ABSTRACT
In August 1991, blood samples were taken from neighbors and relatives of people who had died suspect of haemorrhagic fever in Manaus, Amazonas State. Eighty-four serum samples were obtained. All samples were tested against yellow fever, hepatitis B and Delta and leptospirosis. The results were negative. These sera were subsequently submitted by indirect immunofluorescent antibody (IFA) to Hantaan (the aetiological agent of the haemorrhagic fever with renal syndrome) for screening. The results of IFA showed a high prevalence of antibodies to Hantaan, with a positivity of 45.2 per cent. All positive samples (N=38) were tested by ELISA for confirmation and 6 (l9.3 per cent) were positive, 4 of them to Hantaan and 2 to Puumala, another Hantavirus related with human disease. In view of the high positivity, 48 samples from blood donors of Manaus and 48 from Tucuruí, Pará State, were also submitted to IFA with 26 (54.3 per cent) and 5 (1O.4 per cent) samples positive, respectively. As a result of the data obtained we concluded that the infection by Hantaviruses is extremely common in Manaus and recommend attempts to isolate the agent from blood of febrile patients and from tissues and blood of rodents, as well as new studies to characterize the clinical spectrum of human infection and its importance in public health.