Nine people are thought to have died in Chubut province since December as a result of Hantavirus (also known as Orthohantavirus) infection, while another eight people remain in hospital with infections suspected to be related to the virus.
The provincial Health Ministry reported three more deaths on Wednesday, two of which were confirmed as involving the deadly rat virus.
Humans can contract the virus, which infects rodents but does not cause disease in them, as a result of contact with rodent urine, saliva or feces.
All three of patients were hospitalised at the Esquel Hospital. The two confirmed cases of Hantavirus were found in a 30-year-old woman and a 16-year-old boy. The third case involved a woman who, unlike the other two, had not been intensive care prior to her death. However, the case was being treated under "suspicion" of infection, the Health Ministry reported.
The Chubut government declared a health warning for the province on December 3, following a large public event held in the Epuyén district from which contagion is believed to have originated.
At the height of its tourist season, authorities in the southern province are warning people to avoid large public events.
In total, 24 people have been treated in the province for Hantavirus in recent months and another eight suspected cases have been dismissed.
Four people remain in intensive care in Esquel Hospital and another four are in the regular wards awaiting the outcome of tests.
A Chilean woman is also being treated for Hantavirus in the Chilean city of Puerto Montt's Hospital de Alta Complejidad. Chubut authorities are reportedly working in collaboration with Chilean counterparts to contain the outbreak.