Screening for TB before symptoms show yields good results

23 October 2020 - 18:53 By sipokazi fokazi
A new research suggests that testing for TB before symptoms show can help authorities find missing TB cases early.
A new research suggests that testing for TB before symptoms show can help authorities find missing TB cases early.

Testing for tuberculosis before symptoms show can help health authorities find missing TB cases easily and deal with the respiratory disease better, new local research suggests.

Researchers from Boston University and Wits University, who routinely screened over 22,000 patients in 60 clinics across SA, discovered that almost half of all TB patients who sought medical care at clinics had no symptoms and therefore were not aware that they were carriers of the TB bug.

The Targeted Universal Testing for Tuberculosis (Tutt), which evaluated the effectiveness of a risk-factor based laboratory screening found that the technique yielded more results — about 5,500 TB cases per 100,000 people compared to the 3,800 per 100,000 when there are no symptoms.

Overall, 47% of TB cases identified were individuals with no symptoms.

Presenting the study at the 51st Union World Lung Health Conference this week, Rebecca Berhanu of Boston University said that the latest results confirm that the traditional method of only testing for TB after patients reported symptoms did not identify all patients with TB.

The latest research is good news for countries with high burden of TB such as SA that have huge disparities in TB-testing. According to the Global TB Report 2020, released by the World Health Organisation (WHO) last week, SA’s monthly TB notifications dropped below 50% by June — meaning that thousands of TB carriers could be transmitting the bug in their communities.

In 2017, SA notified 227,224 TB patients against the World Health Organisation’s estimation of 332,000 patients in the same year.  

This indicates that an estimated 104,776 TB patients were not diagnosed, notified or ever enrolled in the national treatment programmes. The missing TB patients include patients with undiagnosed TB in communities, or those missed by the health system at the time of diagnosis, treatment or reporting. These system constraints pose a major obstacle to achieving the End TB Strategy targets by 2035. The department of health aimed to find 80,000 missing TB patients by March last year.

Berhanu said that research is required to assess whether routinely screening for TB contributes to reducing TB transmission, morbidity and mortality.  “There is a growing awareness that symptom-based screening doesn’t catch everyone, and our study was designed to find these missing cases,” she said.