London — A hundred years ago there was no way to treat tuberculosis (TB) except with rest, fresh air and nutritious food. Forty years later the discovery of antibiotics transformed treatment and TB has been a curable disease for more than half a century, but the disease still kills nearly 4,000 people a day. The goals set by the World Health Organization (WHO) to halve the incidence of TB by 2015 and eliminate it as a public health problem by 2050 seem far out of reach.
Mario Raviglione, the head of the WHO Stop TB department, told a meeting of TB experts in London on 15 February: "The incidence is coming down at one percent or so a year, which will ensure TB elimination in several millennia, in my perception."
TB is a disease often associated with poverty because latent infections are more easily activated by malnutrition and lowered immune systems, and more quickly passed on in badly ventilated, overcrowded living conditions. As people in Western Europe got richer, ate better, and housing conditions improved, TB became increasingly rare, even before there were effective drugs to treat it.
Now there is interest in seeing whether a new generation of social protection schemes, aimed at reducing poverty and often using cash transfers to the poorest, can be harnessed to bring down the rate of TB in developing countries.
Brazil has achieved a steady decrease in TB and has halved the death rate since 1990, despite not achieving the conventional benchmarks for a successful control programme.
Draurio Barreira, who coordinates Brazil's national programme, told the meeting: "To control TB they say we need to detect 70 percent of those infected, treat and cure at least 85 percent of those... and have default rates not bigger than 5 percent. In Brazil we haven't reached many of these standards, but we have had very good indicators in TB for more than 15 years. So how we can explain that?"
He attributes the achievement to political commitment. "The big news was the transformation of social policy... by a real increase in minimum wage, and cash transfer programmes for the poor - in the last sixteen years poverty in Brazil decreased by 67 percent." And, just as in Europe in the 1800s, as poverty declined, TB declined as well.
Cash works
A study in Malawi, also presented at the meeting, showed clear health benefits from even very modest cash transfers to the most disadvantaged households. A pilot scheme gave regular monthly payments to around 10 percent of households, ranging from just over $4 for an elderly person living alone, to nearly $13 for larger families. Children grew better and were less likely to be malnourished, there was less illness in these families and they had more choice of health providers, with the possibility of sometimes using private clinics.
Social protection issues are fundamental in TB control, and that is why TB control now has to go beyond working with national TB programmes
An evaluation of the pilot looked at what happened to recipients of cash transfers living with HIV and AIDS, and found the money was being used to pay for the more nourishing food they need to support drug treatment, and for transport to get their antiretroviral (ARV) medication. The effect on TB Patients was not specifically monitored, but the need for a better diet and the cost of travel for tests and to collect drugs also affects TB patients. "The impacts that we are seeing with these people living with AIDS and HIV could absolutely translate over to people living with TB," says Candace Miller of Boston University, who presented the study.
The close association of TB with HIV infection and the emergence of multidrug-resistant (MDR) strains are modern complications since the days when eliminating poverty was enough to get rid of the disease. "[But] HIV-TB globally is 12 percent or 13 percent of all cases, so nearly 90 percent are not HIV related," Raviglione told IRIN.
"If you go outside of Africa - and TB is 75 percent outside of Africa - it doesn't have the same impact... 60 percent of TB is in Asia, and HIV has little to do with those [cases]. MDR-TB is mostly in the former Soviet Union. Multidrug-resistance is a big scare, but we are talking about less than five percent of all cases of TB - 95 percent are not drug resistant."
Cash payments and incentives specifically aimed at TB patients are more problematic. A trial in South Africa offering shopping vouchers to patients who complied with the protracted drug regime found no clear difference in the success rate of their treatment. However, the trial was partly undermined by clinic staff who felt the vouchers should be given to the poorest, even those randomly selected for the control group.
This highlights another issue in targeting social support: the perceived unfairness of giving cash or food to people living with TB while denying it to those who - in the words of another speaker - were 'sick and struggling' with other diseases.
Targeted interventions may also not be very effective from the public health point of view. Peter Godfrey-Faussett of the London School of Hygiene and Tropical Medicine, which hosted the meeting, argued that the problem with TB control was not the patients in treatment, even if they stopped taking their medicine. The people spreading TB were those who hadn't been diagnosed but had symptoms and were infectious, and money would be better spent finding those cases and treating them.
Rather than targeting known TB sufferers, Brazil will now specifically target some of its anti-poverty programmes at the social groups where the disease is most prevalent to help control TB - the Afro-Brazilian and indigenous communities, those infected with HIV, and especially prisoners, ex-prisoners and the homeless.
In most countries the people designing social protection programmes do not prioritize TB control and the initial meeting this week is being followed by smaller working meetings on shifting the focus. "Social protection issues are fundamental in TB control, and that is why TB control now has to go beyond working with national TB programmes... they are too low in the hierarchical agenda of countries," Mario Raviglione told IRIN.
"It is those above who set the real policies... we are talking about a quintessential disease of poverty, which is determined by a bunch of factors which go well beyond health."