For the Andes virus, the incubation period—or timeframe between when a person is infected and the onset of symptoms—is typically two to four weeks. But symptoms can take as long as six weeks to begin after initial exposure. “Given the incubation period, it’s possible that more cases could be reported,” Ghebreyesus said.
Did the hantavirus outbreak originate on the cruise ship?
International health officials believe that the initial infection of hantavirus occurred before passengers boarded the ship in Argentina on April 1. The first two infected patients were a married Dutch couple who traveled through Argentina, Chile, and Uruaguay on a birdwatching trip that visited sites where rodents that carry the Andes hantavirus are known to be present, WHO officials said. From there, the virus has appeared to spread to close contacts on board the ship and to at least one member of the ship’s medical staff.
Should travelers be concerned about hantavirus continuing to spread?
“While this is a serious incident, WHO assesses the public health risk as low,” Ghebreyesus said.
Close contact, rather than casual contact, appears to be an important factor in human transmission of the virus, notes Dr. Daniel Kuritzkes, senior physician in the Division of Infectious Diseases at Mass General Brigham. He cites one study that found respiratory droplets—rather than aerosols—are likely to be behind rare cases of human transmission. “The significance being that droplets settle quickly and are less likely to result in infection of people who just happen to be in the same room,” Kuritzkes says.
Overall, experts expect the current situation to remain largely isolated to the passengers on the cruise ship and their close contacts. In past instances of person-to-person spread of hantavirus, quarantine promptly led to the control of the outbreak, according to Kuritzkes. “There is a very low likelihood that the current outbreak will lead to a more generalized epidemic,” he says.
Should travelers take any special precautions if they’re visiting Argentina or South America?
Travelers shouldn’t feel the need to cancel trips to South America or take any measures beyond normal safety precautions. “There’s no reason for people to be concerned about travel to Argentina, but people should be cautious about visiting places where rodents might be nesting,” says Kuritzkes. “People staying at typical hotels, eating in restaurants, and visiting typical tourist attractions most likely have no or minimal risk of acquiring hantavirus.”
Travelers should continue to follow basic health guidelines, such as avoiding areas with poor sanitation practices as well as areas with visible rodents, McWilliams advises. “For prevention, we know that having adequate sanitation practices, adequate ventilatory systems, ensuring that rodents are exterminated and eliminated is all very key and crucial to preventing any transmission,” she says.
Health authorities are postulating that the first cases were contracted in South America. But there’s no need for travelers in the region to panic. “It is important to keep in mind that there is no evidence of a generalized hantavirus outbreak in Argentina, so if the original exposure of the first people to become ill did indeed occur on land it was a very unusual event,” Kuritzkes says.
McWilliams says that cruise passengers should always follow best practices when it comes to health on board. Travelers should maintain good hand hygiene by washing hands frequently, especially before meals, and seek immediate medical attention from the ship’s onboard doctor if they begin to feel unwell.
“I think the cruise industry has come a really long way and generally puts so many safeguards into place to ensure that there is safe travel for passengers,” McWilliams says.
This is a developing news story and will be updated with more information.