الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
Respiratory syncytial virus (RSV) is a negative - stranded RNA virus belonging to the pneumovirus genus and family Paramyxioviridae . There is seasonal incidence of brochiolitis and the isolation of RSV. The close association between the yearly winter-spring outbreaks of RSV infections with the peak occurrence of bronchiolitis is shown clearly. During the peak period of an epidemic, RSV may be isolated from up to 89 percent of young children admitted to the hospital with acute lower respiratory (ALRT) disease. RSV affects mainly extremes of ages. It produces disease in early and late of life. This indicates that RSV has a bimodal distribution in life. Groups of children who clearly identified as being at high risk for fatal RSV infection are those with underlying pulmonary disease, including those with prematurity or bronchopulmonary dysplasia. Also infants who are at especial risk of infection are those with congenital heart disease, patients of all age with immuncompromised conditions, such as neurologic disease and nephrotic syndrome. RSV is highly contagious virus. Transmission occurs through contact with respiratory secretion, handling of fomites contaminated with respiratory secretions and subsequent autoinoculation of nose and eyes provides an important mode of RSV transmission. More adequate means for preventing RSV infection are necessary to prevent nosocomial RSV infection. Isolation of all infants with respiratory disease, strict hand washing and changing of gowns by the staff between infants and rooms will help to reduce the spread of infectious secretion Immunity induced by a single infection had no demonstrable effect on illness associated with reinfection one year later. Early rapid diagnosis of RSV infection is so useful to the physician at a time that it is still helpful in the management of child’s illness. Most of these children had been treated initially with parental antibiotics. Thus the potential toxic effects of such drugs could be lessened. This study was aimed to evaluation of immunofluorescence as a rapid diagnostic technique for RSV and comparison this technique with ELISA technique which also consider as a rapid diagnostic tool. A nasopharyngeal aspiration was collected from one hundred and fifty subjects ranging in age from one month to 11 years with acute respiratory infection from EL – Shatby Childern University hospital. Nasopharyngeal aspiration is the preferred source of specimen for virus culture and direct diagnosis of respiratory infection in paediatric groups. It provides more cells and improve the chance of antigen detection. It is less likely to provoke spasmodic coughing than swabbing of the throat. A process of cell washing was done by centrifugation of the specimen at 1500 rpm for 10 min until the cells became free from any remnants of mucus. After washing the cell pellet were collected. Twenty micron of washed cells was put on microscopic slide then air dried and fixed in cold acetone. Staining was done by applying 30?l of fluorescen isothiocynate conjugated anti – RSV .The presence of brilliant green fluorescence in the correct sub cellular location ( cytoplasmic ) and of characteristic pattern (globular ) of RSV is indication of positive result . ELISA technique was preformed on the second part of specimen. This ELISA depend on the formation of enzyme linked immune complexes of anti-RSV-antibody, RSV antigen anti RSV antibody biotin sandwich complexes. The capture antibody was directed against all viral antigens including RSV-A and RSV-B and react well with bovine-isolates. These antibodies were coated in microwells. RSV antigens contained in the patient’s specimens were bound to the capture antibody during the first incubation. After washing biotin-conjugated anti-RSV antibodies were dispensed into the well, by a second washing unbound biotin conjugated was removed and an avidin-peroxidase conjugate was added, during a third incubation this conjugate binds to the anti-RSV antibody. After further wash, the chromogenic substrate for this peroxidase, O-phenylene diamine dihydrochloride (OPD) was added. Any conjugate present could catalyze the conversion of the substrate to a yellow brown end product. The intensity of the color produced was dependent on the amount of virus antigen present in the clinical specimens. The results of this study revealed that: - • syncytial virus antigen (RSV – Ag ) was detected in 17 cases (11.3) out of 150 infants and young childern with acute respiratory disease by immunofluorescence (IF )technique and in 9 cases (6) by enzyme linked immunosorbant assay (ELISA). • Considering the result of combination of the two techniques, ELISA found no cases negative by IF. • The higher percentage of positive cases was presented with bronchiolitis (83.3).