90-Second Read: Andes Hantavirus Strain Could Linger in Human Semen for Nearly 6 Years, and Change Little Over Time

Learn how researchers discovered traces of Andes virus lingering in a patient's semen nearly six years after infection and why the findings are raising new questions during the current Hantavirus outbreak. According to the Centers for Disease Control and Prevention (CDC), the Andes virus is a type of Hantavirus and the only known strain capable of spreading from person to person. Read More : A Hantavirus Outbreak on a Cruise Ship Leaves 3 Dead, Why Viral Outbreaks Are So Common at Sea The researchers note that finding viral genetic material does not necessarily mean a live infectious virus was still present the entire time. Years later, the team continued detecting viral RNA in semen samples even after it had disappeared from his blood.

However, the study notes that Hantaviruses are notoriously difficult to isolate in laboratory settings, meaning the failed isolation attempts do not prove that infectious particles were absent. The paper also compared Andes virus persistence to viruses such as Ebola and Zika, which are known to linger in semen long after infection. The findings have also sparked discussion about whether some Andes virus survivors may eventually require longer-term sexual health precautions. Most of the viral material also appeared to be hiding inside cells found in semen rather than floating freely in the fluid itself.

In the 2023 study, published in the journal Viruses, researchers followed a 55-year-old Swiss man who contracted the Andes virus while traveling in South America. While viral RNA disappeared from blood samples within months, semen samples continued testing positive throughout the study period. Those recommendations include regular semen testing and precautions aimed at reducing the risk of sexual transmission until patients repeatedly test negative. The CDC says the overall public risk linked to the current outbreak remains extremely low.

Attempts to isolate live virus from the semen samples were unsuccessful. According to The Telegraph, health analytics company Airfinity suggested existing 42-day monitoring periods may not fully address the possibility of long-term viral persistence identified in the study. The company reportedly pointed to World Health Organization guidance created for Ebola survivors as a possible model.