That targeted nutritional support to TB patients and household contacts can improve TB treatment outcomes, reduce the number of new cases and deaths is now well known, particularly after the RATIONS trial carried out in between August 2019 and August 2022 in four districts of Jharkhand among 2,800 pulmonary TB patients and 10,345 household contacts. The trial found that nutritional support provided to household contacts for the duration of treatment reduced the number of new pulmonary TB cases by 48%, and deaths among those under 35 kg body weight (severely underweight) was only 7%.
Now a modelling study has estimated the epidemiological and economic benefits of providing nutritional support for the duration of treatment to both adult TB patients and household contacts. At 50% coverage, providing nutritional care to adult TB patients and household contacts for the duration of treatment could help avert over 361,000 deaths and over 880,000 new TB cases by 2035 at a cost of $167 per disability-adjusted life-year, suggests the study from the London School of Hygiene & Tropical Medicine, London, and Yenepoya Medical College, Mangalore.
This would be equivalent to averting approximately 4.6% TB deaths and 2.2% TB cases, the study notes. It also found that the median number of households needed to treat to prevent one TB death was 24.4 and to prevent one TB case was 10. It also estimates that provision of this support is very likely to be cost-effective. The number of TB deaths prevented and new cases averted will be even bigger if child and adolescent TB patients and their household contacts too are provided nutritional support. The study was published recently in the journal The Lancet Global Health.
The researchers used previously published, age-stratified, compartmental transmission models of TB in India, and incorporated explicit BMI strata linked to disease progression and treatment outcomes, and used the results of the RATIONS trial to estimate the impact and costs of nutritional support. Based on the modelling study the authors write: “A nutritional intervention for tuberculosis-affected households could avert a substantial amount of tuberculosis disease and death in India, and would be highly likely to be cost-effective on the basis of the tuberculosis-specific benefits alone.”
Compared with a population-level intervention to improve nutrition, which could have a substantially larger effect size, an intervention targeting only those on TB treatment and their households is able to avert a relatively low proportion of TB incidence and mortality, they say. However, in a resource-constrained setting such as India, targeting the intervention to high-risk household contacts offers the opportunity to maximise cost effectiveness within a feasible budget, they say.
To understand the impact of nutritional support in preventing deaths and new cases, the authors compared the outcomes when nutrition is provided only to adult TB patients, only to household contacts but not to adult TB patients, and finally to both adult TB patients and household contacts. While nutritional support to adult TB patients alone reduced the number of new cases by 46,700, and deaths by 234,300, nutritional support to household contacts alone (excluding adult TB patients) led to a larger drop in new cases (833,700) and deaths (129,200) but still far less than when both adult TB patients and household contacts were provided nutritional support.
“When we say nutritional support is given to household contacts, we mean just that — not given to people on TB treatment but only to their household contacts. This obviously would not happen in practice, but is a way for us to tell where the intervention effect is coming from,” Dr. Christopher Finn McQuaid from the London School of Hygiene & Tropical Medicine, and the corresponding author of the paper explains in an email to The Hindu.
The study found that nutritional support provided to adult TB patients averts deaths due to improved treatment outcomes. Importantly, it also averts new cases in these people. “These individuals [TB patients] see an increase in their BMI, which leads to reduced reactivation or progression to disease if they are reinfected,” Dr. McQuaid says.
Dr McQuaid says: “This paper could provide guidance for policymakers selecting TB interventions, highlighting the importance of nutritional support in addressing the TB epidemic, and the real benefits this is likely to provide not just to affected households but at a national level.”
Dr Rebecca Clark, a Research Fellow at The London School of Hygiene & Tropical Medicine and a co-author of the paper adds: “International and national decision-makers could use our findings to advocate for better, as well as more targeted and relevant, interventions when it comes to support for TB patients and their families.”
Published – January 25, 2025 09:35 pm IST
