【AI前沿】US hantavirus case was false positive; outbreak cases drop from 11 to 10

Now we waitUS hantavirus case was false positive; outbreak cases drop from 11 to 10WHO announced today that the operation to safely transfer passengers is complete.Beth Mole–May 15, 2026 5:31 pm|2Evacuation by boat of passengers on board the cruise ship MVHondiusanchored near the port of Granadilla, on May 11, 2026 in Granadilla de Abona, Tenerife, Canary Islands, Spain.Credit:Getty | Europa Press CanariasEvacuation by boat of passengers on board the cruise ship MVHondiusanchored near the port of Granadilla, on May 11, 2026 in Granadilla de Abona, Tenerife, Canary Islands, Spain.Credit:Getty | Europa Press CanariasText settingsStory textSizeSmallStandardLargeWidthStandardWideLinksStandardOrange Subscribers onlyLearn moreMinimize to navIn a press briefing Friday, officials for the World Health Organization announced that the case count of thehantavirus outbreak on the cruise shipMV Hondiusin the South Atlantic has shrunk from 11 cases to 10 after a previously reported US case was found to be a false positive.That US case was originally reported byUS health officials as “mildly positive,”and the WHO had considered it “inconclusive,” but still counted in the outbreak as a case in the agency’sMay 13 outbreak reportand in a briefing on May 14.The inconclusive case was in Dr. Stephen Kornfeld, an American doctor aboard the ship who helped respond to the outbreak after the ship’s doctor became ill.In an interview with CNN earlier this week, Kornfeld explained that he and others on board had taken nasal swabs early in May, before evacuation, and those swabs were sent for PCR testing in the Netherlands. Two labs in the Netherlands processed Kornfeld’s swabs; one lab reported a negative result, and the other reported a faint positive.Generally, a faint positive result on a PCR test could suggest low levels of virus at the start or end of an infection, or it could simply suggest contamination.Adding to the complexity of the potential case, Kornfeld said that he had developed a minor illness in early April while on the ship, just a few days after the first hantavirus case fell ill in the outbreak—a Dutch man who died on board from his infection.In an interview with ABC News Friday, Kornfeld reported that his repeat testing was negative and so was his serology testing looking for antibodies against hantavirus—which he would have developed if his illness in April was actually an unusually mild hantavirus infection. Overall, the testing shows that he is not currently infected and has not had a previous infection. As such, he has been transferred from the biocontainment unit to the quarantine unit at the Nebraska Medical Center, where US passengers from theHondiusare being monitored.“I physically feel great—I have felt great for many, many days,” Kornfeld told ABC. “Emotionally, I feel wonderful. It’s nice to be negative for hantavirus.”Evacuation completeOverall, there have been 10 cases: Seven cases who became ill on the ship, one case that disembarked the ship on April 24, before the outbreak was identified, and fell ill in Switzerland. The remaining two cases—one from France, the other from Spain—were identified as the ship was evacuated and passengers were being repatriated. The number of deaths has not changed since May 2, with three total: a Dutch couple and a German woman.Also in the WHO press conference, Director-General Tedros Adhanom Ghebreyesus said that the operation in the Canary Islands to safely evacuate the ship is complete. The operation involved transferring the ship’s 120-plus passengers to their home countries or to quarantine in host countries en route to their final destinations.“Because of the long incubation period of up to six weeks, more cases may be reported in coming days as passengers return to their countries, where they are being quarantined and tested in specialized facilities or at home,” Tedros warned. “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.”The US is monitoring 41 people who may have been exposed. That includes 18 passengers (including Kornfeld) who were evacuated from theHondius, passengers who had disembarked the ship on April 24, and people who shared a flight with a Dutch woman (the wife of the first case) who also fell ill from the infection and died in South Africa, on her way home.Beth MoleSenior Health ReporterBeth MoleSenior Health ReporterBeth is Ars Technica’s Senior Health Reporter. Beth has a Ph.D. in microbiology from the University of North Carolina at Chapel Hill and attended the Science Communication program at the University of California, Santa Cruz. She specializes in covering infectious diseases, public health, and microbes.2 Comments