Which of the following investigations may be used for the diagnosis of pulmonary tuberculosis? 1. Nucleic acid amplification 2. Culture in Middlebrook medium 3. Light emitting diode fluorescent microscopy with auramine staining 4. Peripheral blood smear Select the correct answer using the code given below:
Pulmonary Tuberculosis Diagnosis Investigations
Accurate diagnosis of pulmonary tuberculosis relies on specific microbiological and molecular tests. Let's evaluate the investigations listed:
1. Nucleic Acid Amplification (NAA)
Nucleic acid amplification tests (NAA tests), such as PCR, are highly sensitive and specific for detecting Mycobacterium tuberculosis DNA directly from patient samples (like sputum). They provide rapid results and are a crucial part of modern TB diagnosis.
2. Culture in Middlebrook Medium
Bacterial culture remains a gold standard for diagnosing tuberculosis. Culturing sputum or other relevant specimens in specific media like Middlebrook allows for the confirmation of Mycobacterium tuberculosis growth. It also enables subsequent drug susceptibility testing.
3. LED Fluorescent Microscopy with Auramine Staining
Microscopy is a rapid diagnostic tool. Auramine staining combined with light-emitting diode (LED) fluorescence microscopy significantly increases the sensitivity for detecting acid-fast bacilli (AFB) compared to traditional Ziehl-Neelsen staining. It's an effective method for initial screening of sputum samples.
4. Peripheral Blood Smear
A peripheral blood smear is primarily used to examine blood cells and diagnose conditions like anemia or leukemia. While systemic inflammation in TB might cause secondary changes in blood counts, a peripheral blood smear is not a direct or standard diagnostic investigation for pulmonary tuberculosis itself.
Conclusion on Diagnostic Investigations
Based on the evaluation, Nucleic acid amplification (1), culture in Middlebrook medium (2), and LED fluorescent microscopy with auramine staining (3) are all established and important investigations for diagnosing pulmonary tuberculosis. A peripheral blood smear (4) is not used for the direct diagnosis of TB.
Therefore, the correct combination of investigations used for the diagnosis of pulmonary tuberculosis is 1, 2, and 3.
Important Questions from Tuberculosis
- Recommended first time drug for initial treatment of tuberculosis include all EXCEPT:
The most frequent adverse reaction of significance among people treated for drug-susceptible tuberculosis is:
All adult patients in whom anti-tubercular treatment is being started should undergo baseline assessment of:
- The extrapulmonary sites most commonly involved in tuberculosis are all EXCEPT:
- The Gene X-pert test used for MTB detection has the additional advantage of detection of which of the following?
