Hantavirus at Sea: How Dangerous Is This Outbreak?
May 5, 2026
CONFIRMED CASES
3
aboard MV Hondius, Cape Verde waters
FATALITY RATE (HPS)
~38%
CDC historical average, U.S. cases
CONFINED TO CABIN
~150
passengers under shipboard quarantine
U.S. CASES SINCE 1993
864
confirmed hantavirus cases, CDC registry
HUMAN-TO-HUMAN SPREAD
Rare*
Andes virus only; most strains non-transmissible
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EPIDEMIOLOGICAL ANOMALY
Multiple hantavirus cases on a single vessel are statistically rare without person-to-person transmission. Investigators are focused on identifying a shared rodent exposure source aboard MV Hondius.
Case Fatality Rates by Hantavirus Strain
Sin Nombre virus (the strain circulating in North America) carries one of the highest fatality rates of any hantavirus. Even conservative estimates put HPS mortality at 1-in-3.
CFR = Case Fatality Rate. HPS = Hantavirus Pulmonary Syndrome. HFRS = Hemorrhagic Fever with Renal Syndrome. Sources: CDC, PAHO, WHO.
SOURCES:CDC Hantavirus StatisticsWHO IHR 2005ProMED Outbreak ReportsPan American Health Organization
Data sources
CDC Hantavirus Disease Cases and Fatality by State· Centers for Disease Control and PreventionHantavirus Pulmonary Syndrome — Case Definition and Statistics· Centers for Disease Control and PreventionInternational Health Regulations (2005), Third Edition· World Health OrganizationWHO Hantavirus Fact Sheet· World Health OrganizationYosemite Hantavirus Outbreak Investigation 2012· CDC / MMWRProMED Infectious Disease Outbreak Monitor· International Society for Infectious DiseasesPan American Health Organization — Hantavirus Regional Data· PAHO / WHO