The recent outbreak of hantavirus infection on the Dutch cruise ship MV Hondius raises several questions and concerns. Dutch ornithologist Leo Schilperoord was the first person to die of hantavirus infection on the ship on April 11, 2026. He and his wife, Mirjam, 69, had recently visited northern Patagonia in Argentina, 1,500 miles north and before boarding the ship at a southern Argentine port. So far there have been eight cases in total with three fatalities.

A reconstructed timeline of the events from various sources:

• April 1: The ship departs the port Ushuaia in Argentina, which is the southernmost tip of South America, nicknamed the “End of the World.” Scheduled stops included Antarctica and several far-flung islands in the South Atlantic Ocean.
• April 6: Leo Schilperoord, seventy years old, became sick with fever, headache, and mild diarrhea.
• April 11: The patient developed respiratory distress on board and died.
• April 15: An additional six people join the cruise as the ship stops at Tristan da Cunha, a remote group of volcanic islands and a British territory in the South Atlantic. The Dutchman’s body remains on the ship.
• April 24: The ship docks at Saint Helena, part of the same British territory. The wife of the deceased passenger disembarks along with twenty-nine other passengers from 12 countries. This stop was the end of cruise for some of the passengers.
• April 25: The Dutch woman flew on a commercial flight from Saint Helena to Johannesburg, South Africa. The plane carried eighty-eight passengers and crew members. It is not clear how many of the cruise passengers were on that flight.
• April 26: The Dutch woman dies in South Africa after collapsing at the airport while trying to board another flight home to the Netherlands.
• April 27: A third passenger, a British man, became sick on the ship and was evacuated to Ascension Island. He was later moved to South Africa and admitted to an ICU where he had fever, shortness of breath, and signs of pneumonia.
• April 28: A fourth passenger, a German woman, became ill on board the ship docked at Saint Helena.
• May 2: The German woman dies on board the ship, nearly a month after the first passenger’s death. The same day, tests done on the British passenger in South Africa came back positive for hantavirus. This was the first time the virus was identified as the cause of the outbreak.
• May 3: The ship arrives at Cape Verde, a small archipelagic country in the central Atlantic Ocean off the coast of West Africa. WHO says it is responding to the report of a suspected hantavirus infection on board a cruise ship.
• May 4: A hantavirus test done postmortem on the Dutch woman who died in South Africa came back positive.
• May 5: The cruise ship authorities are in a stand-off with the Cape Verde authorities, who declined to disembark the passengers and the crew. Two crew members, including the ship’s doctor, are sick on board.
• May 6: Three people, including two who tested positive for hantavirus, were evacuated from the ship to Europe. The ship sails for the Canary Islands, a Spanish archipelago off the coast of northwestern Africa, which says it will accept the passengers. Another person evacuated to Switzerland tests positive for the Andes virus strain of hantavirus.
• May 7: Contact tracing in various countries such as Switzerland, Britain, the Netherlands, France, Singapore, and South Africa begins.
• May 10: The ship docks at Tenerife, the largest island of Spain’s Canary Islands. There are 114 passengers and 61 crew members from 22 countries. People from different countries start flying home with infection prevention precautions.
• May 11: A French woman and an American test positive for hantavirus after repatriation. Eighteen individuals were repatriated to the continental U.S. They were taken to the University of Nebraska Medical Center, which has a federally funded quarantine facility. Individuals who tested positive were monitored in the adjacent biocontainment unit.

The major issue is the delay in initiating diagnostic and preventive measures and implementing quarantine even after our experience with COVID-19. The first passenger became symptomatic on April 6, but it took a month (on May 11) for the first person to be quarantined in the U.S. Why didn’t the U.S. CDC get involved earlier while there were about two dozen Americans on board?

On May 7, 2026, the CDC sent a team to meet the cruise ship in the Canary Islands, almost a month after the first death due to hantavirus. CDC reported that it is working with partners (federal government, state and local and international) on safely repatriating American passengers from the cruise ship to a facility in Nebraska with specialized medical capabilities. The team was prepared to assess exposure risk among U.S. passengers and determine appropriate monitoring measures. It seems like too little too late. The CDC should have sent investigative teams to South America and coordinated with other health agencies to implement a detailed contact tracing and strict isolation.

Between the epidemiological weeks 1 and 10 of 2026 (4 January to 14 March 2026), the Ministry of Public Health in Argentina reported 12 confirmed hantavirus cases and two deaths in Salta Province, northwestern Argentina. In addition, there were 50 suspected cases. Apparently, there were multiple cases and deaths due to hantavirus in the same area in 2025 also. The Andes virus variant of the hantavirus from this area had already exhibited the troublesome feature of person-to-person spread of the disease. Why was this outbreak not followed up and investigated?

The incubation period of hantavirus is noted to be 1 to 8 weeks. The Nebraska facility is apparently only planning for a total quarantine period of 42 days. It should have been 56 days, if not more. The Dutch couple had been in Argentina for several months, since November last year. Sometime around a month prior to embarking the cruise ship, they took a trip to northern Argentina where hantavirus is endemic. This points to a prolonged incubation period.

Hantavirus is a deadly disease with up to 50 percent mortality and requires specialized PPE including shoe covers to be used by health care personnel. However, pictures circulating in the media show health workers wearing long gowns with exposed shoes spraying the passengers at the Tenerife airport. Are all the mandatory precautions being followed?

Why is the CDC medical journal Emerging Infectious Diseases not publishing the details of the cases and related information so that physicians and other clinicians in the U.S. will become more aware of this emerging disease?

WHO Director-General Tedros Ghebreyesus and the acting CDC Director Jay Bhattacharya were optimistic, saying, “This is not another COVID-19.” Hopefully not, but we do not want to see a repeat of the public health failures of COVID-19. While the CDC and WHO are trying, they can always step it up.

P. Dileep Kumar is a board-certified practicing hospitalist specializing in internal medicine. Dr. Kumar is actively engaged with professional associations such as the American College of Physicians, Michigan State Medical Society, and the American Medical Association. He has held a variety of leadership roles and has authored more than 100 publications in various medical journals and a book on rabies (Biography of Disease Series). Additionally, he has presented more than 50 papers at various national and international medical conferences. Several of his papers are widely cited in the literature and referenced in various textbooks.

Dr. Kumar has been involved in various hospital committees with advanced knowledge of Centers for Medicare & Medicaid Services (CMS) initiatives such as meaningful use, value-based purchasing, and Accountable Care Organizations.

Furthermore, Dr. Kumar has served as a scientific peer reviewer for various medical journals, including the British Medical Journal, Annals of Internal Medicine, American Journal of Cardiology, Physician Leadership Journal, and European Journal of Clinical Microbiology & Infectious Diseases.