Two people have died in Australia from Listeria infections after eating smoked salmon.

The Australian Government Department of Health is investigating three Listeria infections in Victoria, Queensland and New South Wales. The illnesses were in people more than 70 years old that had significant underlying health conditions. The two deaths occurred in New South Wales and Victoria.

Investigations have implicated smoked salmon as the likely source but officials did not name a specific company or brand. Local media reported the salmon came from Tasmania.

In Australia around 150 people are hospitalized with listeriosis and about 15 die each year.

Outbreaks have been associated with rockmelon (cantaloupe), delicatessen meats, raw milk, soft cheeses, pre-prepared salads, unwashed raw vegetables, paté, cold diced chicken and pre-cut fruit and fruit salad.

For those with a weakened immune system or who are pregnant, the best way to avoid Listeria is to eat freshly cooked or freshly prepared food.

Most people exposed to Listeria develop only mild symptoms but illness can be severe in those most at-risk. These people include pregnant women and their unborn or newborn babies, the elderly, and people with immune systems weakened by illness or medication.

Symptoms can include fever, muscle aches, and sometimes nausea and diarrhea. They usually start between three to 70 days with an average of 21 days after eating food contaminated with the bacteria.