"We want to be as conservative as possible," city health director Scott Leroy said. By conservative, he means opening the circle of people to be tested to include the girl's casual contacts, to make sure no one has been infected with the disease.

Dr. John Gundy, the school's medical adviser, said the girl ran a fever last winter while school was in session, then recovered. This summer, she developed active TB and is now being treated for the disease.

Gundy said because the disease in its early stage can manifest itself with a fever, health officials in the city can't be sure she did not have the first signs of active TB last winter.

The city learned last week from state laboratories that the girl had active TB. On Monday, the school system sent out letters to students and staff informing them of the situation. The high school will have an informational session and TB skin tests for them Aug. 27 at 1 p.m. at the high school.

Mark Hasskarl, Danbury Library director, said his staff has been notified. They will be tested Monday, he said.

Dr. Thomas Draper, the city's associate health director, said there is no need to test people who simply entered the library or the school when the girl was there.

"You really need close, prolonged contact with a patient while they are coughing to get the disease," he said.

Draper said in the past 30 years there have been many TB cases in the city. In all those cases, the index case - the person with active TB - has never spread it to another person, including those in close contact with the patient.

"It can happen," he said, "but it's very rare."

Danbury superintendent Salvatore Pascarella and the schools' health director, Suzanne Levasseur, learned of the problem from the city health department.

"The city and state officials had long discussions about the notification, and ultimately the state required this level of notification," Levasseur said.

"We are being cautious in notifying anyone who might have had contact with her. There is no guarantee that the girl was an active TB case during the school year, but we are looking back six months."

The school district mailed a letter Monday to classmates and staff who might have been exposed, so they can attend the information session and be tested if they want.

"We contacted the people who were in her classes, approximately 130 students and staff," Levasseur said. "We are also in the process of contacting the people on her bus list."

Levasseur said the letter makes it clear TB is not an easily transmitted disease.

"We don't expect a lot of exposure from this, but we wanted to be cautious," she said. "A lot will be explained at the information meeting."

Tuberculosis is caused by a bacterial infection. People spread the bacteria by coughing and breathing it into the air, allowing those in close contact to the patient to breathe in and become infected.

Ancient texts show that people suffered from TB for centuries, but the urban overcrowding caused by the Industrial Revolution in the 18th and 19th century made it a terrible threat to human life. At its worst rate of infection, TB caused about 30 percent of the deaths in Europe.

Today, modern antibiotics can cure the disease, although it takes several months of drug therapy to do so.

There were hopes those drugs could conquer the disease; however, in recent years, drug-resistant TB has shown the illness will not be easily eradicated.

Leroy said public health officials now control infectious diseases like TB by contacting the ring of people most likely to have been infected, then testing them. The city decided to make that ring a broad one.

Often, people have latent TB - they have had contact with someone who had the disease and test positive for it on a skin test - even though they have no symptoms of the disease.

"Just because you test positive doesn't mean you're contagious," Gundy said.

Leroy said if any of the people tested because of their contact with the student have a positive skin test, they'll get more tests - including sputum tests and chest X-rays - to make sure they don't have the active form of the disease.

If they do, they will also get antibiotic treatment.

Contact Robert Miller

at bmiller@newstimes.com

or (203) 731-3345.