Dr Francis Ogaro MTRH ELDORET

Transcription

1 Dr Francis Ogaro MTRH ELDORET

2 TB in children often severe, disseminated and can progress rapidly and with poor outcome TB diagnosis in children has relied on clinical, imaging, microscopy and TST findings. With emerging DR- TB epidemic microbiological confirmation and drug susceptibility testing is becoming increasingly important. 1M new TB cases globally in children annualy, 140,000 die annualy (400 daily) 14,000 new cases in kenya annually

3 Difficulties with diagnosing EPTB Pauci-bacillary nature of disease. Difficulties with obtaining sputum specimen Bacteriological diagnosis still remains the gold standard No typical X-ray features for TB Issue of radiation with CT scanner Need for sedation with MRI

4 Clinical presentations suggestive of TB in children. chronic cough, persistent fever, weight loss, known TB exposure and Lymphodenopathy,fatigue,night sweats Signs and symptoms can be nonspecific or absent Special investigations will be required to confirm the TB diagnosis. The combination of careful history, physical examination and investigation results will usually confirm the diagnosis

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6 The ability of any diagnostic test to detect TB depends on the quality of specimen collected. Tests Smear Microscopy, Culture of TB bacilli and Identifying MTB DNA (PCR-DNA rapid test) Sputum sample collection Expectoration, Hypertonic saline sputum induction, Gastric aspirate and String test Sputum specimen handling and rapid transportation to the Lab

7 Simple and well tolerated by most children including infants. One well taken IS specimen is superior to 3 gastric aspirate specimens in terms of bacteriological yield. Increased yield with second specimen? cost The procedure needs trained staff (Nurse or physiotherapist) Time consuming Appropriately designed room Necessary equipments/devices and drugs

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9 Used in all levels of care Requires minimal bio-safety conditions. Cheap Low sensitivity especially in HIV negative. Diagnostic accuracy depends on the proficiency of the personnel Can t differentiate MTB from NTM Can t differentiate viable from death bacilli. Useful in monitoring response to Rx

10 Currently the gold standard for MTB diagnosis More accurate than smear microscopy Use Solid or Liquid media Waiting time 3-8 weeks Requires heavy infrastructure investment with biosafety features Drug susceptibility can be done in the culture positive growths. Bacilli can be cultured from various specimens including CSF, Pleural effusion, ascitic fluid, FNA from LNs and tissue biopsies, pus, abscess and discharging ears. Best in monitoring response to Rx especially in DRTB

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12 Integrated sample processing and nucleic acid amplification test. Detects both MTB and Rif. resistance Sensitive, rapid and specific with results within 2 hours.

13 Sputum FNA CSF Gastric aspirate Urine Autopsy specimen Pleural effusion Ascitic fluid

14 Specimen Buffer cartridge

15 WHO approved first line test for all cases of suspected/presumed TB. Strongly recommended in High risk of DR-TB including all re-rx categories failure, return after loss to followup, return after relapse. Suspected HIV associated TB Seriously ill and suspected of having TB regardless of HIV status

16 Results are available quickly Minimal technical trainings are required. Early detection of MDR TB. Minimal risk of cross contamination as each cartridge is for one specimen. Minimal infrastructure investment requirements Has increased case detection rates by up to threefold in some countries.

17 All Rif. resistance specimens have to be cultured to confirm the resistance and determine resistance to other anti-tb drugs. Cannot be used for monitoring therapy. A stable power supply is essential to avoid result loss cartridge wastage machine damage need for new sample in the event of power interruption Does not confirm Rif. susceptibility as other Rif. resistance mechanism not detected by Xpert do exist

18 Should be interpreted alongside clinical, radiographic and other laboratory findings. Test will compliment and not replace smear microscopy, Culture, DST and genotyping. Results MTBC detected or not detected RIF. resistance Detected Not detected Indeterminate

19 All positive RR Results Negative RR in MDR high risk patients Retreament cases MDR contact Smear positive at 2 months of treatment Those who develop TB while on IPT treatment RR indeterminate cases

20 Children suspected of having TB with a single negative Xpert test should undergo futher diagnostic testing, if clinical suspicion of TB is high TB treatment should be initiated even if xpertmtb/rif result is negative.

21 Done all children with suspected TB but not for routine screening. Inexpensive and widely available examination High quality frontal X-ray, lateral is useful but not essential Presence of mediastinal and hilar adenopathy is the cardinal sign of intra-thoracic TB in children (R>L) (Hilar LN enlargement is the typical CXR appearance in primary TB)

22 Radiological improvement often lags behind clinical improvement Check x-ray at 2 months in those with severe disease on CXR at diagnosis thereafter no need for check X-ray if child improving. Repeat CXR at end of treatment period in those who had initial abnormal radiography. Abnormal but greatly improved radiograph at the end of treatment is not an indication to continue therapy until resolution of radiographic disease

23 Parenchymal (lung) involvement Focal consolidation Patchy consolidation Cavities No lung lesions Lobe or segmental atelectaxis (RML most involved) Pleural effusion Miliary TB Bronchiectasis Normal CXR is common in children with TB

24 More sensitive than CXR in demonstrating lungs and mediastinial lesions CT identifies lympodenopathy up to 60% TB patients with reported normal CXR use is limited due to Radiation dose with CT Need for sedation with MRI Cost of the investigation Limited availability

25 Availability of high quality portable ultrasound allows for point of care/bed side examinations. Clinicians, Ultra-sound radiographers can be trained in absence of a radiologist Advantages of ultra sound No radiation No sedation

26 No radiation Sedation not necessary Useful in detecting and characterizing pleural effusion, pericardial effusion and mediastinal lymphodenopathy Abdominal ultra sound Ascites, abdominal nodes liver and splenic hypo-echoic lesions

27 Window through suprasternal notch or parasternal intercostal spaces easily detects nodes in the anterior and superior mediastinum. Useful in detecting pleural,and pericardial effusion, pneumonic consolidation and lymphodenopathy Ultrasound can detects lympodenopathy in 65-70% of children with TB who have a normal CXR

28 Digital images, reports and expert opinions can be transmitted anywhere in the world allowing for expert interpretation and opinion. Done via or other internet based platforms Useful in underserved areas where there are no radiologists

29 Reactive 4-8 weeks after infection. Correct technique and proper PPD storage are essential Negative up to 15% of children with TB disease Merely a marker of TB exposure (LTBI diagnosis) Influence of BCG minimal after 2 years (fades with time unlike TB infection) 5-9mm induration BCG effect in the under 2 yr olds NTM infection Immunosuppressed child with TB infection

30 Detects gamma interferon released by MTB sensitized lymphocytes Confirms TB infection just like TST but is very specific for MTB Cannot differentiate LTBI from TB disease Can differentiate MTB infection from BCG Expensive Not recommended in standard care

31 HIV screening a must for all children with TB TB diagnosis is more difficult in the HIV child. TST may be negative overlapping clinical features with other OIs, CXR features may be same as other HIV related lung diseases Need for ARVs ARVs and anti-tb drug interactions and medication adjustments

32 In the absence of bacteriological confirmation TB in children is often diagnosed based on a combination of contact history, suggestive clinical features and consistent radiographic information

33 Thank you