p.3
Roles of Medical Technologists in TB Diagnosis
Why is Direct Sputum Smear Microscopy (DSSM) considered economical?
Because the procedure is simple and cost-effective.
p.3
Diagnosis and Testing Methods for TB
What is the primary diagnostic method adopted by the NTP?
Direct Sputum Smear Microscopy (DSSM).
p.3
Classification of TB Disease
What is a clinically-diagnosed TB case?
A PTB patient diagnosed with active TB by a clinician without bacteriological confirmation.
p.3
Roles of Medical Technologists in TB Diagnosis
What is one of the primary roles of medical technologists in the NTP?
To provide a definitive diagnosis of active TB.
p.4
Diagnosis and Testing Methods for TB
What is the only contraindication for collecting sputum for DSSM?
Massive hemoptysis, which is expectoration of large volumes of blood.
p.1
Laboratory Identification of Tuberculosis
What is the primary method for laboratory identification of tuberculosis?
Direct sputum smear microscopy (DSSM).
p.2
Case Finding Policies for TB
How can presumptive TB be identified?
Through systematic screening in health facilities or targeted populations using symptom-based screening, chest X-ray, or both.
p.2
Case Finding Policies for TB
What is the primary screening tool for systematic screening in health facilities?
Symptom screening using at least two of the four cardinal signs: cough lasting ≥2 weeks, unexplained fever, unexplained weight loss, and night sweats.
p.4
Diagnosis and Testing Methods for TB
What is considered a positive TST reaction for immunocompromised children?
An induration of at least 5 mm.
p.3
Diagnosis and Testing Methods for TB
What tests are utilized by the NTP for diagnosing TB?
Direct sputum smear microscopy, TB culture, drug susceptibility test, tuberculin skin test, and rapid molecular diagnostic tests.
p.5
Direct Sputum Smear Microscopy (DSSM)
What is the advantage of fluorescence microscopy over conventional microscopy?
Increased sensitivity and can be five times faster.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
What can happen if the smear is overheated?
It can damage the bacilli, burn the smear, or break the slide.
p.2
Case Finding Policies for TB
What did the National TB Prevalence Survey in 2016 reveal about TB screening?
Screening for TB cases using symptoms alone would have missed one-third to two-thirds of bacteriologically confirmed pulmonary TB cases.
p.7
Recent Advances in TB Diagnostic Techniques
How does LED microscopy impact TB detection rates?
It increases detection rates, especially in low-resource settings.
p.7
Quality Control and Proficiency Testing in TB Laboratories
What is the purpose of RITM Proficiency Testing for AFB in the Philippines?
To maintain and improve the accuracy and reliability of TB diagnosis using Direct Sputum Smear Microscopy.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
What is the first step in air-drying and heat-fixing a sputum smear?
Air dry the smear on a clean glass slide for 15-30 minutes on a rack.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
What is a critical consideration when heat-fixing smears?
Heat fixing does not always kill Mycobacteria; exercise care when handling slides.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
What is a cause of false-positive acid-fast smears?
Insufficient decolorization.
p.4
Diagnosis and Testing Methods for TB
What should be done if Xpert MTB/RIF is not accessible?
Smear microscopy or TB LAMP shall be used as alternative diagnostic tests.
p.8
Recent Advances in TB Diagnostic Techniques
What technology does the GENEXPERT test utilize?
Real-time polymerase chain reaction (PCR) technology.
p.3
Case Finding Policies for TB
What is the current approach to case finding in TB diagnosis?
Includes passive and intensified case finding.
p.1
Mycobacterium tuberculosis Characteristics
What type of bacteria is Mycobacterium tuberculosis?
Weakly gram-positive, strongly acid-fast, aerobic bacilli.
p.5
Direct Sputum Smear Microscopy (DSSM)
What is the first step in the DSSM procedure?
Record the patient information in the Form 3 NTP Laboratory Register.
p.5
Acid-Fast Bacilli (AFB) Staining Techniques
What is the final step after counterstaining in AFB staining?
Air or blot dry and examine under OIO (1000x total magnification).
p.4
Diagnosis and Testing Methods for TB
What is the maximum time frame for collecting two sputum specimens?
The two specimens should be collected within 3 days.
p.3
Classification of TB Disease
What are the two classifications of TB based on anatomical site?
Pulmonary TB (PTB) and Extra-pulmonary TB (EPTB).
p.8
Recent Advances in TB Diagnostic Techniques
What are the key features of the GENEXPERT system?
Cartridge-based system, uses fluorescent probes, and allows multiplex testing.
p.5
Direct Sputum Smear Microscopy (DSSM)
What are the two microscopy methods used for DSSM?
Conventional Ziehl-Neelsen microscopy and fluorescence microscopy (FM).
p.1
Diagnosis and Testing Methods for TB
What are the common culture media for Mycobacterium tuberculosis?
L-J media, Dubos’, Middlebrook’s, Proskauer and Beck’s, Sula’s, and Sauton’s media.
p.4
Diagnosis and Testing Methods for TB
What is TB LAMP used for?
To process large sample loads, especially in ACF activities, but not for children, PLHIV, and MDR-TB risk groups.
p.8
Diagnosis and Testing Methods for TB
What is the primary use of the GENEXPERT test?
Detection of Mycobacterium tuberculosis (MTB) and its resistance to rifampicin (RIF).
p.7
Recent Advances in TB Diagnostic Techniques
What is a key advantage of LED fluorescence microscopy over traditional fluorescent lamps?
It is more energy-efficient.
p.5
Direct Sputum Smear Microscopy (DSSM)
What should you gargle with prior to sputum collection?
Lukewarm distilled water only.
p.4
Quality Control and Proficiency Testing in TB Laboratories
What is the procedure for labeling sputum cups?
Label the body of the sputum cup with the patient’s complete name and order of specimen collection.
p.7
Quality Control and Proficiency Testing in TB Laboratories
What are the positive control slides used in quality control for AFB?
Positive AFB – Mycobacterium tuberculosis ATCC 25177.
p.5
Acid-Fast Bacilli (AFB) Staining Techniques
What is the primary stain used in AFB staining?
Aqueous carbol fuchsin solution.
p.8
Mycobacterium tuberculosis Characteristics
What gene does the GENEXPERT system target for detecting rifampicin resistance?
The rpoB gene in the M. tuberculosis complex (MTBC).
p.3
Classification of TB Disease
What defines a bacteriologically-confirmed TB case?
A TB patient with a positive biological specimen by smear microscopy, culture, or rapid diagnostic tests.
p.2
Case Finding Policies for TB
What is case finding in relation to tuberculosis (TB)?
The identification of presumptive TB through clinical signs, symptoms, or chest X-ray, followed by diagnosis through bacteriological testing or clinical diagnosis.
p.4
Quality Control and Proficiency Testing in TB Laboratories
What should be done after collecting sputum specimens?
Seal the sputum cup, pack it securely, and transport it to a microscopy center or Xpert MTB/RIF site.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
How many fields should be read to assess AFB presence?
A total of 300 fields (150 left to right and 150 right to left).
p.7
Acid-Fast Bacilli (AFB) Staining Techniques
How does Fluorochrome staining improve the speed of TB diagnosis?
It allows for rapid scanning under lower magnification.
p.7
Recent Advances in TB Diagnostic Techniques
What are the benefits of digital microscopy systems in TB diagnosis?
They automate smear scanning, reduce human error, and allow for image archiving and remote review.
p.1
Mycobacterium tuberculosis Characteristics
What is the causative agent of tuberculosis?
Mycobacterium tuberculosis (Mtb).
p.1
Acid-Fast Bacilli (AFB) Staining Techniques
What is the significance of acid-fastness in Mycobacterium?
It is due to the presence of mycolic acid or a semipermeable membrane around the cell.
p.5
Acid-Fast Bacilli (AFB) Staining Techniques
What is the purpose of using a flame during smear preparation?
To create a sterile zone that coagulates aerosols raised during preparation.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
What is the purpose of heating/steaming the smear during staining?
To temporarily remove mycolic acid while the smear is flooded with stain.
p.7
Acid-Fast Bacilli (AFB) Staining Techniques
What staining method has shown greater sensitivity for detecting TB bacteria compared to the Ziehl-Neelsen stain?
Fluorochrome Staining (Auramine - O).
p.4
Direct Sputum Smear Microscopy (DSSM)
What should be done to ensure good quality sputum?
Clean the mouth, breathe deeply, and cough strongly to bring up sputum from deep within the lungs.
p.4
Roles of Medical Technologists in TB Diagnosis
What should health facilities with TB services establish?
Their own in-house TB diagnostic laboratory such as Xpert MTB/RIF, SM, and TB LAMP.
p.7
Quality Control and Proficiency Testing in TB Laboratories
What type of quality assurance process is included in RITM Proficiency Testing?
External Quality Assessment (EQA).
p.7
Quality Control and Proficiency Testing in TB Laboratories
What is the negative control used in quality control for AFB?
Negative – Non AFB – Escherichia coli ATCC 25922.
p.2
Case Finding Policies for TB
What steps are involved in screening for pulmonary TB in adults?
Ask about cardinal signs and symptoms lasting ≥2 weeks, and offer chest X-ray screening if no symptoms are present or if it has been over a year since the last X-ray.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
What can lead to a false-negative acid-fast smear?
Overzealous decontamination.
p.3
Roles of Medical Technologists in TB Diagnosis
What is one use of DSSM in TB management?
To monitor the progress of patients on anti-TB treatment.
p.8
Diagnosis and Testing Methods for TB
What types of results can the GENEXPERT system indicate?
MTB detected/not detected, RIF resistance detected/not detected, and indeterminate result.
p.5
Direct Sputum Smear Microscopy (DSSM)
What should not be done before sputum collection?
Do not gargle with mouthwash, brush teeth, eat, or drink.
p.2
Diagnosis and Testing Methods for TB
What is the recommended bacteriological test for TB diagnosis?
A rapid diagnostic test, such as Xpert MTB/RIF.
p.1
Epidemiology of Tuberculosis
What is the global impact of tuberculosis as of 2020?
1.5 million people died from TB, making it the 13th leading cause of death.
p.5
Acid-Fast Bacilli (AFB) Staining Techniques
Which bacteria are considered non-acid fast?
All bacteria except Mycobacteria, Nocardia, Rhodococcus, Tsukamurella, Gordonia, and Legionella micdadei.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
How is the smear fixed after air drying?
By passing the slide 2-3 times over the flame of a spirit lamp for 3-4 seconds each time.
p.2
Case Finding Policies for TB
Who should be screened for TB co-infection?
All people living with HIV (PLHIV).
p.1
Epidemiology of Tuberculosis
How has the COVID-19 pandemic affected tuberculosis cases?
There has been an increase in TB cases due to disruptions caused by the pandemic.
p.1
Epidemiology of Tuberculosis
Which countries account for the majority of new TB cases?
India, China, Indonesia, Philippines, Pakistan, Nigeria, Bangladesh, and South Africa.
p.6
Acid-Fast Bacilli (AFB) Staining Techniques
What are the components of the Ziehl-Neelsen stain?
3 grams Carbolfuchsin and 5% phenol.
