By Deborah L. Shelton
The Chicago Tribune
CHICAGO — Early test results for close associates of a doctor-in-training infected with tuberculosis have been negative, health authorities said Monday.
About 10 close contacts of a 26-year-old female pediatric resident who tested positive for TB last week have undergone screening, according to Chicago health officials. The contacts include relatives, friends and hospital colleagues who worked in close proximity to her.
Dr. Susan Gerber, chief medical officer at the Chicago Department of Public Health, said the lack of infection was a positive sign that suggests the bacterial disease probably had not spread.
Some people who were tested will have to undergo follow-up screening to be on the safe side, because infection with TB bacteria can take up to 10 weeks to be detected following exposure.
Three area hospitals are identifying and contacting hundreds of patients and employees who may have been exposed to TB from the pediatric resident. The resident most recently worked at Children’s Memorial Hospital from Nov. 20 to April 3, where she had contact with at least 122 children and more than 300 workers.
A spokeswoman for Children’s Memorial Hospital said seven patients have returned for screening so far and that all tested negative.
The risk of transmission is seen as low because it requires close contact during a significant period.
The Centers for Disease Control and Prevention defines significant exposure as 120 hours of face-to-face contact with an infected person in a month.
Early testing indicates the woman’s TB is not drug-resistant. But authorities will not know for at least several weeks, because it takes that long to grow bacteria culture and test it against different medications.
Gerber said the resident had been tested for TB according to CDC standards, which require health-care workers to be checked at least annually, and her results were negative.
About 175 people called the city Health Department on Friday and during the weekend seeking either screening or information about TB.
Facts about tuberculosis
Tuberculosis is a bacterial disease that usually affects the lungs but can also affect the brain, kidneys, spine and other body parts. Left untreated, it can be fatal.
Symptoms: Feelings of sickness or weakness, weight loss, fever, night sweats. For tuberculosis of the lungs: coughing, chest pain, coughing up blood.
Transmission: TB spreads from person to person through the air. If a person with the disease in the lungs or throat coughs, sneezes, speaks or sings, the germs can stay in the air for several hours, depending on the environment.
Exposure: Significant exposure is defined as being in close contact with an infected person for at least 120 hours.
Testing: If an exposed person is considered at high risk, he or she typically is given a skin test. Follow-up tests are sometimes conducted if the last exposure occurred fewer than 10 weeks previously.
Latent versus active: People with a latent infection have inactive TB in their bodies. They do not have symptoms and are not infectious, but they are often prescribed treatment to prevent them from developing the disease.
People with TB have active germs, meaning they are multiplying and destroying tissue in the body, usually causing symptoms. These patients can spread germs to others. Prescription drugs are given to treat the disease.
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