IT WAS a birthday celebration one family will never forget - for all the wrong reasons.

Twenty-three of the 30 family members at the gathering suffered severe food poisoning after eating the birthday cake, a 1.5kg salmonella-laced chocolate cake with nuts from bakery chain Prima Deli.

Among those felled was an 11-month-old baby, who was so ill he had to be admitted to the National University Hospital for three days.

The rest had to put up with fever, diarrhoea, shivering and even breathing difficulties, in between repeated visits to their family doctors.

Miss Anizah Yusof, 19, one of the family members who had been stricken, reckons her four-day illness to be the worst episode of diarrhoea she has ever had.

She said: 'I was also very giddy and couldn't walk properly, so I just lay down on the bed. It was also very difficult to breathe.'

She and her relatives were among a total of 109 people here who came down with food poisoning from contaminated chocolate cakes baked by Prima Deli, over the past two weeks.

Of these, eight people - including Miss Anizah's nephew and two other children - were hospitalised, for three to four days each.

All of them have since been discharged, and most of the others have also recovered.

Miss Anizah's family gathering, a full-day picnic at Pasir Park, had been held two Sundays ago to celebrate the birthdays of her mother and her niece.

Her mother, Madam Zahriah Abdul Gani, turned 45 about three weeks ago, while her niece's second birthday was two days after the celebration.

First to succumb, on that very night, was Miss Anizah's cousin, whose 11-month-old son also fell ill later.

Madam Zahriah also had diarrhoea that night.

The next morning, the family realised that something was wrong when Miss Anizah, her two sisters aged 14 and 21, and their father, and her other cousins, also came down with diarrhoea, and then fever.

Miss Anizah said: 'All of us were thinking: What did we eat yesterday?'

Her father provided the key to solving the mystery. The 45-year-old bus driver had missed the party as he was working, and the only food he ate that had been brought home from the event was the cake.

The cakes appear to have been contaminated, probably through poor hygiene, by a type of bacteria known as salmonella enteritidis.

Read the full story in Wednesday's edition of The Straits Times.