A 28-year study of human parainfluenza in Rio Grande do Sul, Southern Brazil.

PROBLEM: Human parainfluenza virus (hPIV) is an important pathogen in respiratory infections, however the health burden of hPIV is underestimated. This study describes the infections by hPIV1-3 in Rio Grande do Sul, Brazil, from 1990 to 2017, providing data of the frequency and seasonality of cases and associated clinical symptoms. METHOD OF STUDY: Nasopharyngeal samples of patients with respiratory infection were collected, clinical data were analyzed, and immunofluorescence was used to detect hPIV. RESULTS: Respiratory viruses were detected in 33.63% of respiratory infections. In a total of 11 606 cases of viral respiratory infection, 781 were positive for hPIV; hPIV prevalence ranged from 2.14% to 27% of viral respiratory infections. hPIV1 circulates mainly during fall; hPIV3 circulation, in turn, starts in fall and peaks during spring; and cases of hPIV2 are reported along the year, with peaks in fall and early spring. The most affected age group was children, with hPIV prevalence of 74.23% in patients for less than 1 year. A higher proportion of girls were infected than boys, however, no difference by sex was observed considering all age groups. The most frequent type was hPIV3, especially in hospitalized patients. Both hPIV1 and 3 were associated with dyspnea, while hPIV2 caused mild symptoms mainly in nonhospitalized patients. Nineteen fatalities occurred, 89.5% of them associated with risk factors (prematurity; chronic diseases; age, <1 or >60 years). CONCLUSION: hPIV causes a high number of respiratory infections, leading to hospitalization especially in children; epidemiological and surveillance studies are important for the control and management of respiratory infections.

Oseltamivir-resistant influenza A(H1N1)pdm09 virus in southern Brazil.

The neuraminidase (NA) genes of A(H1N1)pdm09 influenza virus isolates from 306 infected patients were analysed. The circulation of oseltamivir-resistant viruses in Brazil has not been reported previously. Clinical samples were collected in the state of Rio Grande do Sul (RS) from 2009-2011 and two NA inhibitor-resistant mutants were identified, one in 2009 (H275Y) and the other in 2011 (S247N). This study revealed a low prevalence of resistant viruses (0.8%) with no spread of the resistant mutants throughout RS.

Correction to: Temporal dynamics of Human mastadenovirus species in cases of respiratory illness in southern Brazil.

The original version of this article unfortunately contained a mistake. The term "mortality rate" should be rather read as "morbidity rate" in the following fragment of the "Discussion" section.

Temporal dynamics of Human mastadenovirus species in cases of respiratory illness in southern Brazil.

Human mastadenovirus (HAdV) genus is related to several diseases, among them upper and lower respiratory tract illness. HAdV species B, C, D, and E are mainly associated with respiratory infections. The goal of this work was to identify the HAdV species associated with respiratory infections in hospitalized patients from southern Brazil. Samples were collected from 1996 to 2004 and 2011 to 2017. During this period, 28,524 samples were collected, and 9983 were positive for respiratory viruses, being 435 for HAdV. From these 435 samples, 57 were selected for characterization of HAdV species. For screening the presence of HAdV, a partial sequence of the DNA polymerase gene (DNApol gene) was amplified by nested PCR. Partial nucleotide sequencing was performed in positive samples, and HAdV (DNApol gene) was detected in 53 samples: species B (28; 49.1%), C (16; 28.0%), D (2; 3.5%), E (5; 8.7%), and untyped (2; 3.5%). Specie D was found only in 2017 and specie E in 2011 and 2012. The age of the patients ranged from < 1 to 81 years old, and 62.3% were male. No relationship between gender or age and identified HAdV species were observed. In addition, in the period of 2013-2017, 18 samples from patients who died were analyzed: 11 were related to species B, 4 to C, and 2 to D and 1 remained untyped. Circulation of HAdV species D and E varied over the years, but species B and C were present throughout the evaluated period. In addition, respiratory infections by HAdV affect elderly and children mainly.

Human metapneumovirus in Southern Brazil.

INTRODUCTION: Infections caused by respiratory viruses are important problems worldwide, especially in children. Human metapneumovirus (hMPV) is a respiratory pathogen and causes severe infections with nonspecific symptoms. This study reports the hMPV occurrence and dissemination in southern Brazil and compares the frequency of occurrence of this virus and the human respiratory syncytial virus (hRSV) in the epidemiological weeks in a three-year period (2009-2011). METHODS: In total, 545 nasopharyngeal (NP) specimens from individuals with Severe Acute Respiratory Syndrome (SARS) who were negative for other seven respiratory viruses were analyzed for the presence of hMPV. Human metapneumovirus was detected by direct immunofluorescence and real-time reverse transcription polymerase chain reaction. RESULTS: hMPV was detected in 109 patients from the main geographic regions of the southernmost state of Brazil, presenting similar overall prevalence in males (46.8%) and females (53.2%). Among children who were less than six years old, hMPV was detected in 99 samples of all age groups, with a higher frequency in infants who were less than one year old (45.7%) compared to all other age groups until six years. hMPV and hRSV infection occurred in almost the same epidemiological weeks (EWs) of each year, with peaks of incidence between EW 31/37 and EW 26/38 for the years 2009 and 2011, respectively. hMPV was further detected in several cases of SARS and it was the only virus detected in three deaths. CONCLUSIONS: These findings indicate that hMPV is in circulation in southern Brazil and highlight the importance of diagnosing hMPV for influenza-like illness in the population.

Performance of direct immunofluorescence assay for the detection of human metapneumovirus under clinical laboratory settings.

INTRODUCTION: Human metapneumovirus (hMPV) is an emergent human respiratory pathogen. This study aimed to evaluate the performance of direct immunofluorescence (DIF) to detect hMPV in a clinical laboratory setting. METHODS: Nasopharyngeal aspirate samples (448) of children and adults with respiratory illness were used to detect hMPV by using DIF and real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assays. RESULTS: In all, 36 (8%) samples were positive by DIF and 94 (21%) were positive by qRT-PCR. Direct immunofluorescence specificity was 99% and sensitivity was 38%. CONCLUSIONS: DIF is not very sensitive under clinical laboratory settings.

Temporal dynamics of human mastadenovirus species in cases of respiratory illness in southern Brazil

Human mastadenovirus (HAdV) genus is related to several diseases, among them upper and lower respiratory tract illness. HAdV species B, C, D, and E are mainly associated with respiratory infections. The goal of this work was to identify the HAdV species associated with respiratory infections in hospitalized patients from southern Brazil. Samples were collected from 1996 to 2004 and 2011 to 2017. During this period, 28,524 samples were collected, and 9983 were positive for respiratory viruses, being 435 for HAdV. From these 435 samples, 57 were selected for characterization of HAdV species. For screening the presence of HAdV, a partial sequence of the DNA polymerase gene (DNApol gene) was amplified by nested PCR. Partial nucleotide sequencing was performed in positive samples, and HAdV (DNApol gene) was detected in 53 samples: species B (28;49.1%), C (16;8.0%), D (2; 3.5%), E (5; 8.7%), and untyped (2; 3.5%). Specie D was found only in 2017 and specie E in 2011 and 2012. The age of the patients ranged from < 1 to 81 years old, and 62.3%were male. No relationship between gender orage and identified HAdV species were observed. In addition, in the period of 2013­2017, 18 samples from patients who died were analyzed: 11 were related to species B, 4 to C, and 2 to D and 1 remained untyped. Circulation of HAdV species D and Evaried over the years, but species B and C were present throughout the evaluated period. In addition, respiratory infections by HAdVaffect elderly and children mainly. (AU)

Human metapneumovirus in Southern Brazil

INTRODUCTION Infections caused by respiratory viruses are important problems worldwide, especially in children. Human metapneumovirus (hMPV) is a respiratory pathogen and causes severe infections with nonspecific symptoms. This study reports the hMPV occurrence and dissemination in southern Brazil and compares the frequency of occurrence of this virus and the human respiratory syncytial virus (hRSV) in the epidemiological weeks in a three-year period (2009-2011). METHODS: In total, 545 nasopharyngeal (NP) specimens from individuals with Severe Acute Respiratory Syndrome (SARS) who were negative for other seven respiratory viruses were analyzed for the presence of hMPV. Human metapneumovirus was detected by direct immunofluorescence and real-time reverse transcription polymerase chain reaction. RESULTS: hMPV was detected in 109 patients from the main geographic regions of the southernmost state of Brazil, presenting similar overall prevalence in males (46.8%) and females (53.2%). Among children who were less than six years old, hMPV was detected in 99 samples of all age groups, with a higher frequency in infants who were less than one year old (45.7%) compared to all other age groups until six years. hMPV and hRSV infection occurred in almost the same epidemiological weeks (EWs) of each year, with peaks of incidence between EW 31/37 and EW 26/38 for the years 2009 and 2011, respectively. hMPV was further detected in several cases of SARS and it was the only virus detected in three deaths. CONCLUSIONS These findings indicate that hMPV is in circulation in southern Brazil and highlight the importance of diagnosing hMPV for influenza-like illness in the population. (AU)

Performance of direct immunofl uorescence assay for the detection of human metapneumovirus under clinical laboratory settings

Introduction: Human metapneumovirus (hMPV) is an emergent human respiratory pathogen. This study aimed to evaluate the performance of direct immunofl uorescence (DIF) to detect hMPV in a clinical laboratory setting. Methods: Nasopharyngeal aspirate samples (448) of children and adults with respiratory illness were used to detect hMPV by using DIF and real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assays. Results: In all, 36 (8%) samples were positive by DIF and 94 (21%) were positive by qRT-PCR. Direct immunofl uorescence specifi city was 99% and sensitivity was 38%. Conclusions: DIF is not very sensitive under clinical laboratory settings. (AU)

Oseltamivir-resistant influenza A(H1N1)pdm09 virus in southern Brazil

The neuraminidase (NA) genes of A(H1N1)pdm09 influenza virus isolates from 306 infected patients were analysed. The circulation of oseltamivir-resistant viruses in Brazil has not been reported previously. Clinical samples were collected in the state of Rio Grande do Sul (RS) from 2009-2011 and two NA inhibitor-resistant mutants were identified, one in 2009 (H275Y) and the other in 2011 (S247N). This study revealed a low prevalence of resistant viruses (0.8%) with no spread of the resistant mutants throughout RS.

Diagnóstico laboratorial da infecçäo pela Chlamydia trachomatis: vantagens e desvantagens das técnicas / Laboratory diagnosis of Chlamydia trachomatis infection: advantages and disadvantages of the tests

O objetivo deste artigo é revisar e comentar as vantagens e desvantagens dos diferentes tipos de testes de detecçäo de Chlamydia trachomatis na rotina de laboratórios clínicos, com ênfase nas técnicas de amplificaçäo. A Chlamydia trachomatis é considerada a bactéria sexualmente transmissível mais freqüente em países desenvolvidos e de grande impacto no sistema reprodutivo das mulheres. É o agente causador de doenças do trato urogenital, linfogranuloma venéreo (LGV), tracoma, conjutivite de inclusäo e pneumonia no recémðnascido. Um dos fatores de risco para a infecçäo é a prática sexual entre adolescentes. A recorrência das infecções é comum. Episódios sucessivos de infecçäo aumentam o risco de desenvolver seqüelas e a chance de contrair a infecçäo pelo vírus da imunodeficiência humana. O dignóstico da infecçäo pela Chlamydia trachomatis ainda é crítico, devido à freqüência de infecções assintomáticas. As técnicas de amplificaçäo de ácidos nucléicos permitem utilizar urina para a detecçäo da clamídia, simplificando a coleta. Apresentam maior sensibilidade do que a cultura e do que os testes mais utilizados, como a imunofluorescência direta e o enzimaimunoensaio. A cultura celular, utilizada como padräoðouro, tem especificidade de 100 por cento e sensibilidade de 70 por cento a 85 por cento. De acordo com o Centers for Disease Control (CDC), um diagnóstico é considerado definitivo quando positivo em cultura ou em pelo menos dois testes näoðculturais distintos. Os testes de amplificaçäo säo mais dispendiosos do que os demais testes näoðculturais, mas de menor custo que a cultura

Diagnóstico laboratorial da SIDA/AIDS / Laboratory diagnosis of AIDS

O diagnóstico laboratorial da SIDA envolve testes que fazem o diagnóstico da infecçäo pelo Vírus da Imunodeficiência Humana (HIV) e testes que detectam as alteraçöes imunológicas secundárias a infecçäo. Os primeiros pesquisam antígenos virais circulantes ou anticorpos ao HIV. A presença de vírus pode ser detectada por cultura ou pelo achado de antígenos virais em fluidos ou tecidos. A pesquisa de anticorpos se divide em testes de triagem e testes complementares, mas podem diferir ainda pelo antígeno viral utilizado e pelo princípio em que se baseia a reaçiao. no nosso meio, testes EIA (Enzyme Immune Assay) de fácil execuçäo, têm sido usados para triagem e o Western blot e a imunofluorescência indireta como complementares. Os testes de triagem têm melhorado em especificidade e têm alto valor preditivo positivo em pessoas de grupo de risco. Outros pacientes, no entanto, necessitam testes complementares. Os marcadores de progressäo da doença säo: o declínio ou desaparecimento de anticorpos anti-p24, o reaparecimento de antígenos virais circulantes e a queda de linfócitos T cooperadores/indutores. O indicador prognóstico de severa disfunçiao imune induzida pelo HIV é a diminuiçäo do número absoluto destas células

Auxilio e limitacoes do fator antinuclear. / Usefulness and limitations of the antinuclear factor

As autoras apresentam uma revisao bibliografica sobre fatores antinucleares, sua importancia no diagnostico e no acompanhamento de pacientes e sobre a sensibilidade e especificidade das tecnicas utilizadas para detecta-los no Laboratorio de Imunologia

Estudo da contagem de celulas CD4 pelo metodo de "imunobeads" e sua relaçao com a dosagem de B2-microglobulinas / CD4 study count using immunobeads and relationship of B2-microglobulin levels

Fizemos um estudo nos dois principais marcadores de evoluçao para AIDS: um celular, contagem de linfocitos CD4 pelo metodo de "imunobeads" e outro sorologico,dosagem de B2-microglobulina, pelo metodo ELISA. Avaliamos a correlaçao destes dois marcadores e, partindo de um grupo controle,tentamos estabelecer um valor de referencia adequado ao nosso meio. Para este estudo, utilizamos amostras de 100 pacientes infectados pelo virus da imunodeficiencia humana, dos quais nao se conhece dados clinicos, e 13 individuos heterossexuais saudaveis,HIV soronegativos como controle. Concluimos que, apesar das conhecidas dificuldades tecnicas do nosso metodo para contagem de celulas CD4,podemos obter resultados comparaveis aos encontrados pelo metodo de citometria de fluxo. Em relaçao a B2-microglobulina verificamos importante associaçao entre este e a contagem de celulas CD4.

Análise da sorologia para sífilis utilizando o VDRL e a hemaglutinaçäo passiva quantitativos e comparaçäo dos resultados com o FTA-ABS / Serological analysis of syphilis using the VDRL and passive quantitative hemogglutination and comparison of the results with FTA-ABS

Com o objetivo de melhorar a qualidade da sorologia para sífilis, em nosso serviço, e familiarizar o clínico com um teste treponêmico de maior reprodutividade e, pelo menos, täo sensível quanto o FTA-ABS em sífilis latente e tardia, introduzimos a hemaglutinaçäo passiva na rotina. A nossa maior motivaçäo para publicar os resultados obtidos é a pobreza de informaçöes, na literatura, sobre a utilizaçäo destes dois testes quantitativos na sorologia. Os resultados de dois anos e oito meses de rotina säo analisados neste artigo e as informaçöes, obtidas com a associaçäo da hemaglutinaçäo passiva, discutidas, correlacionando os dados obtidos com a sensibilidade e especificidade de cada teste. Acreditamos que a MHA-TP realmente melhorou a qualidade da sorologia para sífilis em nosso laboratório, e o FTA-ABS deva ser usado apenas para complementar a sorologia ou como teste confirmatório. Surpreendemo-nos, também, com a baixa incidência de falso-positivos em nossa populaçäo

Diagnóstico laboratorial da infecçäo por vírus da imunodeficiência humana / Laboratory diagnosis of human immunodeficiency virus infection

Os autores revisam a sensibilidade e especificidade dos testes existentes para o diagnóstico da infecçäo pelo Vírus da Imunodeficiência Humana, com a finalidade de auxiliar o clínico na escolha dos testes mais adequados para cada estágio desta entidade