Global Outbreak Tracker

Generally, no. Most hantavirus species — including Sin Nombre virus, Puumala, Hantaan, and Seoul — are transmitted only through contact with infected rodents or their droppings, urine, and saliva. The single documented exception is the Andes virus (ANDV), found primarily in Argentina and Chile. Andes virus has been linked to limited person-to-person transmission, but only in cases of close, prolonged contact (e.g., household members or healthcare workers without protection). The MV Hondius cluster involves Andes virus, which is why contact tracing is being conducted internationally despite the rarity of human-to-human spread.

Ebola virus disease has a historical case-fatality rate of 25-90% depending on strain, with Bundibugyo ebolavirus — the strain driving the active 2026 outbreak in the Democratic Republic of the Congo and Uganda — historically around 25-40%. Per the WHO Situation Report of 18 May 2026, the outbreak had recorded 528 reported cases (2 lab-confirmed in Uganda, 526 under investigation) and 132 deaths, with 668 contacts identified. No vaccine or monoclonal antibody therapy is currently approved for the Bundibugyo strain, unlike Zaire ebolavirus which has Ervebo and two approved antibody treatments. WHO declared the outbreak a Public Health Emergency of International Concern on 18 May 2026.

The MV Hondius 2026 cluster is the first documented hantavirus outbreak linked to cruise ship travel, but the ship environment was not itself the source of transmission. Hantavirus does not spread easily from person to person — the source was an index case who had spent four months in Andes virus-endemic areas of Argentina, Chile, and Uruguay before boarding. Andes virus is the only hantavirus strain with documented (but limited) person-to-person transmission, requiring prolonged close contact. WHO and ECDC assessed the risk to the general public from the MV Hondius cluster as 'low' to 'very low'. The episode demonstrates that travelers returning from Andes-endemic South American regions within 8 weeks of symptoms should disclose that travel history to clinicians immediately.

Hantavirus incubation typically ranges from 1 to 8 weeks after exposure, with most cases presenting symptoms 2-4 weeks after contact (CDC). This long incubation is one reason WHO continues active monitoring of MV Hondius passengers and contacts: passengers who disembarked at Saint Helena on 24 April 2026 returned home to multiple countries, so new cases linked to the cluster could emerge as late as mid-June 2026. The live country list and contact tracing scope are shown on the homepage.

Hantavirus is diagnosed using a combination of laboratory tests and clinical criteria. The gold standard for Hantavirus Pulmonary Syndrome (HPS) is serology: IgM and IgG ELISA antibody tests that become positive within days of symptom onset. RT-PCR (reverse-transcription polymerase chain reaction) can detect viral RNA in blood during the early febrile phase before antibodies develop, and was used to confirm Andes virus in the MV Hondius cluster cases. Supportive CBC findings include thrombocytopenia (platelets often below 150,000/µL), immunoblasts (activated lymphocytes), hemoconcentration (rising hematocrit), and left-shifted neutrophilia. Chest X-ray and CT show bilateral interstitial infiltrates as HPS progresses to pulmonary edema. Diagnosis typically combines a compatible clinical picture, recent rodent exposure or travel to an endemic area, and confirmatory serology or PCR. Standard influenza or COVID-19 tests will NOT detect hantavirus — physicians must order specific hantavirus serology panels, available through most state and national reference laboratories in the US, EU, Argentina, and Chile.