A Hamilton woman in her 20s has been diagnosed with West Nile virus in the first case to be reported this year.

Hamilton public health officials say that the local risk of infection has now moved from moderate to high.

The woman has a moderately severe case of West Nile with a fever but is recovering, Dr. Hamidah Meghani told CBC Hamilton Thursday.

Hamilton's Associate Medical Officer of Health said it is likely the woman contracted West Nile in Hamilton in the past six weeks.

Public health officials were notified of the test results Thursday. The woman was tested in the past week, Meghani said.

The woman was recovering at home and had not been hospitalized, she said. Public health would not release the woman's name.

"The risk of being infected with West Nile virus locally has now moved from moderate to high," said Meghani.

"It is very possible we will see more cases this year than in the past two years," she added.

Medical officials have noted that the virus has appeared a couple of weeks earlier this year than the last two years, but Meghani said she is not sure why.

Most people infected with West Nile virus will have no symptoms or a very mild illness with fever.

A small proportion may develop a more serious illness, in some cases inflammation of the brain, on the lining of the brain or of the spinal cord, according to public health. The incubation period, after being bitten by an infected mosquito, is two to 14 days.

More information and regular updates are available on the city’s website.

To report by phone or for questions about standing water, mosquito control, or human health, please call the department’s Health Protection Division at 905-546-3575.