Active case finding of rifampicin sensitive and resistant TB among household contacts of drug resistant TB patients in Andhra Pradesh and Telangana states of India - A systematic screening intervention.

Background: India has the world's highest estimated burden of multi-drug-resistant tuberculosis (MDR-TB). While prevalence of MDR-TB is known to be 2-3% among new TB patients and 12-17% in previously treated patients, programmatic information on the extent of transmission of TB and MDR-TB among household contacts of known MDR-TB patients is scarce. Systematic screening of household contacts of all MDR-TB patients on treatment was implemented as an intervention in the states of Andhra Pradesh and Telangana states of India. We undertook this prospective interventional study to measure the extent of TB symptoms developed among the household contacts of the known MDR-TB patients treated under Revised National TB Control Programme (RNTCP). The extent of rifampicin sensitive or resistance TB, bacteriologically confirmed using Xpert MTB-RIF, was examined among the symptomatic household contacts.

Methods: All MDR-TB patients registered and on treatment under RNTCP between July 2011 and Sep 2013 in Andhra Pradesh and Telangana States were selected for the study. They were contacted through home visit by the trained RNTCP teams during 11th Dec 2013 and 7th Jan 2014. All household contacts of MDR-TB patients were screened once for TB symptoms such as cough, fever, weight loss, night sweats, and haemoptysis and extra pulmonary site specific symptoms if any. If found symptomatic, two sputum specimen were collected (spot-morning) from each of the contact and transported for testing on Xpert MTB-RIF for detection of pulmonary TB with or without RR-TB.

Results: A total of 1750 MDR-TB patients were registered between July 2011 and Sep 2013. Of these, 1602 (91.5%) MDR-TB patients were included in the study. A total of 4858 household contacts of these 1602 patients were identified with an average of 3 contacts per MDR-TB patient. Of these, after excluding 87 (1.8%) contacts with past history of diagnosis and/or treatment for TB, 4771 (98.2%) contacts were screened for current signs and symptoms suggestive of TB. Their mean age was 28.5 years and 2151 (45%) were females. Of the 4771 contacts screened, 793 (16.6%) had at least one of the symptoms suggestive of TB of whom 781 (98.5%) had two sputum specimen transported and tested on Xpert MTB-Rif. Specimen could not be collected during the study period in 12 symptomatic patients including 4 with symptoms of extra pulmonary TB. Among 781 symptomatic contacts examined, 34 (4.4%) were bacteriologically confirmed with TB and 15 (44%) also had Rif resistance (RR).

Conclusions: High extent of TB, particularly RR-TB was observed among household contacts of known MDR-TB patients with symptom screening and early diagnosis using Xpert-MTB-Rif. Regular systematic active screening for TB and MDR-TB among this highly vulnerable group using Xpert-MTB-Rif is useful in India for early diagnosis among close contacts of known MDR-TB patients.