Human Bocavirus Infection in Children with Gastroenteritis, Brazil

Human bocavirus (HBoV) was detected in 14 (2%) of 705 fecal specimens from Brazilian children with gastroenteritis. Coinfection with rotavirus, adenovirus, or norovirus was found in 3 (21.4%) HBoV-positive specimens. None of the HBoV-positive patients had respiratory symptoms

Detection and characterization of human rotavirus in hospitalized patients in the cities of Ponta Grossa, Londrina and Assai - PR, Brazil

Acute diarrheal disease is still one of the major public health problems worldwide. Rotaviruses (RV) are the most important viral etiologic agents and children under five years of age are the target population. OBJECTIVE: To investigate the rate of RV infection in hospitalized patients due to acute diarrhea in the cities of Ponta Grossa, Londrina and Assai - Paraná. METHODS: Latex agglutination (LA); immunochromatography (ICG); polyacrylamide gel electrophoresis (PAGE) and negative staining electron microscopy (ME) tests were used to detect the virus. For the genotyping, RT-PCR and RT-PCR-ELISA were used, respectively, for NSP4 and VP4/VP7. RESULT: Out of 124 samples there were 69 positive stool samples for RV, for at least one of the used tests, 67 of them being RV group A (RV-A). Overall, most of the RV positive stool samples came from children under thirteen years of age. However, 12 positive cases occurred in patients aged 13 years or above, including an 81-year old patient. CONCLUSION: The data showed similar electropherotypes and genotypes G, P and NSP4 of the inland wild circulating strains of RV

Development of an enzyme immunoassay for poliovirus antigens

An indirect solid-phase enzyme immunoassay (EIA) was developed for the detection of poliovirus antigen. Virus antigen was obtained in LLC-MK2 cell cultures and used to prepare antibodies in rabbit and guinea pig. Antibodies were evaluated by double immunodiffusion and neutralization test. Optimal concentrations of guinea pig and rabbit immunoglobulins were determined by checkerboard titration. Microtitre plates were coated with 15.0 µg/ml guinea pig anti-polio immunoglobulin and rabbit anti-polio immunoglobulin at the concentration of 7.94 µg/ml was used as detecting antibody. The standard curve with eight different antigen concentrations in eight replicates resulted in a coefficient of variation (CV) between 2.1% to 7.8%. The dose-response relationship was determined by simple linear regression with a coefficient of correlation (R²) equal to 96.4%. The assay detected a minimum of 2.3 µg/ml poliovirus antigen.<br>O trabalho apresenta o desenvolvimento de um ensaio imunoenzimático indireto para a detecção de antígeno de poliovírus. O antígeno viral foi obtido em cultura de células LLC-MK2 e usado para imunização de coelho e cobaia. Os soros hiperimunes foram avaliados por imunodifusão dupla e teste de neutralização. Após padronização, o soro de captura, produzido em cobaia, foi usado na concentração protéica de 15.0 µg/ml para sensibilizar microplacas de poliestireno e o soro de coelho (detector) foi usado na concentração de 7.94 µg/ml. A curva padrão resultante da utilização de oito diferentes concentrações do antígeno padrão definiu um coeficiente de variação de 2.1% a 7.8%. A relação dose-resposta foi determinada por regressão linear simples com o estabelecimento do coeficiente de correlação (R²) igual a 96.4%. O ensaio possibilitou a detecção mínima de 2.3 µg/ml de antígeno de poliovírus