Unit 9: Diagnosis and Treatment of Paediatric Tuberculosis Botswana National Tuberculosis Programme Manual Training for Medical Officers Objectives At the end of this unit, participants will be able to: • Diagnose TB in children • Discuss the use of the tuberculin skin test (TST) • Explain treatment regimens for children • Explain the interaction between ART and TB treatment Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-2 Worldwide Burden of Paediatric Tuberculosis • 8.3 million new cases of TB in 2000* • 884,019 (10.7%) were in children • Est. 9 million new cases in 2006** • 1 million (11%) in children • varies from 3-25% depending on the country • 75% occurs in 22 high-burden countries Sources: *Nelson LJ, et al. Int J Tuber Lung Dis, 2004. ** WHO, 2006. Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-3 Botswana Paediatric TB • In 2000, 12% of all reported TB in Botswana occurred among children <15 years of age, though children represented only 2% of smear positive cases* • • • • Reported cases in children 0–9 years of age 1996: 813 (case rate 199/100 000) 2000: 1029 (case rate 229/100 000) An increase of 15% from 1996-2000 Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Source: *B Koosimile, BNTP, 2005. Slide 9-4 TB Notification Rates by Sex and Age Group, Botswana 2005 Source: BNTP, 2005. Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-5 Diagnosis Lung Diseases at Autopsy in African Children Dying from Respiratory Illnesses, 1997-2000, Zambia Total HIV-positive (n=180) HIV-negative (n=84) Acute pyogenic pneumonia 116(44%) 74 (41%) 42 (50%) PCP 58 (22%) 52 (29%) 6 (7%) Tuberculosis 54 (20%) 32 (18%) 22 (26%) CMV 43 (16%) 40 (22%) 3 (4%) Interstitial Pneumonia 30 (11%) 15 (8%) 15 (18%) Source: Chintu C, et al. The Lancet, 2002. Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-6 Key Risk Factors for TB in Children • Household contact with newly diagnosed smear-positive case • Fewer than 5 years old • HIV infection • Severe malnutrition Source: WHO, 2006. Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-7 Young Children Exposed to TB • Children should be evaluated for illness • If not ill and < 5 years old: INH preventive therapy • If ill, evaluate for need of TB treatment Courtesy of: Hampton G, Lung Health Image Library, 2003. Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-8 TB Prevention and Control from Smear Positive Mother-to-Child • Infants should take INH prophylaxis for 6 months • The infant receives BCG after completion of INH prophylaxis Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-9 Recommended Approach to Dx in Children: Assessment • Patient history • Contact to PTB+ • Symptoms consistent with TB • • • • Clinical Exam TST Investigations for PTB and EPTB HIV test Source: WHO, 2006. Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-10 Diagnosis of TB in HIV-Infected Children • TST less reliable (false-negatives) • More extrapulmonary disease- harder to diagnose • Broader differential diagnosis with poor tests • Culture yield- similar to non-HIV-infected children Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-11 Symptoms of Pulmonary TB in Children • Clinical manifestations may include: • • • • • • Chronic cough not improving and present for 2-3 weeks Night sweats Fever of > 38 degrees for 2 weeks Weight loss or failure to thrive Fatigue* Blood-streaked sputum • Shortage of signs and symptoms relative to chest radiograph findings Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis *Source: Marais B, et al. Pediatrics, 2006. Slide 9-12 Radiographic Manifestations of Pulmonary TB in Children • Prominent hilar and/or mediastinal adenopathy (not always discernable on plain radiographs) • Any lobe of lung involved; 25% multilobar • Collapse-consolidation or segmental pattern common • Obstructive signs/symptoms with endobronchial lesions • Not contagious Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-13 Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Source: Botswana-Baylor Children’s Slide 9-14 Clinical Centre of Excellence Bacteriological Confirmation • If sputum can be obtained, 3 samples should be sent for smear microscopy • Perform gastric aspirate smear and culture • Perform sputum induction TEST SENSITIVITY AFB smear – gastric aspirate 5-10% Mycobacteria culture – gastric aspirate 0-40% Mycobacteria culture – infants Up to 75% Source: Botswana-Baylor Children’s Clinical Centre of Excellence Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-15 Triad Approach • Contact with a case + • Positive TST + • Consistent clinical and/or radiographic evidence THIS IS HIGHLY SUGGESTIVE OF TB Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-16 Differential Diagnoses of Pulmonary TB (1) • • • • • Bacterial pneumonia Lymphocytic interstitial pneumonitis (LIP) Pneumocystis carinii (jeroveci) pneumonia Bronchiectasis Others • Fungal pneumonia • Pulmonary lymphoma • Pulmonary Kaposi’s Sarcoma Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-17 Differential Diagnoses of Pulmonary TB (2) • • • • • • • Asthma Cardiac disease Severe gastro-oesophageal reflux Aspirated foreign body Pertussis Cystic fibrosis Bronchiectasis Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-18 Extra-Pulmonary TB: Signs (1) • Non-painful, enlarged cervical lymphadenopathy without fistula formation • Meningitis not responsive to antibiotic treatment • Distended abdomen with ascites • Pleural effusion • Gibbus deformity of the spine Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-19 Extra-Pulmonary TB: Signs (2) • Pericardial effusion • Bone or joint swelling • Signs of tuberculin hypersensitivity, such as erythema nodosum • Subacute CNS disease, such as change in behaviour progressing to seizures or coma Courtesy of: Merck & Co., Inc. 2006. Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-20 Time from Infection to Disease • • • • • • Miliary and Meningeal Intrathoracic Lymph node Pleural effusion Skeletal Renal 2 – 6 months 2 – 12 months 2 – 12 months 3 – 12 months 6 months – 2 years 1 – 5 years Source: Botswana-Baylor Children’s Clinical Centre of Excellence Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-21 TB Cervical Lymphadenitis Most common form of extrathoracic TB Courtesy of: B. Marais, Stellenbosch University Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-22 Lymphadenitis Caused by Mycobacterium Tuberculosis • Often unilateral, sometimes bilateral • Chest x-ray usually normal • Usually non-tender, enlarged, fixed, matted nodes • Absence of systemic findings • Often progress and “break down”: suppuration, sinus tracts • Major differential diagnosis = malignancy Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Source: Botswana-Baylor Children’s Clinical Centre of Excellence Slide 9-23 Tuberculous Meningitis • Inflammation of the meninges as a result of infection with M. tuberculosis • Presents with headache, fever, irritability, convulsions, altered mental status • High-pitched cry • Bulging fontanelle • Suspected clinically & confirmed with CSF Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-24 Classic Findings in Cerebrospinal Fluid VIRAL BACTERIAL TB CELLS 0-500 5-10,000 10-500 DIFFERENTIAL Lymph Polys Lymph PROTEIN (g/d1) 20-60 20-400 50-5,000 GLUCOSE (mg/d) 30-80 <20 20-50 Source: Botswana-Baylor Children’s Clinical Centre of Excellence Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-25 CT Scan/MRI Findings in Meningeal (CNS) Tuberculosis • • • • • Basilar enhancement Hydrocephalus (communicating) Vasculitis Infarct “Paradoxical” tuberculomas-- while on ultimately successful chemotherapy • Ring-enhancing lesions, single or multiple Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Source: Botswana-Baylor Children’s Clinical Centre of Excellence Slide 9-26 Disseminated (Miliary) Tuberculosis in Childhood • Usually slow, subtle appearance, but may show rapid progression • CXR usually normal early, then classic miliary appearance • Other common features: hepatosplenomegaly, lymphadenopathy, cutaneous lesions • TST negative in up to 50% of cases Source: Botswana-Baylor Children’s Clinical Centre of Excellence Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-27 Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Source: Botswana-Baylor Children’s Clinical Centre of Excellence Slide 9-28 What Do You See? © Slice of Life and Suzanne S. Stensaas Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-29 What Do You See? © Slice of Life and Suzanne S. Stensaas Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-30 Tuberculous Pleural Effusion in Pediatrics • Primarily in adolescents • Uncommon before age five • Rare before age two • Usually unilateral, but can be bilateral • Usually presents with: fever, chest pain, SOB Source: Marais B, Stellenbosch University Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-31 Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Botswana-Baylor Children’s Clinical Centre of Excellence Slide 9-32 Investigations for Suspected EPTB Site Practical approach to diagnosis Peripheral lymph nodes (especially cervical) Lymph node biopsy or fine needle aspiration Miliary TB (e.g. disseminated) Chest X-ray and lumbar puncture (to test for meningitis) TB meningitis Lumbar puncture (and computerized tomography where available) Pleural effusion (older children and adolescents) Chest X-ray, pleural tap for biochemical analysis (protein and glucose concentrations), cell count and culture Abdominal TB (e.g. peritoneal) Abdominal ultrasound and ascitic tap Osteoarticular X-ray, joint tap or synovial biopsy Pericardial TB Ultrasound and pericardial tap Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-33 Tuberculin Skin Test (TST) • Latent TB uncommon in children, therefore a positive skin test is more likely to represent recent infection and the presence of TB disease • Used in tandem with other diagnostic tests in children • Mantoux method is recommended test Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-34 Applying the TST (PPD or Mantoux Test) • TST useful in young children who have low prevalence of latent TB infection • Placed by intradermal injection similar to BCG application Courtesy of: Knobloch G, CDC, 2004 Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-35 Reading the TST (Mantoux) A positive reaction occurs when a cellmediated immune response to tuberculin antigens produces firm swelling at the intradermal site after 48-72 hours Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Courtesy of:Kopanoff D, CDC, 1969 Slide 9-36 Interpreting the TST Test Mantoux • • Risk Status Reading Interpretation Low ≥ 10 mm Positive High: HIV+, malnourished ≥ 5 mm Positive Positive Result Negative Result Infection with MTB • No infection with MTB Does not prove active • Cannot exclude active TB disease tuberculosis disease (20-25% of HIV patients with active TB have negative TST) Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-37 Incorrect TST Results False Negative • Incorrect placement • Incorrect reading • HIV infection and other immunosuppression • Viral Infections, e.g. measles • Vaccinated with live viral vaccines (w/in last 6 weeks) Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis False Positive • Incorrect interpretation of test • Infection with M. bovis or MOTT • Recent BCG Slide 9-38 BCG Vaccination • BCG vaccine prevents severe forms of TB in infants (up to 85% reduction) and is recommended for newborns • TB meningitis • Miliary TB • Negligible effect on TB epidemiology • Does not prevent infection • Little effect on reactivation disease Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-39 BCG Dosages Age Dose Site At birth 0.05 ml Intra-dermal Above 1 year 0.10 ml Intra-dermal Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-40 BCG Vaccination in Children Administer BCG vaccine Do not administer BCG vaccine Known HIV negative children Known HIV positive children with or without signs or symptoms of HIV infection Children of unknown HIV status without signs or symptoms of HIV infection, regardless of HIV status of mother Children of unknown HIV status with signs or symptoms of HIV infection present, regardless of HIV status of mother Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-41 Normal Reaction Course to BCG Vaccination At vaccination Approximately 3 wk post-vacc Approximately 1 yr post-vacc Approximately 6 wk post-vacc Courtesy of: Kim SJ, Korean Institute of Tuberculosis, 2001 Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-42 Complications of BCG • • • • Swelling of lymph nodes adjacent to vaccination site Subcutaneous abscess in babies Excessive ulceration Local ulcers and BCG adenitis persisting for more than 8 weeks • Note: Routine follow-up of infants is recommended for early identification and treatment of any BCGrelated complication Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-43 Interaction of BCG Vaccines with the Tuberculin Skin Test • 79% of vaccinated children ages 3-60 months did not react to a TST (MMWR 1997) • Most non-infants who get one or more BCG vaccinations will react to a TST (usually <15 mm), but effect wanes over 5 – 10 years • Outside infancy, “positive” TST more likely to indicate infection with M. tuberculosis than be residual from BCG Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Source: Lockman S, et al., Int J Tuberc Lung Dis, 1999. Slide 9-44 HIV Testing • In Botswana, HIV testing is part of the diagnostic work-up for ALL TB suspects (including children) • In HIV positive children: • Lymph node and pulmonary TB are Clinical Stage 3 • EPTB other than lymph node is Clinical Stage 4 Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-45 Impact of HIV on Diagnosis and Management of TB in Children • HIV makes diagnosis and management of TB in children more difficult for the following reasons: • Other HIV-related disease, such as lymphocytic interstitial pneumonitis, may present in a similar way to PTB or miliary TB • Interpretation of tuberculin skin testing and CXR is less reliable • Pill burden of TB treatment and ART can be difficult for children to tolerate • Drug-drug interactions between rifampicin and NNRTIs and PIs Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Source: WHO, 2003 Slide 9-46 Anti-tuberculosis Drug Dosing in Children R 150 mg Average dose mg/kg/day (Range) 10 (8-12) H 100 mg 5 (4-6) Z 500 mg 25 (20-30) E 100 mg 15 (15-20) S IM 15 (12-18) Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-47 Recommended Treatment Regimens for Children • Category I • Children with severe disease, such as disseminated TB: 2HRZE/4HR • Children with TB meningitis: 2SHRZ/4HR • Category II • 2SHRZ/1HRZ/5HR • Category III • 2HRZ/4HR Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-48 Role of Adjuvant Steroid Therapy • TB meningitis • 2mg/kg/day for 4 weeks and then taper over 6 weeks • TB pericarditis • 2mg/kg/day for 4 weeks then 1mg/kg/day for 4weeks then taper for 6 weeks • Massive lymphadenopathy with airway obstruction • 2mg/kg/day for 4 weeks then taper over 6 weeks Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-49 Tuberculosis in Children: Drug-Resistance • Usually must link the child with an adult case to identify it • Adults with drug-resistant TB are as contagious as those with susceptible disease • Disease expression in children the same as with susceptible strains • Children tolerate and respond well to secondline drugs Source: Botswana-Baylor Children’s Clinical Centre of Excellence Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-50 Treating the Dually Infected Child • Use the same guidelines for initiating ART for children with tuberculosis as you would for any HIV+ child • Cotrimoxazole should always be given Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-51 Cotrimoxazole Dosing Age/ Recommended Suspension (5ML syrup = weight of daily dose 200mg/40mg) child 6 weeks to 6 months (<5kg) 100mg sulfamethoxazole/ 20mg trimethoprim 6 months to 200mg 5 years (5- sulfamethoxazole/ 15kg) 40mg trimethoprim 6 to postpubertal 400mg sulfamethoxazole/ 80mg trimethoprim Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Child tablet (100mg/ 20mg) Single strength adult tablet (400mg/80mg) 2.5ml One tablet 5ml Two tablets Half tablet 10ml Four tablets One tablet Slide 9-52 ART and Rifampicin-Based TB Therapy for Children >3 years • Efavirenz + 2 nucleosides • Choice of nucleosides • Zidovudine + lamivudine (AZT/3TC) • Alternate: stavudine + lamivudine (d4T/3TC) • d4T should be used in place of AZT if baseline anaemia is present Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-53 ART and Rifampicin-Based TB Therapy for Children <3 years • Nevirapine + 2 nucleosides • Choice of nucleosides • Zidovudine + lamivudine (AZT/3TC) • Alternate: stavudine +lamivudine (d4T/3TC) • d4T should be used in place of AZT if baseline anaemia is present Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-54 Key Points (1) • TB is a significant cause of morbidity and mortality in children in Botswana • Use INH preventative treatment to prevent TB disease in children <5 years • Prevent serious TB disease in newborns with BCG Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Unit 9: Diagnosis and Treatment of Paediatric TB Slide 9-55 Key Points (2) • In children <10 years old • Smear positive PTB unusual • Diagnosis made on clinical and suggestive evidence (CXR, TST, physical findings) • Severe forms of EPTB are frequent • HIV makes diagnosis and management of TB in children more difficult Unit 9: Diagnosis and Treatment of Paedatric Tuberculosis Slide 9-56