Performance of indirect immunofluorescence assay, immunochromatography assay and reverse transcription-polymerase chain reaction for detecting human respiratory syncytial virus in nasopharyngeal aspirate samples

Comparison of the use of indirect immunofluorescence assay (IFA), immunochromatography assay (ICA-BD) and reverse transcription-polymerase chain reaction (RT-PCR) for detecting human respiratory syncytial virus (HRSV) in 306 nasopharyngeal aspirates samples (NPA) was performed in order to assess their analytical performance. By comparing the results obtained using ICA-BD with those using IFA, we found relative indices of 85.0 percent for sensitivity and 91.2 percent for specificity, and the positive (PPV) and negative (NPV) predictive values were 85.0 percent and 91.2 percent, respectively. The relative indices for sensitivity and specificity as well as the PPV and NPV for RT-PCR were 98.0 percent, 89.0 percent, 84.0 percent and 99.0 percent, respectively, when compared to the results of IFA. In addition, comparison of the results of ICA-BD and those of RT-PCR yielded relative indices of 79.5 percent for sensitivity and 95.4 percent for specificity, as well as PPV and NPV of 92.9 percent and 86.0 percent, respectively. Although RT-PCR has shown the best performance, the substantial agreement between the ICA-BD and IFA results suggests that ICA-BD, also in addition to being a rapid and facile assay, could be suitable as an alternative diagnostic screening for HRSV infection in children.

Anticorpos anti-Biomphalaria em soros de pacientes e camundongos infectados por Schistosoma mansoni. / Anti-Biomphalaria antibodies in sera of patients and mice infected by Schistosoma mansoni

Com a finalidade de estudar a ocorrencia e a dinamica de surgimento de anticorpos anti-Biomphalaria no soro de seres humanos e camundongos infectados por Schistosoma mansoni, analisaram-se atraves de reacao de hemaglutinacao passiva 52 soros de pacientes comprovadamente parasitados pelo trematodeo e 40 soros de camundongos experimentalmente infectados. Como grupos controle utilizaram-se, no primeiro caso, 42 soros de individuos nao esquistossomoticos e, no segundo, 15 soros de camundongos nao infectados pelo helminto. Os resultados revelaram que nos pacientes esquistossomoticos e especialmente nos camundongos experimentalmente infectados os titulos do anticorpos anti-Biomphalaria sao mais elevados do que nos grupos controles. O exame de camundongos infectados, em diversas ocasioes, revelou a presenca de anticorpos anti-Biomphalaria, em niveis pouco variaveis, a partir do 15o dia apos a infeccao e, pelo menos, ate o 95o dia, ocasiao em que se encerrou o experimento