This is an editorial with the view that TB and its control are manifestations of social and economic development. During the past eight years, active TB cases increased substantially in the US and other industrialized countries due to several social, economic and epidemiological factors. Available data suggest that two important steps are necessary for TB control: 1) to identify all persons with active disease and ensure their complete treatment and, 2) to identify high-risk persons with TB infection (such as HIV-infected persons) and provide them with complete preventive treatment. Four articles in the American Journal of Public Health (Nov. 1994, Vol. 84, No. 11), illustrated the challenges and priorities of modern TB control. Buskin et al (p. 1750), after reviewing risk factors for active TB among patients in King County, Washington, USA, suggested expanded outreach and services. Leonbardt et al (p. 1834) showed that with persistence, sensitivity and a mobile van, public health workers gained the trust and participation of patients and their social network which allowed 74% of infected contacts complete isoniazid preventive therapy. The need to provide services to underserved populations and, to improve the co-ordination and communication among health care workers, public health programs, clinics and other agencies in serving difficult-to-reach places were emphasised by Ciesie et al (p. 1729). Lastly, Dr. George Comstock (p. 1729), after a review of the past and prospective strategies for controlling TB, called for a renewed investigation of the epidemiology of TB, especially, to find answers to questions such as: Where does most transmission occur? How can risk of infection best be predicted? Following the collective recommendations of these studies and improving the social and economic environment globally would enhance successful anti-TB efforts.

Much of the global strategy for TB control was established in India, but every year, there are an estimated 2 million cases of TB. To describe the policies, initial results and lessons learnt from implementation of a RNTCP using the principles of DOTS is the objective of this study. The RNTCP was designed and implemented starting in 1993. With funding from Government of India, State Governments, the World Bank and bilateral donors, regular supply of drugs and logistics was ensured. Persons with chest symptoms who attend health facilities are referred to microscopy centres for diagnosis. Diagnosed cases are categorized as per WHO guidelines and treatment is given by direct observation. Systematic recording and cohort reporting is done. From October 1993 through mid-1999, 146012 patients were put on treatment in the programme. The quality of diagnosis was improved, with the ratio of smear-positive to smear-negative patients being maintained at 1:1. Case detection rates varied greatly between project sites and correlated with the percentage of patients who were smear-positive among those examined for diagnosis, suggesting heterogeneous disease rates. Treatment success was achieved in 81% of new smear-positive patients, 82% of new smear-negative patients, 89% of patients with extra-pulmonary TB and 70% of re-treatment patients.

The RNTCP has successfully treated approximately 80% of patients in 20 districts of 15 states of India. Treatment success rates are more than double and death rates are less than a seventh those of the previous programme. Starting in late 1998, the programme began to scale up and now covers more than 130 million people. Maintaining the quality of implementation during the expansion phase is the next challenge.