The number of E. coli cases believed to be linked to the PNE has climbed from 13 last week to 18, and the mother of one sick child is questioning health officials' response.

Coquitlam, B.C., mother Caroline Neitzel says her 14-month-old daughter, Jacklyn, was infected with E. coli after a visit to the annual Vancouver fair on Sept. 5.

Neitzel said her daughter touched a number of different animals at the petting farm. She said she did her best to wipe her daughter's hands with wet wipes during that visit.

Despite her efforts, Jacklyn became very ill. At first doctors thought the toddler had the flu. Jacklyn was sent home twice before being admitted to Royal Columbian Hospital, according to her family.

"By that time, her eyes were rolling into the back of her head. She was just so lethargic," Neitzel told CTV News on Friday.

The toddler spent four days in hospital. Neitzel said she thinks her daughter would have been diagnosed earlier if health officials had issued a public warning when a cluster of E. coli cases was discovered.

Anna Marie D'Angelo, a spokeswoman for Vancouver Coastal Health, said the public was not alerted because there was no risk at the time.

"We became aware of the situation three days after the PNE had closed. So there was no risk to any future people getting this E. coli," she said.

Health officials say an alert would not have changed how a patient was treated at the hospital.

The PNE says E. coli has never been a problem in the past at the petting farm and that the fair has stringent hygiene measures in place, including signs and staff directing visitors to hand-washing stations.

Meanwhile, Jacklyn is doing better each day.

Her mother says the experience has made her more watchful than ever, and is less inclined to let her daughter pet farm animals until she's a little older.

With a report from CTV British Columbia's Michele Brunoro.