A toddler who contracted a potentially lethal form of E. coli poisoning has been discharged from the hospital and is home with his family in Auburn.

Meanwhile, tests for the bacteria conducted on animal bedding from the Oxford County Fair petting zoo were inconclusive. Samples now will be sent to the federal Centers for Disease Control and Prevention for more comprehensive testing.

Victor Herschaft of Auburn said in a Facebook post that his son Myles, who is 17 months old, returned home Wednesday night.

The Maine Center for Disease Control and Prevention confirmed last week that two children had contracted the same strain of E. coli last month. Both had been at the Oxford County Fair and had visited the petting zoo. The children were diagnosed with hemolytic uremic syndrome, a type of acute kidney failure caused when damaged red blood cells clog the filtering system in the kidneys.

Colton James-Brian Guay of Poland, who was 20 months old, died from the infection.

Jon Guay said his son experienced severe diarrhea shortly after going to the fair and visiting the petting zoo last month. His condition quickly worsened and he eventually began experiencing brain seizures that led to his death.

The Guays said they met the Herschaft family at Maine Medical Center in Portland and realized their children had visited the same petting zoo.

Myles was at one point in critical condition but recovered.

Most types of E. coli are harmless, but some cause symptoms such as stomach pain or diarrhea, or illness that can lead to death.

The Maine CDC said Friday that tests at the Maine Health and Environmental Testing Laboratory were recently completed on samples taken from the county fair. A spokesman for the center, John Martins, said the tests did not provide any conclusive evidence and the investigation into the source of the infection continues.

Martins said samples are now being sent to the federal facility for more comprehensive tests. While the Maine lab can conduct a wide array of tests, the national facility has more advanced molecular testing capabilities and can test for more bacteria, he said.

Maine officials are asking for the testing to be prioritized but have no timetable for how long it will take.

E. coli contamination can have many sources, including undercooked food – especially ground meat – raw milk, or contact with contaminated fecal matter. To learn more about it and precautions to prevent contamination, go to the federal government’s food safety website.