Health experts say testing people for hantavirus before they develop symptoms may not provide reliable results, as Canadian health officials continue monitoring passengers exposed during the recent outbreak aboard the cruise ship MV Hondius.
Bonnie Henry said public health agencies around the world are still assessing how effective early testing may be in rare hantavirus exposure cases.
“There are limitations to testing before symptoms appear,” Henry explained, noting that some viruses cannot be accurately detected during the early incubation period.
Officials in Canada are currently monitoring 10 people believed to have been exposed to the virus. Health authorities say anyone who develops symptoms will immediately undergo testing and receive appropriate medical care.
Henry said there are currently two main types of hantavirus tests available:
- A blood test that checks for antibodies developed by the body in response to infection
- A PCR test designed to detect fragments of the virus itself
However, experts caution that both methods may fail to detect infection during the early stages after exposure.
Bryce Warner, who works at the University of Saskatchewan Vaccine and Infectious Disease Organization, said the situation is highly unusual because hantavirus is extremely rare and often only identified after symptoms begin.
“Because the incubation period can be several weeks, an early negative test does not necessarily mean someone is free of infection,” Warner said.
He explained that someone exposed to the virus could initially test negative through PCR testing, only for the virus to become detectable days or weeks later.
The outbreak aboard the MV Hondius has drawn international attention after additional cases were confirmed in multiple countries following the evacuation of passengers in Spain’s Canary Islands.
According to the World Health Organization, the total number of confirmed infections linked to the outbreak has risen to seven, with three deaths reported internationally.
The virus involved in the outbreak is the Andes virus, a rare strain of hantavirus found mainly in South America and the only known type capable of spreading from person to person.
Despite growing concern, infectious disease specialists continue to stress that the virus does not pose a pandemic-level threat.
Health officials say person-to-person transmission of Andes virus generally requires prolonged and close contact with an infected person, making widespread community spread unlikely.
Canadian public health authorities continue to monitor exposed individuals closely while emphasizing that the overall risk to the public remains very low.