More than half of patients with TB had no symptoms before testing positive
Click Here to Manage Email Alerts
Researchers found high rates of tuberculosis among high-risk patients who sought care at primary health care clinics, many of whom had no preceding symptoms suggesting a high rate of subclinical TB.
“WHO estimates that each year, more than 4 million out of the 10 million people with active TB are not diagnosed or started on treatment. Identifying and treating this group is central to the global End TB strategy,” Rebecca H. Berhanu, MD, infectious diseases physician and clinical researcher at the Vanderbilt Institute for Global Health, told Healio.
“The objective of this study was to see if we could find people who were asymptomatic or did not have overt symptoms of TB by testing all high-risk people attending primary health care clinics, including people with HIV, those with a close household contact with TB and people with a prior history of treated TB,” she said.
Berhanu added that she and colleagues called this strategy “Targeted Universal Testing for TB.”
The researchers assessed clinic attendees in primary health care facilities in South Africa who were classified as high risk for TB due to HIV-positive status, contact with a patient with TB in the past year or having TB themselves and having undergone sputum testing for pulmonary TB in the previous 2 years.
According to the study, a single sample was collected for Xpert Ultra and culture and the results were analyzed.
Overall, 30,513 patients had a TB test result available for analysis. Of these, 21,734 (71%) were HIV positive, 12,492 (41%) reported close contact with a person with TB and 1,573 (5%) reported a prior TB diagnosis. In total, 8.3% of these patients were positive for Mycobacterium tuberculosis by culture and/or Xpert, compared with 6% with trace-positive results excluded.
Additionally, and also with trace-positives excluded, the study showed a yield of 6.7% for asymptomatic patients and 10.1% for symptomatic patients, whereas only 10% of trace-positive results were culture positive.
Berhanu added that more than half (55%) of patients with a positive test did not report any preceding TB symptoms, which she said suggests a high rate of subclinical TB among people attending primary health care clinics.
“Universal testing of individuals at high risk for TB in primary health care clinics may be a good way of identifying subclinical TB cases sooner. However, we have to be cautious of the interpretation of Xpert Ultra test results, especially Xpert Ultra-trace positive results, in this population,” Berhanu concluded.
Collapse
Read more about
Click Here to Manage Email Alerts