Scientists Detect Antibiotics in Fingerprints, Enhancing Fight Against Drug-Resistant TB

A fingerprint may soon be all a doctor needs to check whether tuberculosis patients are taking their antibiotics, according to a new study conducted by scientists from the University of Surrey and published in the International Journal of Antimicrobial Agents.

Tuberculosis (TB) is amongst the leading causes of death from an infectious agent, with an estimated 1.3 million deaths worldwide.

Drug-susceptible (DS) TB is curable, but around 50% of patients do not fully adhere to their lengthy antibiotic regimens, leading to treatment failure, increased relapse risk, and the development of drug-resistant TB, which is harder and costlier to treat with lower survival rates.

Therapeutic drug monitoring (TDM), which measures drug levels to adjust dosing, is recommended in TB care. While traditionally done with serum or plasma, less invasive methods like dried blood spots, saliva, and now finger sweat are being explored. Finger sweat collection is quick, easy, non-biohazardous, and requires no specialist training, making it suitable for any location. This method could reduce clinic burdens, improve patient experiences, and enhance treatment adherence in TB care.

For the study, scientists aimed to determine the optimal timing for testing and the ability to quantify the medication taken by patients. They tested ten TB patient's finger sweat, blood and saliva samples at the University Medical Center Groningen (UMCG) using mass spectrometry, which analyses the sample's composition.

The results showed that antibiotics were detected in finger sweat with 96% accuracy, while the metabolite, produced by ingesting the drug, was identified with 77% accuracy. The drug itself was present in finger sweat between one and four hours after ingestion, whereas the metabolized version appeared most accurately after six hours.

“Doctors need to check whether tuberculosis patients are taking their antibiotics. It's much quicker and more convenient to do that using fingerprints rather than taking blood. This could ease the time pressure on a busy health service and offer patients a more comfortable solution. For some patients, like babies, blood tests are not feasible or desirable – so techniques like this one could be really useful,” said Dr Katie Longman, co-author of the study.

Reference: K. Longman, O.W. Akkerman, S. Ghimire, M.S. Bolhuis, M.A. Chambers, M.G.G. Sturkenboom, M.J. Bailey; Measurement of isoniazid in tuberculosis patients using finger sweat with creatinine normalisation: A controlled administration study; International Journal of Antimicrobial Agents; 2024; https://doi.org/10.1016/j.ijantimicag.2024.107231