The number of cases of whooping cough continues to rise, with almost 1,100 reported to GPs since the start of the year.
The condition causes intense bouts of coughing and can last for three months. It is a cyclical disease with the number of cases peaking every three to four years.
Scotland is experiencing the worst outbreak of whooping cough since the 1980s. Case numbers have now reached 1,084 for this year compared with 46 over the same period last year, according to Health Protection Scotland.
Commenting on the figures, Conservative health spokesman Jackson Carlaw said: "We may consider infections like whooping cough to be diseases of the past, but that clearly is not the case in Scotland right now. It is a thoroughly miserable illness to endure.
"Given that there has been a real spike in infections, we have to find out why that is, understand what is behind it and what we need to do stop it becoming an epidemic. Investigating which groups of people are being affected would be a good way of doing this to ensure we can stop this rise and ensure it isn't repeated."