Global Influenza Hospital-based Surveillance Network (GIHSN): results of surveillance of influenza and other respiratory viruses in hospitalised patients in Brazil, 2015.

BACKGROUND: Influenza-like illness occurs annually worldwide, with peak timing and severity varying seasonally, resulting in significant annual mortality. OBJECTIVES: There were three objectives: (1) to describe the epidemiological and clinical features of hospitalised patients with severe acute respiratory infection caused by influenza and other respiratory viruses (ORVs); (2) to report the influenza seasonality in the region and (3) to correlate findings of influenza circulation and immunisation time in Brazil. PATIENTS/METHODS: This study took place in three Brazilian hospitals located in cities with different climatic conditions (Curitiba (south), Rio de Janeiro (south-east) and Fortaleza (north-east)). Patients presenting with an acute process with indication for admission consisting of a predefined set of conditions potentially associated with recent influenza infection were enrolled. RESULTS: We screened 1666 patients, with 595 meeting the inclusion criteria. Influenza viruses and ORVs were detected in 6.5% and 59% of patients, respectively. Influenza-positive cases fell into the severe spectrum as compared with those with ORVs (30% vs 11%), but without any difference in mortality rates. Epidemiological results revealed variations in the peak time of influenza infections between north-east (Fortaleza) and south (Curitiba) Brazil, basically following the rain period of each region. In north-east Brazil, viral circulation was prevalent in the first 4 months of the year, indicating that the vaccination campaign occurred in a postseasonal period, possibly explaining the low effectiveness. CONCLUSIONS: The active-surveillance model is a valuable tool for investigating respiratory virus impact on hospitalised patients, with influenza-infection monitoring enabling implementation of adequate preventive measures.

Confirmatory molecular method for HTLV-1/2 infection in high-risk pregnant women.

Human T-cell lymphotropic virus types 1/2 (HTLV-1/2) are transmitted through sexual intercourse, transfusion of blood components, and vertical transmission, predominantly through breastfeeding. Six hundred forty-three pregnant women from a high-risk prenatal care unit at a general hospital were tested by serological tests using chemiluminescence (CMIA) for screening, followed by a molecular confirmatory test. Four patients (0.6%) tested positive for HTLV-1/2 by CMIA, two samples (0.3%) for each patient were confirmed as having HTLV-1 or HTLV-2 by PCR. The results show the importance of inclusion of HTLV-1/2 screening for pregnant women in high-risk prenatal care and the need for a molecular biological method to confirm HTLV-1/2 infection.

Molecular epidemiology of influenza B virus and implications in immunization strategy, Southern Brazil.

Epidemiological indicators have shown the substantial impact of influenza B (Flu B) on the development of severe acute respiratory infection (SARI) and on mortality rates. In Brazil, the trivalent vaccine, composed of only one Flu B lineage is available. We investigated Flu B infections in clinical samples collected by the epidemiological surveillance service of Paraná State, Brazil, from 2013 to 2016. The Flu B lineages Yamagata- (B/Yam) and Victoria-like (B/Vic) were identified using the qRT-PCR assay, and notification forms were reviewed. Among 379 Flu B positive samples evaluated, 370 (98%) were characterized as B/Yam or B/Vic lineages. Both co-circulated with a frequency of 47% and 53%, respectively. B/Yam infected equally both genders, while B/Vic was more frequent in females (71%). The median age of patients infected by B/Vic (23y; 11-35) was lower than that of patients infected by B/Yam (32y; 12-50). Mismatch between the vaccine and the circulating strain was observed in the 2013 season, with a high number of SARI cases. B/Vic lineage was associated with a larger number of SARI cases (62%), while B/Yam with influenza-like illness (ILI) (61%). Differences were observed in the strains circulating in separate regions of Paraná State. B/Vic was prevalent in the northwestern (67%) and B/Yam in the southeastern region (60%). The unpredictability of Flu B lineage circulation causes a substantial increase in severe disease during epidemics in a vaccine mismatch season. In addition, the differences in the epidemiological profile of the target population of Flu B infections in relation to other respiratory viruses, as well as among the B/Vic and B/Yam lineages may also be associated to an increase in disease burden. These findings have direct consequences on vaccination strategies. Therefore, further molecular epidemiology studies of Flu B in Brazil are required to corroborate these primary results.

Impact and seasonality of human rhinovirus infection in hospitalized patients for two consecutive years / Impacto e sazonalidade da infecção por rinovírus humano em pacientes internados por dois anos consecutivos

Abstract Objectives: To report epidemiological features, clinical characteristics, and outcomes of human rhinovirus (HRV) infections in comparison with other community acquired respiratory virus (CRV) infections in patients hospitalized for two consecutive years. Methods: This was a cross-sectional study. Clinical, epidemiological, and laboratory data of patients hospitalized with acute respiratory syndrome in a tertiary care hospital from 2012 to 2013 were reviewed. Results: HRV was the most common CRV observed (36%, 162/444) and was present in the majority of viral co-detections (69%, 88/128), mainly in association with human enterovirus (45%). Most HRV-infected patients were younger than 2 years (57%). Overall, patients infected with HRV had a lower frequency of severe acute respiratory infection than those infected with other CRVs (60% and 84%, respectively, p = 0.006), but had more comorbidities (40% and 27%, respectively; p = 0.043). However, in the adjusted analysis this association was not significant. The mortality rate within the HRV group was 3%. Detection of HRV was more prevalent during autumn and winter, with a moderately negative correlation between viral infection frequency and temperature (r = −0.636, p < 0.001) but no correlation with rainfall (r = −0.036, p = 0.866). Conclusion: HRV is usually detected in hospitalized children with respiratory infections and is often present in viral co-detections. Comorbidities are closely associated with HRV infections. These infections show seasonal variation, with predominance during colder seasons.

Resumo Objetivos: Relatar as características epidemiológicas, as características clínicas e os resultados das infecções por rinovírus humano (RVH) em comparação a outras infecções por vírus respiratórios adquiridos na comunidade (VRCs) em pacientes internados por dois anos consecutivos. Métodos: Este foi um estudo transversal. Foram revisados os dados clínicos, epidemiológicos e laboratoriais de pacientes internados com síndrome respiratória aguda em um hospital terciário de 2012 a 2013. Resultados: O RVH foi o VRC mais comum observado (36%, 162/444) e esteve presente na maior parte das codetecções virais (69%, 88/128), principalmente em associação ao enterovírus humano (45%). A maioria dos pacientes infectados por RVH possuía menos de 2 anos (57%). De modo geral, os pacientes com RVH apresentaram uma menor frequência de infecção respiratória aguda grave que os pacientes infectados por outros VRCs (60% e 84%, respectivamente, p = 0,006), porém mais comorbidades (40% e 27%, respectivamente; p = 0,043). Contudo, em uma análise ajustada, essa associação não foi significativa. A taxa de mortalidade no grupo RVH foi 3%. A detecção de RVH foi mais prevalente durante o outono e inverno, com uma correlação negativa moderada entre a frequência de infecção viral e a temperatura (r = -0,636, p < 0,001), porém nenhuma correlação com a precipitação (r = −0,036, p = 0,866). Conclusão: O RVH é normalmente detectado em crianças internadas com infecções respiratórias e normalmente está presente em codetecções virais. As comorbidades estão estreitamente associadas a infecções por RVH. Essas infecçõesmostram variação sazonal, com predominância durante as estações mais frias.

Molecular characterization and clinical epidemiology of human respiratory syncytial virus (HRSV) A and B in hospitalized children, Southern Brazil.

Human respiratory syncytial virus (HRSV) is a major etiologic agent of pediatric respiratory infections. Genetic variability of its glycoprotein G enables HRSV to evade the immune response and determines its seasonal dissemination. This study reports genetic variability and clinical profiles of HRSV-infected patients from Southern Brazil. Seventy positive samples, 78% type A and 22% type B, were analyzed. Of the patients (median age, 6 months; interquartile range, 2-11 years), 16% had co-morbidities and 17% developed severe disease. The ON1 HRSV genotype first appeared in 2012, and patients infected with this genotype showed an increased tendency to develop severe disease.

Impact and seasonality of human rhinovirus infection in hospitalized patients for two consecutive years.

OBJECTIVES: To report epidemiological features, clinical characteristics, and outcomes of human rhinovirus (HRV) infections in comparison with other community acquired respiratory virus (CRV) infections in patients hospitalized for two consecutive years. METHODS: This was a cross-sectional study. Clinical, epidemiological, and laboratory data of patients hospitalized with acute respiratory syndrome in a tertiary care hospital from 2012 to 2013 were reviewed. RESULTS: HRV was the most common CRV observed (36%, 162/444) and was present in the majority of viral co-detections (69%, 88/128), mainly in association with human enterovirus (45%). Most HRV-infected patients were younger than 2 years (57%). Overall, patients infected with HRV had a lower frequency of severe acute respiratory infection than those infected with other CRVs (60% and 84%, respectively, p=0.006), but had more comorbidities (40% and 27%, respectively; p=0.043). However, in the adjusted analysis this association was not significant. The mortality rate within the HRV group was 3%. Detection of HRV was more prevalent during autumn and winter, with a moderately negative correlation between viral infection frequency and temperature (r=-0.636, p<0.001) but no correlation with rainfall (r=-0.036, p=0.866). CONCLUSION: HRV is usually detected in hospitalized children with respiratory infections and is often present in viral co-detections. Comorbidities are closely associated with HRV infections. These infections show seasonal variation, with predominance during colder seasons.

Red blood cells in cerebrospinal fluid as possible inhibitory factor for enterovirus RT-PCR.

The presence of hemoglobin in samples are considered an important inhibitory factor for polymerase chain reaction (PCR). The aim of this study was to examine the influence of red blood cells (RBC)s in cerebrospinal fluid (CSF) as an inhibitory factor to reverse transcription polymerase chain reaction (RT-PCR) for enteroviruses (EV). Forty-four CSF samples from patients showing characteristics of viral meningitis were assessed for EV by RT-PCR. Viral RNA extracted with guanidine isothyocianate buffer and virus detection was performed by in-house nested PCR. Positivity for EV RT-PCR was higher in CSF samples without RBCs than in samples with RBCs: 13(26%) and 36(9.2%), p = 0.001. In the group with positive EV RT-PCR, the mean + SD CSF RBC was 37 ± 183 cell/mm3; the group with negative results had 580 + 2,890 cell/mm3 (p = 0.007). The acceptable upper limit for CSF RBCs that could not influence RT-PCR was 108 cells/mm3. CSF samples with negative results for EV RT-PCR have more erythrocytes.

Red blood cells in cerebrospinal fluid as possible inhibitory factor for enterovirus RT-PCR / Presença de hemácias no líquido cefalorraquidiano como possível fator inibitório da RT-PCR para detecção de enterovirus

ABSTRACT The presence of hemoglobin in samples are considered an important inhibitory factor for polymerase chain reaction (PCR). The aim of this study was to examine the influence of red blood cells (RBC)s in cerebrospinal fluid (CSF) as an inhibitory factor to reverse transcription polymerase chain reaction (RT-PCR) for enteroviruses (EV). Forty-four CSF samples from patients showing characteristics of viral meningitis were assessed for EV by RT-PCR. Viral RNA extracted with guanidine isothyocianate buffer and virus detection was performed by in-house nested PCR. Positivity for EV RT-PCR was higher in CSF samples without RBCs than in samples with RBCs: 13(26%) and 36(9.2%), p = 0.001. In the group with positive EV RT-PCR, the mean + SD CSF RBC was 37 ± 183 cell/mm3; the group with negative results had 580 + 2,890 cell/mm3 (p = 0.007). The acceptable upper limit for CSF RBCs that could not influence RT-PCR was 108 cells/mm3. CSF samples with negative results for EV RT-PCR have more erythrocytes.

RESUMO A presença de hemoglobina em amostras de fluidos corporais é considerada um fator inibitório importante da reação em cadeia da polimerase (PCR). O objetivo deste estudo era examinar a influencia de hemácias no líquido cefalorraquidiano (LCR) como um fator inibitório da RT-PCR para enterovirus (EV). Quatrocentos e quarenta amostras de LCR de pacientes com características de meningite viral foram avaliados para enterovirus por RT-PCR. RNA viral foi extraído com tampão de isotiocianato de guanidina e a detecção viral foi feita com nested PCR in-house. A positividade do EV RT-PCR no LCR foi maior nas amostras de LCR sem hemácias do que as amostras com hemácias: 13 (26%) e 36 (9,2%), respectivamente (p = 0,001). No grupo com resultados EV RT-PCR positivo, a media ± DP do número de hemácias no LCR foi 37 ± 183 cell/mm3 e no grupo com resultados negativos foi 580 ± 2.890 cell/mm3 (p = 0,007). O limite superior aceitável de hemácias no LCR para não inibir o resultado do PCR foi 108 cells/mm3. As amostras de LCR com resultados negativos para RT-PCR EV tem mais eritrócitos em comparação com amostras com resultados positivos.

Human coronavirus and severe acute respiratory infection in Southern Brazil.

Human coronaviruses (HCoVs) are an important cause of respiratory tract infection and are responsible for causing the common cold in the general population. Thus, adequate surveillance of HCoV is essential. This study aimed to analyze the impact of HCoV infections and their relation to severe acute respiratory infection (SARI) in a hospitalized population in Southern Brazil. A cross-sectional study was conducted at a tertiary care hospital, and assessed inpatients under investigation for SARI by the hospital epidemiology department, and all patients who had nasopharyngeal aspirates collected from January 2012 to December 2013 to detect respiratory viruses (RVs). Viral infection was detected by multiplex reverse transcriptase polymerase chain reaction (RT-PCR), with primers specific to the subtypes HCoV-229E/NL63 and OC43/HKU1. The overall positivity rate was 58.8% (444/755), and HCoVs were detected in 7.6% (n = 34) of positive samples. Children below two years of age were most frequently affected (62%). Comorbidities were more likely to be associated with HCoVs than with other RVs. Immunosuppression was an independent risk factor for HCoV infection (OR = 3.5, 95% CI 1.6-7.6). Dyspnea was less frequently associated with HCoV infection (p < 0.001), and HCoV accounted for 6% of the SARI cases. Three patients infected with HCoV (9%) died from respiratory infection. HCoVs are important respiratory pathogens, especially in hospitalized children under 2 years of age and in immunosuppressed patients. They may account for a small proportion of SARI diagnoses, increased need for mechanical ventilation, intensive care unit admission, and death.

Acute gastroenteritis and enteric viruses in hospitalised children in southern Brazil: aetiology, seasonality and clinical outcomes.

Viral acute gastroenteritis (AG) is a significant cause of hospitalisation in children younger than five years. Group A rotavirus (RVA) is responsible for 30% of these cases. Following the introduction of RVA immunisation in Brazil in 2006, a decreased circulation of this virus has been observed. However, AG remains an important cause of hospitalisation of paediatric patients and only limited data are available regarding the role of other enteric viruses in these cases. We conducted a prospective study of paediatric patients hospitalised for AG. Stool samples were collected to investigate human adenovirus (HAdV), RVA, norovirus (NoV) and astrovirus (AstV). NoV typing was performed by nucleotide sequencing and phylogenetic analysis. From the 225 samples tested, 60 (26%) were positive for at least one viral agent. HAdV, NoV, RVA and AstV were detected in 16%, 8%, 6% and 0% of the samples, respectively. Mixed infections were found in nine patients: HAdV/RVA (5), HAdV/NoV (3) and HAdV/NoV/RVA (1). The frequency of fever and lymphocytosis was significantly higher in virus-infected patients. Phylogenetic analysis of NoV indicated that all of these viruses belonged to genotype GII.4. The significant frequency of these pathogens in patients with AG highlights the need to routinely implement laboratory investigations.

Acute gastroenteritis and enteric viruses in hospitalised children in southern Brazil: aetiology, seasonality and clinical outcomes

Viral acute gastroenteritis (AG) is a significant cause of hospitalisation in children younger than five years. Group A rotavirus (RVA) is responsible for 30% of these cases. Following the introduction of RVA immunisation in Brazil in 2006, a decreased circulation of this virus has been observed. However, AG remains an important cause of hospitalisation of paediatric patients and only limited data are available regarding the role of other enteric viruses in these cases. We conducted a prospective study of paediatric patients hospitalised for AG. Stool samples were collected to investigate human adenovirus (HAdV), RVA, norovirus (NoV) and astrovirus (AstV). NoV typing was performed by nucleotide sequencing and phylogenetic analysis. From the 225 samples tested, 60 (26%) were positive for at least one viral agent. HAdV, NoV, RVA and AstV were detected in 16%, 8%, 6% and 0% of the samples, respectively. Mixed infections were found in nine patients: HAdV/RVA (5), HAdV/NoV (3) and HAdV/NoV/RVA (1). The frequency of fever and lymphocytosis was significantly higher in virus-infected patients. Phylogenetic analysis of NoV indicated that all of these viruses belonged to genotype GII.4. The significant frequency of these pathogens in patients with AG highlights the need to routinely implement laboratory investigations.

Human cytomegalovirus detection by real-time PCR and pp65-antigen test in hematopoietic stem cell transplant recipients: a challenge in low and middle-income countries.

AIM: Cytomegalovirus (CMV) infection is one of the most common complications in patients submitted to hematopoietic stem cell transplant (HSCT). Pre-emptive therapy has been indicated in patients with laboratory evidence of CMV replication. The aims of this study were to compare real-time PCR or pp65 antigen assay methodologies to detect CMV replication in HSCT patients, define a viral load threshold for initiation of pre-emptive therapy, and assess the feasibility of its implementation in hospitals of countries with low and middle income. MATERIAL AND METHODS: Human CMV detection by real-time PCR and pp65 antigen assay was carried out in blood and plasma samples of HSCT patients collected weekly during 3 months. Pre-emptive therapy was based on CMV antigenemia results. RESULTS: Twenty-one patients were monitored with a total of 227 samples collected; 13 (62%) patients were children. A poor correlation was observed between qualitative results, though quantitative results showed statistically significant difference, with higher viral loads detected in patients with positive antigenemia. Compared to a positive antigenemia, a cutoff value of 1067·5 copies/ml, 3·03 log10/ml, for viral load was obtained with 100% sensitivity and 71% specificity. CONCLUSION: CMV real-time PCR in whole blood was suitable for monitoring HSCT patients. However, its high cost is a limiting factor, and it could be used to monitor selected patients, those with prolonged leukopenia and underweight children, and subsequently switched to pp65 antigen test. Further studies involving larger numbers of patients should be performed to confirm this statement.

Caracterização molecular dos genótipos do rotavírus em pacientes pediátricos imunossuprimidos e não imunossuprimidos / Molecular characterization of rotavirus genotypes in immunosuppressed and non-immunosuppressed pediatric patients

OBJETIVO: Descrever a variabilidade genotípica do rotavírus grupo A (RVA) encontrado em pacientes pediátricos imunocompetentes e imunocomprometidos tratados no Hospital de Clínicas/Universidade Federal do Paraná (HC/UFPR), Curitiba, Paraná. MÉTODOS: Foi realizado um estudo transversal com 1.140 amostras de fezes coletadas, de abril de 2001 a dezembro de 2008, em pacientes ambulatoriais e pacientes hospitalizados com gastroenterite aguda encaminhados ao hospital. As técnicas usadas foram o método da aglutinação do látex e imunoensaio enzimático para diagnóstico de RVA. Foi realizada transcrição reversa, seguida por PCR multiplex semi-nested e sequência de nucleotídeos para caracterização do genótipo. Foram relatados dados de combinações de genótipos, clínicos, epidemiológicos, laboratoriais e sobre a presença de infecções hospitalares. RESULTADOS: Foi analisado um total de 80 amostras de fezes positivas para rotavírus. As associações mais frequentes entre os genótipos G e P foram: G4 P[8] (38,9%), G1 P[8] (30,5%), G9 P[8] (13,9%), G2 P[4] (6.9 %) e G3 P[8] 1,4%). O genótipo prevalente foi G2 P[4] depois da implementação da vacina nos anos de 2006 e 2008. Verificou-se que um total de 62,5% das crianças com idade abaixo de 12 meses estavam infectadas. Destas, 55,6% tinham grave desidratação, e 26,7% precisaram de cuidados intensivos. Encontrou-se uma frequência de 12,5% de infecções hospitalares. Não se observou correlação entre o genótipo e a gravidade da infecção nos pacientes estudados. CONCLUSÃO: As infecções por RVA podem associar-se a manifestações clínicas graves e é crucial a vigilância da variabilidade genotípica desse vírus para monitorizar a emergência de novas cepas e o impacto da imunização nesses pacientes.

OBJECTIVE: To describe the genotypic variability of group A rotavirus (RVA) found in immunosuppressed and non-immunosuppressed pediatric patients treated at the Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR), Curitiba, Paraná. METHODS: A cross-sectional study was conducted with 1,140 stool samples collected from April, 2001 to December, 2008 in outpatients and hospitalized patients with acute gastroenteritis referred to the hospital. RVA diagnosis was performed through the latex agglutination method and enzyme immunoassay. Reverse transcription followed by multiplex hemi-nested polymerase chain reaction (PCR) and nucleotide sequencing were used for genotype characterization. Genotype combinations, clinical data, epidemiological data, laboratory data, and presence of hospital-acquired infections were reported. RESULTS: A total of 80 rotavirus-positive stool samples were analyzed. The most frequent associations between genotypes G and P were: G4 P[8] (38.9%), G1 P[8] (30.5%), G9 P[8] (13.9%), G2 P[4] (6.9%), and G3 P[8] (1.4%). G2 P[4] was the most prevalent genotype after the vaccine implementation in the years 2006 and 2008. A total of 62.5% of children aged less than 12 months were found to be infected. Of these, 55.6% had severe dehydration and 26.7% needed intensive care. A frequency of 12.5% of nosocomial infections was found. No correlation was observed between genotype and severity of infection in the study patients. CONCLUSION: RVA infections can be associated with severe clinical manifestations, and the surveillance of genotypic variability of this virus is crucial to monitor the emergence of new strains and the impact of the immunization in these patients.

Molecular characterization of rotavirus genotypes in immunosuppressed and non-immunosuppressed pediatric patients.

OBJECTIVE: To describe the genotypic variability of group A rotavirus (RVA) found in immunosuppressed and non-immunosuppressed pediatric patients treated at the Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR), Curitiba, Paraná. METHODS: A cross-sectional study was conducted with 1,140 stool samples collected from April, 2001 to December, 2008 in outpatients and hospitalized patients with acute gastroenteritis referred to the hospital. RVA diagnosis was performed through the latex agglutination method and enzyme immunoassay. Reverse transcription followed by multiplex hemi-nested polymerase chain reaction (PCR) and nucleotide sequencing were used for genotype characterization. Genotype combinations, clinical, epidemiological, laboratory data, and presence of hospital-acquired infections were reported. RESULTS: A total of 80 rotavirus-positive stool samples were analyzed. The most frequent associations between genotypes G and P were: G4 P[8] (38.9%), G1 P[8] (30.5%), G9 P[8] (13.9%), G2 P[4] (6.9%), and G3 P[8] (1.4%). G2 P[4] was the most prevalent genotype after the vaccine implementation in the years 2006 and 2008. A total of 62,5% of infected children were aged less than 12 months. Of these, 55.6% had severe dehydration and 26.7% needed intensive care. A frequency of 12.5% of nosocomial infections was found. No correlation was observed between genotype and severity of infection in the study patients. CONCLUSION: RVA infections can be associated with severe clinical manifestations, and the surveillance of genotypic variability of this virus is crucial to monitor the emergence of new strains and the impact of the immunization in these patients.

Rotavirus infection in a tertiary hospital: laboratory diagnosis and impact of immunization on pediatric hospitalization.

BACKGROUND AND OBJECTIVES: Rotavirus (RV) is the main etiological agent of diarrhea in childhood; its laboratory diagnosis is crucial to guide the clinical management and prevention of its spread. RV immunization was introduced in Brazilian 6-month-old children in 2006. The present study was aimed to evaluate three methodologies used for human RV detection in stool samples obtained from patients hospitalized due to gastroenteritis in a teaching hospital and report the impact of RV immunization in hospitalization by diarrhea. METHODS: 293 stool samples collected in the 2001-2008 period were analyzed by enzyme immunoassay (EIA), latex agglutination (LA) and polyacrylamide gel electrophoresis (PAGE). RESULTS: Rotavirus was detected in 34.8% of samples by LA assay, 28.3% of samples by EIA assay and in 25.6% of samples by PAGE assay. Considering the PAGE method as gold standard, the sensitivity, specificity and accuracy of EIA were 94.6%, 94.4% and 94.5%, and to LA were 82.6%, 81.6% and 81.9%, respectively. CONCLUSION: These results indicate that antigen detection by EIA is a rapid, sensitive and specific method, and could be used in large-scale applications for screening stool samples suspected of RV infection. This study showed decreased incidence of RV infection in hospitalized children prior to the implementation of the national immunization program against RV.

Rotavirus infection in a tertiary hospital: laboratory diagnosis and impact of immunization on pediatric hospitalization

BACKGROUND AND OBJECTIVES: Rotavirus (RV) is the main etiological agent of diarrhea in childhood; its laboratory diagnosis is crucial to guide the clinical management and prevention of its spread. RV immunization was introduced in Brazilian 6-month-old children in 2006. The present study was aimed to evaluate three methodologies used for human RV detection in stool samples obtained from patients hospitalized due to gastroenteritis in a teaching hospital and report the impact of RV immunization in hospitalization by diarrhea. METHODS: 293 stool samples collected in the 2001-2008 period were analyzed by enzyme immunoassay (EIA), latex agglutination (LA) and polyacrylamide gel electrophoresis (PAGE). RESULTS: Rotavirus was detected in 34.8 percent of samples by LA assay, 28.3 percent of samples by EIA assay and in 25.6 percent of samples by PAGE assay. Considering the PAGE method as gold standard, the sensitivity, specificity and accuracy of EIA were 94.6 percent, 94.4 percent and 94.5 percent, and to LA were 82.6 percent, 81.6 percent and 81.9 percent, respectively. CONCLUSION: These results indicate that antigen detection by EIA is a rapid, sensitive and specific method, and could be used in large-scale applications for screening stool samples suspected of RV infection. This study showed decreased incidence of RV infection in hospitalized children prior to the implementation of the national immunization program against RV.

Laboratory diagnosis, epidemiology, and clinical outcomes of pandemic influenza A and community respiratory viral infections in southern Brazil.

Community respiratory viruses (CRVs) are commonly associated with seasonal infections. They have been associated with higher morbidity and mortality among children, elderly individuals, and immunosuppressed patients. In April 2009, the circulation of a new influenza A virus (FLUA H1N1v) was responsible for the first influenza pandemic of this century. We report the clinical and epidemiological profiles of inpatients infected with CRVs or with FLUA H1N1v at a tertiary care hospital in southern Brazil. In addition, we used these profiles to evaluate survivor and nonsurvivor patients infected with FLUA H1N1v. Multiplex reverse transcription-PCR (RT-PCR) and real time RT-PCR were used to detect viruses in inpatients with respiratory infections. Record data from all patients were reviewed. A total of 171 patients were examined over a period of 16 weeks. Of these, 39% were positive for FLUA H1N1v, 36% were positive for CRVs, and 25% were negative. For the FLUA H1N1v- and CRV-infected patients, epidemiological data regarding median age (30 and 1.5 years), myalgia (44% and 13%), need for mechanical ventilation (44% and 9%), and mortality (35% and 9%) were statistically different. In a multivariate analysis comparing survivor and nonsurvivor patients infected with influenza A virus H1N1, median age and creatine phosphokinase levels were significantly associated with a severe outcome. Seasonal respiratory infections are a continuing concern. Our results highlight the importance of studies on the prevalence and severity of these infections and that investments in programs of clinical and laboratory monitoring are essential to detect the appearance of new infective agents.

Adenovirus respiratory infection: significant increase in diagnosis using PCR comparing with antigen detection and culture methods / Infecção respiratória aguda por adenovirus: comparação dos métodos de PCR e imunofluorescência indireta para o seu diagnóstico e dados clínicos dos pacientes infectados

Adenovirus (AdV) respiratory infections are usually described as being associated with high mortality rates. Laboratory diagnosis is essential for the establishment of the appropriate therapy, and for guiding the implementation of preventive measures in order to prevent the spread of the infection. Aiming to analyze the sensitivity and specificity of the laboratorial diagnosis methods available, we compared antigen detection by indirect immunofluorescence assay (IF), and a specific nested polymerase chain reaction (PCR), to detect AdV in respiratory samples collected from patients admitted to hospital with acute respiratory disease. Positive samples were inoculated into a cell culture to confirm the results. We analyzed 381 samples from the nasopharyngeal aspirates collected during the year 2008; of these, 2.6 percent tested were positive for adenovirus through IF and 10 percent through PCR; positive isolation was obtained in 40 percent and 26 percent of these cases, respectively. Most infected patients were children under six months of age, and despite of the fact that a significant number of patients required intensive care, the mortality rate was low (5 percent). In conclusion, molecular methods were found to be useful for rapid diagnosis of adenovirus infections with higher sensitivity than antigen detection; their introduction permitted a significant increase in diagnoses of adenovirus infections.

Infecções respiratórias por Adenovírus (ADV) são geralmente descritas associadas com alta mortalidade. O diagnóstico laboratorial é essencial para o estabelecimento da terapêutica adequada e para orientar a implantação de medidas preventivas evitando a propagação da infecção. Com o objetivo de analisar a sensibilidade e a especificidade dos métodos de avaliação de diagnóstico laboratorial, foi comparada a detecção de antígeno por imunofluorescência indireta (IF) com a reação em cadeia da polimerase específica (PCR) para detectar AdV em amostras respiratórias coletadas de pacientes internados com doença respiratória aguda. As amostras com resultados positivos foram inoculadas em cultura celular. Foram analisadas 381 amostras da secreção nasofaríngea coletadas durante o ano de 2008, das quais 2,6 por cento foram positivas pela IF e 10 por cento pela PCR, isolamento positivo foi obtido em 40 por cento e 26 por cento dos casos positivos pelos testes anteriores, respectivamente. A maioria dos pacientes infectados eram crianças com menos de seis meses de idade, e apesar do fato de que um número significativo de pacientes necessitou de cuidados intensivos, a taxa de mortalidade foi baixa (5 por cento). Em conclusão, os métodos moleculares são úteis para o diagnóstico rápido de infecções por adenovírus com maior sensibilidade do que a detecção do antígeno, a sua introdução na rotina permitiu um aumento significativo no diagnóstico de infecções por adenovírus.

Adenovirus respiratory infection: significant increase in diagnosis using PCR comparing with antigen detection and culture methods.

Adenovirus (AdV) respiratory infections are usually described as being associated with high mortality rates. Laboratory diagnosis is essential for the establishment of the appropriate therapy, and for guiding the implementation of preventive measures in order to prevent the spread of the infection. Aiming to analyze the sensitivity and specificity of the laboratorial diagnosis methods available, we compared antigen detection by indirect immunofluorescence assay (IF), and a specific nested polymerase chain reaction (PCR), to detect AdV in respiratory samples collected from patients admitted to hospital with acute respiratory disease. Positive samples were inoculated into a cell culture to confirm the results. We analyzed 381 samples from the nasopharyngeal aspirates collected during the year 2008; of these, 2.6% tested were positive for adenovirus through IF and 10% through PCR; positive isolation was obtained in 40% and 26% of these cases, respectively. Most infected patients were children under six months of age, and despite of the fact that a significant number of patients required intensive care, the mortality rate was low (5%). In conclusion, molecular methods were found to be useful for rapid diagnosis of adenovirus infections with higher sensitivity than antigen detection; their introduction permitted a significant increase in diagnoses of adenovirus infections.

Comparison of immunoperoxidase and immunofluorescence assays for pp65 cytomegalovirus antigen in immunocompromised patients

We compared the pp65 antigen detection by an in house method (immunoperoxidase assay) and by a commercial kit (immunofluorescence assay) available for cytomegalovirus infection diagnosis in immunocompromised patients. Sixty-four blood samples were analyzed in duplicate for both techniques. Eight-six percent of the samples had concordant qualitative results. The discordant results occurred more frequently in samples with low quantity of positive cells. There were no significant differences with qualitative and quantitative results of the methods.