A rare strain of the virus has killed three people linked to a cruise ship outbreak in recent weeks

Russia has stepped up border controls to prevent the potential spread of the deadly Andes hantavirus strain, the country's public health watchdog, Rospotrebnadzor, has said.

The rare strain of the virus - typically spread through contact with infected rodent droppings, urine or saliva - has been linked to at least three deaths connected to a Dutch-flagged cruise ship since April 11. A total of 11 infection cases, including the deaths, have been confirmed among the ship's 147 passengers.

The outbreak was discussed during a Rospotrebnadzor video conference on Tuesday. Hantaviruses are a long- and well-studied group of natural infections, the agency said in a follow-up statement on Wednesday, adding that no outbreaks have been recorded in Russia this year.

The Andes strain is predominantly found in the New World, and is carried by the long-tailed pygmy rice rat, which is indigenous to Argentina and Chile, the watchdog said. Russia's climate is unfavorable for the virus, reducing the risk of introduction into the country.

Nevertheless, as a precaution, "Rospotrebnadzor - together with the Russian Border Service - has taken measures to strengthen border controls," it said. Automated information systems are being used at the border to assess and minimize risks, it added.

Hantaviruses typically do not spread from human-to-human contact, except for the rare Andes strain, according to the World Health Organization (WHO). Precautionary measures to take against infection include avoiding contact with rodent droppings, storing food safely and taking extra hygiene measures, such as keeping homes clean and handwashing.