of COVID-19, a higher, longer, more persistent response was observed. This trend was mirrored in the neutralization assays, where infection, followed by immunization, resulted in higher, longer lasting responses which were conditioned on the presence of levels of RBD antibodies right before the vaccination. This supports the necessity of booster doses of CoronaVac in due course to prevent serious disease.

Phylogenetic-based inference reveals distinct transmission dynamics of SARS-CoV-2 lineages Gamma and P.2 in Brazil.

The COVID-19 epidemic in Brazil experienced two major lineage replacements until mid-2021. The first was driven by lineage P.2, in late 2020, and the second by lineage Gamma, in early 2021. To understand how these SARS-CoV-2 lineages spread in Brazil, we analyzed 11,724 genomes collected throughout the country between September 2020 and April 2021. Our findings indicate that lineage P.2 probably emerged in July 2020 in the Rio de Janeiro state and Gamma in November 2020 in the Amazonas state. Both states were the main hubs of viral disseminations to other Brazilian locations. We estimate that Gamma was 1.56-3.06 times more transmissible than P.2 in Rio de Janeiro and that the median effective reproductive number (Re) of Gamma varied according to the geographic context (Re = 1.59-3.55). In summary, our findings support that lineage Gamma was more transmissible and spread faster than P.2 in Brazil.

Genetic evolution of influenza viruses among selected countries in Latin America, 2017-2018.

OBJECTIVE: Since the 2009 influenza pandemic, Latin American (LA) countries have strengthened their influenza surveillance systems. We analyzed influenza genetic sequence data from the 2017 through 2018 Southern Hemisphere (SH) influenza season from selected LA countries, to map the availability of influenza genetic sequence data from, and to describe, the 2017 through 2018 SH influenza seasons in LA. METHODS: We analyzed influenza A/H1pdm09, A/H3, B/Victoria and B/Yamagata hemagglutinin sequences from clinical samples from 12 National Influenza Centers (NICs) in ten countries (Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Mexico, Paraguay, Peru and Uruguay) with a collection date from epidemiologic week (EW) 18, 2017 through EW 43, 2018. These sequences were generated by the NIC or the WHO Collaborating Center (CC) at the U.S Centers for Disease Control and Prevention, uploaded to the Global Initiative on Sharing All Influenza Data (GISAID) platform, and used for phylogenetic reconstruction. FINDINGS: Influenza hemagglutinin sequences from the participating countries (A/H1pdm09 n = 326, A/H3 n = 636, B n = 433) were highly concordant with the genetic groups of the influenza vaccine-recommended viruses for influenza A/H1pdm09 and influenza B. For influenza A/H3, the concordance was variable. CONCLUSIONS: Considering the constant evolution of influenza viruses, high-quality surveillance data-specifically genetic sequence data, are important to allow public health decision makers to make informed decisions about prevention and control strategies, such as influenza vaccine composition. Countries that conduct influenza genetic sequencing for surveillance in LA should continue to work with the WHO CCs to produce high-quality genetic sequence data and upload those sequences to open-access databases.

Evolutionary Dynamics and Dissemination Pattern of the SARS-CoV-2 Lineage B.1.1.33 During the Early Pandemic Phase in Brazil.

A previous study demonstrates that most of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) Brazilian strains fell in three local clades that were introduced from Europe around late February 2020. Here we investigated in more detail the origin of the major and most widely disseminated SARS-CoV-2 Brazilian lineage B.1.1.33. We recovered 190 whole viral genomes collected from 13 Brazilian states from February 29 to April 31, 2020 and combined them with other B.1.1 genomes collected globally. Our genomic survey confirms that lineage B.1.1.33 is responsible for a variable fraction of the community viral transmissions in Brazilian states, ranging from 2% of all SARS-CoV-2 genomes from Pernambuco to 80% of those from Rio de Janeiro. We detected a moderate prevalence (5-18%) of lineage B.1.1.33 in some South American countries and a very low prevalence (<1%) in North America, Europe, and Oceania. Our study reveals that lineage B.1.1.33 evolved from an ancestral clade, here designated B.1.1.33-like, that carries one of the two B.1.1.33 synapomorphic mutations. The B.1.1.33-like lineage may have been introduced from Europe or arose in Brazil in early February 2020 and a few weeks later gave origin to the lineage B.1.1.33. These SARS-CoV-2 lineages probably circulated during February 2020 and reached all Brazilian regions and multiple countries around the world by mid-March, before the implementation of air travel restrictions in Brazil. Our phylodynamic analysis also indicates that public health interventions were partially effective to control the expansion of lineage B.1.1.33 in Rio de Janeiro because its median effective reproductive number (R e ) was drastically reduced by about 66% during March 2020, but failed to bring it to below one. Continuous genomic surveillance of lineage B.1.1.33 might provide valuable information about epidemic dynamics and the effectiveness of public health interventions in some Brazilian states.

High incidence of rhinovirus infection in children with community-acquired pneumonia from a city in the Brazilian pre-Amazon region.

Community-acquired pneumonia (CAP) is the leading cause of child death worldwide. Viruses are the most common pathogens associated with CAP in children, but their incidence varies greatly. This study investigated the presence of respiratory syncytial virus (RSV), adenovirus, human rhinovirus (HRV), human metapneumovirus (HMPV), human coronavirus (HCoV-OC43 and HCoV-NL63), and influenza A virus (FluA) in children with CAP and the contributing risk factors. Here, children with acute respiratory infections were screened by pediatrics; and a total of 150 radiographically-confirmed CAP patients (aged 3 months to 10 years) from two clinical centers in Sao Luis, Brazil were recruited. Patient's clinical and epidemiological data were recorded. Nasopharyngeal swab and tracheal aspirate samples were collected to extract viral nucleic acid. RSV, adenovirus, rhinovirus, FluA, HMPV, HCoV-OC43, and HCoV-NL63 were detected by real-time polymerase chain reaction. The severe CAP was associated with ages between 3 and 12 months. Viruses were detected in 43% of CAP patients. Rhinovirus infections were the most frequently identified (68%). RSV, adenovirus, FluA, and coinfections were identified in 14%, 14%, 5%, and 15% of children with viral infection, respectively. Rhinovirus was associated with nonsevere CAP (P = .014); RSV, FluA, and coinfections were associated with severe CAP (P < .05). New strategies for prevention and treatment of viral respiratory infections, mainly rhinovirus and RSV infections, are necessary.

Siaα2-3Galß1- Receptor Genetic Variants Are Associated with Influenza A(H1N1)pdm09 Severity.

Different host genetic variants may be related to the virulence and transmissibility of pandemic Influenza A(H1N1)pdm09, influencing events such as binding of the virus to the entry receptor on the cell of infected individuals and the host immune response. In the present study, two genetic variants of the ST3GAL1 gene, which encodes the Siaα2-3Galß1- receptor to which influenza A(H1N1)pdm09 virus binds for entry into the host cell, were investigated in an admixed Brazilian population. First, the six exons encoding the ST3GAL1 gene were sequenced in 68 patients infected with strain A(H1N1)pdm09. In a second phase of the study, the rs113350588 and rs1048479 polymorphisms identified in this sample were genotyped in a sample of 356 subjects from the northern and northeastern regions of Brazil with a diagnosis of pandemic influenza. Functional analysis of the polymorphisms was performed in silico and the influence of these variants on the severity of infection was evaluated. The results suggest that rs113350588 and rs1048479 may alter the function of ST3GAL1 either directly through splicing regulation alteration and/or indirectly through LD with SNP with regulatory function. In the study the rs113350588 and rs1048479 polymorphisms were in linkage disequilibrium in the population studied (D' = 0.65). The GC haplotype was associated with an increased risk of death in subjects with influenza (OR = 4.632, 95% CI = 2.10;1.21). The AT haplotype was associated with an increased risk of severe disease and death (OR = 1.993, 95% CI = 1.09;3.61 and OR 4.476, 95% CI = 2.37;8.44, respectively). This study demonstrated for the first time the association of ST3GAL1 gene haplotypes on the risk of more severe disease and death in patients infected with Influenza A(H1N1)pdm09 virus.

The CCR5Δ32 (rs333) polymorphism is not a predisposing factor for severe pandemic influenza in the Brazilian admixed population.

BACKGROUND: Recent studies have tried to identify host genetic variants that could explain severe cases and deaths in infection with Influenza A(H1N1)pdm09, especially among children and young adults. CCR5 is a chemokine receptor expressed on T cells, macrophages and dendritic cells, which is an important mediator of leukocyte chemotaxis during the immune response. A deletion mutation (Δ32) in this gene interferes with the response of immune cells, impairing viral clearance. We evaluated the CCR5Δ32 polymorphism (rs333) in individuals of the Brazilian admixed population with a diagnosis of Influenza A(H1N1)pdm09 infection. METHODS: A total of 330 subjects with a diagnosis of Influenza A(H1N1)pdm09, evaluated at health services in the northern and northeastern regions of Brazil between June 2009 and August 2010, were genotyped for the Δ32 deletion (rs333). The cases were classified according to the progression of infection into a group of hospitalized patients (n = 156) and a group of non-hospitalized patients (n = 174). RESULTS: No significant differences in the allele or genotype frequencies of the CCR5Δ32 polymorphism were observed between non-hospitalized and hospitalized patients (p = 0.289 and p = 0.431, respectively). CONCLUSION: The Δ32 deletion in the CCR5 gene is not associated with an unfavorable outcome in patients infected with Influenza A(H1N1)pdm09 in the Brazilian admixed population.

Norovirus infection in children admitted to hospital for acute gastroenteritis in Belém, Pará, Northern Brazil.

Noroviruses are the leading cause of epidemic, non-bacterial outbreaks of acute gastroenteritis, and are also a major cause of sporadic acute gastroenteritis in infants. The aim of the present study was to identify norovirus infections in children not infected by rotavirus admitted to hospital for acute gastroenteritis in Belém. A total of 348 fecal specimens were obtained from children with diarrhea aged less than 5 years, all of whom had tested negative for rotavirus, between May 2008 and April 2010. Fecal samples were screened for norovirus antigen using enzyme-immunoassay (EIA). Specimens were subjected to reverse-transcription polymerase chain reaction (RT-PCR) using the primers Mon432/434-Mon431/433 for detection of the GI and GII norovirus strains, respectively. Based on both methods, the overall norovirus positivity rate was 36.5% (127/348). Of the 169 samples collected in the first year, 44.4% (n = 75) tested positive for norovirus using both methods, 35.5% (n = 60) by EIA and 40.8% (n = 69) by RT-PCR. Using RT-PCR as a reference standard, a sensitivity of 78.3%, specificity of 94%, and agreement of 87.6% were recorded. Genome sequencing was obtained for 22 (31.9%) of the 69 positive samples, of which 90.9% (20/22) were genotype GII.4d and 9.1% (2/22) were genotype GII.b. Norovirus infection was most frequent in children under 2 years of age (41.5%-115/277). The peak incidence (62.1%) of norovirus-related acute gastroenteritis in these patients (not infected by rotavirus) was observed in February 2010. These findings emphasize the importance of norovirus as a cause of severe acute gastroenteritis among children in Belém, Pará, Northern Brazil.

Prevalence and clinical features of respiratory syncytial virus in children hospitalized for community-acquired pneumonia in northern Brazil.

BACKGROUND: Childhood pneumonia and bronchiolitis is a leading cause of illness and death in young children worldwide with Respiratory Syncytial Virus (RSV) as the main viral cause. RSV has been associated with annual respiratory disease outbreaks and bacterial co-infection has also been reported. This study is the first RSV epidemiological study in young children hospitalized with community-acquired pneumonia (CAP) in Belém city, Pará (Northern Brazil). METHODS: With the objective of determining the prevalence of RSV infection and evaluating the patients' clinical and epidemiological features, we conducted a prospective study across eight hospitals from November 2006 to October 2007. In this study, 1,050 nasopharyngeal aspirate samples were obtained from hospitalized children up to the age of three years with CAP, and tested for RSV antigen by direct immunofluorescence assay and by Reverse Transcription Polymerase Chain Reaction (RT-PCR) for RSV Group identification. RESULTS: RSV infection was detected in 243 (23.1%) children. The mean age of the RSV-positive group was lower than the RSV-negative group (12.1 months vs 15.5 months, p<0.001) whereas gender distribution was similar. The RSV-positive group showed lower means of C-reactive protein (CRP) in comparison to the RSV-negative group (15.3 vs 24.0 mg/dL, p<0.05). Radiological findings showed that 54.2% of RSV-positive group and 50.3% of RSV-negative group had interstitial infiltrate. Bacterial infection was identified predominantly in the RSV-positive group (10% vs 4.5%, p<0.05). Rhinorrhea and nasal obstruction were predominantly observed in the RSV-positive group. A co-circulation of RSV Groups A and B was identified, with a predominance of Group B (209/227). Multivariate analysis revealed that age under 1 year (p<0.015), CRP levels under 48 mg/dL (p<0.001) and bacterial co-infection (p<0.032) were independently associated with the presence of RSV and, in the analyze of symptoms, nasal obstruction were independently associated with RSV-positive group (p<0.001). CONCLUSION: The present study highlights the relevance of RSV infection in hospitalized cases of CAP in our region; our findings warrant the conduct of further investigations which can help design strategies for controlling the disease.

Molecular characterization of norovirus, sapovirus and astrovirus in children with acute gastroenteritis from Belém, Pará, Brazil / Caracterização molecular de norovírus, sapovírus e astrovírus em crianças com gastroenterite aguda em Belém, Pará, Brasil

The importance of norovirus (NoVs), sapovirus (SaVs) and human astrovirus (HAstVs) as causes of gastroenteritis outbreaks are already well-defined, but a few studies have described sporadic cases of acute gastroenteritis caused by these viral entities. The aim of this study was to determine the role of these viruses in the etiology of acute gastroenteritis in children enrolled to participate in hospital – and emergency department – based intensive surveillance carried out in Belém, Brazil, from March to September 2003. A total of 305 stool specimens from patients with severe gastroenteritis were collected and screened by reverse transcription followed by polymerase chain reaction (RT-PCR), using the specific primers Mon 269 and Mon 270 for HAstVs, p289 and p290 for human calicivirus (HuCVs), and Mon 431/433 and Mon 432/434 for NoVs. Sequencing of RT-PCR HAstV, HuCVs and NoVs amplicons was carried out using the same primers. Of the 305 samples tested, 96 (31.5 percent) were positive, with 51 diagnosed as HuCVs, 40 as HAstVs and five as mixed infections. Of the 56 (18.4 percent) HuCVs sequenced, 30 were NoVs (9.8 percent) of genogroups GI-4 and GII-4, and 15 (4.9 percent) were SaVs of types GI-1, GI-2 and GII-1. HAstVs, including genotypes 1, 8 and 2, were detected in 45 (14.7 percent) samples. This study has highlighted the importance of these viruses as causes of acute gastroenteritis and established the circulation of different genotypes during the study period. These results reinforce the need for establishing an intensive surveillance for gastroenteritis caused by these viruses to assess the burden of disease and to monitor the circulation of genotypes.

A importância dos norovírus (NoVs), sapovírus (SaVs) e astrovírus humanos (HAstVs) como causa de surtos de gastroenteritis já está bem definida. Entretanto, poucos estudos têm descrito casos esporádicos de gastroenterites aguda causados por esses agentes. O objetivo deste estudo foi determinar o papel destes vírus na etiologia da gastroenterite aguda em crianças atendidas durante uma vigilância intensiva realizada em hospitais e ambulatórios de Belém, Brasil, de março a setembro de 2003. Um total de 305 espécimes fecais de pacientes com gastrenterite grave foram coletados e testados por reação em cadeia da polimerase precedida de transcrição reversa (RT-PCR), utilizando iniciadores específicos Mon 269 e Mon 270 para os HAstVs; p289 e p290 para os calicivírus humanos (HuCVs); e Mon 431/433 e Mon 432/434 para os NoVs. Sequenciamento dos amplicons de HAstV, HuCVs e NoVs, obtidos por RT-PCR, foi realizado usando os mesmos iniciadores. Das 305 amostras testadas, 96 (31,5 por cento) apresentaram resultados positivos, sendo que 51 diagnosticadas como HuCVs, 40 como HAstVs e cinco infecções mistas. Das 56 (18,4 por cento) amostras de HuCVs sequenciadas, 30 foram NoVs (9,8 por cento) pertencentes aos genogrupos GI-4 e GII-4, e 15 (4,9 por cento) SaVs dos grupos GI-1, GI-2 e GII-1. HAstVs foram detectados em 45 (14,7 por cento) das amostras, incluindo os genótipos 1, 8 e 2. Esta pesquisa ressalta a importância destas viroses como causa de gastrenterite aguda e demonstra a circulação de diferentes genótipos durante o período de estudo. Estes resultados reforçam a necessidade de se estabelecer uma vigilância intensiva das gastrenterite causadas por estes vírus, de forma a poder avaliar o impacto da doença e monitorar os genótipos circulantes.

Ocorrência de Bocavírus Humano associado às infecções respiratórias agudas em crianças de 0 a 2 anos de idade na Cidade de Belém, Pará, Brasil / Ocurrence of Human Bocavirus associated with acute respiratory infections in children up to 2 years old in the City of Belém, Pará State, Brazil

INTRODUÇÃO: As Infecções Respiratórias Agudas (IRA) permanecem como um dos principais problemas de saúde pública em todo o mundo. Essas infecções são associadas a diversos patógenos sendo os vírus os prevalentes. Recentemente, foi descrito na literatura um novo parvovírus denominado Bocavírus Humano (HBoV). Investigações ainda são escassas na associação deste novo agente a casos de IRA na população em geral. Neste contexto, o presente artigo relata a pesquisa do HBoV em um segmento populacional da Amazônia. MATERIAIS E MÉTODOS: Neste estudo, foram analisadas amostras de aspirado nasofaríngeo de pacientes com diagnóstico de IRA atendidos ambulatorialmente na Cidade de Belém, Pará, Brasil. A pesquisa, com a identificação laboratorial do vírus, foi realizada mediante o emprego da técnica de reação em cadeia mediada pela polimerase, utilizando pares de oligonucleotídeos específicos, seguida da análise filogenética das sequências nucleotídicas encontradas. RESULTADOS: Das 397 amostras clínicas analisadas, encontrou-se positividade em amostras de três pacientes, sendo um destes em coinfecção com o vírus respiratório sincicial. DISCUSSÃO: O percentual de positividade obtido na investigação se revelou inferior ao descrito na literatura. Entretanto, vale ressaltar que os estudos já publicados envolveram pacientes hospitalizados, diferentemente do grupo populacional presentemente abordado. As análises filogenéticas realizadas evidenciaram expressiva similaridade dos vírus encontrados com as cepas virais já descritas. CONCLUSÃO: A presente pesquisa se caracteriza como o primeiro relato associando o HBoV à IRA na Região Amazônica.

INTRODUCTION: Acute Respiratory Infections (ARI) are one of the main public health problems in the world. Most of these infections are associated with several pathogens, and viruses are the most prevalent agents. Recently, a new parvovirus named Human Bocavirus (HBoV) has been described. Investigations on the relationship between this new agent and cases of ARI in individuals are still scarce. Herein, we review a study of HBoV in a population segment in the Amazon. MATERIALS AND METHODS: In this study, samples of nasopharyngeal aspirates from patients with ARI treated in Health Care Units in Belém, Brazil, were analyzed. Identification of the virus was carried out by polymerase chain reaction using pairs of specific oligonucleotides, followed by phylogenetic analysis of the nucleotide sequences obtained. RESULTS: Of the 397 samples studied, three specimens were HBoV-positive, and one presented as a co-infection with the respiratory syncytial virus.DISCUSSION: The positivity rate obtained in this investigation was lower than that described in other studies; however, previous studies involved hospitalized patients, which constitute a different population group. The phylogenetic analyses revealed a significant similarity between the virus strains found and those previously described. CONCLUSION: This is the first report associating HBoV with ARI in the Amazon.

The dilemma of influenza vaccine recommendations when applied to the tropics: the Brazilian case examined under alternative scenarios.

Since 1999 the World Health Organization issues annually an additional influenza vaccine composition recommendation. This initiative aimed to extend to the Southern Hemisphere (SH) the benefits-previously enjoyed only by the Northern Hemisphere (NH)--of a vaccine recommendation issued as close as possible to the moment just before the onset of the influenza epidemic season. A short time between the issue of the recommendation and vaccine delivery is needed to maximize the chances of correct matching between putative circulating strains and one of the three strains present in the vaccine composition. Here we compare the effectiveness of the SH influenza vaccination adopted in Brazil with hypothetical alternative scenarios defined by different timings of vaccine delivery and/or composition. Scores were based on the temporal overlap between vaccine-induced protection and circulating strains. Viral data were obtained between 1999 and 2007 from constant surveillance and strain characterization in two Brazilian cities: Belém, located at the Equatorial region, and São Paulo, at the limit between the tropical and subtropical regions. Our results show that, among currently feasible options, the best strategy for Brazil would be to adopt the NH composition and timing, as in such case protection would increase from 30% to 65% (p<.01) if past data can be used as a prediction of the future. The influenza season starts in Brazil (and in the equator virtually ends) well before the SH winter, making the current delivery of the SH vaccination in April too late to be effective. Since Brazil encompasses a large area of the Southern Hemisphere, our results point to the possibility of these conclusions being similarly valid for other tropical regions.