New heat maps show frontlines in war on TB
As lab data identifies communities with a high burden of drug-resistant TB, intervention becomes possible
The frontlines in the war on tuberculosis (TB) have been identified in research that will enable medics to deploy countermeasures where they are most needed.
A team from the Boston Medical Center in the US used routinely collected laboratory data to identify Western Cape communities with a high burden of drug-resistant TB.
“It is critically important that we understand how drug-resistant TB impacts people in specific areas over time,” said study leader Karen Jacobson, who specialises in infectious diseases.
“By locating emerging and chronic hot spots of the disease in real time, public health providers can evaluate the most effective interventions and monitor progress towards TB-reduction goals.”
SA has the world’s highest TB rates, and 4% of cases are resistant to first-line medication. It also has a centralised laboratory database that includes TB test results, and Jacobson’s team said in the journal PLOS Medicine that this made it ideal for a surveillance system tracking drug-resistant TB cases by clinic location.Researchers developed an algorithm to identify unique patients and episodes of disease from the data, and created heat maps of the Western Cape to see which areas were most affected between 2008 and 2013.
The group identified 799,779 people who had specimens submitted for TB tests. About 28% were diagnosed with TB, and 4.6% of those infections were resistant to first-line TB treatment.
There were significant annual fluctuations in drug-resistant TB percentages at several locations, and the communities that had the highest rates of drug-resistant TB were Cape Town townships and informal settlements, the rural region of the West Coast, and areas bordering the Eastern Cape.
“Our model of mapping high-burden communities can serve as a roadmap for regions working to reduce TB incidence by initiating treatment as soon as possible,” said Jacobson, assistant professor of infectious diseases at Boston University School of Medicine.
She emphasised the role routinely collected laboratory data plays in identifying ongoing and short-term TB outbreaks. Constant monitoring could lead to more effective public health interventions, resulting in fewer cases of drug-resistant TB.