Central and South American HPS pathogens
Choclo virus vs Laguna Negra virus
| Feature | Choclo virus (CHOV) | Laguna Negra virus (LANV) |
|---|---|---|
| Syndrome | HPS (often milder than ANDV/SNV) | HPS |
| Reservoir | Fulvous pygmy rice rat (Oligoryzomys fulvescens) | Small vesper mouse (Calomys laucha) |
| Geography | Panama (Azuero peninsula and beyond) | Paraguay (Chaco), Bolivia, parts of Argentina |
| CFR | ≈ 10% | ≈ 12–15% |
| First described | 1999–2000, Panama | 1995–1997, Paraguay |
| Person-to-person | Not documented | Not documented |
Choclo virus (CHOV) and Laguna Negra virus (LANV) are the two most epidemiologically important non-Andes-virus hantaviruses of Central and South America. Both produce hantavirus pulmonary syndrome, both circulate in pygmy rodents of the lowland Neotropics, and both are under-surveilled relative to ANDV and SNV.
Choclo virus. First described after a 1999–2000 outbreak on Panama's Azuero peninsula, CHOV is now recognised as the endemic hantavirus of Panama and has been detected in neighbouring Costa Rica. Its reservoir is the fulvous pygmy rice rat (Oligoryzomys fulvescens). Clinically, CHOV-HPS is on average less severe than ANDV or SNV disease — case-fatality has been estimated at around 10% — but the syndrome is still life-threatening and requires intensive care. There is no documented human-to-human transmission.
Laguna Negra virus. First described in Paraguay in the mid-1990s, LANV's reservoir is the small vesper mouse (Calomys laucha), a grassland and chaco species. The virus circulates across Paraguay, Bolivia, and parts of northern Argentina, with sporadic outbreaks among rural agricultural workers and in indigenous Chaco communities. Case-fatality is roughly 12–15% — lower than ANDV but materially severe. LANV is not known to spread between people.
Why are these less famous? Surveillance intensity. ANDV and SNV emerged in countries with mature public-health laboratory systems; CHOV and LANV emerged in regions where laboratory confirmation of an HPS-compatible illness is the exception rather than the rule. Most experts believe both pathogens cause significantly more disease than is currently captured in surveillance data.