08/10/2026
A scientific case study on one man who survived a severe hantavirus infection is drawing renewed public attention, after researchers reported that traces of the virus remained detectable in his semen for nearly six years.
The study, published in November 2023 in the peer-reviewed journal Viruses, was carried out by researchers in Switzerland, including scientists at the Spiez Laboratory. It followed a 55-year-old Swiss man who caught the Andes virus, a type of hantavirus, while traveling in South America. He developed hantavirus cardiopulmonary syndrome, a serious illness that can affect the heart and lungs, and later recovered.
According to the researchers, the virus's genetic material, known as RNA, disappeared from his blood within months and was no longer found in his urine or respiratory tract. However, it continued to show up in semen samples for at least 71 months after infection. Reports note the latest positive result came more than 2,000 days after he first became ill.
The scientists also found that the virus changed very little over that time, which they said suggests only limited activity. The man also kept a strong, long-lasting antibody response.
Experts point out an important limit to the findings. Detecting viral RNA is not the same as finding live, infectious virus. Attempts to grow live virus from the samples were not successful, and the study involved only one patient. According to reports, sexual transmission of Andes virus after recovery has not been documented in humans. The researchers concluded that the virus has the potential for sexual transmission, and said larger studies are needed to understand how common this is and what it means in practice.
Scientists believe the male reproductive tract may be partly shielded from the immune system, which could allow viral material to remain there longer than in other parts of the body. Similar long-term persistence in semen has previously been seen with other viruses, such as Ebola and Zika.
Andes virus stands out among hantaviruses. Most hantaviruses spread to people through contact with infected rodents, but Andes virus is the only known type that can spread from person to person. It is found mainly in Chile and Argentina and can be severe, with reported fatality rates of around 25 to 40 percent depending on the outbreak. The study has gained fresh interest this year following reports of Andes virus cases linked to a cruise ship outbreak, although health officials have said the virus is not expected to cause a pandemic.
This case is a reminder that recovery from an illness is not always the end of the story inside the body. A single careful follow-up of one patient can open new questions that help doctors protect survivors and their families. Good science moves step by step, and studies like this one show why patience, long-term care, and clear public information matter just as much as headlines.
