The low specificity of screening ELISAs for antibodies to hepatitis C virus in blood donors has called for confirmatory tests. Two types of supplementary antibody assays are available, recombinant immunoblot assays (RIBA-1 and RIBA-2) and an antibody consumption test referred to as a neutralization assay. Amplification of viral nucleic acid by the polymerase chain reaction (PCR) provides an antibody independent mode of detecting viral infection. We applied reverse transcription-double PCR to detect an HCV 5'-noncoding viral RNA sequence in serum specimens and compared PCR findings with confirmatory antibody tests. This study includes sera from 37 blood donors found positive by the Ortho anti-HCV (C100-3) ELISA out of 14,591 donations. Of the 37 positive sera, 8 were positive by RIBA-1 and 1 further by RIBA-2. Seven of the RIBA positive sera contained HCV RNA by PCR. Among the 8 indeterminate and the 21 negative donor sera by RIBA-1, no PCR positive serum was found. The 37 anti-HCV positive donor sera identified by Ortho ELISA were also tested by Abbott anti-HCV (C100-3) ELISA whereby 22 were positive. Of these 22 sera plus 1 further with ELISA OD just below cutoff, 8 were positive by the "neutralization assay," (Abbott Laboratories, North Chicago, IL, USA) and 6 of these, including the borderline serum, were PCR positive. One of the two neutralizable but PCR negative sera was RIBA positive and the other was indeterminate. However, one ELISA (Abbott Laboratories) positive (OD 1.99) serum was not neutralizable but nevertheless contained HCV RNA by PCR.(ABSTRACT TRUNCATED AT 250 WORDS)

There was no significant difference in GBV-C/HGV viremia in the group with elevated ALT levels and the group with normal ALT levels. The frequency and subtype distribution in the present series were similar to those in other Western countries.

The relation between donor alanine aminotransferase (ALT) and recipient post-transfusion hepatitis (PTH) non-A, non-B was studied in patients tested before and 6 and 12 weeks after transfusion. The minimum ALT criterion for PTH was 105 IU/l (>2.5 times the upper normal of 42 IU/1). In 8.8% of donors, ALT was >42 IU/l, and in 2.3% ALT was >63 IU/l, i.e., 1.5 times elevated. PTH non-A, non-B occurred in 14 of 742 recipients. The PTH incidence increased when donor ALT was above 63 IU/l (1.5 vs. 5.6%; p<0.05). However, if the confounding factor of volume variations was compensated for, elevated donor ALT and PTH were only statistically linked among recipients <70 years (p<0.02; Mantel-Haenszel test).

The prevalence of asthma among 10,527 children aged 7-16 years was investigated in 1985. Children were assigned to the asthma group when replies to a questionnaire stated that at least two of four stipulated symptoms had been experienced in the preceding year. A validation study, comprising exploration of medical history, pulmonary auscultation and physiological tests (spirometry and methacholine inhalation challenge) was performed in 73 children. The overall prevalence of asthma was 4%. The most common symptom-inducing factors were physical exertion, upper respiratory tract infection, contact with animals and tobacco smoke. The methacholine test had limited value as a diagnostic aid, being positive in only 25% of children with a clear history of asthma.

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