Legend to have same colour as map. Ref to be added
If only a single specimen is taken, nearly 20% of smear-positive patients will be missed. The second specimen will identify most of the remaining patients. A third specimen, which is obtained at the same time the second specimen is submitted, helps confirm the diagnosis. This is also important because patients who have only a single positive specimen (out of 2 or 3) may have had this specimen mis-labeled or mis-read. Even in the best of laboratories, 1-4% of specimens can be cross-contaminated with other specimens. Source: See Toman. With regard to cross-contamination, see, for example, Frieden TR, et al. The molecular epidemiology of tuberculosis in New York City: the importance of nosocomial transmission and laboratory error. Tuberc Lung Dis 1996;77:407-413.
At least one third of patients do not take medicines regularly as prescribed. Furthermore, it is impossible to predict which patients will take medicines. In a programme of directly observed treatment, patients can be rapidly traced in case there are any problems with treatment, or if a single dose is missed. Source: Sbarbaro JA. The patient-physician relationship: Compliance revisited. Annals of Allergy 1990;64:326-332.
Scientific Basis of Diagnosis and Treatment in RNTCP Dr Awadhesh Kumar Sharma , MD Senior resident Department of Medicine, M.L.B. Medical College, Jhansi, UP
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis which is discovered by Robert Koch.
Pulmonary tuberculosis is the most common form of TB.
Transmission occurs by air borne spread of infectious droplets and droplet nuclei containing the tubercle bacilli.
The source of infection is a person with sputum smear-positive pulmonary TB.
India is the highest TB burden country globally accounting for one fifth of the global incidence Source: WHO Geneva; WHO Report 2006: Global Tuberculosis Control; Surveillance, Planning and Financing Globally ~9 million new TB cases occur annually Non-HBCs 20% Ethiopia 3% Philippines 3% South Africa 4% Bangladesh 4% Pakistan 3% Nigeria 4% Indonesia 6% China 15% India 20% Other 13 HBCs 18%
Problems with Over-Reliance on X-ray for TB Diagnosis
Misclassification of non-TB as TB, resulting in unwarranted treatment and avoidable expenditure
Inability to distinguish between smear+ and smear-negative patients, resulting in inadequate priority to true smear+ patients
Failure to give appropriate treatment
Inability to monitor progress accurately
Lower cure rates and increased spread of TB
X-rays of an Dubai based NRI engineer who complaints of cough with expectoration alongwith haemoptysis for 3 months, diagnosed there as case of pulmonary tuberculosis & antituberculosis Rx started. When he did not get relief, he visited India, here on investigation his eosinophillic count and IGE level found to be elevated & diagnosed as case of Allegric Bronchopulomonary Aspergillosis and got relief by antifungal and steroids .
This chest X-ray of Pt. mrs. Vimla 25 yrs. old lady admitted on 7 th April 08 with complaints of high grade fever with productive cough. Treated on the line of right lower lobe pneumonitis with IV antibiotics for 2 weeks but did not get reliefed. Later her sputum examination was done and found to be AFB positive and treated on line of cat. I regimen.
This chest X-ray of Pt. Mr. Gopesh Kumar 50 yrs. old male admitted on 8 th April 08 with complaints of high grade fever with productive cough with chest pain and dyspnoea. TLC was 42000 /cmm and polymorphs were 92%.Treated on the line of right upper lobe lung abcess with IV antibiotics for 2 weeks but did not get relief. Later his sputum examination was done and found to be AFB positive and on repeat chest X-ray the cavity size increased & involved whole of the right upper and middle lobe and treated on the lines of cat. I regimen. After that pt. improved.
A systematic evaluation of well-functioning District TB Centres by the National TB Institute, Bangalore found that nearly 70% of the cases diagnosed and put on treatment on the basis of x-ray, did not have tuberculosis at all
The proportion of cases diagnosed on the basis of x-ray alone and put on treatment unnecessarily is likely to be even higher in many centres
NTI, IJT, 1974 Over- diagnosis
Three sputum Samples collected - SPOT – Early Morning – SPOT
Diagnosis of tuberculosis Tools Merits Demerits Tuberculin test Can identify infection Good epidemiological tool Cannot differentiate infection & disease X-ray Sensitive Not specific Sputum Sm. Microscopy Definitive diagnosis Easy to perform at the periphery Replicability Less costly Sensitivity 60-80% Culture for MTB Highly sensitive & specific Costly, not freely available long waiting period
Treatment after default: A TB patient who received anti TB treatment for one month or more from any source and returns to treatment after having defaulted, i.e., not taken anti TB drugs consecutively for two months or more, and who is found to be sputum smear positive.
Failure: Any TB patient who is smear positive at 5 months or more after starting treatment. Failure also includes a patient who was treated with category III regimen but who becomes smear positive during treatment.
Chronic: A TB patient who remains smear positive after completing a re-treatment regimen.
Multi-drug regimens and DOT necessary even though risk of emergence of drug resistance is less as fewer bacilli remain
Treatment Regimens 2H 3 R 3 Z 3 / 4H 3 R 3 New smear negative and extra-pulmonary, not seriously ill Cat III 2H 3 R 3 Z 3 E 3 S 3 / 1H 3 R 3 Z 3 E 3 / 5H 3 R 3 E 3 Previously treated smear positive (relapse, failure, treatment after default) Cat II 2H 3 R 3 Z 3 E 3 / 4H 3 R 3 New smear positive; seriously ill smear negative; seriously ill extra-pulmonary Cat I
Side Effect of Anti-TB Drugs Symptom Drug Action to be taken Gastrointestinal upset Any oral medication Reassure patient Give drugs with less water Do not give drugs on empty stomach. Itching Burning in the hands and feet Isoniazid Give pyridoxine 100 mg/day until symptoms subside Joint pains Pyrazinamide evaluate Impaired vision Ethambutol STOP ethambutol and evaluate Ringing in the ears Loss of hearing Streptomycin STOP streptomycin and evaluate Jaundice Isoniazid, Rifampicin, Pyrazinamide STOP if liver enzymes elevated 5 times of normal.
The WHO working group on DOTS- Plus for MDR-TB was established in 1999 to lead the global effort to control MDR-TB (Cat. IV) (Whose sputum culture isolates are resistant to at least isoniazid and rifampicin).
Treatment is for a minimum duration of 18 months beyond sputum conversion (At least to sets of consecutive negative smears and cultures taken 30 days apart).
Regimens should consist of at least four drugs with either certain, or almost certain, effectiveness.
Asymptomatic children under 6 yrs of age, exposed to a patient with infectious (smear positive) TB from the same household, need to be given 6 months of daily isoniazid (5 mg/kg) as chemoprphylaxis against the disease.
Whenever possible , follow up sputum examination is to be performed with the same frequency as in adults.
Since this may not be possible for the majority of children with pulmonary TB, clinical or symptomatic improvement is to be assessed at the end of the intensive phase of treatment and at the end of the treatment.
Improvement should be judged by absence of fever or cough, a decrease in the size of lymph node(s), weight gain, radiological assessment etc.
Diagnostic Algorithm for Pediatric Tuberculosis
History of contact with suspected or diagnosed case of active TB
Is expectoration present? If yes, examine 3 sputum smears If no, then diagnosed based on a combination of Clinical presentation Chest X-ray Mantoux test History of contact 2 or 3 positives 3 negatives Antibiotics 10-14 days Cough Persists Repeat 3 sputum examinations Sputum positive TB 1 Positive X- Ray Suggestive of TB Negative of TB Non TB Negative 2 or 3 positives X-Rays + Mantoux Sputum Positive TB Suggestive of TB Sputum negative TB
Patient on treatment Review at 2 months shows satisfactory response assessed by: - improvement in symptoms - no weight loss and or weight gain Review at 2 months shows non - satisfactory response assessed by - poor or non adherence to treatment - weight loss - worsening of symptoms Follow up clinically Clinical assessment and X-ray at completion of treatment Refer to for assessment (Consider sputum examination) Sputum positive Failure Category II Sputum negative or not available
The current recommendations on ART are to use a triple drug combination. A combination of stavudine/zidovudine plus lamivudine plus Efavirenz/Nevirapine is usually used.
Co-administration of Rifampicin with any of the protease inhibitors or non-nucleoside reverse transcriptase inhibitors should be avoided as Rifampicin induces cytochrome P450 and substantially decrease blood levels of these antiretroviral drugs.
In TB patients co-infected with HIV, TB treatment should be completed prior to starting ART, unless there is a high risk of HIV disease progression and death during the period of TB treatment (i.e. a CD4 count <200/cmm or the presence of disseminated TB)