District health department sources said that the child has Vaccine Derived Polio Virus (VDPV) type 2, a very rare variety of the disease.
The boy has been now sent to Latur for further treatment.
Dr A K Singare, residential medical office of Swami Ramanand Teerth Hospital, Ambejogai, said that the child might not have got vaccination doses on time.
A team from World Health Organisation is likely to visit the district tomorrow, sources said.