Tuberculin Skin Test Positivity in Hospitalized Patients in Baghdad Teaching Hospital Wathiq Mohammed FICMS, Faleh Albayati MRCP

Keywords: Active tuberculosis, Tuberculin skin test.


Background: One third of earth population are infected with Mycobacterium tuberculosis. In the majority, infection is asymptomatic (latent) and is detected by positive tuberculin skin test. It constitutes an important source of infection and may activate later in life. Iraq has been identified as middle-TB burden country in the world.
Objectives: To determine the frequency of latent tuberculosis infection among patients admitted to a medical ward in Baghdad teaching hospital.
Methods: One hundred and thirty three adult patients of both genders free of any evidence of active tuberculosis were included in the study. The Mantoux technique was used and two units of purified protein derivative were applied by an intradermal injection in the middle third of the inner forearm. Skin reaction was quantified 48 to 72 hours after the injection and considered positive with induration of ≥10 mm.
Results: A positive tuberculin skin test result was observed in 13 patients (9.8%). Two patients (15.4%) were ≤ 45 year old, 8 patients (61.5 %) between ages of 46-65 and 3 patients (23.1%) older than 65 years. Eight responders (61.5%) were males. Among TST positive group, six patients (46.2%) had spent some time in prison, whereas only three patients (2.5%) of TST negative group reported such story.
Conclusion: History of incarceration is the only factor associated with significant tuberculin reactivity among hospitalized patients in a single medical unit in Baghdad teaching hospital