Third Person in Ontario in Isolation After Contact With Confirmed Hantavirus Case

One person in Ontario’s Peel Region is in isolation after being exposed to a person infected with hantavirus, Ontario’s health minister said.

The individual, a visitor to Canada and not a local resident, is currently asymptomatic, Health Minister Sylvia Jones said at a press conference on May 11.

Jones confirmed that the person was isolating and being monitored by health officials. The case marks the third person in Ontario being monitored in connection with the hantavirus outbreak on the MV Hondius cruise ship first reported to the World Health Organization on May 2, though none of the three Ontario individuals have been confirmed infected.

Jones did not say if the person isolating in Peel was on the cruise ship or where they may have been exposed.

A couple in Grey Bruce area of southwestern Ontario were on the cruise ship and were the first people in the province to be connected to the outbreak. Jones said the couple is still isolating and remains asymptomatic.

None of the three have yet been tested for hantavirus infection, and Jones said they would not be tested if they did not develop symptoms.

“Initial conversations and feedback from [Ontario Chief Medical Officer of Health] Dr. Kieran Moore suggests that testing on asymptomatic may not have the appropriate results,” she said. “It may not be the best way to monitor. That’s why we are self isolating.”

A guidance document for health-care providers published by Public Health Ontario on May 11 says that the Andes strain of hantavirus identified in the outbreak requires heightened precautions due to its potential for human-to-human spread in close contact settings.

Health-care facilities must treat suspected cases with high containment infection prevention and control measures to prevent outbreaks in hospitals, it says. Health-care workers with exposure should be monitored for symptoms and follow occupational health protocols, including clear protocols for contact tracing and risk assessment within health facilities, the document adds.

A May 8 statement from the Public Health Agency of Canada says that the overall risk to the general population in connection with the outbreak is low, and that onward spread within Canada is not expected, even if an infection were confirmed.

The WHO said on May 8 that the overall public health risk from the cruise ship outbreak remains low, including for passengers. It said that although the Andes virus can be severe—showing a high case fatality rate of 38 percent in this cluster—it does not usually spread easily in community settings. However, human-to-human transmission can occur through prolonged close contact, which is why risk is higher in confined environments like cruise ships.

It recommended that passengers and crew monitor themselves for symptoms for 42 days after exposure, while high-risk contacts should undergo active monitoring or quarantine. Those who develop symptoms are advised to isolate immediately and seek medical care, as there is no specific treatment or vaccine. Despite the outbreak, the WHO said there is no need for travel or trade restrictions and emphasized continued focus on monitoring and infection control measures.