Cryptic circulation of chikungunya virus in São Jose do Rio Preto, Brazil, 2015-2019.

BACKGROUND: Chikungunya virus (CHIKV) has spread across Brazil with varying incidence rates depending on the affected areas. Due to cocirculation of arboviruses and overlapping disease symptoms, CHIKV infection may be underdiagnosed. To understand the lack of CHIKV epidemics in São José do Rio Preto (SJdRP), São Paulo (SP), Brazil, we evaluated viral circulation by investigating anti-CHIKV IgG seroconversion in a prospective study of asymptomatic individuals and detecting anti-CHIKV IgM in individuals suspected of dengue infection, as well as CHIKV presence in Aedes mosquitoes. The opportunity to assess two different groups (symptomatic and asymptomatic) exposed at the same geographic region aimed to broaden the possibility of identifying the viral circulation, which had been previously considered absent. METHODOLOGY/PRINCIPAL FINDINGS: Based on a prospective population study model and demographic characteristics (sex and age), we analyzed the anti-CHIKV IgG seroconversion rate in 341 subjects by ELISA over four years. The seroprevalence increased from 0.35% in the first year to 2.3% after 3 years of follow-up. Additionally, we investigated 497 samples from a blood panel collected from dengue-suspected individuals during the 2019 dengue outbreak in SJdRP. In total, 4.4% were positive for anti-CHIKV IgM, and 8.6% were positive for IgG. To exclude alphavirus cross-reactivity, we evaluated the presence of anti-Mayaro virus (MAYV) IgG by ELISA, and the positivity rate was 0.3% in the population study and 0.8% in the blood panel samples. In CHIKV and MAYV plaque reduction neutralization tests (PRNTs), the positivity rate for CHIKV-neutralizing antibodies in these ELISA-positive samples was 46.7%, while no MAYV-neutralizing antibodies were detected. Genomic sequencing and phylogenetic analysis revealed CHIKV genotype ECSA in São José do Rio Preto, SP. Finally, mosquitoes collected to complement human surveillance revealed CHIKV positivity of 2.76% of A. aegypti and 9.09% of A. albopictus (although it was far less abundant than A. aegypti) by RT-qPCR. CONCLUSIONS/SIGNIFICANCE: Our data suggest cryptic CHIKV circulation in SJdRP detected by continual active surveillance. These low levels, but increasing, of viral circulation highlight the possibility of CHIKV outbreaks, as there is a large naïve population. Improved knowledge of the epidemiological situation might aid in outbreaks prevention.

[Relationship between air temperature and dengue incidence: time series study in Minas Gerais, Brazil (2010-2019)]. / Relação entre temperatura do ar e incidência de dengue: estudo de séries temporais em Minas Gerais, Brasil (2010-2019).

Air temperature is a climatic factor that affects the incidence of dengue, with effects varying according to time and space. We investigated the relationship between minimum air temperature and dengue incidence in Minas Gerais, Brazil, and evaluated the influence of socioeconomic and geographic variables on this relationship. This is a time series study with analysis conducted in three distinct stages: modeling using a distributed lag non-linear model, meta-analysis of models obtained, and meta-regression with geographic and socioeconomic data. Minimum temperature was a protective factor at extreme cold temperatures (RR = 0.65; 95%CI: 0.56-0.76) and moderate cold temperatures (RR = 0.71; 95%CI: 0.64-0.79), and a risk factor at moderate hot temperatures (RR = 1.15; 95%CI: 1.07-1.24), but not at extreme hot temperatures (RR = 1.1; 95%CI: 0.99-1.22). Heterogeneity of the models was high (I2 = 60%), which was also observed in meta-regression. Moderate and extreme cold temperatures have a protective effect, while moderate hot temperatures increase the risk. However, minimum air temperature does not explain the variability in the region, not even with the other variables in meta-regression.

A temperatura do ar é um fator climático que afeta a incidência da dengue, com efeitos variando conforme o tempo e o espaço. Investigamos a relação entre a temperatura mínima do ar e a incidência da doença em Minas Gerais, Brasil, e avaliamos a influência de variáveis socioeconômicas e geográficas nessa relação, calculando-se o risco relativo (RR). Este é um estudo de série temporal com análise conduzida em três etapas distintas: modelagem por uso de distributed lag non-linear model (modelos não-lineares distributivos com defasagem), metanálise dos modelos obtidos e metarregressão com dados geográficos e socioeconômicos. A temperatura mínima foi um fator de proteção quando em temperaturas frias extremas (RR = 0,65; IC95%: 0,56-0,76) e moderadas (RR = 0,71; IC95%: 0,64-0,79) e fator de risco em temperaturas de calor moderado (RR = 1,15; IC95%: 1,07-1,24), mas não em extremo (RR = 1,1; IC95%: 0,99-1,22). A heterogeneidade dos modelos foi elevada (I2 = 60%) e essa medida não foi alterada em metarregressão. Temperaturas frias moderadas e extremas causam efeito protetivo, enquanto moderadas quentes aumentam o risco. No entanto, a temperatura mínima do ar não explica nem a variabilidade da região, nem mesmo com as outras variáveis em metarregressão.

La temperatura del aire es un factor climático que afecta la incidencia del dengue, con efectos que varían según el tiempo y el territorio. Investigamos la relación entre la temperatura mínima del aire y la incidencia de la enfermedad en Minas Gerais, Brasil, y evaluamos la influencia de variables socioeconómicas y geográficas en esta relación. Se trata de un estudio de serie temporal cuyo análisis se realiza en tres etapas distintas: modelación mediante el uso de distributed lag non-linear model (modelos distributivos no lineales con retraso), metaanálisis de los modelos obtenidos y metarregresión con datos geográficos y socioeconómicos. La temperatura mínima fue un factor de protección ante temperaturas extremadamente frías (RR = 0,65; IC95%: 0,56-0,76) y moderadas (RR = 0,71; IC95%: 0,64-0,79) y factor de riesgo en temperaturas de calor moderado (RR = 1,15; IC95%: 1,07-1,24), pero no en extremo (RR = 1,1; IC95%: 0,99-1,22). La heterogeneidad de los modelos fue alta (I2 = 60%), y esta medida no se modificó en la metarregresión. Las temperaturas frías moderadas y extremas tienen un efecto protector, mientras que las temperaturas moderadamente altas aumentan el riesgo. Sin embargo, la temperatura mínima del aire no explica la variabilidad de la región, ni siquiera con las demás variables en metarregresión.

Relação entre temperatura do ar e incidência de dengue: estudo de séries temporais em Minas Gerais, Brasil (2010-2019) / Relationship between air temperature and dengue incidence: time series study in Minas Gerais, Brazil (2010-2019) / Relación entre la temperatura del aire y la incidencia del dengue: estudio de series temporales en Minas Gerais, Brasil (2010-2019)

Resumo A temperatura do ar é um fator climático que afeta a incidência da dengue, com efeitos variando conforme o tempo e o espaço. Investigamos a relação entre a temperatura mínima do ar e a incidência da doença em Minas Gerais, Brasil, e avaliamos a influência de variáveis socioeconômicas e geográficas nessa relação, calculando-se o risco relativo (RR). Este é um estudo de série temporal com análise conduzida em três etapas distintas: modelagem por uso de distributed lag non-linear model (modelos não-lineares distributivos com defasagem), metanálise dos modelos obtidos e metarregressão com dados geográficos e socioeconômicos. A temperatura mínima foi um fator de proteção quando em temperaturas frias extremas (RR = 0,65; IC95%: 0,56-0,76) e moderadas (RR = 0,71; IC95%: 0,64-0,79) e fator de risco em temperaturas de calor moderado (RR = 1,15; IC95%: 1,07-1,24), mas não em extremo (RR = 1,1; IC95%: 0,99-1,22). A heterogeneidade dos modelos foi elevada (I2 = 60%) e essa medida não foi alterada em metarregressão. Temperaturas frias moderadas e extremas causam efeito protetivo, enquanto moderadas quentes aumentam o risco. No entanto, a temperatura mínima do ar não explica nem a variabilidade da região, nem mesmo com as outras variáveis em metarregressão.

Abstract Air temperature is a climatic factor that affects the incidence of dengue, with effects varying according to time and space. We investigated the relationship between minimum air temperature and dengue incidence in Minas Gerais, Brazil, and evaluated the influence of socioeconomic and geographic variables on this relationship. This is a time series study with analysis conducted in three distinct stages: modeling using a distributed lag non-linear model, meta-analysis of models obtained, and meta-regression with geographic and socioeconomic data. Minimum temperature was a protective factor at extreme cold temperatures (RR = 0.65; 95%CI: 0.56-0.76) and moderate cold temperatures (RR = 0.71; 95%CI: 0.64-0.79), and a risk factor at moderate hot temperatures (RR = 1.15; 95%CI: 1.07-1.24), but not at extreme hot temperatures (RR = 1.1; 95%CI: 0.99-1.22). Heterogeneity of the models was high (I2 = 60%), which was also observed in meta-regression. Moderate and extreme cold temperatures have a protective effect, while moderate hot temperatures increase the risk. However, minimum air temperature does not explain the variability in the region, not even with the other variables in meta-regression.

Resumen La temperatura del aire es un factor climático que afecta la incidencia del dengue, con efectos que varían según el tiempo y el territorio. Investigamos la relación entre la temperatura mínima del aire y la incidencia de la enfermedad en Minas Gerais, Brasil, y evaluamos la influencia de variables socioeconómicas y geográficas en esta relación. Se trata de un estudio de serie temporal cuyo análisis se realiza en tres etapas distintas: modelación mediante el uso de distributed lag non-linear model (modelos distributivos no lineales con retraso), metaanálisis de los modelos obtenidos y metarregresión con datos geográficos y socioeconómicos. La temperatura mínima fue un factor de protección ante temperaturas extremadamente frías (RR = 0,65; IC95%: 0,56-0,76) y moderadas (RR = 0,71; IC95%: 0,64-0,79) y factor de riesgo en temperaturas de calor moderado (RR = 1,15; IC95%: 1,07-1,24), pero no en extremo (RR = 1,1; IC95%: 0,99-1,22). La heterogeneidad de los modelos fue alta (I2 = 60%), y esta medida no se modificó en la metarregresión. Las temperaturas frías moderadas y extremas tienen un efecto protector, mientras que las temperaturas moderadamente altas aumentan el riesgo. Sin embargo, la temperatura mínima del aire no explica la variabilidad de la región, ni siquiera con las demás variables en metarregresión.

Serine proteases in neutrophil extracellular traps exhibit anti-Respiratory Syncytial Virus activity.

Human respiratory syncytial virus (hRSV) is an infectious agent in infants and young children which there are no vaccines or drugs for treatment. Neutrophils are recruited for airway, where they are stimulated by hRSV to release large amounts of neutrophil extracellular traps (NETs). NETs are compound by DNA and proteins, including microbicidal enzymes. They constitute a large part of the mucus accumulated in the lung of patients, compromising their breathing capacity. In contrast, NETs can capture/inactivate hRSV, but the molecules responsible for this effect are unknown. OBJECTIVES: We selected microbicidal NET enzymes (elastase, myeloperoxidase, cathepsin-G, and proteinase-3) to assess their anti-hRSV role. METHODS AND RESULTS: Through in vitro assays using HEp-2 cells, we observed that elastase, proteinase-3, and cathepsin-G, but not myeloperoxidase, showed virucidal effects even at non-cytotoxic concentrations. Elastase and proteinase-3, but not cathepsin-G, cleaved viral F-protein, which is responsible for viral adhesion and fusion with the target cells. Molecular docking analysis indicated the interaction of these macromolecules in the antigenic regions of F-protein through the active regions of the enzymes. CONCLUSIONS: Serine proteases from NETs interact and inactive hRSV. These results contribute to the understanding the role of NETs in hRSV infection and to designing treatment strategies for the inflammatory process during respiratory infections.

Adjusting RT-qPCR conditions to avoid unspecific amplification in SARS-CoV-2 diagnosis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in December 2019 and quickly spread around the world, forcing global health authorities to develop protocols for its diagnosis. Here we report dimer formation in the N2 primers-probe set (CDC 2019-nCoV Real-Time RT-PCR) used in the diagnostic routine, and propose alternatives to reduce dimerization events. Late unspecific amplifications were visualized in 56.4% of negative samples and 57.1% of no-template control, but not in positive samples or positive control. In silico analysis and gel electrophoresis confirmed the dimer formation. The RT-qPCR parameters were optimized and the late unspecific amplifications decreased to 11.5% in negative samples and no-template control. The adjustment of PCR parameters was essential to reduce the risk of false-positives results and to avoid inclusive results requiring repeat testing, which increases the costs and generates delays in results or even unnecessary requests for new samples.

Genomic Analyses of Potential Novel Recombinant Human Adenovirus C in Brazil.

Human Adenovirus species C (HAdV-C) is the most common etiologic agent of respiratory disease. In the present study, we characterized the nearly full-length genome of one potential new HAdV-C recombinant strain constituted by Penton and Fiber proteins belonging to type 89 and a chimeric Hexon protein of types 1 and 89. By using viral metagenomics techniques, we screened out, in the states of Tocantins and Pará, Northern and North regions of Brazil, from 2010 to 2016, 251 fecal samples of children between 0.5 to 2.5 years old. These children were presenting acute diarrhea not associated with common pathogens (i.e., rotavirus, norovirus). We identified two HAdV-C strains in two distinct patients. Phylogenetic analysis performed using all complete genomes available at GenBank database indicated that one strain (HAdV-C BR-245) belonged to type 1. The phylogenetic analysis also indicated that the second strain (HAdV-C BR-211) was located at the base of the clade formed by the newly HAdV-C strains type 89. Recombination analysis revealed that strain HAdV-C BR-211 is a chimera in which the variable regions of Hexon gene combined HAdV-C1 and HAdV-C89 sequences. Therefore, HAdV-C BR-211 strain possesses a genomic backbone of type HAdV-C89 and a unique insertion of HAdV-C1 in the Hexon sequence. Recombination may play an important driving force in HAdV-C diversity and evolution. Studies employing complete genomic sequencing on circulating HAdV-C strains in Brazil are needed to understand the clinical significance of the presented data.

Excess mortality is associated with influenza A (H1N1) in patients with severe acute respiratory illness.

BACKGROUND: Acute respiratory infections caused by viruses are among the leading causes of morbidity and mortality. The inflammatory response that follows viral infection is important for the control of virus proliferation. However, if overwhelming, may be associated with complicated outcomes. OBJECTIVES: We assessed the clinical characteristics of patients with severe acute respiratory illness (SARI) evolving to acute respiratory distress syndrome (ARDS) and the factors related to death. STUDY DESIGN: Prospective study in 273 adult patients with SARI performed in a university-affiliated 800-bed hospital serving an area of epidemiologic vigilance of 102 municipalities and more than 2 million inhabitants. Influenza A (H1N1) 2009 (A/H1N1), influenza A H3N2, and influenza B were tested in all patients by RT-PCR. RESULTS: The overall hospital mortality rate was 17.6%. A total of 30.4% of patients tested positive for influenza A/H1N1. Patients with SARI that evolved to ARDS took significantly longer to take the first dose of oseltamivir (6.0 vs 1.0 days, p=0.002). Patients with H1N1 positive tests had almost 3 times higher probability of death, despite having significantly less comorbidities (p=0.027). The influenza A/H1N1 pdm09 vaccine reduced the odds of death by 78%. Nonsurvivors had a more intense inflammatory response than did survivors at 48 h (C-reactive protein: 31.0 ± 17.5 vs. 14.6 ± 8.9 mg/dl, p=0.001) as well as a more positive fluid balance. CONCLUSIONS: Hospital mortality associated with influenza H1N1-associated SARI and ARDS continued to be high years after the 2009 pandemic in a population with low vaccine coverage. Antiviral treatment started more than two days after onset of symptoms was more frequently associated with ARDS and death and, having had vaccine against influenza A (H1N1) was a factor independently related to survival.

Viral immunogenicity determines epidemiological fitness in a cohort of DENV-1 infection in Brazil.

The dynamics of dengue virus (DENV) circulation depends on serotype, genotype and lineage replacement and turnover. In São José do Rio Preto, Brazil, we observed that the L6 lineage of DENV-1 (genotype V) remained the dominant circulating lineage even after the introduction of the L1 lineage. We investigated viral fitness and immunogenicity of the L1 and L6 lineages and which factors interfered with the dynamics of DENV epidemics. The results showed a more efficient replicative fitness of L1 over L6 in mosquitoes and in human and non-human primate cell lines. Infections by the L6 lineage were associated with reduced antigenicity, weak B and T cell stimulation and weak host immune system interactions, which were associated with higher viremia. Our data, therefore, demonstrate that reduced viral immunogenicity and consequent greater viremia determined the increased epidemiological fitness of DENV-1 L6 lineage in São José do Rio Preto.

Complete Genome Sequences of Six Human Bocavirus Strains from Patients with Acute Gastroenteritis in the North Region of Brazil.

Human bocavirus (HBoV) is commonly associated with acute respiratory tract illness and gastroenteritis. We report six complete genomic sequences of HBoV strains from patients with gastroenteritis in Belém do Pará and Tocantins in the North Region of Brazil. Phylogenetic analysis indicated that the six HBoV strains belong to genotypes 1, 2, and 3.

Respiratory syncytial virus evaluation among asymptomatic and symptomatic subjects in a university hospital in Sao Paulo, Brazil, in the period of 2009-2013.

BACKGROUND: The respiratory syncytial virus (RSV) is recognized as an important cause of respiratory tract infections. Immunocompromised patients, healthcare workers (HCWs) and children contacts are at increased risk of acquiring the infection. However, the impact of asymptomatic infection in transmission has not been well studied. OBJECTIVES: this study evaluated the frequency and viral load (VL) of RSV in nasal swab samples of individuals with different risk factors for acquiring infection in a university hospital in Sao Paulo, Brazil. METHODS: We included 196 symptomatic children and their 192 asymptomatic caregivers, 70 symptomatic and 95 asymptomatic HCWs, 43 samples from symptomatic HIV-positive outpatients, and 100 samples of asymptomatic HIV patients in the period of 2009-2013. RESULTS: RSV infection was detected in 10.1% (70/696) of samples, 4.4% (17/387) of asymptomatic patients, and 17.1% (53/309) from symptomatic patients. (P < .0001). The VL of symptomatic patients (4.7 log copies/mL) was significantly higher compared to asymptomatic patients (2.3 log copies/mL). RSV detection among asymptomatic caregivers (6.8%; 13/192) was significantly higher compared to other asymptomatic adults, HIV and HCWs (2.0%; 4/195; P = .0252). A close contact with an infected child at home was an important risk to RSV acquisition [OR 22.6 (95% CI 4.8-106.7)]. Children who possibly transmitted the virus to their asymptomatic contacts had significantly higher viral load than children who probably did not transmit (P < .0001). CONCLUSIONS: According to our results, it is important to know if people circulating inside the hospital have close contact with acute respiratory infected children.

Rotavirus genotypes as etiological agents of diarrhoea in general populations of two geographic regions of Brazil.

Rotavirus is the main global cause of severe childhood diarrhoea among children. In 2006, Rotarix® (G1P[8]) was introduced into Brazil's National Immunization Program. The vaccine coverage rate was 84.4% in 2009. Evidences of increasing G2P[4] after 2006 opened up the discussion about the vaccine effectiveness to non-G1 strains. The aim of this study was to identify the circulating rotavirus genotypes in two Brazilian regions during 2009. A total of 223 positive samples by immunochromatography and latex agglutination assay from the Northeast (Bahia/Pernambuco States) and Southeast (São Paulo/Rio de Janeiro States) regions were included in the study. The samples were submitted to genotyping by nested-PCR according to VP7(G) and VP4(P) and 175 samples (78.5%) were able to be characterized. Considering the characterization of VP7, the G-types detected were G1, G2, and G4 in the Northeast, and G2, G3, G5, and G9 in the Southeast. Considering the characterization of VP4, the P-types detected were P[4], P[8], and P[6]/P[9] in the Northeast and the Southeast. The most frequent mixed types found were G2P[4]/G2P[NT](81.4%), G2P[6](5.2%), G1P[6](5.2%) in the Northeast, and G2P[4]/G2P[NT](78.8%), G2P[6](8.2%), G9P[8](4.7%) in the Southeast. Among immunized individuals whose age ranged from 0-4 years, the G2P[4]/G2P[NT] genotype was identified in 91,0% of cases, and among non-immunized individuals of the same age, the G2P[4]/G2P[NT] genotype was identified in 85.7% of the cases. In accordance with the high level of vaccine coverage, the data suggest that the circulation of G2P[4] in these regions had a considerable increase after the introduction of Rotarix®.

Application of molecular assay for adenovirus detection among different pediatric patients / Aplicação de teste molecular para detecção de adenovírus em pacientes pediátricos distintos

OBJECTIVE: Adenoviruses play an important role in the etiology of severe acute lower respiratory infection, especially in young children. The aim of the present study was to evaluate the Human Adenovirus (HAdV) detection by different methods (Direct Fluorescence Assay DFA and Nested Polymerase Chain Reaction nested PCR), among samples collected from different groups of pediatric patients. METHODS: Collection of samples was made in children with congenital heart disease (CHD 123 nasal aspirates collected in the years of 2005, 2007 and 2008) and in community children (CC 165 nasal aspirates collected in 2008). Children were eligible if they presented acute respiratory infection (ARI) of probable viral etiology, within up to 7 days of symptoms' onset. All studied samples were evaluated by DFA and nested PCR assay. RESULTS: Of the 290 samples included during the study period, 43 (14.8%) were positive on at least one test: 17/165 (10.3%) of the CC and 26/125 (20.8%) of the CHD children. The nested PCR detection rates in the community children were 15/165 (9.1%), and for children with CHD, 24/125 (19.2%). Molecular method showed higher detection rates when compared to the DFA test (p<0.001). Univariate analysis showed that children with congenital heart disease presented a significantly higher chance for acquiring the HAdV (Odds Ratio 2.3; 95% CI: 1.18-4.43). CONCLUSIONS: Based on data obtained in the present evaluation, we suggest that a routine surveillance should be performed in high risk patients by molecular methods, thus improving diagnostic flow and efficiency.

OBJETIVO: Os adenovírus desempenham um papel importante na etiologia da infecção aguda grave do trato respiratório inferior, especialmente entre crianças. O objetivo do estudo foi avaliar a detecção do adenovírus humano (HAdV) por diferentes métodos (imunofluorescência direta DFA e reação em cadeia da polimerase nested nested PCR) em amostras coletadas de diferentes populações de pacientes pediátricos. MÉTODOS: O material foi coletado de crianças portadoras de doença cardíaca congênita (DCC 123 aspirados nasais coletados em 2005, 2007 e 2008) e de crianças da comunidade (CC 165 aspirados nasais coletados em 2008). As crianças eram consideradas elegíveis se apresentassem infecção respiratória aguda (IRA) de provável etiologia viral, com até sete dias de início dos sintomas. Todas as amostras coletadas no estudo foram avaliadas por meio de DFA e nested PCR. RESULTADOS: De 209 amostras incluídas, 43 (14,8%) foram positivas em pelo menos um dos testes feitos: 17/165 (10,3%) das crianças da comunidade e 26/125 (20,8%) das crianças cardiopatas. As taxas de detecção por nested PCR foram 15/165 (9,1%) em crianças da comunidade e 24/125 (19,2%) em crianças cardiopatas. O método molecular mostrou maiores taxas de detecção quando comparado com a DFA (p<0,001). A análise univariada mostrou que as crianças portadoras de cardiopatia congênita apresentaram chance significativamente maior de adquirir HAdV (odds ratio 2,3; IC 95%: 1,18-4,43). CONCLUSÕES: Baseado nos resultados obtidos na presente avaliação, recomenda-se a vigilância de rotina em pacientes de risco (DCC) por métodos moleculares, que melhora o fluxo diagnóstico e a eficiência da detecção.

[Application of molecular assay for adenovirus detection among different pediatric patients]. / Aplicação de teste molecular para detecção de adenovírus em pacientes pediátricos distintos.

OBJECTIVE: Adenoviruses play an important role in the etiology of severe acute lower respiratory infection, especially in young children. The aim of the present study was to evaluate the Human Adenovirus (HAdV) detection by different methods (Direct Fluorescence Assay - DFA and Nested Polymerase Chain Reaction - nested PCR), among samples collected from different groups of pediatric patients. METHODS: Collection of samples was made in children with congenital heart disease (CHD - 123 nasal aspirates collected in the years of 2005, 2007 and 2008) and in community children (CC - 165 nasal aspirates collected in 2008). Children were eligible if they presented acute respiratory infection (ARI) of probable viral etiology, within up to 7 days of symptoms' onset. All studied samples were evaluated by DFA and nested PCR assay. RESULTS: Of the 290 samples included during the study period, 43 (14.8%) were positive on at least one test: 17/165 (10.3%) of the CC and 26/125 (20.8%) of the CHD children. The nested PCR detection rates in the community children were 15/165 (9.1%), and for children with CHD, 24/125 (19.2%). Molecular method showed higher detection rates when compared to the DFA test (p<0.001). Univariate analysis showed that children with congenital heart disease presented a significantly higher chance for acquiring the HAdV (Odds Ratio 2.3; 95% CI: 1.18-4.43). CONCLUSIONS: Based on data obtained in the present evaluation, we suggest that a routine surveillance should be performed in high risk patients by molecular methods, thus improving diagnostic flow and efficiency.

Avaliação situacional de influenza pós pandemia de 2009 - uma breve revisão / Situational assessment of influenza post 2009 Pandemic - a brief review

Os vírus influenza são responsáveis por epidemias anuais com gravidade da doença variável. Causam infecção respiratória aguda com elevada transmissibilidade devido sua alta variabilidade genética, capacidade de adaptação e rápida disseminação. Os vírus influenza apresentam genoma fragmentado,o que ocasiona variações antigênicas frequentes, e consequentemente pode induzir o aparecimento de subtipos mais virulentos, como ocorreu em 2009,quando foi registrada pandemia por um novo vírus Influenza A H1N1. A Organização Mundial de Saúde(OMS) estima que a gripe acometa 5 a 15% da população,ocasionando 3 a 5 milhões de casos graves e 250.000 a 500.000 mortes anualmente. As epidemias anuais de gripe e o risco de novas pandemias tornamo monitoramento epidemiológico do vírus influenza fundamental e, para isto, a OMS coordena a Rede Mundial de Vigilância da Influenza com a finalidade de fornecer informações necessárias para a escolha das variantes virais que farão parte da composição anual da vacina, visto que a vacinação é uma das medidas mais efetivas para prevenção da gripe e suas complicações. Além disso, a rede constitui uma vigilância rápida para identificações de vírus influenza emergentes com potencial epidêmico ou pandêmico.Esta vigilância é viabilizada pelos resultados dos testes laboratoriais que são ferramentas importantes para a Saúde Pública, sendo fundamentais para a contenção e prevenção dos vírus circulantes. O objetivo deste estudo foi apresentar informações relacionadas ao vírus influenza e a doença, como são realizados o diagnóstico e monitoramento pelas redes de vigilâncias mundiais pós-pandemia e, ainda, quais os novos desafios que se apresentam.

Influenza viruses are responsible for annual epidemics with patients presenting variable degrees of diseases everity. These virus can cause acute respiratory infection with a high transmissibility due to its high genetic variability, adaptability and rapid spread. Influenza viruses have fragmented genome which causes frequent antigenic variation, which can result in more virulent subtypes emergence, as occurred in 2009 when it was described a new pandemic influenza virus H1N1. WHO estimates that flu affects 5-15% of the population and it causes 3 to 5 million of severe cases and 250.000 to 500.000 deaths annually. The annual influenza epidemics and the new pandemics risk high lights the importance of Influenza virus epidemiological monitoring. Based in this concern WHO created and coordinates the Global Influenza Surveillance and Response System in order to provide necessary information for viral variants selection that will be part of vaccine annual composition, since that, vaccination is one of the most effective measures for influenza prevention and its complications. In addition, the network is a rapid surveillance of emerging influenza virus identifications with potential to cause epidemic or pandemic situations. The surveillance isenable due to laboratory tests results which are important tools for public health, with essential role for circulating viruses containment and prevention. The aim of this study was to present information related to influenza virus and flu disease, how the diagnosis and monitoring are performed by global surveillance networks at post pandemic time and, also,the new challenges facing.

A survey strategy for human respiratory syncytial virus detection among haematopoietic stem cell transplant patients: epidemiological and methodological analysis.

Human respiratory syncytial virus (HRSV) causes severe infections among children and immunocompromised patients. We compared HRSV infections among Haematopoietic Stem Cell Transplant program (HSCT) patients and children using direct immunofluorescence (DFA), point-of-care RSV Bio Easy® and a polymerase chain reaction (PCR) assay. Overall, 102 samples from HSCT patients and 128 from children obtained positivity rate of 18.6% and 14.1% respectively. PCR sensitivity was highest mainly on samples collected after five days of symptoms onset. A combination of both DFA and reverse transcriptase-PCR methods for HSCT high-risk patients is the best diagnostic flow for HRSV diagnosis among these patients.

A survey strategy for human respiratory syncytial virus detection among haematopoietic stem cell transplant patients: epidemiological and methodological analysis

Human respiratory syncytial virus (HRSV) causes severe infections among children and immunocompromised patients. We compared HRSV infections among Haematopoietic Stem Cell Transplant program (HSCT) patients and children using direct immunofluorescence (DFA), point-of-care RSV Bio Easy® and a polymerase chain reaction (PCR) assay. Overall, 102 samples from HSCT patients and 128 from children obtained positivity rate of 18.6% and 14.1% respectively. PCR sensitivity was highest mainly on samples collected after five days of symptoms onset. A combination of both DFA and reverse transcriptase-PCR methods for HSCT high-risk patients is the best diagnostic flow for HRSV diagnosis among these patients.

Frequency of human bocavirus respiratory infections among at-risk patients in São Paulo, Brazil / Frequência de bocavírus humano em infecções respiratórias entre pacientes de risco na cidade de São Paulo, Brasil

BACKGROUND AND OBJECTIVES: Human Bocavirus (HBoV) has been described since 2005 as an etiological agent of respiratory virus infections. From 2001 to 2008 we investigated the etiology of HBoV among adults and children in different groups at risk of presenting complications arising from acute respiratory infection, the investigation was carried out in a tertiary hospital health care system in Brazil. METHODS: HBoV DNA was assayed in 598 respiratory samples from community and hospitalized patients by PCR. RESULTS: Of the 598 tested samples, 2.44% (8/328) of children, including five children with heart disease, and 0.4% (1/270) of adult bone-marrow-transplant were HBoV positive. CONCLUSIONS: These data suggested lower HBoV frequency among different at-risk patients and highlights the need to better understand the real role of HBoV among acute respiratory symptomatic patients.

INTRODUÇÃO E OBJETIVOS: O bocavírus humano (HBoV) tem sido descrito desde 2005 como agente etiológico de infecções respiratórias virais. O presente estudo tem como objetivo investigar a etiologia da infecção respiratória pelo HBoV em pacientes adultos e crianças de diferentes grupos de risco para complicação de infecções respiratórias agudas desde 2001 até 2008 em um hospital terciário no Brasil. PACIENTES E MÉTODOS: O HBoV foi investigado, através de reação em cadeia da polimerase, em 598 amostras respiratórias coletadas de pacientes hospitalizados e não hospitalizados. RESULTADOS: Das 598 amostras testadas o HBoV foi detectado em 2,44% (8/328) das crianças, incluindo cinco crianças portadoras de cardiopatia congênita, e 0,4% (1/270) dos adultos em programa de transplante de células tronco hematopoiéticas. CONCLUSÃO: Os dados do presente estudo sugerem baixa freqüência de detecção do HBoV entre pacientes de risco, e destaca a necessidade de novos estudos para um melhor entendimento do verdadeiro papel desse agente em infecções respiratórias agudas em pacientes sintomáticos.

Frequency of human bocavirus respiratory infections among at-risk patients in São Paulo, Brazil.

BACKGROUND AND OBJECTIVES: Human Bocavirus (HBoV) has been described since 2005 as an etiological agent of respiratory virus infections. From 2001 to 2008 we investigated the etiology of HBoV among adults and children in different groups at risk of presenting complications arising from acute respiratory infection, the investigation was carried out in a tertiary hospital health care system in Brazil. METHODS: HBoV DNA was assayed in 598 respiratory samples from community and hospitalized patients by PCR. RESULTS: Of the 598 tested samples, 2.44% (8/328) of children, including five children with heart disease, and 0.4% (1/270) of adult bone-marrow-transplant were HBoV positive. CONCLUSIONS: These data suggested lower HBoV frequency among different at-risk patients and highlights the need to better understand the real role of HBoV among acute respiratory symptomatic patients.

Surveillance of influenza A H1N1 2009 among school children during 2009 and 2010 in São Paulo, Brazil.

INTRODUCTION: Influenza A H1N1 2009 is associated with a high morbidity rate among children around the world, including Brazil. This survey was conducted on samples of symptomatic children (< 12 years) to investigate the influenza virus as the etiological agent of respiratory infections in a day care school in a health facility during the first and second pandemic wave of H1N1 (2009-2010) in São Paulo, Brazil. METHODS: Influenza infections were determined by real-time PCR in 34% (47/137) of children with a median age of 5 years (8 months - 12 years), from June to October 2009 and in 16% (14/85) of those with median age of 6 years (1-12 years), from March to November 2010. RESULTS: In general, most positive cases (64%) occurred in children aged 5-12 years, this age group was significantly the most affected (39.8%, p = 0.001, OR = 8.3, CI 95% 1.9-36.9). Wheezing was reported by 31% (19/61) and dyspnea by 23% (14/61) of the studied patients. An outbreak of influenza H1N1 with an attack rate of 35.7% among children (median age 6 years) was documented in April 2010, before the vaccination campaign against the pandemic virus was extended for children up to 5 years in Brazil. CONCLUSIONS: Therefore, the study reinforces the recommendation to immunize school children to reduce the incidence of the disease.