AN OUTBREAK OF HANTAVIRUS PULMONARY SYNDROME IN WESTERN PARAGUAY

During an investigation of hantavirus pulmonary syndrome (HPS) in Para guay in 1995, sera from persons with HPS-like illness, houshold contac ts of confirmed PIPS case-patients, and a sample of the area residents were analyzed by ELISA for antibodies to Sin Nombre virus (SNV). Rode nt serosurveys and analysis of precipitation records were also conduct ed. Twenty-three of 24 available probable cases were SNV antibody-posi tive, 17 of whom were ill between July 1995 and January 1996. Four (14 .8%) of 27 case-contacts and 44 (12.8%) of 345 community residents wer e also seropositive. Calomys laucha (vesper mouse) was the most common rodent species captured and the most frequently SNV-seropositive. Rai nfall in May 1995 was 10-fold greater than that seen in May over the p receding 11 years. This 17 case-cluster represents the largest documen ted outbreak since PIPS was first recognized in 1993. Calomys laucha i s the likely primary rodent reservoir for a SNV-like hantavirus in wes tern Paraguay. Fluctuations in monthly precipitation rates may have co ntributed to increased risk for HPS in this region.