ABSTRACT
Tuberculosis prevalence surveys have demonstrated the benefit of screening with chest x-ray (CXR) and sensitive diagnostic tests compared to symptoms and smear microscopy. However, in programmatic practice there is little evidence on the yield of different algorithms. We implemented contact tracing in Chennai, India for adult sputum-positive TB patients registered from January 2015 to March 2016. Patients with symptoms or abnormal X-ray findings further underwent testing using Xpert MTB/RIF (Xpert) and smear microscopy. A retrospective cohort study was done to summarize the key findings. We verbally screened 5553 contacts for symptoms, CXR through private sector collaboration, Xpert, and smear microscopy. Overall, 1312 (23.6%) contacts screened positive. CXR alone identified 531 (40.5%) of them, 679 (51.8%) were symptom-positive only, while 102 (7.8%) were positive on both the symptom and CXR screen. Overall, 35 bacteriologically positive cases were identified (0.7%). A standard approach of symptoms screening followed by microscopy identified only 9 (25.7%) of the total number of bacteriologically positive cases, whereas the combination of a CRX screening followed by microscopy identified 13 (37.1%) of the cases. The algorithm of symptoms screening followed by Xpert testing, detected 20 cases, whereas the combination of symptoms and CXR followed by Xpert increased this number to 35 (75% increase compared to symptoms and Xpert). Optimal use of more sensitive screening tests, better diagnostic tests, and novel private sector engagement can improve diagnostic yield in a programmatic setting.
Subject(s)
Contact Tracing/methods , Mass Screening/methods , Mycobacterium tuberculosis/isolation & purification , Sputum/microbiology , Tuberculosis, Pulmonary/diagnosis , Adolescent , Adult , Antibiotics, Antitubercular/pharmacology , Antibiotics, Antitubercular/therapeutic use , Contact Tracing/statistics & numerical data , Drug Resistance, Bacterial , Female , Humans , India/epidemiology , Male , Mass Screening/statistics & numerical data , Microscopy , Middle Aged , Molecular Diagnostic Techniques/statistics & numerical data , Radiography/statistics & numerical data , Reagent Kits, Diagnostic/statistics & numerical data , Retrospective Studies , Rifampin , Tuberculosis, Pulmonary/drug therapy , Tuberculosis, Pulmonary/epidemiology , Tuberculosis, Pulmonary/microbiology , Young AdultABSTRACT
BACKGROUND: Private physicians in India see and treat more than half of all people with tuberculosis (TB) each year and thus have potential to make significant contributions to TB control. The EQUIP project was designed as a prospective cohort study to assess the potential of private providers to diagnose and appropriately treat drug-resistant TB (DR-TB) in the Central and South districts of Chennai, India. METHODS: The private-sector engagement model consisted of free access to rapid diagnostics; choice of free daily or thrice-weekly treatment regimens; support for notification of patients; and patient support including directly observed therapy through EQUIP centers staffed by a community-based interface agency. Data were collected on provider participation; referral results; treatment regimens prescribed; and treatment outcomes. RESULTS: From October 2015 through June 2017, 227 of the 466 (48.7%) private providers approached referred at least 1 patient to an EQUIP center for evaluation. A total of 2,621 patients received testing and 1,232 (47.0%) were diagnosed with TB. Of those, 727 (59.0%) were bacteriologically confirmed, including 694 (56.3%) using GeneXpert and 33 (2.7%) using smear microscopy. A total of 26 (3.7% of GeneXpert diagnosed) patients were confirmed as rifampicin-resistant cases. EQUIP-related notifications comprised approximately 10% of TB and DR-TB notifications in Chennai during the project period. The project initiated 1,167 (96.8%) drug-sensitive TB patients on treatment. Of those, 691 (59.2%) received standard daily regimens with EQUIP support and 288 (24.7%) received standard intermittent regimens. At the time of writing, 89.4% of 868 drug-susceptible TB patients receiving EQUIP support had treatment success. Of the 26 rifampicin-resistant TB cases notified, 20 (77%) started and continued on second-line treatment; 2 died and 4 were lost to follow-up prior to treatment initiation. CONCLUSION: Private providers can make a substantial contribution to detection and appropriate treatment of patients with TB and DR-TB in India when provided with access to rapid diagnostics, support for notification and patient treatment through interface agencies, and free, quality anti-TB drugs.
