Assay for hepatitis C virus in peripheral blood mononuclear cells enhances sensitivity of diagnosis and monitoring of HCV-associated hepatitis.

Hepatitis C virus (HCV) is a major etiological factor in chronic hepatitis affecting up to 24% of blood donors in Egypt. Since fluctuating levels of HCV RNA loads, including undetectable values, have been frequently observed in sera of chronic hepatitis patients, this study was designed to assess the sensitivity of PCR amplification for the plus- and minus-RNA strands in peripheral blood mononuclear cells (PBMC) compared to single serum PCR assay. Since the latter test detects viremia in only 79.5% of seropositive cases, the highest sensitivity for HCV diagnosis was achieved (93.20% when applying the combined triple test including PCR amplification of plus-strand in serum, together with plus-strand in PBMC and minus-strand in PBMC. The results of this study indicate that the triple test provides significant information on extrahepatic replication of HCV in a sizable sample of seropositive subjects (429 cases) and improves the assessment of HCV viremia. The cost/effectiveness and speed were upgraded by using capillary/air rapid thermal cycler. The use of the triple assay in HCV diagnosis and post-therapy monitoring is recommended.

Chloramphenicol drug failure in typhoid fever.

Two hundred positive blood culture typhoid patients admitted to Embaba Fever Hospital, Giza province, were subjected to: 1) Careful history and thorough clinical examination. 2) Complete blood picture. 3) Widal agglutination test. 4) Urine and stool cultures for Salmonellae. 5) To the isolates of the cultures, disk diffusion chloramphenicol susceptibility test, minimum inhibitory concentrations and chloramphenicol acetyl transferase test were performed. The dose of chloramphenicol was restricted to 50 mg per Kg body weight daily, whatever the route used; whether oral, rectal or intravenous. When fever did not drop up to 5 days or the patient presented with typhoid complications or the blood culture revealed resistant Salmonellae, quinolones or third generation, cephalosporins were administered. Measurement of the level of chloramphenicol in the blood was performed for every patient. Fifty (25%) patients were found to be resistant in vitro and in vivo to chloramphenicol. All their Salmonellae isolates were resistant to chloramphenicol, the mean zone size was 10 mm, the mean inhibitory concentration was 64 microgram per ml. and all were positive for chloramphenicol acetyl transferase. There was no significant difference in the serum level of chloramphenicol between susceptible and resistant groups to the drug. Results were interpreted and discussed.