Mara Jana Broadhurst, MD, PhD, FCAP, member of the College of American Pathologists’ Microbiology Committee and associate professor in the University of Nebraska Medical Center’s Department of Pathology, Microbiology, and Immunology, as well as an expert in BSL-4 pathogens, shares insights on common hantavirus questions circulating in the media, along with a statement available here.
How is hantavirus diagnosed?
Hantavirus is typically diagnosed using blood tests that detect antibodies produced by the immune system in response to the virus. Hantavirus infection can also be diagnosed by detecting viral RNA in blood using PCR-based testing. In some cases, these molecular tests may be more sensitive during the earliest stages of infection and can sometimes detect infection before symptoms or antibodies are detectable, but they are usually only available in select public health or reference laboratories.
What makes hantavirus difficult to detect early?
Early symptoms of hantavirus, such as fever, fatigue, headache, and muscle aches, are nonspecific and can resemble many other viral illnesses. In addition, antibody tests may not detect infection until symptoms have developed, which can make early diagnosis more challenging.
How does hantavirus spread?
Most hantavirus infections occur after exposure to infected rodents or their droppings, particularly through inhalation of contaminated particles. Person-to-person transmission is rare and has only been documented with certain strains, such as Andes hantavirus. In rare cases involving Andes hantavirus, transmission appears to require close and prolonged contact, such as direct caregiving or other sustained close interactions. The virus has been detected in body fluids including blood, saliva, urine, and semen, although the precise mechanism of transmission between people has not been definitively established.
How contagious is hantavirus?
Hantavirus is not considered highly contagious. Even in cases involving the Andes strain, person-to-person transmission appears to require close and prolonged contact and does not spread efficiently through casual interaction.
How serious is hantavirus infection?
Hantavirus can cause a severe illness known as Hantavirus Cardiopulmonary Syndrome, which can be life-threatening. This condition has a mortality rate of approximately 40%. While infections are rare, they can be serious, which is why early recognition and supportive medical care are important.
Is there a specific treatment or vaccine for hantavirus?
There is no specific antiviral treatment or widely available vaccine for hantavirus infection. Care is primarily supportive and focused on managing symptoms, particularly in patients who develop severe respiratory complications.
What is Andes hantavirus, and why is it being closely monitored?
Andes hantavirus is the most common hantavirus causing human infection in South America. It is a strain that can cause a severe respiratory illness known as Hantavirus Cardiopulmonary Syndrome. Like Sin Nombre virus in the United States, it is associated with severe disease. It is the only hantavirus strain for which person-to-person transmission has been clearly documented, which is why public health officials monitor it closely during outbreaks.
Who is most at risk for hantavirus infection?
Individuals who are exposed to rodents or environments contaminated with rodent droppings are at highest risk. This can include people in certain occupational settings or those spending time in areas where rodents are present. The risk to the general public remains low.
Do close-quarters environments, like cruise ships, increase risk?
Close-quarters environments can make it easier for some infectious diseases to spread because people are in prolonged contact in shared spaces. However, hantavirus behaves differently from common respiratory viruses, and there is no evidence that it spreads efficiently through casual contact in these settings. Transmission, when it occurs, appears to require close and prolonged contact rather than brief or incidental exposure, and does not spread efficiently in the way respiratory viruses such as COVID-19 or influenza do.
Should travelers be concerned about hantavirus on cruise ships?
The current situation appears to be a rare event, and there is no indication that it increases the risk of hantavirus outbreaks on other ships. Travelers should be aware of general health risks in crowded environments but do not need to avoid cruise travel specifically because of hantavirus.
Could this situation become a larger outbreak?
While additional cases may occur among close contacts, the overall risk of widespread transmission is low. The largest documented outbreaks of Andes hantavirus have involved relatively small numbers of cases. Past outbreaks have involved relatively small numbers of cases, and public health measures are effective at helping limit further spread.
Is hantavirus a concern in the United States?
Hantavirus infections occur in different regions of the world, including the United States, where cases are typically associated with the Sin Nombre virus. In the U.S., infections are rare and are most often linked to environmental exposure to infected rodents rather than person-to-person transmission.
What happens when an affected ship docks? Is there a risk to the public?
Public health officials monitor exposed individuals and implement precautions to reduce transmission. Because hantavirus does not spread easily between people, the risk of broader community spread remains low.
How does hantavirus compare to COVID-19?
Hantavirus behaves very differently from COVID-19. COVID-19 spreads efficiently through respiratory droplets and aerosols, while person-to-person transmission of hantavirus is rare and requires close, prolonged contact. It is not considered a highly transmissible virus.
How can travelers reduce their risk?
General infection prevention measures remain effective, including good hand hygiene, cleaning frequently touched surfaces, and avoiding close contact with people who are visibly ill. Travelers should also avoid contact with rodents or areas that may be contaminated by rodent droppings.
What role do pathologists play in responding to hantavirus cases?
Pathologists play an important role in diagnosing hantavirus infection and helping guide appropriate patient care. Through laboratory testing and collaboration with clinical teams and public health partners, they help identify cases, support accurate diagnosis, and contribute to efforts to monitor and limit the spread of infection.