Laguna Negra virus is one of the hantaviruses which cause Hantavirus pulmonary syndrome (HPS).
In Paraguay, the host is the native rodent Calomys laucha; approximately 12% of rats of this species in western Paraguay are infected with Laguna Negra virus. However, although C. laucha is one of the most common rodents in central Argentina, there is no evidence of Laguna Negra virus in central Argentina. This may be because the populations are disjunct.