Why is Direct Sputum Smear Microscopy (DSSM) considered economical?
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Because the procedure is simple and cost-effective.
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Why is Direct Sputum Smear Microscopy (DSSM) considered economical?
Because the procedure is simple and cost-effective.
What is the primary diagnostic method adopted by the NTP?
Direct Sputum Smear Microscopy (DSSM).
What is a clinically-diagnosed TB case?
A PTB patient diagnosed with active TB by a clinician without bacteriological confirmation.
What does the RITM Proficiency Testing evaluate?
Laboratory competency.
What is one of the primary roles of medical technologists in the NTP?
To provide a definitive diagnosis of active TB.
What is the only contraindication for collecting sputum for DSSM?
Massive hemoptysis, which is expectoration of large volumes of blood.
What is the primary method for laboratory identification of tuberculosis?
Direct sputum smear microscopy (DSSM).
How can presumptive TB be identified?
Through systematic screening in health facilities or targeted populations using symptom-based screening, chest X-ray, or both.
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.
What is considered a positive TST reaction for immunocompromised children?
An induration of at least 5 mm.
What is the minimum volume of sputum required for Xpert MTB/RIF?
At least 1 ml.
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.
What is the advantage of fluorescence microscopy over conventional microscopy?
Increased sensitivity and can be five times faster.
What can happen if the smear is overheated?
It can damage the bacilli, burn the smear, or break the slide.
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.
Where can microscopy centers be established according to the NTP?
Even in remote areas.
How does LED microscopy impact TB detection rates?
It increases detection rates, especially in low-resource settings.
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.
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.
What is a critical consideration when heat-fixing smears?
Heat fixing does not always kill Mycobacteria; exercise care when handling slides.
What is the recommended size for a good quality smear?
3 cm by 2 cm.
What is a cause of false-positive acid-fast smears?
Insufficient decolorization.
What should be done if Xpert MTB/RIF is not accessible?
Smear microscopy or TB LAMP shall be used as alternative diagnostic tests.
What technology does the GENEXPERT test utilize?
Real-time polymerase chain reaction (PCR) technology.
How quickly can the GENEXPERT system provide results?
Within 2 hours.
What is the current approach to case finding in TB diagnosis?
Includes passive and intensified case finding.
What type of bacteria is Mycobacterium tuberculosis?
Weakly gram-positive, strongly acid-fast, aerobic bacilli.
What is the first step in the DSSM procedure?
Record the patient information in the Form 3 NTP Laboratory Register.
What color do acid-fast bacilli (AFB) appear after staining?
Red (carbol fuchsin).
What is the final step after counterstaining in AFB staining?
Air or blot dry and examine under OIO (1000x total magnification).
What is the maximum time frame for collecting two sputum specimens?
The two specimens should be collected within 3 days.
What are the two classifications of TB based on anatomical site?
Pulmonary TB (PTB) and Extra-pulmonary TB (EPTB).
What are the key features of the GENEXPERT system?
Cartridge-based system, uses fluorescent probes, and allows multiplex testing.
What are the two microscopy methods used for DSSM?
Conventional Ziehl-Neelsen microscopy and fluorescence microscopy (FM).
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.
What was the estimated number of TB cases globally in 2021?
Around 10.6 million.
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.
What is the primary use of the GENEXPERT test?
Detection of Mycobacterium tuberculosis (MTB) and its resistance to rifampicin (RIF).
What is a key advantage of LED fluorescence microscopy over traditional fluorescent lamps?
It is more energy-efficient.
What should you gargle with prior to sputum collection?
Lukewarm distilled water only.
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.
What are the positive control slides used in quality control for AFB?
Positive AFB – Mycobacterium tuberculosis ATCC 25177.
What is the primary stain used in AFB staining?
Aqueous carbol fuchsin solution.
What gene does the GENEXPERT system target for detecting rifampicin resistance?
The rpoB gene in the M. tuberculosis complex (MTBC).
What defines a bacteriologically-confirmed TB case?
A TB patient with a positive biological specimen by smear microscopy, culture, or rapid diagnostic tests.
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.
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.
What annual screening is recommended for all health facility consults?
Chest X-ray screening.
What was the estimated number of active TB cases in the Philippines in 2021?
599,000 active TB cases.
How many fields should be read to assess AFB presence?
A total of 300 fields (150 left to right and 150 right to left).
How does Fluorochrome staining improve the speed of TB diagnosis?
It allows for rapid scanning under lower magnification.
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.
What is the causative agent of tuberculosis?
Mycobacterium tuberculosis (Mtb).
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.
What is the purpose of using a flame during smear preparation?
To create a sterile zone that coagulates aerosols raised during preparation.
What is the purpose of heating/steaming the smear during staining?
To temporarily remove mycolic acid while the smear is flooded with stain.
What staining method has shown greater sensitivity for detecting TB bacteria compared to the Ziehl-Neelsen stain?
Fluorochrome Staining (Auramine - O).
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.
What should health facilities with TB services establish?
Their own in-house TB diagnostic laboratory such as Xpert MTB/RIF, SM, and TB LAMP.
What type of quality assurance process is included in RITM Proficiency Testing?
External Quality Assessment (EQA).
What is the negative control used in quality control for AFB?
Negative – Non AFB – Escherichia coli ATCC 25922.
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.
What can lead to a false-negative acid-fast smear?
Overzealous decontamination.
What is one use of DSSM in TB management?
To monitor the progress of patients on anti-TB treatment.
What types of results can the GENEXPERT system indicate?
MTB detected/not detected, RIF resistance detected/not detected, and indeterminate result.
What should not be done before sputum collection?
Do not gargle with mouthwash, brush teeth, eat, or drink.
What is the recommended bacteriological test for TB diagnosis?
A rapid diagnostic test, such as Xpert MTB/RIF.
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.
Which bacteria are considered non-acid fast?
All bacteria except Mycobacteria, Nocardia, Rhodococcus, Tsukamurella, Gordonia, and Legionella micdadei.
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.
Who should be screened for TB co-infection?
All people living with HIV (PLHIV).
How has the COVID-19 pandemic affected tuberculosis cases?
There has been an increase in TB cases due to disruptions caused by the pandemic.
Which countries account for the majority of new TB cases?
India, China, Indonesia, Philippines, Pakistan, Nigeria, Bangladesh, and South Africa.
What are the components of the Ziehl-Neelsen stain?
3 grams Carbolfuchsin and 5% phenol.
