Diagnosis of hepatitis C virus infection using different methods

Hepatitis C virus [HCV] is now recognized as one of the major health problems allover the world. More than 50 percent of individuals exposed to HCV develop chronic infection. Approximately 20 percent to 30 percent will develop liver cirrhosis or hepatocellular carcinoma. HCV is generally transmitted by the parentral route. Methods to identify HCV include a highly sensitive second generation immunoassay that detects antibodies to structural and non-structural proteins in serum. Viremia is detected by polymerase chain reaction [PCR] technology. This study was done on 200 subjects who were divided into four groups, and 30 apparent healthy persons [blood donors] as a control group. Sera were subjected to detection of antibodies to HCV using enzyme linked immunosorbant assay [ELISA] test and the detection of viral RNA by PCR. HCV antibodies were present in 82 [35.36 percent] out of 230 tested subjects. Sera from these subjects [230] were subjected to detection of HCV- RNA, we found HCV - RNA in 22 [14.9 percent] out of 148 hCV antibody - negative subjects and in 72 [87.8 percent] out of 82 HCV antibody - positive subjects

Evaluation of different techniques used for diagnosis of chlamydia pneumoniae infection

Chlamydia pneumoniae is a common respiratory tract pathogen. Serological methods currently used for the diagnosis of C. pneumoniae infection lack specificity, give ambiguous results from a single serum sample and often provide only a retrospective diagnosis. Many studies were undertaken to assess whether polymerase chain reaction [PCR] could be a useful addition to the serological techniques routinely practiced for diagnosis. This study investigated 100 patients with a diagnosis of acute respiratory tract infection. Nasopharyngeal swab [NPS] obtained from these 100 patients were evaluated by PCR- enzyme immunoassay [PCR - EIA] for the presence of C pneumoniae DNA and by direct immunofluorescence [DIF] and staining by Giemsa stain for detection of its antigens. Serological determination of IgG antibodies against C. pneumoniae were performed by means of an enzyme linked immunosorbant assay [rELISA]. Seventeen patients [17 percent] were positive by both PCR and rELISA, while 5 patients [5 percent] were positive by rELISA and negative by PCR. By using DIP test, 13 patients [13 percent] were positive. There were 8 patients [8 percent] positive by Giemsa staining. Better definition of the serological criteria and improved performance of the PCR technique, are necessary to confirm the etiological role of C. pneumoniae in acute and chronic respiratory infections