Lessons Learned

Lessons Learned: TB Misdiagnosed as Pneumonia

Case: A 46-year-old substance-dependent male went to the Emergency Department for sweating, chest pain and one week of cough, and the emergency physician had a chest x-ray ordered for him. The patient was diagnosed with pneumonia and was discharged with a prescription for an antibiotic. For weeks later, the patient returned to the ED because he was coughing up blood. The clinical team completed both a tuberculosis skin test (TST) and sputum for acid-fast bacilli. The results were returned negative for the TBT and positive for the sputum 48 hours later, and the patient was informed about his condition by phone. Before the patient could return to hospital, he died at home that afternoon.

TB bacteria are found in the lungs and can be found in other areas of the body such as the kidney and brain. TB is deadly and if it goes untreated, it can be deadly. It is the 7th leading cause of death in the world. As an airborne disease, it can be spread when an individual with TB coughs, sneezes, or speaks.

It is not uncommon for pulmonary tuberculosis (TB) to be misdiagnosed as pneumonia, particularly in the acute phase when they both present identically. Between five and ten per cent of infected people not receiving treatment for latent TB infection will develop TB during their lives. The Centers for Disease Control and Prevention highlights a number of risk factors to those vulnerable to the disease and group of researchers argue those measures can be taken a step further. The score they developed, the CAPO TB (community-acquired pneumonia organization), consists of: 1) night sweats; 2) haemoptysis; 3) combined weight loss/10% or less of idea body weight; 4) combined prior history of TB/recent exposure to TB/history of positive PPD; and 5) upper lobe infiltrate localization. Establishing these factors among patients should drive hospitals to isolate patients meeting these criteria.

Hospitals are challenged with using the TST due to its low specificity and low sensitivity. In the case above, a false negative may have been attributed to the patient’s weak immune system. The patient may have had renal issues, gastrectomy and immunosuppressed conditions that were possibly overlooked. 

Of note, patients with suspected infectious TB must be isolated to prevent hospital-associated infections for both patient and staff safety. This case underscores the importance of recognizing TB particularly since it is not common in most hospitals. Equally important is the misdiagnosis of the disease with pneumonia. The delay in treatment for the patient was fatal. The patient’s condition may have compromised the health of friends, families, hospital staff and the public. Lastly, hospitals can evaluate the way in which they can improve patient diagnosis and treatment by training their staff, as well as attention to case management and follow-up.

Resources

Basic TB Facts. Centers for Disease Control and Prevention. 13 March 2012. http://www.cdc.gov/tb/topic/basics/default.htm

Cavalazzi, R. (2013) Predicting Mychobacterium tuberculosis in patients with community-acquired pneumonia. Eur Respir J; 43; 178-184.

Conducting Sputum Induction Safety. Francis J. Curry National Tuberculosis Center. San Francisco, 1999. (page 39 features the Harbor-UCLA triage criteria for respiratory isolation tuberculosis precautions (RIPT).

Effective TB Interviewing for Contact Investigation: Self-Study Modules. Centers for Disease Control and Prevention. 1 September 2012. http://www.cdc.gov/tb/publications/guidestoolkits/interviewing/selfstudy/module1/1_5.htm

Pinto, LM et al. (2011) Pulmonary tuberculosis masquerading as community acquired pneumonia. Resp Med; 4; 138-140. http://www.sciencedirect.com/science/article/pii/S175500171000062X 

Risk Factors. Centers for Disease Control and Prevention. 1 September 2012. www.cdc.gov/tb/topic/basics/risk.htm

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