In May 2026, as the World Health Organization monitored an outbreak of hantavirus that started on board the MV Hondius cruise ship, some social media users shared an alleged fact sheet (archived) about the virus that included the sentence, "The virus is not contagious (passed from person to person) and is not transmitted by dogs or cats that catch and eat rodents."
Some social media users appeared to share the alleged fact sheet to discourage people from taking hantavirus vaccines (such a vaccine did not exist at the time of these posts). One Threads user wrote, "You are being lied to again…Hantavirus Fact sheet from the early 90's from a Government Health Department, clearly states Hantavirus is NOT contagious! Do not comply with bioweapon jabs"
The alleged fact sheet and its claim that hantavirus could not pass from person to person also circulated on Facebook (archived), Instagram (archived) and X (archived).
The screenshots of the claimed fact sheet carried the logo of the San Juan Basin Health Department, a dissolved health authority that operated in Archuleta and La Plata counties in Colorado until the end of 2023. Spokespeople from the Archuleta and La Plata county health departments could not verify the authenticity and date of the fact sheet.
At the time of this writing, researchers had only proven that one hantavirus, called the Andes virus, could spread between people, and such spread was rare. Scientists first documented human-to-human transmission of hantavirus in Argentina in 1996. It was possible that the health authority fact sheet predated these findings, as U.S. health authorities started tracking the virus in 1993.
Rodents carrying Andes virus have not been found in the U.S
Because Snopes could not independently verify the authenticity and date of the fact sheet, we leave this claim unrated.
Deer mice are the most common carriers of hantavirus in the U.S., per the CDC page. This type of mouse does not carry Andes virus.
Hantavirus in the U.S. can cause hantavirus pulmonary syndrome, which affects the lungs. Nearly 40% of the people who develop respiratory symptoms from HPS may die from the virus, according to the CDC.
Though Snopes could not locate a digital version of the alleged fact sheet, we found an archived version of San Juan Basin Health Department's website from June 2001.
That website — located at sjbhd.org, the URL the fact sheet provided — used near-identical language to the fact sheet. The website said hantavirus carried by deer mice in Colorado "is not contagious (passed from person to person)." That remained true in 2026, according to the CDC, because deer mice have not been found to carry the Andes virus.
It was unclear when the page about hantavirus first appeared on the San Juan Basin Health Department website. It was possible the alleged fact sheet predated the website, with some claims saying it was from the 1990s.
At the time of this writing, the WHO said it registered 11 suspected or confirmed hantavirus cases from the MV Hondius outbreak, including three deaths. On May 8, the WHO said in a news release that six of these cases had been confirmed as Andes virus in laboratory testing. According to the CDC, Andes virus spreads through close contact with people who have the infection.
By May 12, passengers from the MV Hondius had returned to their home countries across the world on medical evacuation flights. In the U.S., passengers were screened and quarantined at the University of Nebraska Medical Center where medical professionals would assess whether they could travel home.
MV Hondius was due to dock in Rotterdam, Netherlands, on May 17 or 18, where 25 crew and two medical staff would disembark and quarantine according to Dutch regulations.
The risk to the public remained low, according to the WHO.
For further reading, Snopes has covered a number of other claims involving the MV Hondius hantavirus outbreak.