Summary: This review of six publications on Hantavirus delivers key information points all healthcare professionals should know. Current concern centers on a cruise-associated cluster of Andes virus infections, a rare Hantavirus uniquely capable of person-to-person transmission and severe disease. 

Summary of Key Information
Hantaviruses are zoonotic, negative-sense RNA viruses primarily maintained in rodent reservoirs, with each viral species typically associated with a specific host. Human infection most commonly occurs through inhalation of aerosolized rodent urine, feces, or saliva. Old World hantaviruses are classically associated with hemorrhagic fever with renal syndrome (HFRS), whereas New World hantaviruses, including Sin Nombre virus and Andes virus, are associated with hantavirus cardiopulmonary syndrome (HCPS), a rapidly progressive cardiopulmonary disease with substantially higher case fatality rates than most forms of HFRS.^1,2 

HCPS pathogenesis appears to be driven primarily by endothelial dysfunction and capillary leak mediated by host immune responses rather than extensive direct cytopathic injury.^3,4 Infection of endothelial cells triggers intense immune activation, cytokine dysregulation, thrombocytopenia, and vascular permeability, leading to rapid pulmonary edema, hypotension, and cardiogenic shock.³ Clinically, patients often present with a nonspecific prodromal phase characterized by fever, myalgia, headache, and gastrointestinal symptoms before progressing to respiratory compromise and hemodynamic collapse.⁴ Laboratory findings commonly include thrombocytopenia, hemoconcentration, leukocytosis with neutrophil left shift, and elevated lactate dehydrogenase.³ Mortality for HCPS may exceed 30–40%, particularly in severe cardiopulmonary disease.^3,4 Early recognition and aggressive intensive care support, including use of extracorporeal membrane oxygenation (ECMO) in severe cases, significantly improve survival.⁴ 

Ecologically, hantavirus emergence is closely linked to environmental and climatic factors that influence rodent population density and human exposure risk.^1,2 Rainfall, food availability, habitat disruption, agricultural activity, and climate oscillations can promote rodent population expansion and increase spillover events.¹ Since the original recognition of Sin Nombre virus during the 1993 Four Corners outbreak in the US, the diversity of hantaviruses and associated reservoir hosts has expanded substantially, including identification of hantavirus-like viruses in shrews, moles, and bats.² Seroprevalence studies indicate that human exposure is more common than clinically recognized disease, with higher antibody prevalence observed in rural and occupationally exposed populations, suggesting frequent subclinical or mild infections alongside sporadic severe disease.¹ 

A defining feature of Andes virus is its documented ability to transmit person-to-person, distinguishing it from most other hantaviruses.⁵ Epidemiologic investigations in Argentina and Chile demonstrated household and nosocomial transmission associated with prolonged close contact, particularly during the prodromal and early cardiopulmonary phases of illness.⁵ Transmission appears relatively inefficient and generally requires intimate or extended exposure, but these findings have major implications for outbreak management, quarantine protocols, and healthcare infection control.⁵ 

The incubation period for HCPS is variable, typically ranging from approximately 1–5 weeks following exposure.⁴ This prolonged incubation window complicates contact tracing and outbreak containment, particularly in settings involving dispersed travelers or confined environments.⁴

There are currently no widely approved antiviral therapies or broadly available vaccines for HCPS; treatment remains largely supportive.⁶ Ribavirin has shown inconsistent outcomes, particularly in New World hantavirus disease.^3,6 Current research priorities include monoclonal antibodies, antiviral agents targeting viral entry and replication, endothelial-stabilizing therapies, and predictive ecological modeling to improve outbreak forecasting and preparedness.^2,6 

(Image Credit: iStock/BlackJack3D)

References:

1. Jonsson et al., 2010. A Global Perspective on Hantavirus Ecology, Epidemiology, and Disease. Clinical Microbiology Reviews.
2. Safronetz et al., 2023. Sin Nombre Virus and the Emergence of Other Hantaviruses: A Review of the Biology, Ecology, and Disease of a Zoonotic Pathogen. Biology (Basel).
3. MacNeil et al., 2011. Hantavirus Pulmonary Syndrome. Virus Research.
4. Vial et al., 2006. Incubation Period of Hantavirus Cardiopulmonary Syndrome. Emerging Infectious Diseases.
5. Martínez-Valdebenito et al., 2014. Person-to-Person Household and Nosocomial Transmission of Andes Hantavirus, Southern Chile, 2011. Emerging Infectious Diseases. 
6. Vial et al., 2023. Hantavirus in Humans: a Review of Clinical Aspects and Management. Lancet Infectious Diseases.