The PAP Community Foundation (PCF) is looking for new cooks to join its pre-schools as it puts a stop to catering services in the wake of a recent outbreak of food poisoning across several centres.

Chief executive Victor Bay said PCF is also open to reviewing its pay and benefit packages for cooks.

More administrative staff who have completed Basic Food Hygiene courses conducted by training providers accredited by the National Environment Agency (NEA) will also be redeployed to help out in the kitchen.

Since Monday, 15 of the 16 Sparkletots pre-schools using Kate's Catering, which is linked to the latest spate of gastroenteritis, have switched back to using in-house cooks.

In an update yesterday, the PCF said it is also exploring plans for the last centre at Punggol North - which has more than 400 children - to build bigger kitchen facilities for in-house cooking.

Another three centres - which were using a different caterer - have also gone back to in-house cooks.

As of Thursday, 239 children and 12 staff from 13 PCF Sparkletots pre-schools reported symptoms linked to food poisoning, with 31 of them hospitalised. Forty of the 239 cases had been diagnosed as food poisoning.

All children have been discharged from hospital, and 90 per cent of the children in reported cases have returned to school. There have been no new cases since Tuesday.

The outbreak across the pre-schools, which were mainly in Sengkang and Punggol, was traced to the consumption of food prepared by Kate's Catering, which PCF has since stopped using.

Ms Marini Khamis, senior director of PCF's Pre-school Management Division, said that so far, it has helped seven families with medical expenses incurred in relation to the incident.

In the last three decades of operations, PCF has not experienced an outbreak of food poisoning on such a scale, said Ms Marini, adding that any incident would have been contained within individual centres.

Before the latest outbreak, 35 of PCF's 356 centres used catering services, after it conducted a pilot to hire external caterers in January last year. Currently, 17 centres are still using catering services.

Ms Marini said PCF plans to switch to in-house cooks for these centres as well.

The Straits Times understands that the cost of catering is slightly higher than hiring in-house cooks, and the impetus for trying out caterers was not a financial one.

Ms Marini said it has been increasingly difficult to find competent cooks in recent years, and the 35 centres which had opted for caterers had experienced high turnover rates of their cooks. This could be because the centres are largely in new towns such as Sengkang and Punggol, which have a younger population who may not be inclined to being cooks."When in-house cooks resign, our pre-schools must find replacements quickly to ensure continued supply of food for our children," Ms Marini said.

It can also be a challenge for cooks to keep up with the demands of the job today, which include taking into account children's food allergies and having an understanding of nutrition. The cooks and kitchen helpers also need to be physically fit to cook three meals a day for up to 300 children per centre.

Despite these difficulties, PCF - the biggest pre-school operator with 40,000 children across its centres - will be transitioning back to relying on in-house cooks.

The outbreak is still under investigation by the Health Ministry, the Early Childhood Development Agency and the Singapore Food Agency.

Correction note: This article has been edited for clarity.