Employees in Philadelphia City Hall's 311 call center were sent home Thursday after a bedbug was found in the office, city officials said.

The office, which has about 50 employees who have been busy fielding citizen inquiries in the lead-up to Pope Francis' visit, closed at about 1 p.m. and will reopen at 8 a.m. Friday after the space is treated, according to Mayor Nutter's spokesman, Mark McDonald.

He said 311 staff would continue to take requests for information via email and social media while the office was closed.

McDonald initially said bedbugs were found in the office's carpet but then said that was misinformation and that one bug was found on a desk in the call center. He said an exterminator inspected the office, but found no other signs of bedbugs.

McDonald said the office is being treated as a precaution.

He said he has not heard of other parts of City Hall being affected and no other offices near the center, which is on the building's first floor, are being checked for bedbugs.

"We're dealing with the problem in the appropriate way," he said.

Michelle Niedermeier, chair of the city's recently created Bed Bug Task Force, said that when bedbugs are found in a room, she typically recommends any adjoining room is searched, including those on the floors above or below. She said bedbugs can travel through any cracks and crevices, such as electrical outlets.

But Niedermeier, who is an education specialist at Pennsylvania State University's department of entomology, added that if only a single bed bug was found, there might not be reason to panic.

"If it is just one bedbug it could have just been a hitchhiker," she said. "And that's the end of the story."