Sudbury’s health unit is digging through data to figure out why the city has such a high rate of HIV infection, after a recent report indicated Sudbury has one of the highest number of HIV cases in the province.

The report — done by the Ontario HIV Epidemiologic Monitoring Unit — noted large numbers of the HIV cases in Sudbury are linked to intravenous drug use among women.

The news came as a shock to Dr. Robert Remis, who is with the provincial network that monitors HIV cases.

"The rates are definitely higher in Sudbury than many other health units across Ontario,” he said.

On average, 11 people are diagnosed with HIV in Sudbury each year.

Women sharing needles

But it's the demographic behind the diagnosis that has researchers at the public health unit baffled.

The majority are women.

"Not only are they IV drug users,” said Shannon Dowdall-Smith, a Sudbury nursing researcher on the project.

“They're sharing needles with their sexual partners and may also be sex trade workers."

Dowdall-Smith said women tend to share needles more often — a trend that’s seen around the globe.

But Remis said other cities aren't seeing the same connection between intravenous drug use and HIV.

He said all other cities show that most HIV infection is diagnosed in men who have sex with men. HIV infection is also found in men who are immigrants from sub-Saharan Africa.