PART I. Identifying a Problem
This morning the local health department (large town health department) received a telephone call from the infection control practitioner (ICP) from a nearby hospital reporting that 2 patients were seen in the emergency department (ED) late yesterday with complaints of fatigue, fever, night sweats, and cough. As part of their work-up, the ED physician ordered chest x-rays for both patients. The health department was informed that, in both cases, the radiology report indicated abnormal findings consistent with TB. As a result, both patients were admitted to the hospital with a diagnosis of suspected pulmonary TB. Once admitted, sputum samples collected from both patients were read as positive on microscopic smear with final culture identification pending.
You know that tuberculosis (TB) is an infectious disease caused by bacteria called Mycobacterium tuberculosis. The bacteria usually affect the lungs (pulmonary TB) but also can affect any part of the body outside the lungs (extrapulmonary TB) with the most common sites being the lymph nodes, bone, kidney, and pleura. While TB disease was once the leading cause of death in the United States, it can now be treated successfully with appropriate antibiotics. However, if not diagnosed early or not treated appropriately, TB disease can be fatal.
You also know that according to the CDC the “presence of acid-fast-bacilli (AFB) on a sputum smear or other specimen often indicates TB disease. Acid-fast microscopy is easy and quick, but it does not confirm a diagnosis of TB because some acid-fast-bacilli are not M. tuberculosis. Therefore, a culture is done on all initial samples to confirm the diagnosis. (However, a positive culture is not always necessary to begin or continue treatment for TB.) A positive culture for M. tuberculosis confirms the diagnosis of TB disease. Culture examinations should be completed on all specimens, regardless of AFB smear results. Laboratories should report positive results on smears and cultures within 24 hours by telephone or fax to the primary health care provider and to the state or local TB control program, as required by law.”2 While some microbiology laboratories have access to advanced technology and have the ability to identify TB in a specimen in just a few days, your laboratory requires 4 to 8 weeks for growth and final identification. Therefore, you will need to wait for the results on these 2 suspected cases.
Your health department (large town health department) receives calls of suspected TB cases several times a week. At total of 40% of these reports turn out to be negative for TB.
What questions should you ask and what information should you collect from the ICP while he/she is on the telephone with you? At this early juncture, should you consider initiating an investigation about these 2 cases?
The CDC classifies TB as a notifiable disease. “A notifiable disease is one for which regular, frequent, and timely information regarding individual cases is considered necessary for the prevention and control of the disease.”3
At this point, would you consider this an outbreak?
You decide that the next step you should take is to visit the patients in the hospital, collect information from their medical records, and interview them.
Question 3: What should you have as goals in your interviews with these suspected TB cases?
Question 4: What types of questions should you ask the suspected cases?