RS virus diagnosis: comparison of isolation, immunofluorescence and enzyme immunoassay

Abstract

Two techniques for rapid diagnosis, immunofluorescence (IFAT) and enzyme immunoassay (EIA), have been compared with virus isolation in tissue culture for the detection of respiratory syncytial virus (RSV) in specimens of nasopharyngeal secretions. The specimens were obtained from children under five years of age suffering from acute respiratory illness, during a period of six months from January to June 1982. Of 471 specimens examined 54 (11.5%) were positive by virus isolation and 180 (38.2%) were positive by immunofluorescence. The bacterial contamination of inoculated tissue cultures unfortunately prevented the isolation of virus from many samples. Specimens from 216 children were tested to compare enzyme immunoassay and immunofluorescence. Of these 60 (27%) were positive by EIA and 121 (56%) were positive by IFAT. Our results suggest that the EIA technique although highly specific is rather insensitive. This may be because by the time these tests were done the original nasopharyngeal secretions were considerably diluted and contained more mucus fragments than the cell suspension used for IFAT. Of the three techniques, IFAT gives the best results although EIA may be useful where IFAT is not possible.

Respiratory syncytial virus infections during an epidemic period in Salvador, Brazil: viral antigenic group analysis and description of clinical and epidemiological aspects

“…Viral isolation -An aliquot of about 0.5 ml of NPS was processed and placed in tubes containing 2 ml of phosphate-buffered saline solution and 0.5% gelatin for isolation of HEp-2 cells in fresh monolayers, as described previously (Siqueira et al 1986).…”

Infecções do trato respiratório inferior pelo vírus sincicial respiratório em crianças hospitalizadas menores de um ano de idade

“…As amostras foram coletadas em um período inferior a três dias após a admissão no hospital, nos anos de 1997 e 1998, durante os meses de maio, junho e julho, que correspondem às estações de final de outono e inverno no Rio de Janeiro. Cada espécime foi processado para detecção dos antígenos virais nas células de descamação do trato respiratório por imunufluorescência indireta, utilizando soros imunes policlonais ou anticorpos monoclonais (antiVSR, antiinfluenza A, antiinfluenza B e antiparainfluenza tipo 3 (PF3), segundo a técnica convencional 15 .…”

Isolation of respiratory syncytial virus from nasopharyngeal aspirates stored at 20ºC from one to fifteen months after collection

“…Rates of 11.5% and 35.7% for isolation of RSV from NPA have been cited in two Brazilian studies (Siqueira et al 1986, Moura et al 2002. In one them, the samples were processed immediately for isolation in three different cells lines (Siqueira et al 1986). In the other, HEp-2 cells were used but the samples were stored at -70 o C before being inoculated (Moura et al 2002).…”

“…The rate of RSV isolation observed in this study was surprising. Rates of 11.5% and 35.7% for isolation of RSV from NPA have been cited in two Brazilian studies (Siqueira et al 1986, Moura et al 2002. In one them, the samples were processed immediately for isolation in three different cells lines (Siqueira et al 1986).…”