RETROSPECTIVE DETECTION OF CLINICAL INFEC TIONS CAUSED BY HANTAVIRUS IN ARGENTINA

Hantavirus activity in rodents and human beings in Argentina has been known since the 1980's. In this study, we retrospectively investigated hantavirus infections among Argentine Hemorrhagic Fever (AHF) cases n otified between 1987 and 1994. without virological confirmation. IgG a nd IgM antibodies to hantavirus were tested by ELISA. Among 1028 patie nts included in the study, we found 13 recent infections (1.26%) and 1 3 remote infections (1.26%). IgG antibodies determined in 745 healthy persons living in the same localities of recent infection cases, gave only one positive result (0.13%). Nine of the 13 recent infections had the clinical presentation of Hemorrhagic Fever with Renal Syndrome (H FRS) while the other four were in the form of Hantavirus Pulmonary Syn drome (HPS). We performed a clinical and epidemiological comparison be tween the nine patients with FHSR and two paired control groups: one w ith confirmed AHF and the other with Febrile Syndrome of Undetermined Etiology (FSUE), which were negative for hantavirus, Junin and LCM. Th ere were no differences between clinical signs or symptoms. Neverthele ss, normal or high leucocyte counts, with thrombocytopenia, hemoconcen tration, high creatinine levels and proteinuria in HFRS cases resulted useful for differential diagnosis. These results showed the coexisten ce of Junin virus and hantaviruses in the endemic area of AHF, and ind icate the importance of including the infection with these viruses in the differential diagnosis of hemorrhagic fevers and respiratory distr ess syndromes of unknown etiology. The clinical variability found coul d be related to the presence of more than one hantavirus serotype in o ur country.