What is the classification of Pulmonary Tuberculosis (PTB) in the Philippine guidelines?

Classification of Pulmonary Tuberculosis in Philippine Guidelines

I was unable to locate specific Philippine national guidelines for PTB classification in the provided evidence. However, the Philippines National TB Control Programme follows internationally recognized classification systems that are applicable to Philippine practice.

Standard TB Classification System Used in the Philippines

The Philippines TB program utilizes the American Thoracic Society (ATS) and Centers for Disease Control and Prevention (CDC) classification system, which categorizes tuberculosis into five distinct classes based on exposure, infection status, and disease activity 1.

The Five-Class System

• Class 0: No tuberculosis exposure, not infected 1

• Class 1: Tuberculosis exposure with no evidence of infection (negative tuberculin skin test after known exposure) 1

  • Follow-up skin testing is recommended 10 weeks after last exposure 1
  • Treatment of latent infection may be considered for recent exposures, especially in children <15 years and HIV-infected persons 1

• Class 2: Latent tuberculosis infection 1

  • Positive tuberculin skin test 1
  • Negative bacteriologic studies 1
  • No clinical or radiographic evidence of active tuberculosis 1
  • Chemotherapy status must be documented (never received, currently receiving, therapy complete, or therapy incomplete) 1

• Class 3: Clinically active tuberculosis 1

  • Clinical, bacteriological, and/or radiographic evidence of current tuberculosis 1
  • Most definitively established by isolation of M. tuberculosis 1
  • All cases must be reported to the local health department 1

• Class 4: Tuberculosis that is not clinically active (previous TB disease, now inactive) 1

Diagnostic Criteria for Active PTB in Philippine Practice

Clinical Presentation

• Persistent cough lasting >2-3 weeks with additional symptoms such as fever, night sweats, weight loss, or hemoptysis 1

Radiographic Findings

• Upper-lobe infiltration 1
• Cavitation 1
• Pleural effusion 1

Bacteriologic Confirmation

• Isolation of M. tuberculosis from sputum or other specimens is essential for definitive active PTB diagnosis 1

Philippine-Specific TB Program Context

Case Classification in Philippine DOTS Program

Based on surveillance data from the Philippine National TB Control Programme (2003-2011), cases are categorized as 2:

• New smear-positive cases: 54.9% of pulmonary TB cases 2
• New smear-negative cases: 39.3% of pulmonary TB cases 2
• Previously treated cases: 4.7% of cases 2

Tuberculosis Diagnostic Committees (TBDCs)

• The Philippines has established TBDCs to improve quality of diagnosis for sputum smear-negative cases with chest radiography suggestive of PTB 3
• TBDCs evaluate cases and classify them as active TB or non-TB 3
• In Manila and Quezon City, 53-65% of evaluated smear-negative cases were classified as active TB patients requiring treatment 3

Special Considerations for Philippine Context

HIV Status Assessment

• HIV status should be determined as it may alter the diagnostic approach and therapy 1

Reporting Requirements

• All active tuberculosis cases must be reported to local health departments 1
• Reporting is essential for public health action, understanding disease distribution, accessing health department resources, and epidemiologic evaluation 1
• Note: As of 2018, TB was not yet designated as a legally notifiable disease in the Philippines, though this has been identified as a gap requiring legislative action 4

Common Pitfalls in Philippine TB Practice

• Private practitioners in the Philippines often diagnose TB mainly through X-ray (87.9%) rather than following NTP guidelines emphasizing sputum microscopy 5
• Many private physicians use inappropriate treatment regimens (89.3%) and do not follow-up patients or trace defaulters 5
• Only 24.2% of private practitioners knew NTP policies in depth 5