RAPID DIAGNOSIS OF ARGENTINE HEMORRHAGIC-FEVER BY REVERSE-TRANSCRIPTASE PCR-BASED ASSAY

Argentine hemorrhagic fever (AHF) is an endemo-epidemic disease caused by Junin virus. This report demonstrates that a reverse transcriptase (RT) PCR-based assay developed in our laboratory to detect Junin viru s in whole blood samples is sensitive and specific. The experiments we re conducted in a double-blinded manner using 94 clinical samples coll ected in the area in which AHF is endemic. The RT-PCR-based assay was compared with traditional methodologies, including enzyme-linked immun osorbent assay, plaque neutralization tests, and occasionally viral is olation, The calculated parameters for RT-PCR diagnosis, with seroconv ersion as the ''gold standard,'' were 98% sensitivity and 76% specific ity. It is noteworthy that 94% of the patients with putative false-pos itive results (RT-PCR positive and no seroconversion detected) exhibit ed febrile syndromes of undefined etiology. These results could be int erpreted to mean that most of those patients with febrile syndromes we re actually infected with Junin virus but did not develop a detectable immune response. Furthermore, 8 laboratory-fabricated samples and 25 blood samples of patients outside the area in which AHF is endemic tes ted in a similar way were disclosed correctly (100% match). The RT-PCR assay is the only laboratory test available currently for the early a nd rapid diagnosis of AHF. It is sensitive enough to detect the low vi remia found during the period in which immune plasma therapy tan be us ed effectively, reducing mortality rates from 30% to less than 1%.