{
  "abstract": "Early diagnosis of tuberculosis brings clinical and public health benefits. The NICE guidance for TB (not substantially updated since 2016) states that for HIV-negative individuals TB PCR is an additional test available on the primary specimen ‘if it would alter management’. 1 At a time of general cost saving on pathology tests it has become necessary to justify the use of TB PCR. We looked at 127 consecutive cases treated for TB in our hospital over 30 months from Jan 2022 to August 2024 to determine how many cases were diagnosed on the basis of PCR (table 1), lead time advantage over WGS, subsequent tests avoided, and early diagnosis of rifampicin resistant disease.Among 36 pulmonary/miliary cases, 8 were sputum smear negative/PCR positive, and 2 were BAL smear negative, PCR positive. We estimated that the availability of early diagnosis through PCR avoided 3 thoracoscopies, 2 bronchoscopies, 7 repeat biopsies and 1 repeat EBUS. The average delay between positive PCR and receiving final WGS result was 67.2 days for pulmonary cases and 44.8 days for non pulmonary cases. 4 cases of rifampicin resistant disease were diagnosed on PCR.Abstract M40 Table 1Initial (final) basis of diagnosis for consecutive TB cases Jan 2022 - Aug 2024 PCR Culture Histology Clinical Total extrathoracic LN 14 (8) 5 (14) 17(14) 0 36 pulmonary 31 (6) 0 (25) 3 (3) 0 34 bone/spinal 4 (2) 3 (7) 4 (2) 0 11 pleural 3 (3) 1 (1) 2 (2) 4 (4) 10 intrathoracic LN 3 (1) 0 (3) 5 (4) 0 8 ocular 0 0 0 8 (8) 8 abdominal 2 (0) 0 (3) 5 (4) 0 7 miliary 2 (0) 0 (2) 0 0 2 other 0 0 7 (7) 4 (4) 11 Total 59 (20) 9 (55) 43 (36) 16 (16) 127 Conclusion In 127 consecutive cases (January 2022 to August 2024) PCR provided the initial diagnosis in 46.4% of cases and the final diagnosis in 15.7%. It provided the initial diagnosis in 91% pulmonary cases (excluding resected pulmonary nodules). PCR is particularly helpful in sputum, BAL, pus and fluid samples where there is not an option for histological diagnosis; and in early diagnosis of rifampicin resistance.Reference NICE Guideline Tuberculosis NG33 Published 13th January 2016.",
  "authors": [
    {
      "affiliations": [
        "Royal Berkshire Hospital NHS Foundation Trust, Reading, UK"
      ],
      "name": "AD McGown"
    },
    {
      "affiliations": [
        "Royal Berkshire Hospital NHS Foundation Trust, Reading, UK"
      ],
      "name": "K Nyikadzino"
    },
    {
      "affiliations": [
        "Royal Berkshire Hospital NHS Foundation Trust, Reading, UK"
      ],
      "name": "S Moore"
    }
  ],
  "title": "M40 When does TB PCR change management? – A retrospective case series examining role of PCR in initial and final TB diagnosis in a general hospital",
  "uid": "39d92e39-45fb-5f02-b736-417905afa1aa"
}