Hantavirus pulmonary syndrome: current situation among rodent reservoirs and human population in the Xth Region, Chile

Background In Chile, three rodent species (O longicaudatus, A olivaceus and A longipilis) are distributed from The Pacific coast to the Andes mountains and represent nearly 90% of the rodents captured in the Xth Region. Aim: To stud)) the seroprevalence of Hantavirus among captured rodent species a) W its relationship with the appearance of human cases of pulmonary syndrome. Material and methods: From May 1998 to September 2001, 675 rodents were captured in the region. Serum samples were tested by ELISA for The presence of IgG antibodies against Andes and Sin Nombre virus. Sera from human cases with a suspected Hantavirus infection were analyzed for IgM antibodies against Black Lagoon virus and for IgG antibodies against Andes and Sin Nombre virus. Results: Twenty two of the 675 rodents were seropositive for the virus, 18 0 longicaudatus and 4 A longipilis. Regional seroprevalence ice changed from 2.2% in 1998, 0.0% in 1999, 1.0% in 2000 and up to 7.1% in 2001. A total of 77 positive human cases were studied from 1998 to March 2002. Although there were positive cases in all seasons, data showed a spring-summer seasonal preponderance. A relationship between the flowering of 'colihue' hushes and the increased values of rodent abundance, seroprevalence and positive animals was established. Conclusions: A dispersal movement of O longicaudatus to open habitals close to human outdoor activities during the dry season was confirmed (Rev Med Chile 2003; 131: 169- 76)