coli 0157 and salmonella have increased this year, according to official figures.
Health Protection Scotland (HPS) has revealed the number of people infected with E. coli 0157 almost doubled in the first half of 2014, compared to the previous year.
In total 129 cases have been confirmed, up on 66 for the same period in 2013.
However, Dr Eleanor Anderson, epidemiologist for HPS, said levels of illness from the bacteria were particularly low in 2013.
There have also been two large E. coli outbreaks this year, including one associated with burgers cooked at Glasgow's Hydro concert venue, which affected 21 people.
Another outbreak was linked to a Fife restaurant.
Dr Anderson added that it was usual for cases to peak during the summer. "It might be something to do with people cooking outdoors," she said. "Some cases will be travel related."
The number of people who have become ill with salmonella so far this year is 315, up 6 per cent last year to 297, according to the HPS report. Dr Anderson said this was not a significant jump, but HPS would be continuing to monitor the situation.