The child, from the Southern Health region, was likely exposed in early July and experienced neurological symptoms, the province said.
Health department director Dr. Sarah Moyer said in the release that precautions should be taken.
"I think it's important for us to talk a little bit about it today because it's one of those unusual years where there's not a lot of biting pressure from the so-called nuisance mosquitoes", he said. The first batch of mosquitoes with the virus was detected three weeks later in the season compared to 2017, according to Callanan.
The West Nile Virus is spread to humans through the bite of an infected mosquito, according to health officials.
Health officials say infected mosquitoes can transmit the virus to people and other animals.
The number of confirmed infections can vary from year to year.
Kozhikode: A 24-year-year-old woman has been diagnosed with West Nile fever here.
The positive test came from one of the Haldimand-Norfolk Health Unit's mosquito traps in Simcoe.
The state is checking the case of an Allegheny County resident, sending samples to the Centers for Disease Control and Prevention. WNV infections are generally mild but can, in more serious cases, cause encephalitis, meningitis, loss of vision, paralysis, coma, tremors, convulsions and death.
The most vulnerable to the virus are people age 50 and older and those who have weakened immune systems because of diseases such as diabetes and cancer.
As always, eliminate standing water on your property to prevent the development of Culex tarsalis mosquito populations.