Hantavirus Global Situational Briefing — May 16, 2026

Institut Pasteur has completed full-genome sequencing of the Andes virus strain from the French ECMO patient at Hôpital Bichat and found no evidence of a more transmissible or dangerous variant — ruling out the mutation hypothesis raised on May 12. Dr. Stephen Kornfeld's serology returned negative, confirming the shipboard PCR signal was a false positive and closing the sole US inconclusive case; WHO has revised the global total downward to 10 cases. Spain's confirmed patient is progressing favourably, and all 26 of his contacts tested PCR-negative. MV Hondius is due at Rotterdam on Monday, May 18, with a RIVM-approved quarantine protocol in place for all 27 people aboard.

This briefing covers the delta window May 15 08:44 UTC+8 → May 16 00:00 UTC+8.

Global case count revised to 10 — Kornfeld serology closes the US inconclusive

At his May 15 media briefing, WHO Director-General Tedros Adhanom Ghebreyesus announced a downward revision to the global case tally. 1 "As of today, a total of 10 cases, including three deaths, have been reported to WHO, including eight people who were laboratory-confirmed for Andes virus infection and two probable." 1 The previous count was 11 (8 confirmed + 2 probable + 1 inconclusive). The reduction reflects the reclassification of the sole US inconclusive case — Dr. Stephen Kornfeld, the MV Hondius ship physician — as negative after both PCR and serology cleared at the University of Nebraska Medical Center (UNMC). 2 Per officials cited by NBC News, "the physician does not have antibodies to hantavirus, indicating he was never exposed to or ill with it." 2 CDC incident manager Dr. David Fitter assessed the original shipboard positive as a false positive. Kornfeld has moved from UNMC's biocontainment unit into standard quarantine alongside 15 other repatriated US passengers.

No new deaths have been recorded since May 2. The WHO Director-General noted that further cases may still be reported as testing continues, but framed that prospect explicitly: "This does not mean the outbreak is expanding; it shows that the control measures are working, that laboratory testing is ongoing, and that people are being cared for with support from their governments." 1 CDC confirmed no known US hantavirus cases; 41 people across 16 states remain under monitoring through a 42-day window running to June 22. 3 On May 15, the UK Health Security Agency convened an open scientific consultation on ANDV medical countermeasures (13:00–16:00 CET), co-organized with the WHO R&D Blueprint. 1

France — Institut Pasteur: no dangerous variant; patient remains on ECMO

Institut Pasteur completed full-genome sequencing of the Andes virus isolated from the 65-year-old French female patient at Hôpital Bichat. The result carries considerable significance: it directly addresses concerns raised on May 12 by Dr. Xavier Lescure (Bichat) about a possible mutation driving the observed clinical severity. French Health Minister Stéphanie Rist stated: "No evidence suggests the emergence of a variant likely to be more transmissible or more dangerous." 4 The Institut Pasteur added that "no element suggests at this stage the emergence of a particular variant with new characteristics," and that the sequence is "very close" to those of other infected passengers and to known Andes strains circulating in southern Latin America. 4

The French patient remains alive in the ICU at Bichat on ECMO (extracorporeal membrane oxygenation), her condition described as unchanged as of the close of the reporting window. 4 Approximately 20 French contacts remain in hospital isolation; none are symptomatic. The Argentine scientific mission to Ushuaia — aimed at understanding the outbreak's origin — is expected to arrive "very soon," according to WHO. 1

Spain — patient progressing favourably; quarantine relaxed from Monday

Spain's confirmed ANDV patient, a 70-year-old male in the UATAN high-isolation unit at the Hospital Central de la Defensa Gómez Ulla in Madrid, is in "stable condition and progressing favourably," per Health Minister Mónica García. 5 He developed fever and respiratory symptoms on May 14 and is showing clinical improvement. All 13 other Spanish passengers quarantined at Gómez Ulla tested PCR-negative. Pending negative Sunday PCR results, quarantine conditions ease from Monday May 18: contacts may leave their rooms, use common areas, and receive visitors; if all PCRs remain negative, the medical team will assess home quarantine for the remainder of the 42-day window (to June 21). 5 García: "With all due caution, this is good news." 5

Italy's Ministry of Health has confirmed all four Italian contacts (an Argentine tourist with pneumonia, a 25-year-old from Calabria identified on flight KL592, a British tourist in Milan, and her companion) tested negative at the Spallanzani Infectious Disease Hospital in Rome. 6 The Ministry stated that "the risk connected with the virus remains very low in Europe and therefore also in Italy." 6

MV Hondius — Rotterdam arrival Monday; RIVM sets quarantine protocol for crew

The Dutch government communicated to parliament on May 15 — through a joint letter signed by Health Minister Sophie Hermans and Foreign Minister Tom Berendsen — that MV Hondius is expected to arrive at the Port of Rotterdam on Monday, May 18. 7 Rotterdam serves as the Netherlands' designated port for handling infectious diseases in shipping.

Twenty-seven people are aboard: 25 crew members and 2 medical personnel, all currently asymptomatic. 1 The crew includes 17 Filipinos, 4 Dutch nationals, 4 Ukrainians, 1 Russian, and 1 Polish national. 7

RIVM (the Netherlands Institute for Public Health and the Environment) has recommended that the 17 Filipino crew members remain in the Netherlands for the full six-week quarantine. The rationale, as set out in the government's parliamentary letter: "limited possibilities for implementing and enforcing quarantine in the country of origin, as well as limited access to optimal medical care." 7 Crew members able to quarantine at home will do so; others will be placed in designated Dutch quarantine facilities. Ship decontamination is assigned to a specialized external company following RIVM and WHO guidelines; cleaning staff will use PPE and are not required to quarantine. 7

ECDC publishes IPC guidance for ANDV patients in healthcare settings

The European Centre for Disease Prevention and Control (ECDC) published a new Rapid Scientific Advice on Infection, Prevention and Control Measures for Patients in Healthcare Settings with Andes Virus (ANDV) Disease on May 15. 8 The guidance updates two prior documents — the May 6 Threat Assessment Brief and the May 9 Rapid Scientific Advice on passenger management — and targets healthcare facilities specifically: how to apply IPC measures when caring for suspected or confirmed ANDV patients. The document is available as a 364 KB PDF from the ECDC website.

Traws Pharma — Q1 2026 results confirm hantavirus antiviral pipeline

Traws Pharma (NASDAQ: TRAW) released first-quarter 2026 results on May 15 — three days ahead of the scheduled May 18 date. 9 Net loss was $7.1 million ($0.53 per share); R&D expense reached $4.9 million (up from $2.5 million in Q1 2025), reflecting antiviral clinical trial milestones. Cash and equivalents stood at $3.1 million as of March 31, 2026.

A $60 million PIPE (private investment in public equity) completed on April 15, 2026 — $10 million upfront plus up to ~$50 million through milestone-based payments and three-year warrants — extends the cash runway into Q1 2027. 9

CEO Iain Dukes: "Our pipeline now also includes a potential antiviral therapy for hantavirus. The recent outbreak brought new attention to a disease with no approved treatments." 9 No compound name or clinical timeline has been disclosed for the hantavirus program. The company's lead asset, tivoxavir marboxil (TXM) — an influenza antiviral — is scheduled for a human challenge trial at hVIVO in the UK in Q2 2026; a US FDA clinical hold on the TXM Investigational New Drug application remains unresolved. 9

Americas endemic surveillance — no new bulletins; Brazil records first 2026 death

Argentina — The Boletín Epidemiológico Nacional for SE17 (published May 12) holds the 2025–26 season total at 102 confirmed cases and 32 deaths (CFR 31.4%), with only 1 new case notified in the last two weeks, from Buenos Aires province. 10 BEN SE18 is expected around May 19. ANLIS Malbrán has confirmed genetic similarity between the Hondius cluster strain and strains isolated in Neuquén province in 2018, but the outbreak's geographic origin — where the index case was infected — remains unresolved. 10

Chile — National figures remain at 39 confirmed cases and 13 deaths (CFR 33%) through early May. 11 Chile's Ministry of Health confirmed in a May 11 declaration that the Andes virus is the sole confirmed etiological agent of human hantavirus in Chile; the last documented person-to-person Andes virus transmission in Chile occurred in 2019. 11

Brazil — Brazil's Ministry of Health official case table (updated May 12) records 7 confirmed hantavirus cases in 2026 (preliminary), distributed across Minas Gerais, São Paulo, Paraná, Santa Catarina, Rio Grande do Sul, and one case with location under review. 12 A 46-year-old man from Carmo do Paranaíba, Minas Gerais, who died in February 2026, was confirmed as Brazil's first hantavirus death of 2026 on May 11 — a diagnostic delay of approximately three months. 13 Brasília's Distrito Federal health secretariat continues to investigate three suspect cases (symptom onset April 2026); none are yet confirmed. 14

Illinois (US) — The Illinois Department of Public Health continues to investigate a potential hantavirus case in Winnebago County unconnected to the MV Hondius cluster. 15 The suspected strain is a North American variant (Sin Nombre or related) acquired through contact with rodent droppings in a residence — not the Andes strain, and not transmissible person-to-person. The individual had mild symptoms and is recovering without hospitalization. CDC confirmatory testing is pending, with results expected around May 22. 15

ENSO outlook — NOAA's Climate Prediction Center placed the probability of El Niño emergence at 82% for May–July 2026 and 96% through December 2026–February 2027 in its May 14 diagnostic discussion. 16 El Niño has historically been associated with elevated rodent populations in the Southern Cone — a recognized precursor to higher HPS incidence. Next NOAA ENSO update: June 11. 16

Watchlist for May 17–18

MV Hondius Rotterdam arrival (Monday May 18): RIVM disinfection and crew PCR outcomes to follow docking. Quarantine arrangements for the 17 Filipino crew members are being finalized.
French ECMO patient at Bichat: The Institut Pasteur sequencing result removes variant concern; ECMO trajectory remains the key clinical variable to watch.
Spain quarantine easing: Sunday PCR results will determine whether the May 18 relaxation proceeds as announced.
Argentina BEN SE18: Expected around May 19.
Illinois CDC confirmatory result: Expected around May 22; if confirmed, the eighth Illinois hantavirus case since 1993.
ECDC IPC guidance PDF: Detailed clinical recommendations for healthcare workers managing ANDV patients — full-text review recommended for hospital infection control teams.

Briefing covers May 15 08:44 UTC+8 → May 16 00:00 UTC+8. Previous edition: Hantavirus Global Situational Briefing — May 15, 2026. Next scheduled publication: May 17, 2026.

Cover image: AI-generated.