More Canadians have been sickened in a listeriosis outbreak linked to plant-based beverages, according to health officials.

Nearly 20 Silk and Great Value-brand refrigerated milk products were pulled from shelves due to concerns about potential listeria contamination on July 8.

The Public Health Agency of Canada said Tuesday that 18 people in four provinces have now become ill, up from 12 two weeks ago.

There have been 12 illnesses in Ontario, four in Quebec, and one each in Nova Scotia and Alberta.

Those sickened have been between the ages of seven and 89 years old, with two-thirds of them aged 50 or older.

One more person has been hospitalized, bringing the total number to 13. The number of reported deaths remains at two.

The Canadian Food Inspection Agency says food contaminated with listeria may not look or smell spoiled but can still make you sick.

Symptoms can include vomiting, nausea, persistent fever, muscle aches, severe headache, and neck stiffness. In severe cases of illness, people may die.

Pregnant women, the elderly and people with weakened immune systems are particularly at risk. The infection can lead to premature delivery, infection of the newborn, or even stillbirth.