Sales continue to be down by one-third to one-half at Springfield-area Subway restaurants more than a month after dozens of Subways in central and northern Illinois threw out all vegetables suspected of causing a salmonella outbreak.

The illness hospitalized at least 26 people and sickened 103.

A total of 103 people — 101 Illinois residents and two people from outside the state — reported becoming ill and testing positive for the salmonella strain.

Subway officials have cooperated with the investigation. They voluntarily discarded all produce — lettuce, tomatoes, green peppers and red onions — suspected to be connected with illnesses.

The affected people ate at 49 Subway locations in 28 Illinois counties and one Subway in Minnesota.