THE USE OF A REVERSE TRANSCRIPTION-POLYMERASE CHAIN-REACTION FOR THE DETECTION OF VIRAL NUCLEIC-ACID IN THE DIAGNOSIS OF CRIMEAN-CONGO HEMORRHAGIC-FEVER

A reverse transcription-polymerase chain reaction (RT-PCR) was applied retrospectively to 80 stored serum samples from 45 confirmed Crimean- Congo haemorrhagic fever (CCHF) patients in southern Africa, and it wa s found that viral RNA could be detected in a proportion of samples up to day 16 of illness. Early in the disease there is relatively good c orrelation between the results obtained by RT-PCR and virus isolation, but after the first week it appears that infective virus is progressi vely cleared from serum while nucleic acid remains demonstrable in a p roportion of patients well into convalescence. A further 47 serum samp les from 38 patients with suspected viral haemorrhagic fever, 19 of wh om proved to be cases of CCHF, were tested prospectively on being rece ived at the laboratory. The combined use of RT-PCR with ethidium bromi de stained gels for the detection of viral RNA, plus indirect immunofl uorescence for the detection of IgG and IgM antibodies to CCHF virus, permitted a presumptive diagnosis to be reported within 8 h of receivi ng the first specimen from 18/19 cases of the disease studied prospect ively. The nineteenth case was confirmed within 48 h when antibody res ponse was demonstrated in a second serum sample. Viral nucleic acid wa s not detected in serum samples from 19 patients in whom alternative d iagnoses were established. (C) 1998 Elsevier Science B.V. All rights r eserved.