A large trial undertaken in India has underscored the role of nutritional supplementation in sharply cutting down tuberculosis (TB) disease rate in the household contacts of an index patient, and mortality reduction in people diagnosed with active pulmonary TB. The trial was conducted in four districts in Jharkhand between August 2019 and August 2022. The results of the study were published on Wednesday (August 9) in The Lancet and The Lancet Global Health.
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In the randomised controlled trial involving household contacts of patients with pulmonary TB, nutritional support led to 39-48% reduction in TB disease in the intervention group compared with the control arm. In the study that lasted for six months, 122 people in the control group developed TB whereas the intervention arm had only 96 TB cases.
The 39% reduction in TB disease included all forms of TB (pulmonary and extra-pulmonary), while the 48% reduction was in microbiologically confirmed pulmonary TB. The intervention arm had 5,621 household contacts, and the control group had 4,724 family members.
Each adult family member in the intervention arm received monthly nutritional support for six months — 5 kg of rice, 1.5 kg of split pigeon peas (tur dal), and a micronutrient pill; each child below 10 years received 50% of the adult nutrition support. Those in the control arm did not get any nutritional supplementation and were on a usual diet.
The trial also provided nutritional supplementation to all 2,800 people with active pulmonary TB undergoing treatment.
Treatment was successful in nearly 94% (2,623) of TB patients. There were only about 4% (108) deaths during the six-month follow-up. The trial was conducted on 2,800 people with pulmonary TB (1,979 men and 821 women). Over 80% of the participants had a BMI less than 18 and nearly 49% had a BMI less than 16 (severely underweight).
Monthly nutritional support — 5 kg of rice, 1.5 kg of milk powder, 3 kg of roasted chickpea flour, 500 ml of oil, and a micronutrient pill — was provided for six months for people with drug-susceptible TB, and 12 months for people with MDR (Multidrug Resistant)-TB.
“In our trial, the mortality was 7% in those under 35 kg body weight compared with 15% in a study carried out by the Chennai-based NIRT in Tiruvallur district, Tamil Nadu,” Anurag Bhargava from the Yenepoya Medical College, Mangaluru, who led the trial and is the corresponding author of both papers, said.
Early weight gain in the first two months was associated with 60% lower risk of TB mortality.
For ethical reasons, all 2,800 TB patients were provided with nutritional support.
The study documented high levels of severe and extremely severe undernutrition in patients at diagnosis. “Severe undernutrition is one of the contributory causes of deaths in TB patients,” Dr. Bhargava said. “Nutrition support provides protection against TB disease akin to a vaccine.”
“Among the risk factors for TB, undernutrition accounts for over 40% of new TB cases every year. While other risk factors like diabetes, HIV infection, smoking and alcohol also need attention, the one risk factor that stands out is undernutrition. Studies conducted by the NIRT (National Institute for Research in Tuberculosis), Chennai many years ago showed that TB patients who weighed less than 35 kg had four times higher mortality than those who weighed over 45 kg,” Soumya Swaminathan, former Chief Scientist, World Health Organization, and co-author of one paper, said during a press briefing.