But, more than half of the people diagnosed with TB in South Africa's first National TB Prevalence Survey would have been missed had asymptomatic people not been offered additional tests as part of the survey. Evidence is mounting that, as with COVID-19, people can have active TB disease and be infectious without having any symptoms.
Dr Lucy Connell, TB programme head at Right to Care , conducted the independent assessment of the Global Fund-supported parts of the pilot. She says that in each of the six districts with clinic-based digital chest X-ray containers, case finding has dramatically increased since 2019 - three-fold in some instances."Early results show that augmenting TB symptom screening with DCXR screening helps to detect more people with TB," she says.
In clinics in the OR Tambo district that hosted DCXR units, the number of people testing positive for TB went from 2 out of every 1000 clinic visitors in 2019 to 6 out of every 1000 clinic visitors in the period when DCXR augmented TB symptom screening took place. This occurred even though the capacity of the DCXR units in their current form is limited to approximately 80 people a day, far short of the number of clinic attendees.
"In addition to detecting more TB among symptomatic patients," Connell says,"DCXR TB screening has also detected TB in asymptomatic people: 28% of all people diagnosed with TB in this phase of the project were asymptomatic and would have been missed if the clinic was relying on symptom screening alone."
"There would need to be a purchase of X-ray equipment for each facility or a mobile unit that moves from facility to facility and there would need to be about nine to ten such units. As far as I know, they have not been routinely implemented. As the technology becomes easier to use and cheaper, it may become more feasible for them to be used routinely in prisons," she says.