The story today is a far cry from the 1960s, when we led the developing countries’ fight against the disease
Tuberculosis is very much in the news, but for all the wrong reasons — a shortage of drugs; increasing multi-drug and extensive drug resistance (MDR, XDR), making treatment both cumbersome and expensive; total drug resistance (TDR) as a veritable death warrant; popularly used serological tests for diagnosis being declared worse than useless, and a government order for mandatory case notification. Private practitioners are legally authorised to treat TB, but without quality check mechanisms. They often bypass the prescribed treatment protocol, while MDR, XDR and TDR result from non-protocol drug treatment.
India pioneered TB control among developing nations. A national TB control project was launched in 1962. With BCG vaccination as the main intervention, there was an air of expectancy that it would protect against TB. Free TB treatment was included to create goodwill in the community, with public-private partnership (PPP). When “directly observed treatment, short course” (DOTS) became popular, PPP was neglected — a fatal flaw in TB control. In 2012, India’s golden jubilee year of TB control, the World Health Organization (WHO) named India the worst performer among developing nations, with 17 per cent of the global population carrying 26 per cent of the global TB burden.
India’s TB control pioneers P.V. Benjamin and Frimodt-Moller introduced the mass BCG vaccination in the hope that it would protect against infection by TB bacilli. Preventing infection is key to disease control. BCG manufacturing began in Chennai and an extensive vaccine trial was launched in Chengalpattu district, Tamil Nadu, to measure its protective efficacy. In 1978, the Expanded Programme on Immunisation took over BCG vaccination. In 1979, preliminary results of a 15-year-long BCG trial showed no protection against infection by TB bacilli. The disappointing results were much debated, and ignored by the then TB control leadership. In 1999, the final results, which were published in the Indian Journal of Medical Research, confirmed that the TB control project had lost the tool of primary prevention.
In 2000, the Indian Academy of Pediatrics called for a major redesign of TB control, with alternative tactics to prevent infection and treat infection before it caused disease. WHO’s 2012 Annual Report on TB confirmed India’s failure. DOTS saves lives from TB mortality, but has failed to control TB.
Infection in the air
TB bacilli spread through the air we breathe in; everyone is at risk of infection. After infection, the majority remains well, but the bacilli stay alive, latent or dormant in body tissues for life. Some 10 per cent will develop TB disease some time in adult life. When disease pathology is in the lungs (pulmonary TB), the bacilli have an easy escape route to the environment. Thus, lung TB is the critical link in the chain of transmission — coughing and spitting allow the bacilli to contaminate the air, and others breathe them in.
In young children, infection can rapidly lead to disease, called childhood TB, which can be serious and life-threatening. BCG fails to protect against infection by TB bacilli, but protects against infection progressing to childhood TB. Thus, universal neonatal BCG vaccination saves thousands of lives and huge costs for diagnosis and treatment. Childhood TB is not infectious; so, treating childhood TB has no role in TB control.
The chances of infection with TB bacilli increase with time and infection prevalence increases with age. In India, about 15 per cent are infected by 15 years of age; 40-60 per cent by 40 years. Among them, a few develop lung TB due to various “risk factors.” They cough/spit out billions of TB bacilli. One way to control TB is by treating everyone with lung TB very early on to break the transmission chain. This is theory; a person with lung TB is infective for many weeks and would have already infected children in contact by the time his sputum is tested and found positive. More often than not, the stable door is shut after the horse has bolted. Yet, if all are treated, over a period of time, the infection rate might decline. Strangely, the target is to treat only 70 per cent with DOTS. WHO estimates that only half of lung TB patients get DOTS. This way, TB cannot be controlled in India. Without PPP, all cases cannot be treated according to protocol.
A public health emergency
The TB control pioneers designed free treatment in the public and private sectors. After all, if the government cannot provide a safe environment for children to grow up in without getting exposed to TB bacilli, the least it should do is to offer free care. They designed a district TB treatment model under PPP. TB control is a Central government project, while health care is a State subject. The private sector has grown enormously. The TB control project has failed to address the yawning gap between private sector health care and TB control.
In the 1980s, AIDS entered India; HIV infection is a major risk factor of TB. Diabetes, another factor, is increasing in India. Poverty and nutritional deficiencies are additional factors. A project review in 1990 confirmed India’s failure to control TB. The Revised National TB Control Programme (RNTCP) using DOTS was launched in 1993, the year WHO declared TB a global emergency. Nationwide expansion of RNTCP took 13 years as the government saw no TB emergency in India.
For those fortunate enough to receive DOTS, the cure rate is high. Their death rate is markedly reduced. For those with extra-pulmonary TB, a sputum test will not help in diagnosis. RNTCP is not interested in them as they do not spread TB bacilli. So, the project illustrates incomplete health care and inadequate public health.
As a right
“Control” is a defined term in epidemiology — the disease burden should be reduced to a pre-stated level, within a stipulated period of time, and proven to be due to intervention and because of a “secular trend.” As socio-economic status increases, TB should decline even without specific interventions — that is a “secular trend.” RNTCP has not set control targets in terms of a time frame and disease burden. It is not measuring a secular trend. Thus, the “control” in RNTCP is not epidemiologically sound.
A critical method of TB control, practised in countries with public health infrastructure, is to detect and treat infected children so that the latent bacilli are killed and children removed from the infected pool. They will not develop pulmonary TB as adults. This move is feasible in India, but requires a redesigned TB control strategy. Both interventions, DOTS and treatment of latent infection, must be dovetailed for effective TB control.
Poverty leads to TB and TB worsens poverty. Poverty alleviation requires TB control. The annual economic loss to India on account of uncontrolled TB was assessed by the government at $23.7 billion, while RNTCP’s budget is only $200 million. A redesigned RNTCP deserves at least $1 billion. TB control is at once a humanitarian service, human rights entitlement and investment in socio-economic development. The RNTCP leadership has to get back to the drawing board to redesign TB control.
(T. Jacob John is chairman, Child Health Foundation, New Delhi, retired professor of Christian Medical College, Vellore, and past national president of the Indian Academy of Pediatrics.)