Emerging details about Hantavirus, the illness responsible for three deaths on a British cruise ship, have raised concerns it could be transmitted via sex. According to a 2023 study in the journal Viruses, the rat-borne virus can survive in human semen for up to six years after infection. The Spiez Laboratory, a Swiss government institute tasked with fighting nuclear, biological and chemical threats, investigated a 55-year-old man who had previously had the Andes strain of hantavirus. Researchers discovered that although there was no longer any trace of the virus in the man's blood, urine and respiratory tract, it was still detectable in his semen 71 months later.
Can Hantavirus Live in Semen?
Dr. Suzanne Wylie, a GP and medical adviser for IQdoctor, explains that the testes and male reproductive tract are 'immune privileged' sites. 'The immune system does not patrol them as aggressively as it does other parts of the body,' she says. 'This is partly because sperm cells are biologically unusual and could otherwise trigger immune reactions, so certain viruses are able to persist there for prolonged periods even after they have disappeared from the blood and respiratory tract.'
Is It Infectious?
The study confirms that hantavirus can survive in semen for a long time, but that does not necessarily mean it is highly infectious. Viruses such as Ebola and Zika can behave similarly, and standard advice for those infected is to wear condoms during sex to prevent potential transmission. Dr. Wylie stresses that 'confirmed sexual transmission of hantavirus remains exceptionally rare and the evidence is still very limited. At the moment it is more of a serious scientific and public health question than evidence of a widespread new route of transmission.'
What About Recovered Patients?
If you have currently got hantavirus, you should not be having sex with anyone because the disease can spread through prolonged contact. For those who have recovered, it is not standard practice to recommend condoms, but Dr. Wylie says that could change if more research determines the traces in semen could be infectious. As part of practicing safe sex, it is wise to use condoms regardless of illness history to protect against STIs.
Could This Affect Women Similarly?
There is not enough evidence to know if the virus could live in vaginal or reproductive tissues in the same way it lives in semen. 'Biologically the testes are somewhat unique because of their immune-protected environment, so it may not behave identically in females,' Dr. Wylie says. 'That said, researchers will almost certainly now start looking more carefully at persistence in female reproductive tissues as well.'
Could You Catch Hantavirus Six Years Later?
Potentially, yes. If you have sex with someone who had the virus years ago, there is a possibility you could catch it from them, even if they have recovered. Dr. Wylie explains that 'that does not necessarily mean large numbers of recovered patients are infectious for years, but it does mean the assumption that recovery automatically equals zero transmission risk may not always be true for every hantavirus strain, particularly Andes virus.'
Should It Be Considered an STI?
Most clinicians would not currently describe hantavirus as an STI because its primary mode of transmission remains exposure to infected rodents and their droppings, and person-to-person spread overall is still uncommon outside certain Andes virus outbreaks in South America. However, if further studies confirm viable virus can persist in semen and be sexually transmitted long after recovery, then sexual transmission would clearly need to be recognised as an important secondary route.
First Signs of Hantavirus
Early symptoms can be fatigue, fever, headache, and muscle ache, particularly in the thighs, hips, back, and shoulders. Catching hantavirus can lead to two main illnesses: Hantavirus pulmonary syndrome (HPS) affecting the lungs, and Hemorrhagic fever with renal syndrome (HFRS) affecting the kidneys. In HPS, about half of patients experience headaches, dizziness, chills, and abdominal problems like nausea, vomiting, and diarrhoea. Late symptoms include coughing, shortness of breath, and chest tightness as the lungs fill with fluid. HFRS initial symptoms include intense headaches, back and abdominal pain, fever or chills, nausea, blurred vision, eye inflammation, or a rash. Later symptoms include low blood pressure, acute shock, internal bleeding, and acute kidney failure.
