TORONTO - Some people use Facebook to keep in touch with old friends, others to make new ones. And at least one grateful woman has used the website to find the son she gave up for adoption.

But Toronto Public Health officials have put the online social network to what may be a new use - locating a woman who needed rabies shots because she had handled a rabid bat.

The department's manager of communications, Mary Margaret Crapper, said Toronto Public Health had explored all the traditional methods of trying to find the woman before turning to Facebook.

"Telephone book. Google. In situations like this we even went to the police to see if they may be able to assist. So yeah, we try a lot of different sources of information," Crapper said.

The department had even issued an advisory to the media. Several Toronto radio and television stations and newspapers alerted the public about its search for a woman who had dropped off an injured bat to the Toronto Wildlife Centre in early September. But no one stepped forward.

Then the idea of using Facebook was raised. One of Crapper's colleagues sent messages to a number of women on Facebook with names similar to the person they were seeking.

And Facebook delivered.

"Once we tried a few different spellings on Facebook, we had the individual within an hour," Crapper said.

Ironically, employees of the City of Toronto are barred from using Facebook at work. Crapper actually had to get special dispensation from the department's director of information technology so that a colleague who has a personal Facebook account could trawl its network looking for the woman.

The saga began on Sept. 3, when a bat flew at or was struck by a woman standing at a bus stop at the intersection of Jane Street and Lawrence Avenue in northwest Toronto. A second woman picked up the injured bat and brought it to the wildlife centre.

The unnamed woman - Toronto Public Health can't identify her because of privacy regulations - had been to the wildlife centre before, so her name and address were on file. Problem was, she'd moved and changed her telephone number since her last visit. But no one had updated her file.

The bat was sent for testing and late last week Toronto Public Health was informed the bat was rabid.

People who have had close exposure to bats are often advised to get rabies shots to prevent development of the disease, which is almost always fatal.

But when Toronto Public Health tried to reach the woman to assess the extent of her exposure, they found the phone number and address on file were dead-ends.

A Google search uncovered a woman in Alberta with the same name. When public health officials called her to see if she'd been in Toronto, she had not. But she told them she had a Facebook account and had recently received an email from another user, from Toronto, who had the same name.

It turned out that woman wasn't the one they were seeking, either. But Crapper felt it was worth searching Facebook for other women with the same or similar names. They eventually tracked down the woman they were after using an alternate spelling of a nickname for her first name.

The woman has begun a series of rabies shots.

Unfortunately, however, the woman who had the initial contact with the bat at the bus stop has not yet been found. Authorities know nothing about who she is, Crapper said, and have issued another media advisory. But to date no one has come forward.

As for Facebook, the department is keen to explore how it and another online phenomenon, You Tube, might be used as a public health tool, Crapper said.

"We will certainly use it again in a situation like this," she said. "It's definitely something we need to look at and hear from other people about how they're using it."