Búsqueda de flavivirus en individuos con sospecha clínica de dengue y resultado negativo para el antígeno NS1 en Paraguay / Search of flavivirus in individuals with clinical suspicion of dengue and negative for the NS1 antigen in Paraguay

Los flavivirus son responsables de una considerable morbi-mortalidad a nivel mundial. Entre ellos, el virus del dengue (DENV) es causante de graves problemas de salud pública en Paraguay. El objetivo del estudio fue detectar infecciones por flavivirus a través de una reacción de RT-nested PCR genérica para flavivirus en 195 muestras de individuos con sospecha de dengue, negativos por el test inmunocromatográfico (antígeno NS1 ­ DENV), provenientes del área metropolitana de Asunción entre 2011 y 2013. Las muestras positivas para flavivirus fueron sometidas a dos reacciones de RT-nested PCRs específicas para DENV. El límite de detección (LD) para flavivirus fue de 0,2 UFP/reacción. En total 43/195 muestras fueron positivas para flavivirus. De estas, 38/43 (88,4%) correspondieron a DENV (6 DENV-1, 30 DENV-2 y 2 DENV-3). Además, 5/43 casos (11,6%) positivos para flavivirus fueron negativos para DENV por ambas reacciones específicas, pudiendo deberse a infecciones por otros flavivirus. Los resultados sugieren que la utilización de una reacción genérica seguida de otras reacciones específicas para DENV en casos febriles negativos para NS1 por el método inmunocromatográfico permitiría detectar más casos de infecciones por DENV y además, podría contribuir a la identificación de casos debido a infecciones por otros flavivirus.

Flaviviruses are responsible for considerable worldwide morbidity and mortality. Among them, the dengue virus (DENV) causes serious public health problems in Paraguay. The objective of the study was to detect flavivirus infections using a generic RT-nested -PCR in 195 samples of individuals with suspected dengue and negative for the inmunochromatographic test (NS1 antigen ­ DENV), from the metropolitan area of Asuncion between 2011 and 2013. The flavivirus-positive samples were subjected to two reactions of DENV-specific RT-nested PCRs. The detection limit (DL) for flavivirus was 0.2 PFU / reaction. In total, 43/195 samples were positive for flavivirus. Of them, 38/43 (88,4%) corresponded to DENV (6 DENV-1, 30 DENV-2 and 2 DENV-3). In addition, 5/43 cases (11.6%) positive for flavivirus were negative for DENV by both specific reactions, and may be infections caused by other flaviviruses. The results suggest that the use of a generic reaction followed by other DENV specific reactions in febrile negative cases for NS1 by the immunochromatographic method would allow the detection of more cases of DENV infections and could contribute to the identification of cases due to infections by others flaviviruses.

Uso da técnica de swim-up para a remoção do Vírus da Artrite Encefalite Caprina do sêmen de reprodutores infectados / Use of swim-up technique for removal of the Caprine Arthritis Encephalitis Virus in the semen of infect bucks

Neste estudo, 67 ejaculados foram avaliados, antes e depois da técnica de swim-up, em relação à qualidade seminal e à presença do CAEV. Das 67 amostras testadas por PCRn, antes do swim-up, 47 (70,15%) foram positivas para o DNA pró-viral. No entanto, quatro amostras adicionais foram positivas ao RT-nested PCR após o swim-up, o que permite dizer que, pelo menos, 76,12% (51/67) delas estavam infectadas antes da lavagem. Todavia, em 23,88% (16/67) das amostras não foi detectada a presença do CAEV. Após a aplicação da técnica de swim-up, constatou-se, pela PCRn e RT-nested PCR, que houve uma redução significativa (χ²= 9,078; p<0,001) da presença do CAEV nas amostras seminais, pois 28 de 51 amostras positivas resultaram livres do vírus (54,90%), tanto para DNA pró-viral quanto para o vírus livre. Em relação à motilidade individual progressiva (MIP) e vigor espermático obtidos antes e depois da técnica de swim-up, observou-se uma diminuição significativa em suas médias, sendo o MIP de 86,42% para 71,49%, já o vigor espermático de 4,16 para 3,93. Conclui-se que a eliminação do CAEV no sêmen é de caráter intermitente, e que a associação da PCRn e RT-nested PCR é uma opção segura para a certificação sanitária individual das amostras seminais quanto à presença ou ausência do CAEV. Finalmente, a técnica de swim-up promove uma redução na infectividade de amostras de sêmen contaminadas, e, além disso, é possível promover a recuperação de espermatozoides viáveis.

In this study, 67 ejaculates were assessed before and after the swim-up technique in relation to semen quality and presence of CAEV. Of the 67 samples tested by Nested PCR, before swim-up 47 (70.15%) were positive for viral DNA. Furthermore, four additional samples were positive for RT-nested PCR after swim-up, which allows us to affirm that at least 76.12% (51/67) were infected before washing. However, 23.88% (16/67) of the samples did not detect the presence of CAEV. After application of the swim-up technique it was found, by Nested PCR and RT-nested PCR, that there was a significant decrease (χ² = 9.078, p <0.001) in the presence of CAEV in semen samples, once 28 of 51 positive samples were free from the virus (54.90%) for both proviral DNA and the free form of the virus. Regarding individual progressive motility (IPM) and spermatic vigor obtained before and after the swim-up technique, a significant decrease was observed in the average, being 86.42% of the IPM to 71.49% and the spermatic vigor from 4.16 for the 3.93. It is concluded that the removal of CAEV in semen has an intermittent character, and the combination of PCR and RT-nested PCR is a safe option for health certification of individual semen samples for the presence or absence of CAEV. Finally, the swim-up technique promotes a reduction in the infectivity of contaminated semen samples, and it is possible to promote the recovery of high individual progressive motility sperm and sperm vigor.

Uso da técnica de swim-up para a remoção do Vírus da Artrite Encefalite Caprina do sêmen de reprodutores infectados / Use of swim-up technique for removal of the Caprine Arthritis Encephalitis Virus in the semen of infect bucks

Neste estudo, 67 ejaculados foram avaliados, antes e depois da técnica de swim-up, em relação à qualidade seminal e à presença do CAEV. Das 67 amostras testadas por PCRn, antes do swim-up, 47 (70,15%) foram positivas para o DNA pró-viral. No entanto, quatro amostras adicionais foram positivas ao RT-nested PCR após o swim-up, o que permite dizer que, pelo menos, 76,12% (51/67) delas estavam infectadas antes da lavagem. Todavia, em 23,88% (16/67) das amostras não foi detectada a presença do CAEV. Após a aplicação da técnica de swim-up, constatou-se, pela PCRn e RT-nested PCR, que houve uma redução significativa (²= 9,078, p<0,001) da presença do CAEV nas amostras seminais, pois 28 de 51 amostras positivas resultaram livres do vírus (54,90%), tanto para DNA pró-viral quanto para o vírus livre. Em relação à motilidade individual progressiva (MIP) e vigor espermático obtidos antes e depois da técnica de swim-up, observou-se uma diminuição significativa em suas médias, sendo o MIP de 86,42% para 71,49%, já o vigor espermático de 4,16 para 3,93. Conclui-se que a eliminação do CAEV no sêmen é de caráter intermitente, e que a associação da PCRn e RT-nested PCR é uma opção segura para a certificação sanitária individual das amostras seminais quanto à presença ou ausência do CAEV. Finalmente, a técnica de swim-up promove uma redução na infectividade de amostras de sêmen contaminadas, e, além disso, é possível promover a recuperação de espermatozoides viáveis.(AU)

In this study, 67 ejaculates were assessed before and after the swim-up technique in relation to semen quality and presence of CAEV. Of the 67 samples tested by Nested PCR, before swim-up 47 (70.15%) were positive for viral DNA. Furthermore, four additional samples were positive for RT-nested PCR after swim-up, which allows us to affirm that at least 76.12% (51/67) were infected before washing. However, 23.88% (16/67) of the samples did not detect the presence of CAEV. After application of the swim-up technique it was found, by Nested PCR and RT-nested PCR, that there was a significant decrease (² = 9.078, p <0.001) in the presence of CAEV in semen samples, once 28 of 51 positive samples were free from the virus (54.90%) for both proviral DNA and the free form of the virus. Regarding individual progressive motility (IPM) and spermatic vigor obtained before and after the swim-up technique, a significant decrease was observed in the average, being 86.42% of the IPM to 71.49% and the spermatic vigor from 4.16 for the 3.93. It is concluded that the removal of CAEV in semen has an intermittent character, and the combination of PCR and RT-nested PCR is a safe option for health certification of individual semen samples for the presence or absence of CAEV. Finally, the swim-up technique promotes a reduction in the infectivity of contaminated semen samples, and it is possible to promote the recovery of high individual progressive motility sperm and sperm vigor.(AU)

Uso da técnica de swim-up para a remoção do Vírus da Artrite Encefalite Caprina do sêmen de reprodutores infectados / Use of swim-up technique for removal of the Caprine Arthritis Encephalitis Virus in the semen of infect bucks

Neste estudo, 67 ejaculados foram avaliados, antes e depois da técnica de swim-up, em relação à qualidade seminal e à presença do CAEV. Das 67 amostras testadas por PCRn, antes do swim-up, 47 (70,15%) foram positivas para o DNA pró-viral. No entanto, quatro amostras adicionais foram positivas ao RT-nested PCR após o swim-up, o que permite dizer que, pelo menos, 76,12% (51/67) delas estavam infectadas antes da lavagem. Todavia, em 23,88% (16/67) das amostras não foi detectada a presença do CAEV. Após a aplicação da técnica de swim-up, constatou-se, pela PCRn e RT-nested PCR, que houve uma redução significativa (²= 9,078, p<0,001) da presença do CAEV nas amostras seminais, pois 28 de 51 amostras positivas resultaram livres do vírus (54,90%), tanto para DNA pró-viral quanto para o vírus livre. Em relação à motilidade individual progressiva (MIP) e vigor espermático obtidos antes e depois da técnica de swim-up, observou-se uma diminuição significativa em suas médias, sendo o MIP de 86,42% para 71,49%, já o vigor espermático de 4,16 para 3,93. Conclui-se que a eliminação do CAEV no sêmen é de caráter intermitente, e que a associação da PCRn e RT-nested PCR é uma opção segura para a certificação sanitária individual das amostras seminais quanto à presença ou ausência do CAEV. Finalmente, a técnica de swim-up promove uma redução na infectividade de amostras de sêmen contaminadas, e, além disso, é possível promover a recuperação de espermatozoides viáveis.

In this study, 67 ejaculates were assessed before and after the swim-up technique in relation to semen quality and presence of CAEV. Of the 67 samples tested by Nested PCR, before swim-up 47 (70.15%) were positive for viral DNA. Furthermore, four additional samples were positive for RT-nested PCR after swim-up, which allows us to affirm that at least 76.12% (51/67) were infected before washing. However, 23.88% (16/67) of the samples did not detect the presence of CAEV. After application of the swim-up technique it was found, by Nested PCR and RT-nested PCR, that there was a significant decrease (² = 9.078, p <0.001) in the presence of CAEV in semen samples, once 28 of 51 positive samples were free from the virus (54.90%) for both proviral DNA and the free form of the virus. Regarding individual progressive motility (IPM) and spermatic vigor obtained before and after the swim-up technique, a significant decrease was observed in the average, being 86.42% of the IPM to 71.49% and the spermatic vigor from 4.16 for the 3.93. It is concluded that the removal of CAEV in semen has an intermittent character, and the combination of PCR and RT-nested PCR is a safe option for health certification of individual semen samples for the presence or absence of CAEV. Finally, the swim-up technique promotes a reduction in the infectivity of contaminated semen samples, and it is possible to promote the recovery of high individual progressive motility sperm and sperm vigor.

Detection of an untyped strain of bovine respiratory syncytial virus in a dairy herd / Detecção de uma estirpe não tipável do vírus respiratório sincicial bovino em rebanho leiteiro

Bovine respiratory syncytial virus (BRSV) causes important lower respiratory tract illness in calves. According to F and G proteins genetic sequences, three BRSV subgroups have been reported and characterized in several countries, showing differences in its distribution. In Brazil, the virus is widely disseminated throughout the herds and the few characterized isolates revealed the solely occurrence of the subgroup B. This study describes the detection and characterization of an untyped BRSV strain from a twenty-days-old calf from a herd without clinical respiratory disease. Nasal swabs were analyzed by RT-nested PCR for the F and G proteins genes. One sample has amplified the F protein gene. Sequencing and subsequent phylogenetic reconstruction were accomplished, revealing that the strain could not be grouped with any other BRSV subgroups reported. This result may suggest that the BRSV is in constantly evolution, even in Brazil, where the vaccination is not a common practice. More detailed studies about BRSV characterization are necessary to know the virus subgroups distribution among the Brazilian herds to recommend appropriated immunoprophylaxis.(AU)

O vírus respiratório sincicial bovino (BRSV) é responsável por causar severa doença respiratória principalmente em bezerros. De acordo com sequências genéticas das proteínas F e G deste vírus,três subgrupos de BRSV foram relatados e caracterizados em vários países, mostrando diferenças nas suas distribuições. No Brasil, o vírus encontra-se disseminado pelos rebanhos bovinos e, dos poucos isolados caracterizados, todos foram classificados no subgrupo B. Assim, o estudo descreve a detecção e caracterização de uma estirpe de BRSV não tipável proveniente de um bezerro de vinte dias de idade, de um rebanho sem histórico clínico de doença respiratória. Suabes nasais foram analisados pela técnica de RT-nested PCR para os genes das proteínas F e G do BRSV e uma amostra amplificou o gene da proteína F. O sequenciamento da amostra e subsequente reconstrução filogenética mostrou o não agrupamento da estirpe com quaisquer outros subgrupos de BRSV relatados. Este resultado sugere a constante evolução do BRSV, mesmo no Brasil, onde a vacinação não é uma prática comum. Estudos mais detalhados sobre a caracterização do BRSV são necessários para melhor entender a distribuição dos subgrupos nos rebanhos brasileiros a fim de proporcionar medidas de imunoprofilaxia adequadas.(AU)

Evidence of hepatitis A virus circulation in central Argentina: seroprevalence and environmental surveillance.

BACKGROUND: Hepatitis A virus (HAV) has shown intermediate endemicity in Argentina, but notification of clinical cases has decreased since the introduction of the vaccine in 2005. OBJECTIVES: In order to get insight into the local circulation of this virus after four years of the official introduction of the vaccine, the aims of this study were to provide information on HAV immune status of the adult population of Córdoba city and to conduct environmental surveillance of HAV in sewage and river samples in the same region. STUDY DESIGN: The prevalence of anti-HAV was determined by EIA in 416 samples of people (without prior vaccination) from Córdoba city (2009-2010). Spline regression models were estimated under generalized additive models. Environmental surveillance was conducted in river and sewage samples collected in the same period. Viral detection was performed by RT-Nested PCR of the 5'UTR. RESULTS: In Córdoba, the global prevalence of anti-HAV was 73.5%. It increased with age (p<0.0001) and it was associated with the low-income population (OR: 1.14; 95% CI 1.05-1.25). This prevalence decreased in younger age groups, especially in the high-income population. Environmental monitoring revealed the presence of HAV (IA) in 20.8% and 16.1% of wastewater and river samples, respectively. CONCLUSIONS: As a consequence of a decrease in HAV circulation due to improvements in immunization, socio-economic and hygienic conditions, young adults are becoming increasingly susceptible to HAV infections. Environmental monitoring demonstrated that HAV circulates in the local population; therefore, health care systems should consider the implementation of preventive measures for susceptible adults in order to reduce the risk of HAV infection.

Detection of an untyped strain of bovine respiratory syncytial virus in a dairy herd / Detecção de uma estirpe não tipável do vírus respiratório sincicial bovino em rebanho leiteiro

Bovine respiratory syncytial virus (BRSV) causes important lower respiratory tract illness in calves. According to F and G proteins genetic sequences, three BRSV subgroups have been reported and characterized in several countries, showing differences in its distribution. In Brazil, the virus is widely disseminated throughout the herds and the few characterized isolates revealed the solely occurrence of the subgroup B. This study describes the detection and characterization of an untyped BRSV strain from a twenty-days-old calf from a herd without clinical respiratory disease. Nasal swabs were analyzed by RT-nested PCR for the F and G proteins genes. One sample has amplified the F protein gene. Sequencing and subsequent phylogenetic reconstruction were accomplished, revealing that the strain could not be grouped with any other BRSV subgroups reported. This result may suggest that the BRSV is in constantly evolution, even in Brazil, where the vaccination is not a common practice. More detailed studies about BRSV characterization are necessary to know the virus subgroups distribution among the Brazilian herds to recommend appropriated immunoprophylaxis.

O vírus respiratório sincicial bovino (BRSV) é responsável por causar severa doença respiratória principalmente em bezerros. De acordo com sequências genéticas das proteínas F e G deste vírus,três subgrupos de BRSV foram relatados e caracterizados em vários países, mostrando diferenças nas suas distribuições. No Brasil, o vírus encontra-se disseminado pelos rebanhos bovinos e, dos poucos isolados caracterizados, todos foram classificados no subgrupo B. Assim, o estudo descreve a detecção e caracterização de uma estirpe de BRSV não tipável proveniente de um bezerro de vinte dias de idade, de um rebanho sem histórico clínico de doença respiratória. Suabes nasais foram analisados pela técnica de RT-nested PCR para os genes das proteínas F e G do BRSV e uma amostra amplificou o gene da proteína F. O sequenciamento da amostra e subsequente reconstrução filogenética mostrou o não agrupamento da estirpe com quaisquer outros subgrupos de BRSV relatados. Este resultado sugere a constante evolução do BRSV, mesmo no Brasil, onde a vacinação não é uma prática comum. Estudos mais detalhados sobre a caracterização do BRSV são necessários para melhor entender a distribuição dos subgrupos nos rebanhos brasileiros a fim de proporcionar medidas de imunoprofilaxia adequadas.

Comparative study of two extraction methods for enteric virus recovery from sewage sludge by molecular methods

The aim of this study was to compare two nucleic acid extraction methods for the recovery of enteric viruses from activated sludge. Test samples were inoculated with human adenovirus (AdV), hepatitis A virus (HAV), poliovirus (PV) and rotavirus (RV) and were then processed by an adsorption-elution-precipitation method. Two extraction methods were used: an organic solvent-based method and a silica method. The organic-based method was able to recoup 20 percent of the AdV, 90 percent of the RV and 100 percent of both the PV and HAV from seeded samples. The silica method was able to recoup 1.8 percent of the AdV and 90 percent of the RV. These results indicate that the organic-based method is more suitable for detecting viruses in sewage sludge.

Distribution of Hepatitis C virus (HCV) genotypes in seropositive patients in the state of Alagoas, Brazil / Distribuição de genótipos do Vírus da hepatite C (HCV) em pacientes soropositivos no Estado de Alagoas, Brasil

We determined the frequency of hepatitis C virus (HCV) genotypes in anti-HCV seropositive patients in the state of Alagoas, Brazil, by means of nested-reverse transcription-polymerase chain reaction (RT-nested-PCR) followed by restriction fragment length polymorphism (RFLP) of amplified fragments of the 5ïNCR. The nested-PCR with genotype-specific primers from the core region was carried out when detection was not possible by the first approach. Detectable HCV-RNA was present in 115 (74.7 percent) of 154 serum samples. Genotype 1 was the most frequent (77.4 percent), against 20.9 percent of genotype 3 and 0.8 percent of genotype 2. Subtype 1b was predominant (65.2 percent), followed by subtypes 1a (8.7 percent), and 3a (6.1 percent). Coinfection (1a/3a) was detected in 0.8 percent of the samples. Indeed, there was no significant differences in the prevalence of genotype 1 compared to what has been obtained from anti-HCV seropositive patients from other locations in Brazil. Here we report for the first time the genotype 2 in the state of Alagoas.

A frequência de genótipos do vírus da hepatite C (HCV) em pacientes soropositivos anti-HCV no estado de Alagoas, Brasil, foi determinada através da RT-PCR aninhada da região 5'NCR seguida pela análise do polimorfismo de comprimento dos fragmentos de restrição (RFLP). A RT-PCR aninhada utilizando primers genótipo-específicos da região core foi efetuada quando não foi possível determinar o genótipo pelo primeiro método. Níveis detectáveis de HCV-RNA estavam presentes em 115 (74,7 por cento) das 154 amostras de soro. O genótipo 1 foi o mais freqüente (77,4 por cento), contra 20,9 por cento do genótipo 3 e 0,8 por cento do genótipo 2. O subtipo 1b foi predominante (65,2 por cento), seguido pelos subtipos 1a (8,7 por cento) e 3a (6,1 por cento). Co-infecção (1a/3a) foi detectada em 0,8 por cento das amostras. Não foram encontradas diferenças significativas quanto à prevalência do genótipo 1 em relação ao que tem sido obtido de pacientes soropositivos anti-HCV de outras localidades do Brasil. Este é o primeiro relato da presença do genótipo 2 no estado.

Distribution of Hepatitis C virus (HCV) genotypes in seropositive patients in the state of Alagoas, Brazil.

We determined the frequency of hepatitis C virus (HCV) genotypes in anti-HCV seropositive patients in the state of Alagoas, Brazil, by means of nested-reverse transcription-polymerase chain reaction (RT-nested-PCR) followed by restriction fragment length polymorphism (RFLP) of amplified fragments of the 5´NCR. The nested-PCR with genotype-specific primers from the core region was carried out when detection was not possible by the first approach. Detectable HCV-RNA was present in 115 (74.7%) of 154 serum samples. Genotype 1 was the most frequent (77.4%), against 20.9% of genotype 3 and 0.8% of genotype 2. Subtype 1b was predominant (65.2%), followed by subtypes 1a (8.7%), and 3a (6.1%). Coinfection (1a/3a) was detected in 0.8% of the samples. Indeed, there was no significant differences in the prevalence of genotype 1 compared to what has been obtained from anti-HCV seropositive patients from other locations in Brazil. Here we report for the first time the genotype 2 in the state of Alagoas.

Distribution of Hepatitis C virus (HCV) genotypes in seropositive patients in the state of Alagoas, Brazil

We determined the frequency of hepatitis C virus (HCV) genotypes in anti-HCV seropositive patients in the state of Alagoas, Brazil, by means of nested-reverse transcription-polymerase chain reaction (RT-nested-PCR) followed by restriction fragment length polymorphism (RFLP) of amplified fragments of the 5´NCR. The nested-PCR with genotype-specific primers from the core region was carried out when detection was not possible by the first approach. Detectable HCV-RNA was present in 115 (74.7%) of 154 serum samples. Genotype 1 was the most frequent (77.4%), against 20.9% of genotype 3 and 0.8% of genotype 2. Subtype 1b was predominant (65.2%), followed by subtypes 1a (8.7%), and 3a (6.1%). Coinfection (1a/3a) was detected in 0.8% of the samples. Indeed, there was no significant differences in the prevalence of genotype 1 compared to what has been obtained from anti-HCV seropositive patients from other locations in Brazil. Here we report for the first time the genotype 2 in the state of Alagoas.

A frequência de genótipos do vírus da hepatite C (HCV) em pacientes soropositivos anti-HCV no estado de Alagoas, Brasil, foi determinada através da RT-PCR aninhada da região 5'NCR seguida pela análise do polimorfismo de comprimento dos fragmentos de restrição (RFLP). A RT-PCR aninhada utilizando primers genótipo-específicos da região core foi efetuada quando não foi possível determinar o genótipo pelo primeiro método. Níveis detectáveis de HCV-RNA estavam presentes em 115 (74,7%) das 154 amostras de soro. O genótipo 1 foi o mais freqüente (77,4%), contra 20,9% do genótipo 3 e 0,8% do genótipo 2. O subtipo 1b foi predominante (65,2%), seguido pelos subtipos 1a (8,7%) e 3a (6,1%). Co-infecção (1a/3a) foi detectada em 0,8% das amostras. Não foram encontradas diferenças significativas quanto à prevalência do genótipo 1 em relação ao que tem sido obtido de pacientes soropositivos anti-HCV de outras localidades do Brasil. Este é o primeiro relato da presença do genótipo 2 no estado.