The World Health Organization (W.H.O.) announced on Thursday that the outbreak of the rodent-spread hantavirus believed to have begun in April on the cruise ship M/V Hondius had finally concluded.
The outbreak made international headlines due to the bizarre circumstances surrounding the initial spread of the virus — experts posited a bird-watching couple was exposed to the disease while visiting a landfill on the southern tip of Argentina — as well as the potentially global spread of hantavirus as contacts were traced to some of the remotest locations in the world. The Hondius itself was the subject of much reporting as it spent some time floating in the waters near Cape Verde with nowhere to dock, as governments feared inviting a potentially fatal disease outbreak onto their shores.
The Hondius ultimately docked at its final destination, the Canary Island of Tenerife, on May 10, allowing for close monitoring for symptoms of those exposed aboard the ship. Complicating monitoring and contact tracing is the especially long incubation period for the virus; potential carriers were required to be monitored in isolation for 42 days.
On Thursday, W.H.O. Director-General Tedros Adhanom Ghebreyesus announced that the last individual identified as having potentially been exposed to hantavirus had completed the 42-day incubation period, resulting in the official end of the outbreak.
“All identified contacts have completed the 42 day follow-up period by local health authorities in line with W.H.O. guidance,” the United Nations agency explained in a situation update on Thursday. “The completion of the contact follow up without detection of additional secondary cases demonstrates effective interruption of transmission and confirms outbreak containment.”
“This outbreak no longer poses a public health risk and no further related transmission is expected,” the W.H.O. emphasized.
Public health experts ultimately identified 13 people as confirmed hantavirus cases linked to the outbreak on the Hondius, of which three died. The 13 includes one “probable case” likely to be the individual public health experts have identified as potentially the “patient zero” of the outbreak. All of the confirmed cases, the W.H.O. noted, were individuals who had traveled on the cruise ship — a notable detail given fears in April and May that some individuals on board a flight with one of the confirmed hantavirus patients had been exposed.
While no other potential cases have been identified linked to the Hondius, two people are still receiving medical treatment and have not recovered from their infections, the W.H.O. shared.
In a separate statement, Tedros shared that the W.H.O.’s work is not over as the agency must now research “to advance our understanding of the cause of this outbreak and of hantavirus more generally.” The agency chief added a special note of gratitude to the countries involved in managing the outbreak, especially Spain for allowing the cruise ship to dock after days of rejections from other states.
Public health experts and journalists traced the origin of the outbreak to Tierra del Fuego, the southernmost point of Argentina, where the initial patients carrying hantavirus were identified as Leo and Mirjam Schilperoord, an elderly Dutch couple who were visiting South America to practice bird-watching. Leo Schilperoord is believed to be the patient the W.H.O. identified as a “probable,” but not confirmed, hantavirus case, as he died before doctors were able to test him for the disease. The couple reportedly visited a landfill in the Tierra del Fuego city of Ushuaia, where a prevailing theory states that they were exposed to rats carrying the rare Andes strain of hantavirus, the only one known to spread from human to human.
Notably, local government officials have insisted there is no proof that the outbreak originated in that area, given that the couple traveled throughout South America prior to their arrival in Ushuaia and that the incubation period is 42 days. Bird-watching enthusiasts have also contended that visiting landfills is popular with some bird-watchers due to the biological diversity at such sites.
Leo Schilperoord is believed to have died on the cruise ship on April 11. His wife, Mirjam, reportedly took her husband’s body and got off of the ship on the remote island of St. Helena in the southern Atlantic Ocean, where she boarded a flight to South Africa and then a second to return home to the Netherlands. Flight crew did not allow her to stay onboard, however, due to visible illness, and she was hospitalized and ultimately died on April 25. Mirjam tested positive for hantavirus before her death.
Reports indicated that on April 24, about 12 people from a dozen countries also disembarked the ship, but were not registered as contacts. No reports indicate the spread of hantavirus following their departure from the ship linked to the countries visited.
The W.H.O. became involved in the situation on May 2, after being alerted by the British government while over 140 people were still trapped on the Hondius and the ship was being denied harbor out of concerns of disease spread.
W.H.O. workers had begun to remove those with severe illness from the ship before the Spanish government allowed the ship to dock in Tenerife on May 10.