Child and Chest Health Care Delhi NCR

Pediatric tuberculosis is a burden to society and nation .

It is prevalent in every society and every nation.

It spreads by aerosols which comes in air after coughing by a diseased person and then inhaled by healthy person .

In children ,it is mostly contracted by a diseased adult suffering from pulmonary tuberculosis .

Lifetime risk for an infected child to become diseased is 10%.

CBNAAT-cartridge based nucleic acid amplification test, also known as GeneXpert test is now investigation of choice to detect Mycobacterium tuberculosis in children suspected to be suffering from tuberculosis .

The sensitivity of this test in sputum smear positive case is 98% and specificity is 99% but in smear negative and culture positive  cases its sensitivity is only 72% but specificity is 99%

In GA(gastric aspirate sample ) the sensitivity is only 68% in culture positive sample  and specificity is 99%.

Presently it is done on sputum, gastric aspirate ,CSF ,pleural fluid ,lymph done aspirate ,ascitic fluid,synovial fluid but  not on blood .

In lymph node aspirate,the positivity is 35%.

In some children,in which induced sputum and gastric aspirate are negative ,BALf,bronchoalveolar lavage fluid obtained by bronchoscopy has been found to be positive.

The sensitivity is  low in  Synovial fluid,pericardial fluid,ascitic fluid and very low in pleural fluid.

SO ,NEGATIVE TEST RESULT OF CBNAAT/GeneXpert TEST DOES NOT RULE OUT TUBERCULOSIS

Only one sample is needed and if unable to send the sample to lab immediately, it can be stored safely in refrigerator for 7 days but should not be freezed .

It is a real time PCR test and gives result in 2 hours.

It detects Mycobacterium tuberculosis as well as its resistance to Rifampicin.

If resistance to Rifampicin is detected and there is no suspicion of resistant tuberculosis clinically,then a fresh second sample is sent.

In second sample, if there is sensitivity to Rifampicin, it is labelled as Drug sensitive TB.

In GeneXpert Ultra test,second sample is not required.

The yeild is high in this test if there is chest X-ray findings suggestive of tuberculosis.

In case of only clinical suspicion with no radiological findings,the sensitivity is approximately 10%

SO,FOR THE HIGH YIELD,THIS TEST SHOULD BE SENT WHEN THERE IS SUSPICIOUS LESION ON CHEST X-RAY

In case of pleural effusion,the highest yield is from the examination of pleural biopsy which is positive in 80% cases.

The culture of pleural fluid is positive in only 10% of cases.

Other recommended tests are LPA-Line probe assay and LAMP-Loop mediated isothermal amplification.

These tests (CBNAAT,LPA annd LAMP)are called WRDT-WHO recommended rapid detection test.

The Gold standard diagnostic test is now, liquid culture in the form of MGIT-Mycobacterium growth indicator tube culture which gives result in 3 weeks.Previously it was solid culture.

Culture is positive in 1/3 to 1/2 cases of Tuberculosis.

FUTURE PROSPECT: CBNAAT has been used to detect Mycobacterium tuberculosis in stool sample  in children.Its sensitivity in one study in children and persons with HIV has been found to be over 80% and specificity over 95% when compared to respiratory sample.

After multicentre study,it may become the preferred sample for children in which respiratory sample is difficult to obtain.

TREATMENT:

Category II (CAT II) Treatment comprising of 2HRZES+1HRZE+5HRE has been completely withdrawn now.

There is  only one category now, for all patiens ,comprising of 2HRZE+4HRE,FIRST LINE ATT

For newly diagnosed cases,whether smear positive or smear negative this treatment should be completed for 6 months.

All patients,who have not taken ATT previously or have taken it for less than 4 weeks are labelled as New Case

In cases of neurotuberculosis or spinal tuberculosis,the continuation phase comprising of HRE should be extended for 8 months.

In cases of relapse,defaulters, retreatment,treatment after failure, and any contact with resistance tuberculosis,the sample should be sent for DST-Drug sensitivity test,  while the treatment started as 2HRZE+4HRE.

If the result comes as sensitive to first line medications,the treatment should be completed with this regimen only

If resistance comes to any drug, then the second line drugs should be started according to the sensitivity pattern.

Second line drugs are less potent and should be given for prolonged time.

Two highly potent drugs Dalaminid and Bedaquilline are now recommended for treatment of children with resistant tuberculosis.

Bedaquilline is recommended for children 6 years and above.

Dalaminid is recommended for children 3 years and above.

These two drugs are available at selected centres in India

In cases of LTBI -Latent tuberculosis bacillus infections,in which only Tuberculin sensitivity test or IGRA is positive but there is no clinical symptom and sign or any lesion in any organ suggestive of tuberculosis,no treatment is given in India.

In Western countries,the current recommendation is to treat LTBI with 12 Doses of HP-3HP-(3 months of HP)

Previously it was recommended for adults,but now it is recommended in children also

In such cases(LTBI),weekly doses of Rifapentine and isoniazid is given for 12 weeks.

Currently,it is not recommended for children below 2 years of age.

All children receiving isoniazid should be given daily dose of 10 mg of pyridoxine.

Definite indications of steroid along with ATT are TBM,Pericarditis,Addisons disease,Miliary TB with alveolocapillary block and TB uveitis.

Steroid can be given in endobronchial tuberculosis,pleurisy with severe distress,bronchial compression,mediatinal compression syndrome,laryngeal TB,and TB-IRIS(Immune reconstitution inflammatory sundrome).

Evidence is not sufficient for tuberculoma.

Prednisolone 1-2 mg/kg/day or dexamethasone 0.6mg/kg/day or any steroid in equivalent doses ,should be given for 4 weeks then tapered over next 4 weeks.

REFERENCES:

RNTCP Updated Pediatric TB Guidelines 2019 developed by Revised National TuberculosisControl Programme and Indian Academy of Pediatrics.

Guidance document draft as on 04.02.2019,Central TB division,Ministry of Health and Family Welfare,New Delhi India

CDC:Treatment Regimen for Latent TB infection

CDC:The 12 dose Regimen forLatent Tb infecvtion Treatment:Fact Sheet for clinicians

Eur Respir J 2019 53:1801832; published ahead of print 2018,
doi:10.1183/13993003.01832-2018

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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