One of the cornerstones of ending tuberculosis is TB preventive therapy (TPT) aimed at high risk groups. Household contacts of persons with active TB, especially infants and young children, are at high risk of contracting TB, although TPT can substantially reduce this risk. Implementation of this effective intervention at the global level has so far been poor, with less than 20% of the 24 million household contacts targeted to receive TPT between 2018 and 2022 actually receiving TPT. Anecdotal and published evidence also suggests that the process of screening for and offering TPT can take up to several months, negating its value in breaking household TB transmission.
Innovative action is required to inject urgency and improvement into this intervention. The Union’s Centre for Operational Research, working closely with key partners in India, Pakistan and Kenya as well as the Special Programme for Research and Training in Tropical Diseases at the World Health Organization and Resolve to Save Lives, took inspiration from a new global target of “7-1-7” proposed to improve early detection and rapid control of health threats arising from suspected infectious disease outbreaks or pandemics.
The team adapted the “7-1-7” timeliness metric for the process of household screening and management as follows: First 7 – the index TB patient line-lists household contacts within seven days of treatment initiation; Next 1 – line-listed household contacts have symptom screening outcomes ascertained within the next one day; Second 7 – eligible household contacts start anti-TB treatment or TPT or a firm decision is made to receive no drugs within seven days of symptom screening.
Three out of four studies assessing the feasibility and value of using this metric have been completed and are in press awaiting publication (one from Chennai, India; one from Sindh Province, Pakistan; and one from Kiambu County, Kenya). The first to be published is the paper from Pakistan in PLoS ONE. “7-1-7” was achieved in 92%, 84% and 35% respectively. The principal reason for poor performance with the Second 7 was failure to consult a medical officer for investigation and start of TPT because of travel costs, loss of daily earnings and fear of a TB diagnosis. Nevertheless, field staff in Pakistan reported that timeliness metrics motivated them to take prompt action in household contact screening and TPT provision and they suggested these be included in national guidelines.
Prof Anthony Harries, senior advisor at The Union, said: “More work is needed to assess whether the timeliness metric for household contact management and TPT can work in other settings and in other countries, and indeed what would be the ideal timeliness metric. What is well known is that persons who contract TB and successfully complete TB treatment are often left disabled, with a poor quality of life, and they are at much higher risk of death compared with those never having TB. Prevention is therefore much better than cure. Much more needs to be done to convince health care providers and affected people that timely screening and prevention of TB can work and needs to be scaled up.”