Hantavirus Tracker

An international Andes-virus cluster tied to the MV Hondius—11 confirmed cases and three deaths—has triggered WHO/PAHO alerts, mass evacuations and highlighted cross‑border coordination, biosafety and laboratory shortfalls.

Expect intensified surveillance, contact tracing and repatriation logistics, legal scrutiny of quarantine orders (CDC detention of two U.S. passengers), and close monitoring for additional cases given the virus' long incubation while regional lab capacity and rodent‑control messaging are scaled up.

Tracking: hantavirus

Geography: United States (Four Corners region; New Mexico, Arizona, Colorado, Utah), Chile, Argentina, Bolivia, Brazil, Paraguay, Uruguay, China, South Korea, Russia, Finland, Sweden, Europe (general/Scandinavia)

1. PAHO alerts rising hantavirus cases; cruise ship cluster reported

PAHO issued an epidemiological alert as hantavirus pulmonary syndrome cases rise in the Americas: Argentina reported 134 confirmed HPS cases in 2024 and Chile 62.

PAHO said Andes virus is the primary agent in South America, noted seasonality in late spring–summer, and recommended strengthening surveillance, laboratory diagnostics, and public awareness.

An international cluster on the MV Hondius has 11 confirmed cases, including three deaths; WHO confirmed nine infections as Andes virus and a Spanish evacuee tested positive.

The ship's 147 passengers and crew from over 20 countries are under monitoring; evacuees flew home from Tenerife escorted by personnel in full protective gear and sprayed with disinfectant, a development WHO and PAHO called a global health coordination challenge for cross-border case management.

Key facts:

- PAHO issued an epidemiological alert on rising hantavirus pulmonary syndrome in the Americas.

- Argentina reported 134 confirmed HPS cases in 2024.

- Chile reported 62 confirmed HPS cases in 2024.

- Andes virus is the primary causative agent in South America.

- Andes virus is capable of rare person-to-person transmission.

Why it matters: Rising Southern Cone case counts and an international cruise-ship cluster increase demands on surveillance, diagnostics, and cross-border case management.

Watch reported case trajectories, laboratory confirmations of hantavirus strains, and follow-up monitoring of exposed passengers and crews for timely containment.

Hantavirusreports

2. CDC issues quarantine orders for two cruise passengers after hantavirus deaths

Three passengers from the cruise ship M/V Hondius died of a hantavirus infection, and the CDC has issued federal quarantine orders keeping two U.S. passengers at a Nebraska monitoring facility until the 21-day observation ends May 31.

Until this week, the agency had requested—but not mandated—medical screening and observation for 18 U.S. passengers; two are now being detained under federal order.

Passenger Angela Perryman said she felt "betrayed" after receiving a quarantine order when she planned to continue voluntary isolation on her own.

Public health lawyers note the CDC’s legal basis is unsettled because no hantavirus appears on the presidentially maintained list of quarantinable diseases, and the agency is reportedly classifying Andes hantavirus under a broader "severe acute respiratory syndrome" category to justify detention; Andes is rodent-borne and can cause severe pulmonary disease.

Key facts:

- Three passengers from M/V Hondius died from hantavirus.

- CDC issued federal quarantine orders to two Nebraska-held passengers.

- CDC previously requested screening for 18 U.S. passengers through May 31.

- Quarantine monitoring period is 21 days, ending May 31.

- Hantaviruses are not on the presidential 'quarantinable diseases' list.

Why it matters: Legal ambiguity could prompt court challenges and limit the CDC's ability to detain exposed travelers, affecting outbreak containment strategies.

If courts reject the CDC's use of a broader category, federal quarantine powers may require a presidential executive order to address Andes hantavirus.

Operationally, mixed messaging and high-profile detentions risk undermining public trust and compliance; expect scrutiny of the Nebraska facility, potential litigation, and calls for either an executive order to add Andes to the list or clarified legal guidance on using existing categories.

HealthbeatNpr

3. African lab helped identify hantavirus on cruise ship off Cape Verde

In early May, a cruise ship off Cape Verde was stranded after passengers were suspected of infection by a deadly hantavirus strain.

Reuters reports an African laboratory played a central role in identifying and “cracking” the outbreak, following a call for help to assist the shipboard investigation.

The episode highlights the operational value of regional laboratory capacity for outbreak response and pathogen identification.

Rapid local diagnostics can accelerate clinical decision-making and public-health action for travelers and ports; reporting indicates authorities relied on that lab support to clarify the onboard health emergency.

Key facts:

- Early May: call for help about sick passengers on a cruise ship

- Incident location: cruise ship off Cape Verde

- Passengers suspected infected with a deadly hantavirus strain

- An African laboratory helped 'crack' the outbreak investigation

- Source reporting: Reuters

Why it matters: Regional laboratory capacity materially affected an international public-health incident; rapid in-region diagnostics benefit clinicians, ports, and travel medicine by shortening time to identification and response.

Cruise operators and travel authorities face reputational and operational risk from such outbreaks, while public-health agencies should watch for follow-up bulletins on case counts, exposure routes, and rodent-reservoir investigations to guide surveillance, advisories, and cross-border response coordination.

Reuters

4. Study finds high Sin Nombre prevalence in Pacific Northwest rodents

A Washington State University–led study published in late April in Emerging Infectious Diseases found unexpectedly high Sin Nombre hantavirus prevalence among wild rodents sampled in summer 2023.

Researchers collected fecal and tissue samples from 189 rodents — including voles, mice and chipmunks — on farms and other sites in eastern Washington State and western Idaho; about 10% carried Sin Nombre at sampling and nearly 30% showed past infection.

Sin Nombre transmits from rodents to people via aerosolized excreta and is not spread human-to-human, unlike the Andes virus linked to an early-May cruise ship outbreak that has sickened several people and killed three.

Given Sin Nombre's historic Hantavirus pulmonary syndrome mortality of 35–50% and the Pacific Northwest's disproportionate share of U.S. cases, the higher reservoir prevalence raises exposure risk for farm and rural populations and supports stepped-up surveillance, rodent control, and targeted public communication.

Key facts:

- Study published late April in Emerging Infectious Diseases

- Fieldwork conducted summer 2023

- Researchers sampled 189 rodents

- Sampling locations: eastern Washington State and western Idaho

- Rodent species included voles, mice, and chipmunks

Why it matters: Higher-than-expected reservoir prevalence increases the chance of human exposure, particularly for farmers, rural residents, and others working near rodent habitats.

Public health authorities and clinicians should prioritize enhanced surveillance, targeted rodent-control measures, occupational guidance, laboratory biosafety, and clear risk messaging while watching for any uptick in human cases in the Pacific Northwest.

Scientificamerican

5. Hantavirus cluster linked to MV Hondius cruise: 11 cases, 3 deaths

The WHO has issued a Disease Outbreak News alert after a multinational cluster of hantavirus cases linked to cruise ship travel during visits to ports in Argentina and Chile.

Health authorities report 11 confirmed cases, including three deaths, and nine of the cases were identified as Andes virus; a Spanish passenger evacuated from the MV Hondius tested positive.

The MV Hondius is en route to Tenerife, and 147 passengers and crew from more than 20 countries are under monitoring, with evacuees escorted in full-body protective gear.

WHO convened an expert webinar to pool evidence on hantavirus natural history, clinical management, and infection prevention and control, and Member States are coordinating case management, contact follow-up and repatriation.

Hantavirus pulmonary syndrome carries a reported case fatality rate of 30–40%, prompting WHO advice for travelers to avoid rodent exposure and for cruise operators to intensify cleaning protocols in high-risk port areas.

Authorities are focused on surveillance, contact tracing, laboratory confirmation, and safe transport of suspected cases.

Key facts:

- WHO issued a Disease Outbreak News alert on a cruise-linked hantavirus cluster.

- MV Hondius: Spanish passenger evacuated and tested positive for hantavirus.

- 11 confirmed cases reported, including three deaths.

- Nine of the confirmed cases identified as Andes virus strain.

- 147 passengers and crew from more than 20 countries under monitoring.

Why it matters: A multinational cruise-linked cluster amplifies cross-border contact tracing, repatriation logistics, and multijurisdictional laboratory and clinical workload for public health agencies.

Cruise lines and port authorities face operational disruption and reputational risk while health systems must prioritize rapid diagnostics and critical care capacity because of HPS's high fatality range.

Watch for additional cases among monitored passengers, genomic or strain updates, and further WHO or national guidance on infection control and travel advisories.

World Health OrganizationHantavirusreports

6. Cruise ship hantavirus outbreak confirms 11 cases, three deaths

11 confirmed cases, including three deaths, are linked to the MV Hondius cruise ship; nine of the 11 cases have been confirmed as Andes virus, WHO said.

Evacuations were staged in Tenerife; passengers from more than 20 countries were flown home, with Spanish evacuees taken to a Madrid military hospital where one newly evacuated passenger tested positive and 13 others tested negative under quarantine.

Operational strain and biosafety gaps emerged: 12 staff at Radboud University Medical Center were quarantined after incorrect handling of patient blood and urine.

WHO described public risk as low but warned the virus' long incubation could produce more cases; authorities used strict protective gear and disinfectant and the ship will sail to Rotterdam for disinfection.

Key facts:

- 11 confirmed cases linked to MV Hondius, including three deaths

- Nine of the 11 cases confirmed as Andes virus

- New positive patient quarantined at Madrid military hospital

- 13 other Spanish evacuees at military hospital tested negative

- Passengers from more than 20 countries evacuated via Tenerife

Why it matters: Andes virus identification and a multinational evacuation elevate cross-border clinical, laboratory, and logistics demands; health ministries, port authorities, and receiving hospitals must coordinate testing, isolation, and repatriation.

Biosafety lapses at a treating hospital have already produced staff quarantines, showing that exposure management and specimen-handling protocols are immediate priorities.

What to watch: additional case confirmations among evacuees, outcomes of exposed healthcare workers, results of ship disinfection, and any national travel or public-health advisories that follow.

TpchdHantavirusreports